How farm animals are improving human health and welfare.

The contribution of farm animals to human health and welfare cannot be properly addressed without reflecting on the impact that animal domestication has had upon human civilisation. About 14,000 years ago, the Neolithic revolution started with the domestication of animals and plants, resulting in the emergence of the main agricultural breeds of livestock and crops. In contrast, the breeding of new animal species for biomedical research, such as small rodents and other model species, is a relatively recent activity. The cellular and molecular mechanisms of inheritance have only been understood over the past few decades and translated into approaches to improve breeding success. In recent years, seminal discoveries in the fields of cellular reprogramming, genetic engineering, and whole-genome sequencing have accelerated this development. The first therapeutic proteins produced by biopharming in livestock have been approved to treat human patients. The suitability of pluripotent stem cells as a source for cell replacement therapies is currently being investigated, using farm animals as informative preclinical models. Disease modelling in farm animals allows systematic testing of effective treatments. Within the context of these developments, this concise review will focus on the contribution of farm animals to human health and welfare.

On ne peut traiter de la contribution des animaux d'élevage à la santé et au bienêtre de l'homme sans prendre en compte l'impact de la domestication des animaux sur la civilisation humaine. La révolution néolithique a commencé il y a environ 14 000 ans avec la domestication des animaux et des plantes, ce qui a donné naissance aux principales variétés cultivées et races d'élevage. En revanche, la sélection d'espèces animales nouvelles pour la recherche biomédicale, par exemple certaines espèces de petits rongeurs et d'autres modèles animaux, constitue une activité relativement récente. Ce n'est que depuis quelques dizaines d'années que les mécanismes cellulaires et moléculaires de l'hérédité sont bien compris et appliqués dans des approches permettant d'améliorer le potentiel génétique des élevages. Depuis quelques années, des découvertes fondamentales dans les domaines de la reprogrammation cellulaire, du génie génétique et du séquençage du génome entier ont accéléré cette évolution. Les premières protéines thérapeutiques produites par l'industrie biopharmaceutique chez des animaux d'élevage ont été approuvées pour traiter des patients humains. La recherche examine actuellement les possibilités de recourir à des cellules souches pluripotentes pour mettre en place des thérapies de remplacement, en utilisant des animaux d'élevage comme modèles précliniques. La modélisation des maladies en utilisant des animaux d'élevage permet d'effectuer des essais systématiques de l'efficacité des traitements. Les auteurs consacrent l'essentiel de leur synthèse à la contribution des animaux d'élevage à la santé et au bienêtre de l'homme, dans le cadre de ces évolutions.

No cabe examinar debidamente la contribución de los animales de granja a la salud y el bienestar del ser humano sin detenerse a reflexionar sobre la influencia que ha tenido en la civilización humana la domesticación de los animales. Hace unos 14 000 años, con la domesticación de animales y plantas, dio comienzo la revolución neolítica, que iba a deparar la aparición de las principales razas agrícolas de ganado y cultivos. En marcado contraste, la cría selectiva de nuevas especies animales con fines de investigación biomédica, como pequeños roedores y otras especies utilizadas como modelo, es una actividad relativamente reciente. Solo en los últimos decenios se han desentrañado los mecanismos celulares y moleculares de la herencia y se ha podido traducir este conocimiento en métodos para mejorar los niveles de éxito de la cría selectiva. En los últimos años, esta evolución se ha acelerado gracias a trascendentales descubrimientos en los ámbitos de la reprogramación celular, la ingeniería genética y la secuenciación de genomas completos. Ya están aprobadas las primeras proteínas terapéuticas para tratar a pacientes humanos obtenidas a partir de ganado mediante procedimientos biofarmacéuticos. Actualmente se investiga la idoneidad de las células troncales pluripotentes como fuente de terapias de sustitución celular, utilizando a animales de granja como modelos preclínicos informativos. La modelización de enfermedades en animales de granja permite ensayar tratamientos eficaces de forma sistemática. En el contexto de todos estos adelantos, los autores se centran en repasar concisamente la contribución de los animales de granja a la salud y el bienestar humanos.

m-carboxycinnamic acid bishydroxamide improves developmental competence, reduces apoptosis and alters epigenetic status and gene expression pattern in cloned buffalo (Bubalus bubalis) embryos.

Incomplete or aberrant reprogramming of nuclear genome is one of the major problems in somatic cell nuclear transfer. In this study, we studied the effect of histone deacetylase inhibitor m-carboxycinnamic acid bishydroxamide (CBHA) on in vitro development of buffalo embryos produced by Hand-made cloning. Cloned embryos were treated with CBHA (0, 5, 10, 20 or 50 µM) for 10 hr from the start of reconstruction till activation. At 10 µM, but not at other concentrations examined, CBHA increased (p < .05) the blastocyst rate (63.77 ± 3.97% vs 48.63 ± 3.55%) and reduced (p < .05) the apoptotic index of the cloned blastocysts (8.91 ± 1.94 vs 4.36 ± 1.08) compared to untreated controls, to levels similar to those in IVF blastocysts (4.78 ± 0.74). CBHA treatment, at all the concentrations examined, increased (p < .05) the global level of H3K9ac in cloned blastocysts than in untreated controls to that observed in IVF blastocysts. Treatment with CBHA (10 µM) decreased (p < .05) the global level of H3K27me3 in cloned blastocysts than in untreated controls but it was still higher (p < .05) than in IVF blastocysts. CBHA (10 µM) treatment increased (p < .05) the relative expression level of pluripotency-related genes OCT-4 and NANOG, and anti-apoptotic gene BCL-XL, and decreased (p < .05) that of pro-apoptotic gene BAX than in untreated controls but did not affect the relative expression level of apoptosis-related genes p53 and CASPASE3 and epigenetics-related genes DNMT1, DNMT3a and HDAC1. These results suggest that treatment of cloned embryos with 10 µM CBHA improves the blastocyst rate, reduces the level of apoptosis and alters the epigenetic status and gene expression pattern.

Epigenetic status of buffalo fibroblasts treated with sodium butyrate a chromatin remodeling agent.

The somatic cells having higher levels of DNA methylation and reducing it in donor cells before nuclear transfer (NT) by treating them with chemicals, may improve cloning efficiency of NT embryos by providing donor cells with similar epigenetic characteristics as in vivo embryos. Therefore, the present study was planned to understand mechanism of epigenetic changes in donor cells (buffalo fibroblasts) treated with different concentration of sodium butyrate (NaBu)-a chromatin remodeling agent. The cultured fibroblasts purity and lineage were confirmed by fibroblast specific protein and gene markers (Vimentin, Tubulin and Cytokeratin) at different passages using immuno-staining and qPCR respectively. The buffalo fibroblast cells were treated with 1, 3 and 5 mM of NaBu and observations were taken on their morphological changes, population doubling time and cell proliferation after 48 h of treatment. The epigenetic changes were observed using acetylation (H3K9ac) and methylation (H3K27me3) markers expression. The fibroblast cells derived from new born ear tissue started emerging and anchoring to cell culture flasks within 24 h and showed spindle-shaped morphology. The confluent culture was cryopreserved at different time interval. The post thaw culture behavior of the cryopreserved cells was also observed at different time interval and passages. The morphology of NaBu treated cells were changed with increase of dosages of NaBu treatment. The increase population doubling times and decreases the proliferation rate in the dose dependent manner. The NaBu treatment showed that the significantly increased the acetylation (H3K9ac) and methylation (H3K27me3) level over the control. Based on the observations of fibroblast characterization as well as epigenetic modifications of these cells after treatment with NaBu, results suggest that the cells may provide a useful approach for better epigenetic reprogramming in SCNT embryos.

Differences in developmental competence and gene expression profiles between buffalo (Bubalus bubalis) preimplantation embryos cultured in three different embryo culture media.

The objective of this study was to compare effects of in vitro culture systems on embryonic development and expression patterns of developmentally important genes in preimplantation buffalo embryos. After IVM/IVF presumptive zygotes were cultured in one of three systems: undefined TCM-199, mCR2aa medium supplemented with 10 % FBS and defined PVA-myo-inositol-phosphate-EGF medium. No (P > 0.05) differences at 2-cell, 4-cell and 8-cell to 16- cell stages were observed among the three cultured media used, however, increased (P < 0.05) blastocyst yield, cell number and hatching rate were found in defined medium compared to undefined media. The expression patterns of genes implicated in embryo metabolism (GLUT-1), anti-apoptosis (BCL-2), imprinting (IGF-2R), DNA methylation (DNMT-3A) and maternal recognition of pregnancy (IFNT) were increased (P < 0.05) in hatched blastocysts derived from defined medium compared to undefined media. In conclusion, serum-free, defined medium improved developmental competence of in vitro cultured buffalo embryos. Whether these differences in morphological development and gene expression have long-term effects on buffalo calves born after embryo transfer remains unknown. However, it is possible that early adaptations of the preimplantation embryo to its environment persist during fetal and post-natal development.

Amnion Epithelial Cells of Buffalo (Bubalus Bubalis) Term Placenta Expressed Embryonic Stem Cells Markers and Differentiated into Cells of Neurogenic Lineage In Vitro.

Aim of the present study was the isolation, culture, and characterization of amniotic membrane-derived epithelial cells (AE) from term placenta collected postpartum in buffalo. We found that cultured cells were of polygonal in shape, resistance to trypsin digestion and expressed cytokeratin-18 indicating that they were of epithelial origin. These cells have negative expression of mesenchymal stem cell markers (CD29, CD44, and CD105) and positive for pluripotency marker (OCT4) genes indicated that cultured cells were not contaminated with mesenchymal stem cells. Immunofluorescence staining with pluripotent stem cell surface markers, SSEA-1, SSEA-4, TRA-1-60, and TRA-1-81 indicated that these cells may retain pluripotent stem cell characteristics even after long period of differentiation. Differentiation potential of these cells was determined by their potential to differentiate into cells of neurogenic lineages using retinoic acid. In conclusion, we demonstrate that AE cells expressed pluripotent stem cell markers and have propensity to differentiate into cells of neurogenic lineage upon directed differentiation in vitro.

Treatment of buffalo (Bubalus bubalis) donor cells with trichostatin A and 5-aza-2'-deoxycytidine alters their growth characteristics, gene expression and epigenetic status and improves the in vitro developmental competence, quality and epigenetic status of cloned embryos.

We examined the effects of treating buffalo skin fibroblast donor cells with trichostatin A (TSA), a histone deacetylase (HDAC) inhibitor, and 5-aza-2'-deoxycytidine (5azadC), a DNA methyltransferase (DNMT) inhibitor, on the cells and embryos produced by hand-made cloning. Treatment of donor cells with TSA or 5azadC resulted in altered expression levels of the HDAC1, DNMT1, DNMT3a, P53, CASPASE3 and CASPASE9 genes and global levels of acetylation of lysine at position 9 or 14 in histone 3 (H3K9/14ac), acetylation of lysine at position 5 in histone 4 (H4K5ac), acetylation of lysine at position 18 in histone 3 (H3K18ac) and tri-methylation of lysine at position 27 in histone 3 (H3K27me3). Moreover, global levels of DNA methylation and activity of DNMT1 and HDAC1 were decreased, while global acetylation of H3 and H3K9 was significantly increased in comparison to untreated cells. Simultaneous treatment of donor cells with TSA (50nM) and 5azadC (7.5nM) resulted in higher in vitro development to the blastocyst stage, reduction of the apoptotic index and the global level of H3K27 me3 and altered expression levels of HDAC1, P53, CASPASE3, CASPASE9 and DNMT3a in cloned blastocysts. Transfer of cloned embryos produced with donor cells treated with TSA led to the birth of a calf that survived for 21 days. These results show that treatment of buffalo donor cells with TSA and 5azadC improved developmental competence and quality of cloned embryos and altered their epigenetic status and gene expression, and that these beneficial effects were mediated by a reduction in DNA and histone methylation and an increase in histone acetylation in donor cells.

Effect of donor cell type on developmental competence, quality, gene expression, and epigenetic status of interspecies cloned embryos produced using cells from wild buffalo and oocytes from domestic buffalo.

This study compared the cloning efficiency of donor cells of fibroblast and epithelial origin isolated from ear skin of a wild buffalo (Bubalus arnee) and used with cytoplasts from domestic buffalo (Bubalus bubalis) in interspecies SCNT by hand-made cloning. The cleavage (93.0 ± 2.8% vs. 85.6 ± 2.4%) and blastocyst rates (50.6 ± 4.0% vs. 20.5 ± 2.6%) were higher (P < 0.05) for fibroblasts than those for epithelial cells, whereas the total cell number (490 ± 42 and 492 ± 95, respectively) and apoptotic index (2.3 ± 0.3 and 2.5 ± 0.6, respectively) of blastocysts were similar. The global level of H3K18ac and H3K27me3 was lower (P < 0.05) in fibroblasts than that in epithelial cells. The global level of H3K18ac was higher (P < 0.05) in fibroblast than that in epithelial cell-derived blastocysts, whereas that of H3K27me3 was similar between the two groups. The expression level of HDAC1, DNMT1, DNMT3a, and P53 was higher (P < 0.05) in fibroblasts than that in epithelial cells; that of CASPASE3 showed an opposite pattern (P < 0.001), whereas CASPASE7 expression level was similar in the two groups. In the embryos, the expression level of HDAC1, DNMT3a, and CDX2 was lower (P < 0.05) in fibroblast than that in epithelial cell-derived blastocysts; that of NANOG showed an opposite pattern (P < 0.05), whereas that of OCT4 was similar between the two groups. In conclusion, donor cells of fibroblast origin are easier to reprogram than those of epithelial origin in interspecies SCNT, and cloning efficiency, epigenetic status, and gene expression pattern vary among cells having different origin although they may be from the same tissue.

Trichostatin A alters the expression of cell cycle controlling genes and microRNAs in donor cells and subsequently improves the yield and quality of cloned bovine embryos in vitro.

Trichostatin A (TSA), a histone deacetylase inhibitor, has been used to improve nuclear reprogramming in somatic cell nuclear transfer embryos. However, the molecular mechanism of TSA for the improvement of the pre- and postimplantation embryonic development is unknown. In the present study, we investigated mechanism of cell cycle arrest caused by TSA and also determined embryo quality and gene expression in cloned bovine embryos produced from TSA-treated donor cells compared with embryos produced by in vitro fertilization or parthenogenetic activation. We observed that, 50 nM TSA-treated cells were synchronized at G0/G1 stage with concomitant decrease in the proportion of these cells in the S stage of the cell cycle, which was also supported by significant changes in cell morphology and decreased proliferation (P<0.05). Measurement of relative expression using real-time polymerase chain reaction of a some cell cycle-related genes and microRNAs in treated donor cells showed decreased expression of HDAC1, DNMT1, P53, CYC E1, and CDK4 and increased expression of DNMT3a, CDKN1A, CDK2, CDK3, miR-15a, miR-16, and miR-34a (P<0.05). No change in the relative expression of miR-449a was noticed. Trichostatin A treatment of donor cells significantly improved both cleavage and blastocyst rate (P<0.05) compared with the control embryos, also apoptotic index in treated cloned blastocysts was significantly decreased compared with the nontreated blastocysts (P<0.05) and was at the level of IVF counterpart. Relative expression of HDAC1 and DNMT3a was significantly lower in treated cloned and parthenogenetic embryos than that of nontreated and IVF counterpart, whereas in case of P53, expression level between treated and IVF embryos was similar, which was significantly lower than nontreated cloned and parthenogenetic embryos. In conclusion, our data suggested that TSA improves yield and quality of cloned bovine embryos by modulating the expression of G0/G1 cell cycle stage-related microRNA in donor cells, which support that TSA might be great cell cycle synchronizer apart from potent epigenetic modulator in cloning research in future.

Production of wild buffalo (Bubalus arnee) embryos by interspecies somatic cell nuclear transfer using domestic buffalo (Bubalus bubalis) oocytes.

The objective of this study was to explore the possibility of producing wild buffalo embryos by interspecies somatic cell nuclear transfer (iSCNT) through handmade cloning using wild buffalo somatic cells and domestic buffalo (Bubalus bubalis) oocytes. Somatic cells derived from the ear skin of wild buffalo were found to express vimentin but not keratin and cytokeratin-18, indicating that they were of fibroblast origin. The population doubling time of skin fibroblasts from wild buffalo was significantly (p < 0.05) higher, and the cell proliferation rate was significantly (p < 0.05) lower compared with that of skin fibroblasts from domestic buffalo. Neither the cleavage (92.6 ± 2.0% vs 92.8 ± 2.0%) nor the blastocyst rate (42.4 ± 2.4% vs 38.7 ± 2.8%) was significantly different between the intraspecies cloned embryos produced using skin fibroblasts from domestic buffalo and interspecies cloned embryos produced using skin fibroblasts from wild buffalo. However, the total cell number (TCN) was significantly (p < 0.05) lower (192.0 ± 25.6 vs 345.7 ± 42.2), and the apoptotic index was significantly (p < 0.05) higher (15.1 ± 3.1 vs 8.0 ± 1.4) for interspecies than that for intraspecies cloned embryos. Following vitrification in open-pulled straws (OPS) and warming, although the cryosurvival rate of both types of cloned embryos, as indicated by their re-expansion rate, was not significantly different (34.8 ± 1.5% vs 47.8 ± 7.8), the apoptotic index was significantly (p < 0.05) higher for vitrified-warmed interspecies than that for corresponding intraspecies cloned embryos (48.9 ± 7.2 vs 23.9 ± 2.8). The global level of H3K18ac was significantly (p < 0.05) lower in interspecies cloned embryos than that in intraspecies cloned embryos. The expression level of HDAC1, DNMT3a and CASPASE3 was significantly (p < 0.05) higher, that of P53 was significantly (p < 0.05) lower in interspecies than in intraspecies embryos, whereas that of DNMT1 was similar between the two types of embryos. In conclusion, these results demonstrate that wild buffalo embryos can be produced by iSCNT.

Cryopreservation of zona-free cloned buffalo (Bubalus Bubalis) embryos: slow freezing vs open-pulled straw vitrification.

This study was carried out to compare the post-thaw cryosurvival rate and the level of apoptosis in vitro produced zona-free cloned buffalo blastocysts subjected to slow freezing or vitrification in open-pulled straws (OPS). Zona-free cloned embryos produced by handmade cloning were divided into two groups and were cryopreserved either by slow freezing or by vitrification in OPS. Cryosurvival of blastocysts was determined by their re-expansion rate following post-thaw culture for 22-24 h. The post-thaw re-expansion rate was significantly (p < 0.05) higher following vitrification in OPS (71.2 ± 2.3%) compared with that after slow freezing (41.6 ± 4.8%). For examining embryo quality, the level of apoptosis in day 8 frozen-thawed blastocysts was determined by TUNEL staining. The total cell number was not significantly different among the control non-cryopreserved cloned embryos (422.6 ± 67.8) and those cryopreserved by slow freezing (376.4 ± 29.3) or vitrification in OPS (422.8 ± 36.2). However, the apoptotic index, which was similar for embryos subjected to slow freezing (14.8 ± 2.0) or OPS vitrification (13.3 ± 1.8), was significantly (p < 0.05) higher than that for the control non-cryopreserved cloned embryos (3.4 ± 0.6). In conclusion, the results of this study demonstrate that vitrification in OPS is better than slow freezing for the cryopreservation of zona-free cloned buffalo blastocysts because it offers a much higher cryosurvival rate.

Effect of post-fusion holding time, orientation and position of somatic cell-cytoplasts during electrofusion on the development of handmade cloned embryos in buffalo (Bubalus bubalis).

The present study was conducted primarily to optimize electrofusion conditions for efficient production of zona-free nuclear transfer embryos in buffalos (Bubalus bubalis). We found that 4V AC current for proper triplet alignment and single step fusion method, using a single DC pulse of 3.36 kV/cm for 4-µs duration, produced the most convincing results for efficient reconstitution of zona-free cloned embryos. Lysis rate was very high (84.28 ± 2.59%) when triplets were in physical contact with negative electrode after applying DC current, however, cleavage rate and blastocyst rate were found to be similar when the triplets were not in physical contact with either positive or negative electrodes or when they were in physical contact with the positive electrode. Significant improvement in blastocyst production was observed when the somatic cell faced the positive electrode than when it faced the negative electrode (39.17 ± 2.74% vs. 25.91 ± 2.00%, respectively) during electrofusion. Similarly, the blastocyst rate (52.0 ± 3.4%) was found to be significantly higher when reconstructed embryos were activated 6 h post electrofusion as compared to 0, 2, 4 and 8 h (16.04 ± 6.3%; 18.36 ± 1.4%; 22.44 ± 3.7% and 30.02 ± 4.6%, respectively). This study establishes the application of zona-free nuclear transfer procedures for the production of handmade cloned buffalo embryos through optimization of electrofusion parameters and post fusion holding time for enhancing their preimplantation development.

Production of nuclear transfer embryos by using somatic cells isolated from milk in buffalo (Bubalus bubalis).

Somatic cells in milk are a potential source of nuclei for nuclear transfer to produce genetically identical animals; this is especially important in animals that are susceptible to risks of bacterial infection on biopsy collection. In this study, a minimum of 10 milk samples were collected from each of the three buffaloes representing Murrah breed. All the samples were processed immediately and cell colonies were obtained. Cell colonies from one buffalo (MU-442) survived beyond 10 passages and were evaluated by fluorescence microscopy and used in nuclear transfer experiments. In culture, these cells expressed vimentin, indicating they were of fibroblast origin similar to ear cells. We compared the effectiveness of cloning using those milk-derived fibroblast (MDF) cells and fibroblast cells derived from the ear derived fibroblast (EDF). Fusion and cleavage rates of MDF-NT and EDF-NT embryos were found to be similar (92.43 ± 1.28% vs 94.98 ± 1.24%, and 80.27 ± 1.75% vs 84.56 ± 3.73%, respectively; p > 0.01); however, development to blastocyst stage and total cell number was higher for EDF-NT embryos (50.24 ± 2.54%, 227.14 ± 13.04, respectively, p < 0.01), than for MDF-NT embryos (16.44 ± 0.75%, 170.57 ± 4.50 respectively). We conclude that somatic cells from milk can be cultured effectively and used as nucleus donor to produce cloned blastocyst-stage embryos.

Production of interspecies handmade cloned embryos by nuclear transfer of cattle, goat and rat fibroblasts to buffalo (Bubalus bubalis) oocytes.

The possibility of producing interspecies handmade cloned (iHMC) embryos by nuclear transfer from donor cells of cattle, goat and rat using buffalo oocytes as recipient cytoplasts was explored. Zona-free buffalo oocytes were enucleated by protrusion cone-guided bisection with a microblade. After electrofusion with somatic cells, reconstructed oocytes were activated by calcimycin A23187, treated with 6-dimethylaminopurine and were cultured in K-RVCL-50® medium for 8 days. Although the cleavage rate was not significantly different when buffalo, cattle, goat or rat cells were used as donor nuclei (74.6 ± 3.8, 82.8 ± 5.3, 86.0 ± 4.9 and 82.3 ± 3.6%, respectively), the blastocyst rate was significantly higher (P<0.01) for buffalo (51.4 ± 2.6) than for cattle (3.5 ± 1.0) or the goat (2.2 ± 0.9), whereas none of the embryos crossed the 32-cell stage when rat cells were used. However, the total cell number was similar for buffalo-buffalo (175.0 ± 5.07) and cattle-buffalo embryos (178.0 ± 11.84). Following transfer of 3 buffalo-buffalo embryos each to 6 recipients, 3 were found to be pregnant, though the pregnancies were not carried to full term. These results suggest that interspecies blastocyst stage embryos can be produced by iHMC using buffalo cytoplasts and differentiated somatic cells from cattle and goat and that the source of donor nucleus affects the developmental competence of interspecies embryos.