Open Access

Cellular reprogramming in farm animals: an overview of iPSC generation in the mammalian farm animal species

Journal of Animal Science and Biotechnology20167:10

https://doi.org/10.1186/s40104-016-0070-3

Received: 22 October 2015

Accepted: 11 February 2016

Published: 19 February 2016

Abstract

Establishment of embryonic stem cell (ESC) lines has been successful in mouse and human, but not in farm animals. Development of direct reprogramming technology offers an alternative approach for generation of pluripotent stem cells, applicable also in farm animals. Induced pluripotent stem cells (iPSCs) represent practically limitless, ethically acceptable, individuum-specific source of pluripotent cells that can be generated from different types of somatic cells. iPSCs can differentiate to all cell types of an organism’s body and have a tremendous potential for numerous applications in medicine, agriculture, and biotechnology. However, molecular mechanisms behind the reprogramming process remain largely unknown and hamper generation of bona fide iPSCs and their use in human clinical practice. Large animal models are essential to expand the knowledge obtained on rodents and facilitate development and validation of transplantation therapies in preclinical studies. Additionally, transgenic animals with special traits could be generated from genetically modified pluripotent cells, using advanced reproduction techniques. Despite their applicative potential, it seems that iPSCs in farm animals haven’t received the deserved attention. The aim of this review was to provide a systematic overview on iPSC generation in the most important mammalian farm animal species (cattle, pig, horse, sheep, goat, and rabbit), compare protein sequence similarity of pluripotency-related transcription factors in different species, and discuss potential uses of farm animal iPSCs. Literature mining revealed 32 studies, describing iPSC generation in pig (13 studies), cattle (5), horse (5), sheep (4), goat (3), and rabbit (2) that are summarized in a concise, tabular format.

Keywords

Cellular reprogramming Farm animals Induced pluripotent stem cells Pluripotency

Background

Pluripotent stem cells are unspecialized cells that can evolve to all cell types of an adult organism. Until 2006 they could be isolated only from inner cell mass of early stage embryos. Embryonic stem cell (ESC) lines were first established in mouse [1], and subsequently in human from in vitro-derived embryos [2]. In contrast, derivation of ESCs from embryos of farm animal species was inefficient, probably due to limited knowledge about the biology of the different species ESCs (e.g. timing and isolation of primary cultures, recognition of authentic ESC, and sustaining pluripotency and propagation in culture) [3]. Germline transmission, as the most stringent criteria of pluripotency, has been proved only for murine (mouse and rat) inner cell mas (ICM)-derived ESCs, which are considered true (“naïve”) pluripotent ESCs, whereas most human ICM-derived ESC lines share more common characteristics with mouse epiblast-derived stem cells (mEpiSCs), and are considered “primed” pluripotent stem cells (for a detailed explanation see [4]).

For a long time it was believed that differentiation is a one-way process and that fate of somatic cells is irreversible. The discovery that specialised somatic cells can be reversed back to a non-differentiated state came several decades ago when Gurdon [5] injected frog intestinal epithelium cell nuclei into enucleated frog oocytes and showed that normal feeding tadpoles can be developed from transferred somatic cell nuclei. Proof that reprogramming of mammalian cells is possible was obtained with reproductive cloning of several species (e.g. sheep [6]; cattle [7]; goat [8]; pig [9]) via somatic cell nuclear transfer (SCNT). Interestingly, generation of nuclear transfer ESCs (NT-ESC) in human was not possible for a long time; finally, human somatic cells were successfully reprogrammed by SCNT, first resulting in triploid pluripotent cells [10] and latter in normal (diploid) NT-ESCs [11].

The use of embryos (especially human) for ESC derivation faces ethical concerns and is subjected to rigorous legal restrictions. Reprogramming somatic cells by SCNT is technically challenging, laborious, inefficient (especially in human), and requires the use of oocytes. Reproductive cloning / nuclear transfer experiments showed that oocytes obviously contain factors, which are able to reprogram committed cells. Takahashi and Yamanaka identified these factors and developed a method of direct reprogramming of somatic cells that was simple in principle and circumvented the need for embryo or oocyte manipulations [12]. The so called induced pluripotent stem cells (iPSCs) were generated from mouse embryonic fibroblasts by ectopic expression of only four (Yamanaka set – OSKM: Oct4, Sox2, Klf4, and c-Myc) transduced nuclear transcription factors [12]. Human iPSCs were generated soon after, using a set of slightly different (Thomson set - OSNL: OCT4, SOX2, NANOG, and LIN28) transcription factors [13]. After introduction of the direct reprogramming technology in mouse and human iPSCs were established in various animal species, using the same principle. Different combinations of exogenous reprogramming factors and culture conditions were used, dependent on donor cell type and/or species. Insights from such cell reprogramming experiments could provide missing biological information about pluripotent cells in different species (e.g. optimal conditions for propagation), which might eventually enable derivation and propagation of ICM-derived ESC lines in farm animals.

Transcription factor-directed reprogramming enabled generation of ethically acceptable, individuum-specific, pluripotent stem cells that can be derived from different types of somatic cells, including in species where ESC lines aren’t available. iPSCs closely resemble ESCs in their characteristics and represent practically limitless source of pluripotent stem cells, potentially available for autologous cellular therapies, individuum-specific disease modelling and/or drug screening, and research/testing purposes in medicine and developmental biology. However, there are still many obstacles to overcome. For example, researchers found that numerous subtle but substantial genetic and epigenetic differences exist between iPSCs and ESCs [14], which delay the use of iPSCs for transplantation therapies in human. First, it is necessary to assess survival potential, capability of functional integration into tissues, genetic stability, and absence of tumorigenic potential in reprogrammed cells. Development of animal models, which can be used for preclinical research, is therefore of vast importance [15]. Because of more similar body size, physiology, and characteristics of pluripotent cells to human, development of livestock and non-human primate models seems essential to bridge the gap and enable transfer of iPSCs-based therapy procedures, from rodents (e.g. [16]) to the field of human medicine. For example, preclinical demonstration studies were successfully performed in non-human primates in heart [17] and Parkinson’s disease treatment [18], and in heart disease treatment in post-infarcted swine models [19]. In addition to cell transplantation therapies, interspecies chimeras (farm animals with genetically engineered “organ niches”) could be used in the future to make organs from human pluripotent stem cells, using blastocyst or in utero conceptus complementation in organogenesis-disabled animals, for treating patients that require whole organ replacement [20]. However, interspecies complementation has been shown only between mouse and rat [21, 22], whether chimera generation is possible between more distantly related species, due to interspecies boundaries, remained to be determined. Additionally, existing non-rodent ESCs/iPSCs are mostly considered “primed” state pluripotent stem cells and thus not capable of forming chimeras after blastocyst injection.

Pluripotent stem cells are not promising only for medical applications, but could found numerous uses in biotechnology and agriculture. Advanced reproduction techniques in farm animals could enable development of genetically modified animals from engineered pluripotent stem cells; SCNT is a method of choice when producing transgenic farm animals [23] and use of genetically engineered pluripotent stem cells (i.e. ESCs or iPSCs capable of generating offspring through nuclear transfer) as donor cells could simplify and improve efficiency of the procedure, as already shown in mice [24]. Transgenic animals could improve agricultural production or be used as bioreactors for production of recombinant proteins. For example, anticoagulant antithrombin, the first marketed recombinant protein produced in transgenic animals [25], is expressed in mammary tissue of genetically engineered goats and isolated from their milk. In agriculture, transgenic animals could improve human health by enhanced nutrition value, help protect the environment, decrease livestock diseases, and increase animal welfare [26]. Potential uses of iPSCs are depicted in Fig. 1.
Fig. 1

The most promising applicative uses of iPSCs include regenerative cell therapy, personalised disease modelling and drug screening, and generation of transgenic animals from genetically engineered iPSCs that yet needs to be demonstrated in large farm animals. Some of the symbols used in the figure are a courtesy of the Integration and Application Network, University of Maryland Center for Environmental Science (ian.umces.edu/symbols/)

Reviews on mechanisms and methods of cell reprograming in domestic animals have been published in several articles (e.g. [27, 28]). In the follow up of this article we provide the most recent overview on achievements in iPSC generation in pig, cattle, horse, rabbit, sheep, and goat. Additionally, we provide a comprehensive protein sequence similarity analysis of the most important pluripotency transcription factors (OSKM) between different farm animals, human, and mice, and briefly discuss current trends in reprogramming methodology.

Comparison of pluripotency-related transcription factors between human, mouse, and farm animal species

Research has shown that human and murine transcription factors can reprogram cells of different mammalian species, as well as of non-mammalian vertebrate and even invertebrate species, pointing to high conservation of pluripotency-related signalling network across a wide phylogenetic range [29]. The cross-species reactivity of pluripotency-related transcription factors, also between distantly related species, indicates fundamentality of the reprogramming principle in biological aspect. To determine conservation of transcription factors across the species of interest we aligned GenBank protein (reference – if available) sequences of the most widely used reprogramming factors (OSKM set) for human, mouse, and the selected farm animal species (cattle, goat, sheep, rabbit, horse, and pig) in ClustalW2 multiple sequence alignment tool (EMBL-EBI: http://www.ebi.ac.uk/Tools/msa/clustalo/). The identity matrices (data not shown) showed that OCT4 protein sequence is the least conserved across the compared species, but still exhibits high sequence similarity; i.e. over 89 % between the farm animals and human and over 84 % when mouse is included to the comparison. SOX2 protein sequence is the most conserved (over 95 % identity in all the compared species), while KLF4 and MYC both exhibited over 90 % identity between all the species. Sequence identity between the large farm animals was around 95 % for all the transcription factors, and reached 98–100 % identity between closely related species (e.g. ruminants).

Human or mouse transcription factors are often used for reprogramming animal cells, either because transcription factor sequences are not available for animal species with un/poorly- annotated genomes and/or because vectors containing human or murine factors are already (commercially) available. Based on the sequence similarities, we suggest that human transcription factors should be used over murine when reprogramming cells of the farm animals (Table 1). However, empirical evidences prove that murine transcription factors can as well be successfully used for reprogramming farm animal cells (e.g. in pig, horse, sheep – data available in Table 2).
Table 1

Similarity (%) of OSKM protein sequences of different species to human and mouse (human/mouse)

Species

OCT4

SOX2

KLF4

c-MYC

Pig

93 / 86 [NP_001106531]

99 / 97 [NP_001116669]

96 / 92 [NP_001026952]

93 / 91 [NP_001005154]

Horse

94a / 86a [XP_001490158]

98a / 96a [ACJ12602]

94a / 91a [XP_005605741]

92a / 91a [XP_001498041]

Rabbit

90 / 85 [NP_001093427]

98a / 99a [AJC97786]

96a / 92a [AJC97787]

94a / 92a [XP_008254124]

Sheep

91a / 84a [XP_004019017]

100a / 98a [CAA65725]

96 / 93 [NP_001157691]

93 / 92 [NP_001009426]

Cattle

91 / 84 [NP_777005]

100 / 98 [NP_001098933]

96 / 93 [NP_001098855]

92 / 91 [NP_001039539]

Goat

91 / 84 [NP_001272498]

97 / 96 [NP_001272601]

96a / 92a [XP_005684447]

92a / 92a [XP_005689000]

Human

100 / 86 [NP_002692]

100 / 98 [NP_003097]

100 / 92 [NP_004226]

90 / 100 [NP_002458]

Mouse

86 / 100 [NP_038661]

98 / 100 [NP_035573]

92 / 100 [NP_034767]

100 / 90 [NP_034979]

The GenBank accession numbers are available in square brackets

asimilarity is based on predicted or non-curated sequences

Table 2

Summary of studies describing iPSC generation in the selected farm animal species

Species

Donor cell type

Insertion method

Transcription factorsa

Culture conditions (growth surface; serum or serum replacements, factors/inhibitors)b

Reference

Pig

embryonic fibroblast

retroviral transduction

hOSKM and mOSKM

iMEFs; defined FBS + bFGF

[51]

fetal fibroblasts

lentiviral transduction

hOSKM

iMEFs; KOSR + bFGF

[52]

ear fibroblasts and bone marrow cells

Tet-on-inducible lentiviral transduction

hOSKMNL

iMEFs; KOSR

[53]

mesenchymal stem cells

lentiviral transduction

hOSKMNL

iMEFs; KOSR + bFGF

[45]

ear fibroblasts

retroviral transduction

hOSKM

iMEFs or gelatin; FBS and KOSR (1:1) + bFGF + LIF

[54]

ear fibroblasts

retroviral transduction

mSKM

iMEFs or gelatin; FBS and KOSR (1:1) + bFGF + LIF

[55]

embryonic fibroblasts

Tet-on-inducible lentiviral transduction

hOSKMN

iMEFs; KOSR + bFGF

[56]

fetal fibroblasts

lentiviral transduction

hOSKM

iMEFs; KOSR + bFGF

[57]

fetal fibroblasts

sleeping beauty transposon system

mOSKM

iMEFs or iSNLs or gelatin; KOSR + bFGF

[58]

embryonic fibroblasts

retroviral transduction

hOSKM

iMEFs; FBS and KOSR (1:1) + bFGF + LIF

[59]

embryonic fibroblasts

retroviral transduction

mOSKM

iMEFs; KOSR + bFGF or FBS + bFGF + LIF or FBS + bFGF + LIF + VPA

[60]

mesenchymal stem cells

retroviral transduction

pOK + small molecules

iMEFs; KOSR or FBS + LIF

[61]

 

fetal fibroblasts

episomal plasmid

hOSKMNL

iMEFs; N-2 suppl. + B-27 suppl. + LIF + GSKi + MEKi

[44]

Horse

fetal fibroblasts

piggyBac transposon system

mOSKM

50 % iMEFs and 50 % iEFFs; FBS + bFGF + LIF + GSKi + TGFi + TZV + ALKi

[49]

fibroblasts

retroviral transduction

hOSK

iMEFs; FBS + ITS + EGF + bFGF + LIF

[62]

skin fibroblasts

retroviral transduction

mOSKM

iSNLs; FBS or KOSR + bFGF and/or LIF

[63]

keratinocytes

retroviral transduction

mOSKM

iSNLs; FBS + bFGF + LIF

[64]

skin fibroblasts

lentiviral transduction

hOSKM

- reprogramming: Matrigel; ES-FCS + bFGF + LIF + GSKi + MEKi + TGFi + ALKi

[65]

- putative iPSCs: iMEFs; ES-FCS + LIF or ES-FCS + LIF + bFGF or ES-FCS + LIF + bFGF + MEKi or ES-FCS + LIF + bFGF + PI3K/AKTi or ES-FCS + LIF + bFGF + MEKi + PI3K/AKTi

Rabbit

liver and stomach cells

lentiviral transduction

hOSKM

iMEFs; KOSR + bFGF + LIF

[66]

ear fibroblasts

retroviral transduction

hOSKM

iMEFs; KOSR + bFGF

[67]

Sheep

embryonic fibroblasts

retroviral transduction

hOSKM

iMEFs; FBS + ITS + bFGF + LIF

[68]

ear fibroblasts

Tet-on-inducible lentiviral transduction

hOSKMNL + SV40 T + hTERT

iMEFs; KOSR

[69]

fetal fibroblasts

Tet-on-inducible lentiviral transduction

mOSKM

iMEFs; KOSR or FBS + bFGF

[70]

embryonic fibroblasts

retroviral transduction

mOSKM

iSNLs; KOSR + bFGF

[71]

Cattle

fetal fibroblasts

retroviral transduction

bOSKMNL

iMEFs; KOSR + bFGF

[72]

fetal fibroblasts

lentiviral transduction

hOpSMK

iMEFs; FBS + bFGF + LIF

[73]

embryonic fibroblasts

poly-promoter plasmid

bOSKM

iMEFs; LIF + MEKi + GSKi

[74]

ear fibroblasts

retroviral transduction

hOSKMN

iMEFs; FBS + ITS + bFGF + LIF

[75]

fetal fibroblasts

piggyBac transposon systems

hOSKMNL

iMEFs; KOSR + bFGF + LIF

[76]

Goat

ear fibroblasts

Tet-on-inducible lentiviral transduction

hOSKMNL + SV40 T + hTERT

ND

[77]

fetal ear fibroblasts

lentiviral transduction

hOSKM

iMEFs; KOSR + bFGF

[78]

fetal fibroblasts

lentiviral transduction

bOSKMNL + miR- 302/367

- iMEFs; KOSR + LIF + MEKi + GSKi + VPA or KOSR + bFGF + VPA- iSNLs; KOSR + bFGF + VPA

[79]

aO OCT4, S SOX2, K KLF4, M MYC, L LIN28, N NANOG, SV40 T Simian vacuolating virus 40 large T antigen, TERT telomerase reverse transcriptase, miR-302/367 microRNA cluster 302/367, h human, m mouse, p pig, b bovine

bfor a detailed medium composition and culture conditions see reference – only growth surface/feeder layer and the selected growth medium supplements (serum/serum replacements, growth factors, and signalling pathway inhibitors) are presented in the table. iMEFs inactivated (mitomycin C) or irradiated mouse embryonic fibroblasts, FBS fetal bovine serum, bFGF basic fibroblast growth factor, KOSR knockout serum replacement, LIF leukemia inhibitory factor, iSNLs inactivated transformed mouse fibroblasts with expression of leukemia inhibitory factor, VPA valproic acid, iEFFs inactivated equine fetal fibroblasts, GSKi glycogen synthase kinase inhibitor, MEKi mitogen-activated protein kinase kinase 1 inhibitor, TGFi transforming growth factor-beta inhibitor, TZV thiazovivin, ALKi anaplastic lymphoma kinase inhibitor, ITS insulin/transferrin/selenium supplement, EGF epidermal growth factor, ES-FCS embryonic stem cells-qualified fetal calf serum, PI3K/AKTi phosphatidylinositol 3-kinase/protein B kinase (AKT) inhibitor, ND no data

Current trends in reprogamming methodology

iPSCs were first generated using viral-based (mostly lentiviruses and retroviruses) transduction of transcription factors into the genome of donor cells. The use of genome-integrating methods using viral transduction remains a gold standard in iPSC generation. However, new methods, which surmount genome interventions (so-called “non-integrating techniques”) are being extensively developed and evaluated. Several articles describing reprogramming methods were published in the last years and we recommend them for further reading to readers interested in a more detailed review of the reprogramming methodology (e.g. [30, 31]).

Current trends in reprogramming technology are directed to integration- and feeder-free procedures; the former preventing occurrence of insertional mutagenesis and the latter contamination of donor cells with murine feeders (xeno-free conditions). Inactivated mouse embryonic fibroblast feeders are being replaced by defined components of extracellular matrix, circumventing the need for co-culture. Non-integrating vectors (e.g. adenoviruses, episomes), integrating vectors exhibiting subsequent excision (e.g. piggyBac transposons), or direct input of small molecules, mRNA or proteins into donor cells are being used to bypass genome insertions. Alternatively, studies report that (partial) dedifferentiation of mammalian somatic cells is also possible by cell fusion [32] or addition of extracts to the medium [3337], however these methods are highly inefficient and usually don’t result in stable iPSC lines.

Recent reprogramming methods are focusing on improving mRNA-based procedures [38], for example by employing synthetic self-replicative RNA that circumvents the need for repetitive transfections [39]. With growing knowledge on reprogramming the reduction in number of ectopically expressed transcription factors was achieved that largely depends on donor cell type. In some cases cells were successfully reprogrammed using ectopic expression of only one transcription factor – for example, only OCT4 “master gene” was sufficient to reprogram neural stem cells [40]. Furthermore, it was shown that cells could be reprogrammed without exogenous transcription factors delivery, by using certain chemical compounds that can substitute for transcription factors. At first, such compounds were used in combination with ectopic expression of transcription factors in order to improve reprogramming efficiency or substitute for some of the transcription factors, but usually at least expression of exogenous OCT4 was required (e.g. [41, 42]). However, in 2013 a group of Deng and colleagues succeeded to reprogram mouse somatic cells, by using only a cocktail of seven chemical compounds and called the reprogrammed cells CiPSC – chemically induced pluripotent stem cells [43].

iPSCs in the farm animals

Literature mining revealed 32 studies describing iPSC generation in the farm animals included in the search (13 in pig, 5 in horse, 5 in cattle, 4 in sheep, 3 in goat, and 2 in rabbit) (Table 2). Different insertion methods and sets of transcription factors were employed in iPSC generation of the selected farm animal species. Table 2 represent a concise overview of publications (until 9/2015) regarding iPSC generation in mammalian farm animal species (cattle, pig, goat, sheep, horse, and rabbit).

The studies show that species-specific, human, mouse or combinations of transcription factors from different species can be used for reprogramming farm animal cells. In most cases OSKM set was sufficient to reprogram donor cells of interest. In several cases NANOG and LIN28 factors were added to the reprogramming cocktail and/or expression of nuclear transcription factors was combined with either addition of small chemical compounds or expression of Simian virus 40 large T antigen (SV40 T), catalytic subunit of human telomerase reverse transcriptase (hTERT), or micro RNA cluster 302/367 (miR-302/367) to achieve higher reprogramming efficiency and stability of iPSC lines. It seems that especially cells originating from ruminant species require expression of additional factors – e.g. NANOG, LIN28, and/or SV40 T and hTERT. Additionally, growth surface and reprogramming medium with its supplements (e.g. growth factors, inhibitors) play an important role in reprogramming efficiency.

Mostly integrating (viral transduction- or piggyback transposons-based) methods were used for reprogramming farm animal cells, except for episome-based, non-integrating method, used for reprogramming pig fibroblasts [44]. There are no reports of the more up-to-date methods (e.g. non-integrating virus- or mRNA-based) being used for reprogramming cells in farm animal species. The expression of the delivered exogenous factors was in most cases controlled by a constitutive promoter (e.g. CMV, EF1α) or in some cases by inducible tetracycline controlled transcriptional activation. Fibroblasts were commonly used as a starting cell type, probably because they are easily accessible and maintained in the culture, and previously validated in reprogramming experiments in human and mouse. In the future, different somatic cell types should be used to reveal, which cell type is optimal for production of bona fide iPSCs.

Pluripotent character of the reprogrammed cells in the collected publications was in most cases assessed by determining expression of specific markers, in vitro differentiation, and teratoma formation in immunodeficient mice. Germline contribution potential was not tested or the tested cells were not germline competent, therefore the majority of the iPSCs do not meet pluripotency criteria in the most stringent sense and should be considered iPSC-like cells; except for a pig iPSC line [45], where chimeric pigs, demonstrating germline transmission were reported to be produced from the iPSCs [46]. However, proof was based only on a PCR test that showed high blastocyst complementation (indicating successful incorporation of iPSCs), but germline transmission of chimeric pigs to progeny was very low (only two piglets out of 43 were transgenic). At the moment there are no large animal iPSCs that could reliably produce viable and fertile offspring, possibly because of inability to produce stable transgene-free iPSCs, without sustained expression of exogeneous transcription factors [44]. The reliable assessment of pluripotency is one of the main issues in the field, especially when dealing with human iPSCs, where in vivo tests cannot be performed for obvious ethical reasons. The situation calls for revaluation and standardisation of minimal pluripotency criteria in different species, which should be indisputably proven, prior a study claiming generation of iPSCs could be published.

Regarding number of publications pig has been the most intensively studied farm animal. Pig with its organ size and physiology represents the best available approximation to human [47] and is a valuable model for testing new therapeutic approaches before they can be introduced into clinics. Stem cell research has been extensively focusing on rodent models, which didn’t prove optimal for testing human therapeutic applications, therefore utilization of large animal models has a great potential to expand our knowledge and is expected to increase [48]. For example, equine iPSCs could be used as a model for pre-clinical validation of stem cell therapies for muscles, joints, tendons, ligaments, and bone injuries, which were extensively studied and treated in sport horses, using mesenchymal stem cells [49].

Transgenic mammals (especially those used for milk production), generated by blastocyst complementation or nuclear transfer from genetically modified stem cells, could be used for large scale production of recombinant proteins of biomedical/biotechnological interest. Expression of transgenic proteins in mammary gland is currently the most optimal production systems, because it allows recombinant proteins to be relatively easy isolated from milk [50]. On the other hand, developed transgenic technology, small size, and short gestation period makes rabbits a lower-cost alternative to ruminants in transgenic milk expression systems, especially suitable for molecular pharming on a smaller scale [50].

Conclusions

This review focuses on iPSC generation in farm animals and summarizes the research in the field done so far. Based on the literature review we conclude that although their indisputable potential in biotechnology and agriculture or as models for preclinical research iPSCs in farm animals haven’t received the deserved attention. For example, there are thousands of studies focusing on cell reprogramming in human and murine, but we found only 32 studies describing cell reprogramming in the most important mammalian farm animal species. The promise of cell therapies in human medicine seems by far the most appealing application of iPSCs. However, many obstacles will have to be overcome before iPSC-based treatments could be introduced into the clinical practice. Farm animals represent a valuable model for development and testing of such transplantation procedures. Additional attention should be directed to other uses of iPSCs in farm animals – e.g. biopharming and agricultural applications that seem to be (unjustifiably) outshined by the potential of regenerative medicine applications. With this review we wanted to summarise the achievements of cell reprogramming in the farm animals and encourage further studies in this promising field of science.

Declarations

Acknowledgments

The authors thank to the Slovenian Research Agency (ARRS) for financial support through postdoctoral project Z4-5523 (JO) and research programme P4-0220 (PD).

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Authors’ Affiliations

(1)
Department of Animal Science, Biotechnical Faculty, University of Ljubljana

References

  1. Evans MJ, Kaufman MH. Establishment in culture of pluripotential cells from mouse embryos. Nature. 1981;292:154–6.View ArticlePubMedGoogle Scholar
  2. Thomson JA, Itskovitz-Eldor J, Shapiro SS, Waknitz MA, Swiergiel JJ, Marshall VS, et al. Embryonic stem cell lines derived from human blastocysts. Science. 1998;282:1145–7.View ArticlePubMedGoogle Scholar
  3. Blomberg LA, Telugu BP. Twenty years of embryonic stem cell research in farm animals. Reprod Domest Anim. 2012;47 Suppl 4:80–5.View ArticlePubMedGoogle Scholar
  4. Zhang B, Krawetz R, Rancourt DE. Would the real human embryonic stem cell please stand up? Bioessays. 2013;35:632–8.View ArticlePubMedGoogle Scholar
  5. Gurdon JB. The developmental capacity of nuclei taken from intestinal epithelium cells of feeding tadpoles. J Embryol Exp Morphol. 1962;10:622–40.PubMedGoogle Scholar
  6. Wilmut I, Schnieke AE, McWhir J, Kind AJ, Campbell KH. Viable offspring derived from fetal and adult mammalian cells. Nature. 1997;385:810–3.View ArticlePubMedGoogle Scholar
  7. Kato Y, Tani T, Sotomaru Y, Kurokawa K, Kato J, Doguchi H, et al. Eight calves cloned from somatic cells of a single adult. Science. 1998;282:2095–8.View ArticlePubMedGoogle Scholar
  8. Baguisi A, Behboodi E, Melican DT, Pollock JS, Destrempes MM, Cammuso C, et al. Production of goats by somatic cell nuclear transfer. Nat Biotechnol. 1999;17:456–61.View ArticlePubMedGoogle Scholar
  9. Polejaeva IA, Chen SH, Vaught TD, Page RL, Mullins J, Ball S, et al. Cloned pigs produced by nuclear transfer from adult somatic cells. Nature. 2000;407:86–90.View ArticlePubMedGoogle Scholar
  10. Noggle S, Fung HL, Gore A, Martinez H, Satriani KC, Prosser R, et al. Human oocytes reprogram somatic cells to a pluripotent state. Nature. 2011;478:70–5.View ArticlePubMedGoogle Scholar
  11. Tachibana M, Amato P, Sparman M, Gutierrez NM, Tippner-Hedges R, Ma H, et al. Human embryonic stem cells derived by somatic cell nuclear transfer. Cell. 2013;153:1228–38.PubMed CentralView ArticlePubMedGoogle Scholar
  12. Takahashi K, Yamanaka S. Induction of pluripotent stem cells from mouse embryonic and adult fibroblast cultures by defined factors. Cell. 2006;126:663–76.View ArticlePubMedGoogle Scholar
  13. Yu J, Vodyanik MA, Smuga-Otto K, Antosiewicz-Bourget J, Frane JL, Tian S, et al. Induced pluripotent stem cell lines derived from human somatic cells. Science. 2007;318:1917–20.View ArticlePubMedGoogle Scholar
  14. Robinton DA, Daley GQ. The promise of induced pluripotent stem cells in research and therapy. Nature. 2012;481:295–305.PubMed CentralView ArticlePubMedGoogle Scholar
  15. Nowak-Imialek M, Kues W, Carnwath JW, Niemann H. Pluripotent stem cells and reprogrammed cells in farm animals. Microsc Microanal. 2011;17:474–97.View ArticlePubMedGoogle Scholar
  16. Hanna J, Wernig M, Markoulaki S, Sun CW, Meissner A, Cassady JP, et al. Treatment of sickle cell anemia mouse model with iPS cells generated from autologous skin. Science. 2007;318:1920–3.View ArticlePubMedGoogle Scholar
  17. Chong JJ, Yang X, Don CW, Minami E, Liu YW, Weyers JJ, et al. Human embryonic-stem-cell-derived cardiomyocytes regenerate non-human primate hearts. Nature. 2014;510:273–7.PubMed CentralView ArticlePubMedGoogle Scholar
  18. Hallett PJ, Deleidi M, Astradsson A, Smith GA, Cooper O, Osborn TM, et al. Successful function of autologous iPSC-derived dopamine neurons following transplantation in a non-human primate model of Parkinson’s disease. Cell Stem Cell. 2015;16:269–74.View ArticlePubMedGoogle Scholar
  19. Song G, Li X, Shen Y, Qian L, Kong X, Chen M, et al. Transplantation of iPSc Restores Cardiac Function by Promoting Angiogenesis and Ameliorating Cardiac Remodeling in a Post-infarcted Swine Model. Cell Biochem Biophys. 2015;71:1463–73.View ArticleGoogle Scholar
  20. Rashid T, Kobayashi T, Nakauchi H. Revisiting the flight of Icarus: making human organs from PSCs with large animal chimeras. Cell Stem Cell. 2014;15:406–9.View ArticlePubMedGoogle Scholar
  21. Isotani A, Hatayama H, Kaseda K, Ikawa M, Okabe M. Formation of a thymus from rat ES cells in xenogeneic nude mouse↔rat ES chimeras. Genes Cells. 2011;16:397–405.View ArticlePubMedGoogle Scholar
  22. Kobayashi T, Yamaguchi T, Hamanaka S, Kato-Itoh M, Yamazaki Y, Ibata M, et al. Generation of rat pancreas in mouse by interspecific blastocyst injection of pluripotent stem cells. Cell. 2010;142:787–99.View ArticlePubMedGoogle Scholar
  23. Keefer CL. Artificial cloning of domestic animals. Proc Natl Acad Sci U S A. 2015;112:8874–8.PubMed CentralView ArticlePubMedGoogle Scholar
  24. Zhou S, Ding C, Zhao X, Wang E, Dai X, Liu L, et al. Successful generation of cloned mice using nuclear transfer from induced pluripotent stem cells. Cell Res. 2010;20:850–3.View ArticlePubMedGoogle Scholar
  25. Echelard Y, Meade HM, Ziomek CA. The First Biopharmaceutical from Transgenic Animals: ATryn®. Modern Biopharmaceuticals. Weinheim, Germany: Wiley-VCH Verlag GmbH; 2008. p. 995–1020.Google Scholar
  26. Wheeler MB. Agricultural applications for transgenic livestock. Trends Biotechnol. 2007;25:204–10.View ArticlePubMedGoogle Scholar
  27. Chronowska E. z Induced pluripotent stem (iPS) cells in domestic animals recent achievements - a review. Anim Sci Pap Rep. 2013;31:89–99.Google Scholar
  28. Kumar D, Talluri TR, Anand T, Kues WA. Induced pluripotent stem cells: Mechanisms, achievements and perspectives in farm animals. World J Stem Cells. 2015;7:315–28.PubMed CentralView ArticlePubMedGoogle Scholar
  29. Rosselló RA, Chen CC, Dai R, Howard JT, Hochgeschwender U, Jarvis ED. Mammalian genes induce partially reprogrammed pluripotent stem cells in non-mammalian vertebrate and invertebrate species. Elife. 2013;2:e00036.PubMed CentralView ArticlePubMedGoogle Scholar
  30. González F, Boué S, Izpisúa Belmonte JC. Methods for making induced pluripotent stem cells: reprogramming à la carte. Nat Rev Genet. 2011;12:231–42.View ArticlePubMedGoogle Scholar
  31. Schlaeger TM, Daheron L, Brickler TR, Entwisle S, Chan K, Cianci A, et al. A comparison of non-integrating reprogramming methods. Nat Biotechnol. 2015;33:58–63.PubMed CentralView ArticlePubMedGoogle Scholar
  32. Silva J, Chambers I, Pollard S, Smith A. Nanog promotes transfer of pluripotency after cell fusion. Nature. 2006;441:997–1001.View ArticlePubMedGoogle Scholar
  33. Xu YN, Guan N, Wang ZD, Shan ZY, Shen JL, Zhang QH, et al. ES cell extract-induced expression of pluripotent factors in somatic cells. Anat Rec (Hoboken). 2009;292:1229–34.View ArticleGoogle Scholar
  34. Miyamoto K, Tsukiyama T, Yang Y, Li N, Minami N, Yamada M, et al. Cell-free extracts from mammalian oocytes partially induce nuclear reprogramming in somatic cells. Biol Reprod. 2009;80:935–43.View ArticlePubMedGoogle Scholar
  35. Bharadwaj P, Kumar K, Singh R, Puri G, Yasotha T, Kumar M, et al. Reprogramming of fetal cells by avian EE for generation of pluripotent stem cell like cells in caprine. Res Vet Sci. 2013;95:638–43.View ArticlePubMedGoogle Scholar
  36. Zhu XQ, Pan XH, Wang W, Chen Q, Pang RQ, Cai XM, et al. Transient in vitro epigenetic reprogramming of skin fibroblasts into multipotent cells. Biomaterials. 2010;31:2779–87.PubMed CentralView ArticlePubMedGoogle Scholar
  37. Byrne JA, Simonsson S, Western PS, Gurdon JB. Nuclei of adult mammalian somatic cells are directly reprogrammed to oct-4 stem cell gene expression by amphibian oocytes. Curr Biol. 2003;13:1206–13.View ArticlePubMedGoogle Scholar
  38. Warren L, Manos PD, Ahfeldt T, Loh YH, Li H, Lau F, et al. Highly efficient reprogramming to pluripotency and directed differentiation of human cells with synthetic modified mRNA. Cell Stem Cell. 2010;7:618–30.PubMed CentralView ArticlePubMedGoogle Scholar
  39. Yoshioka N, Gros E, Li HR, Kumar S, Deacon DC, Maron C, et al. Efficient generation of human iPSCs by a synthetic self-replicative RNA. Cell Stem Cell. 2013;13:246–54.View ArticlePubMedGoogle Scholar
  40. Kim JB, Zaehres H, Araúzo-Bravo MJ, Schöler HR. Generation of induced pluripotent stem cells from neural stem cells. Nat Protoc. 2009;4:1464–70.View ArticlePubMedGoogle Scholar
  41. Zhu S, Li W, Zhou H, Wei W, Ambasudhan R, Lin T, et al. Reprogramming of human primary somatic cells by OCT4 and chemical compounds. Cell Stem Cell. 2010;7:651–5.View ArticlePubMedGoogle Scholar
  42. Li Y, Zhang Q, Yin X, Yang W, Du Y, Hou P, et al. Generation of iPSCs from mouse fibroblasts with a single gene, Oct4, and small molecules. Cell Res. 2011;21:196–204.PubMed CentralView ArticlePubMedGoogle Scholar
  43. Hou P, Li Y, Zhang X, Liu C, Guan J, Li H, et al. Pluripotent stem cells induced from mouse somatic cells by small-molecule compounds. Science. 2013;341:651–4.View ArticlePubMedGoogle Scholar
  44. Du X, Feng T, Yu D, Wu Y, Zou H, Ma S, et al. Barriers for Deriving Transgene-Free Pig iPS Cells with Episomal Vectors. Stem Cells. 2015;33:3228–38.View ArticlePubMedGoogle Scholar
  45. West FD, Terlouw SL, Kwon DJ, Mumaw JL, Dhara SK, Hasneen K, et al. Porcine induced pluripotent stem cells produce chimeric offspring. Stem Cells Dev. 2010;19:1211–20.View ArticlePubMedGoogle Scholar
  46. West FD, Uhl EW, Liu Y, Stowe H, Lu Y, Yu P, et al. Brief report: chimeric pigs produced from induced pluripotent stem cells demonstrate germline transmission and no evidence of tumor formation in young pigs. Stem Cells. 2011;29:1640–3.View ArticlePubMedGoogle Scholar
  47. Brevini TA, Antonini S, Cillo F, Crestan M, Gandolfi F. Porcine embryonic stem cells: Facts, challenges and hopes. Theriogenology. 2007;68 Suppl 1:S206–13.View ArticlePubMedGoogle Scholar
  48. Cibelli J, Emborg ME, Prockop DJ, Roberts M, Schatten G, Rao M, et al. Strategies for improving animal models for regenerative medicine. Cell Stem Cell. 2013;12:271–4.PubMed CentralView ArticlePubMedGoogle Scholar
  49. Nagy K, Sung HK, Zhang P, Laflamme S, Vincent P, Agha-Mohammadi S, et al. Induced pluripotent stem cell lines derived from equine fibroblasts. Stem Cell Rev. 2011;7:693–702.PubMed CentralView ArticlePubMedGoogle Scholar
  50. Wang Y, Zhao S, Bai L, Fan J, Liu E. Expression systems and species used for transgenic animal bioreactors. Biomed Res Int. 2013;2013:580463.PubMed CentralPubMedGoogle Scholar
  51. Esteban MA, Xu J, Yang J, Peng M, Qin D, Li W, et al. Generation of induced pluripotent stem cell lines from Tibetan miniature pig. J Biol Chem. 2009;284:17634–40.PubMed CentralView ArticlePubMedGoogle Scholar
  52. Ezashi T, Telugu BP, Alexenko AP, Sachdev S, Sinha S, Roberts RM. Derivation of induced pluripotent stem cells from pig somatic cells. Proc Natl Acad Sci U S A. 2009;106:10993–8.PubMed CentralView ArticlePubMedGoogle Scholar
  53. Wu Z, Chen J, Ren J, Bao L, Liao J, Cui C, et al. Generation of pig induced pluripotent stem cells with a drug-inducible system. J Mol Cell Biol. 2009;1:46–54.View ArticlePubMedGoogle Scholar
  54. Montserrat N, Bahima EG, Batlle L, Häfner S, Rodrigues AM, González F, et al. Generation of pig iPS cells: a model for cell therapy. J Cardiovasc Transl Res. 2011;4:121–30.View ArticlePubMedGoogle Scholar
  55. Montserrat N, de Oñate L, Garreta E, González F, Adamo A, Eguizábal C, et al. Generation of feeder-free pig induced pluripotent stem cells without Pou5f1. Cell Transplant. 2012;21:815–25.View ArticlePubMedGoogle Scholar
  56. Hall VJ, Kristensen M, Rasmussen MA, Ujhelly O, Dinnyés A, Hyttel P. Temporal repression of endogenous pluripotency genes during reprogramming of porcine induced pluripotent stem cells. Cell Reprogram. 2012;14:204–16.PubMedGoogle Scholar
  57. Ezashi T, Matsuyama H, Telugu BP, Roberts RM. Generation of colonies of induced trophoblast cells during standard reprogramming of porcine fibroblasts to induced pluripotent stem cells. Biol Reprod. 2011;85:779–87.PubMed CentralView ArticlePubMedGoogle Scholar
  58. Kues WA, Herrmann D, Barg-Kues B, Haridoss S, Nowak-Imialek M, Buchholz T, et al. Derivation and characterization of sleeping beauty transposon-mediated porcine induced pluripotent stem cells. Stem Cells Dev. 2013;22:124–35.View ArticlePubMedGoogle Scholar
  59. Ruan W, Han J, Li P, Cao S, An Y, Lim B, et al. A novel strategy to derive iPS cells from porcine fibroblasts. Sci China Life Sci. 2011;54:553–9.View ArticlePubMedGoogle Scholar
  60. Cheng D, Guo Y, Li Z, Liu Y, Gao X, Gao Y, et al. Porcine induced pluripotent stem cells require LIF and maintain their developmental potential in early stage of embryos. PLoS One. 2012;7:e51778.PubMed CentralView ArticlePubMedGoogle Scholar
  61. Liu K, Ji G, Mao J, Liu M, Wang L, Chen C, et al. Generation of porcine-induced pluripotent stem cells by using OCT4 and KLF4 porcine factors. Cell Reprogram. 2012;14:505–13.PubMedGoogle Scholar
  62. Khodadadi K, Sumer H, Pashaiasl M, Lim S, Williamson M, Verma PJ. Induction of pluripotency in adult equine fibroblasts without c-MYC. Stem Cells Int. 2012;2012:429160.PubMed CentralView ArticlePubMedGoogle Scholar
  63. Breton A, Sharma R, Diaz AC, Parham AG, Graham A, Neil C, et al. Derivation and characterization of induced pluripotent stem cells from equine fibroblasts. Stem Cells Dev. 2013;22:611–21.PubMed CentralView ArticlePubMedGoogle Scholar
  64. Sharma R, Livesey MR, Wyllie DJ, Proudfoot C, Whitelaw CB, Hay DC, et al. Generation of functional neurons from feeder-free, keratinocyte-derived equine induced pluripotent stem cells. Stem Cells Dev. 2014;23:1524–34.View ArticlePubMedGoogle Scholar
  65. Whitworth DJ, Ovchinnikov DA, Sun J, Fortuna PR, Wolvetang EJ. Generation and characterization of leukemia inhibitory factor-dependent equine induced pluripotent stem cells from adult dermal fibroblasts. Stem Cells Dev. 2014;23:1515–23.PubMed CentralView ArticlePubMedGoogle Scholar
  66. Honda A, Hirose M, Hatori M, Matoba S, Miyoshi H, Inoue K, et al. Generation of induced pluripotent stem cells in rabbits: potential experimental models for human regenerative medicine. J Biol Chem. 2010;285:31362–9.PubMed CentralView ArticlePubMedGoogle Scholar
  67. Osteil P, Tapponnier Y, Markossian S, Godet M, Schmaltz-Panneau B, Jouneau L, et al. Induced pluripotent stem cells derived from rabbits exhibit some characteristics of naïve pluripotency. Biol Open. 2013;2:613–28.PubMed CentralView ArticlePubMedGoogle Scholar
  68. Liu J, Balehosur D, Murray B, Kelly JM, Sumer H, Verma PJ. Generation and characterization of reprogrammed sheep induced pluripotent stem cells. Theriogenology. 2012;77:338–46.View ArticlePubMedGoogle Scholar
  69. Bao L, He L, Chen J, Wu Z, Liao J, Rao L, et al. Reprogramming of ovine adult fibroblasts to pluripotency via drug-inducible expression of defined factors. Cell Res. 2011;21:600–8.PubMed CentralView ArticlePubMedGoogle Scholar
  70. Li Y, Cang M, Lee AS, Zhang K, Liu D. Reprogramming of sheep fibroblasts into pluripotency under a drug-inducible expression of mouse-derived defined factors. PLoS One. 2011;6:e15947.PubMed CentralView ArticlePubMedGoogle Scholar
  71. Sartori C, DiDomenico AI, Thomson AJ, Milne E, Lillico SG, Burdon TG, et al. Ovine-induced pluripotent stem cells can contribute to chimeric lambs. Cell Reprogram. 2012;14:8–19.PubMedGoogle Scholar
  72. Han X, Han J, Ding F, Cao S, Lim SS, Dai Y, et al. Generation of induced pluripotent stem cells from bovine embryonic fibroblast cells. Cell Res. 2011;21:1509–12.PubMed CentralView ArticlePubMedGoogle Scholar
  73. Cao H, Yang P, Pu Y, Sun X, Yin H, Zhang Y, et al. Characterization of bovine induced pluripotent stem cells by lentiviral transduction of reprogramming factor fusion proteins. Int J Biol Sci. 2012;8:498–511.PubMed CentralView ArticlePubMedGoogle Scholar
  74. Huang B, Li T, Alonso-Gonzalez L, Gorre R, Keatley S, Green A, et al. A virus-free poly-promoter vector induces pluripotency in quiescent bovine cells under chemically defined conditions of dual kinase inhibition. PLoS One. 2011;6:e24501.PubMed CentralView ArticlePubMedGoogle Scholar
  75. Sumer H, Liu J, Malaver-Ortega LF, Lim ML, Khodadadi K, Verma PJ. NANOG is a key factor for induction of pluripotency in bovine adult fibroblasts. J Anim Sci. 2011;89:2708–16.View ArticlePubMedGoogle Scholar
  76. Talluri TR, Kumar D, Glage S, Garrels W, Ivics Z, Debowski K, et al. Derivation and characterization of bovine induced pluripotent stem cells by transposon-mediated reprogramming. Cell Reprogram. 2015;17:131–40.View ArticlePubMedGoogle Scholar
  77. Ren J, Pak Y, He L, Qian L, Gu Y, Li H, et al. Generation of hircine-induced pluripotent stem cells by somatic cell reprogramming. Cell Res. 2011;21:849–53.PubMed CentralView ArticlePubMedGoogle Scholar
  78. Song H, Li H, Huang M, Xu D, Gu C, Wang Z, et al. Induced pluripotent stem cells from goat fibroblasts. Mol Reprod Dev. 2013;80:1009–17.View ArticlePubMedGoogle Scholar
  79. Sandmaier SE, Nandal A, Powell A, Garrett W, Blomberg L, Donovan DM, et al. Generation of induced pluripotent stem cells from domestic goats. Mol Reprod Dev. 2015;82:709–21.View ArticlePubMedGoogle Scholar

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