Buffalo Embryos Research Articles

Expression pattern of glucose metabolism genes correlate with development rate of buffalo oocytes and embryos in vitro under low oxygen condition.

This study evaluates the effect of low oxygen conditions (5 Vs 20%) on buffalo embryo development. Expression patterns of key glucose metabolism genes (HK, PFK, LDH, PDH, G6PDH and Glut1) were assessed in buffalo oocytes and embryos cultured at 5 and 20% oxygen and correlated with development rate. Maturation rate was observed by determining MII stages by Aceto-orcein method and blastocyst formation was observed at 7 day post insemination (dpi). Expression levels of genes were determined by real time PCR in oocytes / embryos at 5 and 20% O2. Oocyte maturation and blastocyst formation rates were significantly higher at 5% O2 as compared to 20% O2 (P < 0.05). The expression pattern of glycolytic genes (HK, PFK and G6PDH) indicated that oocytes and embryos under 5% O2 tend to follow anaerobic glycolysis and pentose phosphate pathways to support optimum embryo development. Under 20% O2, oocytes and embryos had high expression of PDH indicating higher oxidative phosphorylation. Further, less G6PDH expression at 20% O2 was indicative of lower pentose phosphate activity. Higher expression of LDH was observed in oocytes and embryos under 20% O2 indicating sub-optimal culture conditions. High Glut1 activity was observed in the oocytes / embryos at 5% O2, indicative of high glucose uptake correlating with high expression of glycolytic genes. The expression patterns of glucose metabolism genes could be a valuable indicator of the development potential of oocytes and embryos. The study indicates the importance of reduced oxygen conditions for production of good quality embryos.

Establishing an in vitro production program for buffalo embryos (Bubalus bubalis) in Colombia

Objective. Evaluate the results of the standardization of the in vitro production program of buffalo embryos, using oocytes obtained by ultrasound guided oocyte puncture during the 2012 breeding season in Colombia. Materials and methods. Fifty seven buffalo females were selected for ultrasound guided transvaginal aspiration of follicles, oocytes were identified within follicular fluid, classified and transported to the laboratory and matured in vitro for 18 to 20 hours. Frozen semen of seven Mediterranean bulls were used, motile sperm was obtained using the Percoll technique and oocytes were inseminated with 2 million sperm/ml. Presumptive zygotes were cultured for 6 days, grade 1 embryos obtained were frozen using ethylene glycol. Embryos were transferred to females on day 5 during natural cycle. Results. 97 aspirations were performed on the 57 animals, in 8.2% of the aspirations no oocytes were found. 8 oocytes/aspiration were obtained. Of the 783 oocytes, 92% were classified as viable (721/783) and were fertilized. The cleavage and blastocyst rate were 23% and 19% respectively. 37 embryos were transferred and 11 pregnancies were obtained, confirmed by rectal palpation 60 days after transfer, with a pregnancy rate of 29.7%. Conclusions. The results presented here are comparable with others in literature and shows the feasibility of producing in vitro embryos and pregnancies after the standardization of current protocols, with normal and sexed semen and transfer during natural cycle in buffalo.Key words: Buffaloes, embryo, fertilization in vitro, reproduction (Source: MeSH).

A comparative study on efficiency of adult fibroblasts and amniotic fluid-derived stem cells as donor cells for production of hand-made cloned buffalo (Bubalus bubalis) embryos.

The efficiency of two cell types, namely adult fibroblasts, and amniotic fluid stem (AFS) cells as nuclear donor cells for somatic cell nuclear transfer by hand-made cloning in buffalo (Bubalus bubalis) was compared. The in vitro expanded buffalo adult fibroblast cells showed a typical "S" shape growth curve with a doubling time of 40.8h and stained positive for vimentin. The in vitro cultured undifferentiated AFS cells showed a doubling time of 33.2h and stained positive for alkaline phosphatase, these cells were also found positive for undifferentiated embryonic stem cell markers like OCT-4, NANOG and SOX-2, which accentuate their pluripotent property. Further, when AFS cells were exposed to corresponding induction conditions, these cells differentiated into osteogenic, adipogenic and chondrogenic lineages which was confirmed through alizaran, oil red O and alcian blue staining, respectively. Cultured adult fibroblasts and AFS cells of passages 10-15 and 8-12, respectively, were used as nuclear donors. A total of 94 embryos were reconstructed using adult fibroblast as donor cells with cleavage and blastocyst production rate of 62.8±1.8 and 19.1±1.5, respectively. An overall cleavage and blastocyst formation rate of 71.1±1.2 and 29.9±2.2 was obtained when 97 embryos were reconstructed using AFS cells as donor cells. There were no significant differences (P>0.05) in reconstructed efficiency between the cloned embryos derived from two donor cells, whereas the results showed that there were significant differences (P<0.05) in cleavage and blastocyst rates between the cloned embryos derived from two donor cell groups. Average total cell numbers for blastocyst generated using AFS cells (172.4±5.8) was significantly (P<0.05) higher than from adult fibroblasts (148.2±6.1). This study suggests that the in vitro developmental potential of the cloned embryos derived from AFS cells were higher than that of the cloned embryos derived from adult fibroblasts in buffalo hand-made cloning.

Low oxygen tension improves developmental competence and reduces apoptosis in hand-made cloned buffalo (Bubalus bubalis) embryos

This study compared the effects of oxygen tension on the developmental competence, quality and expression level of some important genes in somatic cell nuclear transfer (SCNT) buffalo embryos produced through hand-made cloning. Following in vitro culture (IVC) of reconstructed embryos under 5% and 20% oxygen tension, the blastocyst rate (72.0±4.78 vs. 58.0±4.61%) and total cell number (413.5±66.7 vs. 265.4±29.8) were higher (P<0.01), and the apoptotic index (2.46±0.71 vs. 11.13±1.52) was lower (P<0.01), respectively, although there was no effect on the cleavage rate. The relative mRNA abundance of hypoxia inducible factors (HIF1α and HIF2α), was higher (P<0.01) whereas that of oxidative stress – (SOD-2, PRDX1 and GPX-1) and apoptosis-related genes (CASPASE3 and P53) was lower (P<0.05) in reconstructed embryos cultured under 5% oxygen than in those cultured under 20% oxygen tension. In conclusion, these results indicate that lowering the oxygen tension during IVC of SCNT embryos from 20 to 5% improves their developmental competence and quality, reduces the apoptosis level and that many of these effects may be elicited through altering the expression of transcription factors.

25 DEVELOPMENTAL COMPETENCE OF CLONED BUFFALO (BUBALUS BUBALIS) EMBRYOS PRODUCED BY TRANSFECTED OR NONTRANSFECTED FIBROBLASTS TRANSFER TO ENUCLEATED OOCYTES DERIVED FROM OVUM PICK-UP AND ABATTOIR OVARIES

The objective of this study was to explore whether fibroblasts transfection and the source of oocytes – ovum pick-up (OPU) versus abattoir ovaries – affected the in vitro and in vivo developmental competence of somatic cell nuclear transferred (SCNT) embryos in buffalo. To this aim, the serum-starved ear fibroblasts were fused into enucleated oocytes derived from abattoir ovaries (Group 1) and OPU (Group 2). Furthermore, the enucleated buffalo oocytes derived from abattoir ovaries were also fused with pEGFP-N1 transfected ear fibroblasts, and the cloned embryos were enhanced green fluorescent protein (EGFP)-positive confirmed by fluorescence microscopy (Group 3). The reconstructed embryos cultured in Groups 1 to 3 were 262, 83, 120, respectively (5 replicates); and the data were analysed by one-way ANOVA (SPSS Inc., Chicago, IL, USA). As a result, the cleavage rate in Group 3 was significantly higher than that in Group 1 (75.0% v. 54.3%; P &lt; 0.01), and the total blastocyst rate of reconstructed embryos in Group 3 (27.3%) was significantly higher than that in Group 1 (17.4%; P &lt; 0.01) and Group 2 (24.4%; P &lt; 0.05). The SCNT blastocysts were vitrified with 20% ethylene glycol + 20% dimethylsulfoxide + 0.5 M sucrose; the cryosurvival rates of SCNT blastocysts in the 3 groups were not different from each other (90.0%, 94.7%, 92.3%). Following culture, the cryosurvived blastocysts were transferred into synchronized local and crossbred buffaloes, with each recipient receiving 1 or 2 embryos. The pregnancy rates after transferring embryos derived from Groups 1 to 3 were not different from each other, and were 18.75% (3/16), 33.33% (4/12), and 26.67% (4/15), respectively. These results indicate that the oocytes derived from OPU can be enucleated as recipient cytoplasm and transfected fibroblast can be adopted as nuclei donor without decreasing the SCNT efficiency in buffalo.This research was supported by grants from the National Natural Science Foundation of China (31160456) and the Natural Science Foundations of China under Grant No. 0991011, No. 2011GXSFB018045).

135 EFFECT OF L-ERGOTHIONEINE SUPPLEMENTATION DURING CULTURE ON IN VITRO EMBRYO DEVELOPMENT IN BUFFALO (BUBALUS BUBALIS)

It is known that in vitro mammalian embryo development is negatively affected by the increased oxidative stress occurring under culture conditions. The oxidative damage of cell components via reactive oxygen species interferes with proper cell function. Buffalo embryos are particularly sensitive to oxidative stress because of their high lipid content (Boni et al. 1992 Acta Med. Vet. 38, 153–161). l-Ergothioneine (LE) is a powerful scavenger of hydroxyl radicals (OH) and an inhibitor of iron or copper ion-dependent generation of OH from hydrogen peroxide (H2O2). The aim of this study was to evaluate whether enriching the in vitro-culture medium with LE improves in vitro embryo production efficiency in buffalo. Abattoir-derived buffalo oocytes (n = 854, over 6 replicates) were in vitro matured and fertilized according to standard procedures (Gasparrini et al. 2006 Theriogenology 65, 275–287). Twenty hours after IVF presumptive zygotes were cultured in SOFaa supplemented by 8 mg mL–1 BSA in a controlled gas atmosphere consisting of 5% CO2, 7% O2, 88% N2, in humidified air, at 38.5°C with 0 (control; n = 214), 0.05 mM LE (n = 217), 0.1 mM LE (n = 204), and 1 mM LE (n = 219). Cleavage rate was assessed at the time of change of culture (Day 5) and the cleaved elements were cultured for a further 2 days. The embryos obtained by the end of culture, i.e. on Day 7 post-IVF, were scored for quality, based on morphological criteria, and for developmental stage, as previously described (Robertson, Nelson 2010 Manual of the International Embryo Transfer Society 86–105). The percentages of total transferable embryos and Grade 1 and 2 blastocysts in relation to cleaved oocytes were recorded. Because the chronology of development is known to be one of the most reliable parameters for assessing quality, the percentage of fast-developing embryos, i.e. hatched and expanded blastocysts, was also recorded. Data were analysed by Chi-squared test. Cleavage rate was not affected by the treatment (71.4, 66.8, 68.7, and 63.0%, respectively, with 0, 0.05, 0.1, and 1 mM LE). The total embryo output increased in groups supplemented with 0.05 and 0.1 mM LE (31.3, 42.2, 43.8, and 21.7%, respectively, with 0, 0.05, 0.1, and 1 mM LE; P &lt; 0.05). However, the enrichment of in vitro culture with 0.1 mM LE also increased the percentage of Grade 1 and 2 blastocysts compared with the control and to 1 mM LE (21.6, 30.9, 33.9, and 21.7%, respectively, with 0, 0.05, 0.1, and 1 mM LE; P &lt; 0.05). Likewise, 0.1 mM LE gave higher percentages of fast developing embryos than the control and 1 mM LE groups. In conclusion, these results demonstrated a beneficial effect of LE during culture on buffalo in vitro embryo development. The dose response trial indicated that the optimal concentration is 0.1 mM that also influenced the chronology of development and hence embryo viability.

24 BUFFALO (BUBALUS BUBALIS) SOMATIC CELL NUCLEAR TRANSFER EMBRYOS PRODUCED FROM FROZEN–THAWED SEMEN-DERIVED SOMATIC CELLS: EFFECT OF TRICHOSTATIN A ON THE IN VITRO AND IN VIVO DEVELOPMENTAL POTENTIAL, QUALITY, AND EPIGENETIC STATUS

Cryopreservation of semen allows preservation of somatic cells, which can be used for the production of progeny through somatic cell nuclear transfer (SCNT). This approach could enable restoration of valuable high-genetic-merit progeny-tested bulls, which may be dead but the cryopreserved semen is available. We have successfully produced a live buffalo calf by SCNT using somatic cells isolated from &gt;10 year old frozen semen (Selokar et al. 2014 PLoS One 9, e90755). However, the calf survived only for 12 h, which indicates faulty reprogramming of these cells. The present study was, therefore, carried out to study the effect of treatment with trichostatin A (TSA), an epigenetic modifier, on reprogramming of these cells. Production of cloned embryos and determination of quality and level of epigenetic markers in blastocysts were performed according to the methods described previously (Selokar et al. 2014 PLoS One 9, e90755). To examine the effects of TSA (0, 50, and 75 nM), 10 separate experiments were performed on 125, 175, and 207 reconstructed embryos, respectively. The percentage data were analysed using SYSTAT 12.0 (SPSS Inc., Chicago, IL, USA) after arcsine transformation. Differences between means were analysed by one-way ANOVA followed by Fisher's least significant difference test for significance at P &lt; 0.05. When the reconstructed buffalo embryos produced by hand-made clones were treated with 0, 50, or 75 nM TSA post-electrofusion for 10 h, the cleavage percentage (100.0 ± 0, 94.5 ± 2.3, and 96.1 ± 1.2, respectively) and blastocyst percentage (50.6 ± 2.3, 48.4 ± 2.7, and 48.1 ± 2.6, respectively), total cell number (274.9 ± 17.4, 289.1 ± 30.1, and 317.0 ± 24.2, respectively), and apoptotic index (3.4 ± 0.9, 4.5 ± 1.4, and 5.6 ± 0.7, respectively) in Day 8 blastocysts were not significantly different among different groups. The TSA treatment increased (P &lt; 0.05) the global level of H4K5ac but not that of H3K18a in embryos treated with 50 or 75 nM TSA compared with that in controls. In contrast, the level of H3K27me3 was significantly lower (P &lt; 0.05) in cloned embryos treated with 75 nM TSA than in embryos treated with 50 nM TSA or controls. The ultimate test of the reprogramming potential of any donor cell type is its ability to produce live offspring. To examine the in vivo developmental potential of the 0, 50, or 75 nM TSA treated embryos, we transferred Day 8 blastocysts, 2 each to 5, 6, and 5 recipients, respectively, which resulted in 2 pregnancies from 75 nM TSA treated embryos. However, one pregnancy was aborted in the first trimester and the other in the third trimester. In conclusion, TSA treatment of reconstructed embryos produced from semen-derived somatic cells alters their epigenetic status but does not improve the live birth rate. We are currently optimizing an effective strategy to improve the cloning efficiency of semen-derived somatic cells.

208 CLONING AND CHARACTERIZATION OF BUFFALO INTERFERON-TAU AND EFFICACY OF RECOMBINANT BUFFALO INTERFERON-TAU FOR IN VITRO EMBRYO DEVELOPMENT

Interferon tau (IFN-tau) is known as maternal pregnancy recognition factor in ruminants. IFN-tau not only acts as a signalling molecule of pregnancy recognition but also performs various functions for successful implantation and pregnancy establishment. The aim of the present study was to produce recombinant buffalo interferon-tau (BuIFN-Tau) and observe if it has any effect on in vitro embryo development. The BuIFN-Tau gene was obtained through polymerase chain reaction (PCR) from hatched buffalo blastocysts and was cloned into pJET cloning vector. Screening of the recombinant colonies gave 8 distinct buffalo IFN-tau isoforms, out of which the predominant buffalo IFN-t tau1 isoform (gene bank accession number JX481984), was subcloned into expression vector pET22b without signal sequence. The recombinant plasmid was induced to express the recombinant protein by isopropyl b-D-1-thiogalactopyranoside. Analysis of the products of recombinant BuIFN-tau without signal sequence by SDS–PAGE revealed a new 20-kDa protein coinciding with the molecular weight of IFN-tau as reported earlier in literature. The purified recombinant BuIFN-tau was confirmed by Western blot using anti-HIS antibody and was subjected to three steps of large-scale purification using HIS affinity chromatography, anion exchange chromatography, and gel filtration chromatography. Finally, a relatively pure histidine-tagged recombinant protein, which had a purity of at least 90%, was generated as confirmed through SDS. The concentration of recombinant BuIFN-tau was 1 mg mL–1 by Bradford assay. The purified recombinant BuIFN-tau was used as supplement of the culture medium for IVF early buffalo embryos at the following concentrations: control, 1, 2, and 4 µg mL–1. Sixty oocytes each in 4 groups (with 20 oocytes/drop in three replicates for each group) were used for in vitro maturation. After 24 h, the matured oocytes were incubated with in vitro capacitated sperm cells for 18 h; thereafter, the presumptive zygotes were cultured in IVC medium supplemented with 0, 1, 2, or 4 µg mL–1 of the purified recombinant BuIFN-tau. The experiment was repeated 3 times. The data were analysed using SYSTAT 7.0 (SPSS Inc., Chicago, IL, USA) after arcsin transformation of percentage values. The differences were analysed by one-way ANOVA followed by Fisher's least significant difference test. Out of 3 concentrations of recombinant BuIFN-tau, the 2 µg mL–1 concentration significantly promoted the rate of blastocyst development, 45.55% against 31.1% (control; P &lt; 0.01). Blastocyst development rate for low and high concentrations was 29.97% and 10.18% respectively. It is concluded that the addition of 2 µg mL–1 of recombinant BuIFN-tau enhances the blastocyst development rate in buffalo, and hence there is some evidence that BuIFN-tau has not only a role in maternal recognition of pregnancy but also in embryonic development.

Production by in vitro fertilization of vietnam swamp buffalo embryos

This study was undertaken in order to test the ability of replacement of the foetal bovine serum (FBS) supplemented with hormones by the buffalo follicular fluid (BFF) in the oocyte maturation medium and the effect of co-culture with oviduct cells on the subsequent embryo development in Vietnam swamp buffalo. 1400 cumulus enclosed oocytes (COC) were collected from the buffalo ovaries in slaughter-house in the way with minimize temperatural choc. COCs were randomtly cultured in three maturation medium varieties: TCM 199 supplemented with 10% FBS, 10 IU/ml eCG, 5 IU/ml hCG, 1 mg/ml estradiol (M1); TCM 199 with 20% buffalo follicular fluid (BFF) without hormones (M2) or TCM 199 with 20% BFF and the same level of eCG, hCG as M1 but 3 mg/ml estradiol (M3). The effect of oviduct cells was evaluated by the embryo co-culture in two medium varieties: synthetic oviduct fluid (SOF) and SOF with oviduct cells after the maturation in the medium M2 and IVF. No significal differences were observed in the maturation and the formation of morulas and blastocyts by using the routine maturation medium (M1) and TCM 199 supplemented with 20% BFF but the rate of formation of two-cell and more-cell embryos and the rate of total morula and blastocyts were clearly improved in the case of combined BFF and hormones (M3) (26.5% vs 16.3%, P &lt; 0.05). The co-culture with oviduct cells not only improved the percentage of total embryos developed into morula blastocyt stage but also increased the rate of blastocyt formation in comparision with the medium without cells (66.2% vs 44.4%, P &lt; 0.05). This first try of in vitro embryo production in the swamp buffalo indicated the comparable rate (approximately 20%) of blastocyts can be obtained from total using oocytes.

Role of linker histone H1c during the reprogramming of Chinese swamp buffalo (Bubalus Bubalis) embryos produced by somatic cell nuclear transfer.

During reprogramming, there is exchange of histone H1c and the oocyte-specific linker histone, and H1c may play a critically important role in the reprogramming process of somatic cell nuclear transfer (SCNT). The aim of the present study was to investigate the role of the H1c gene in SCNT reprogramming in Chinese swamp buffalo (Bubalus bubalis) using RNA interference (RNAi). Chinese swamp buffalo H1c gene sequences were obtained and H1c-RNAi vectors were designed, synthesised and then transfected into a buffalo fetal skin fibroblast cell line. Expression of H1c was determined by real-time polymerase chain reaction to examine the efficiency of vector interference. These cells were then used as a nuclear donor for SCNT so as to observe the further development of SCNT embryos. Inhibition of H1c gene expression in donor cells significantly improved the developmental speed of embryos from the 1-cell to 8-cell stage. Furthermore, compared with the control group, inhibition of H1c gene expression significantly reduced the blastocyst formation rate. It is concluded that linker histone H1c is very important in SCNT reprogramming in Chinese swamp buffalo. Correct expression of the H1c gene plays a significant role in preimplantation embryonic development in B. bubalis.

Expression profile of developmentally important genes between hand-made cloned buffalo embryos produced from reprogramming of donor cell with oocytes extract and selection of recipient cytoplast through brilliant cresyl blue staining and in vitro fertilized embryos.

To compare the expression profile of developmentally important genes between hand-made cloned buffalo embryos produced from reprogramming of donor cell with oocyte extracts and selection of recipient cytoplast through brilliant cresyl blue staining and in vitro fertilized (IVF) embryos. Hand-made cloned embryos were produced using oocyte extracts treated donor cells and brilliant cresyl blue (BCB) stained recipient cytoplasts. IVF embryos were produced by culturing 15-20 COCs in BO capacitated sperms from frozen thawed buffalo semen and the mRNA expression patterns of genes implicated in metabolism (GLUT1), pluripotency (OCT4), DNA methylation (DNMT1), pro- apoptosis (BAX) and anti-apoptosis (BCL2) were evaluated at 8- to16- cell stage embryos. A significantly (P < 0.05) higher number of 8- to16- cell and blastocyst stages (73.9 %, 32.8 %, respectively) were reported in hand-made cloning (HMC) as compared to in vitro fertilization (49.2 %, 24.2 %, respectively). The amount of RNA recovered from 8- to 16- cell embryos of HMC and in vitro fertilization did not appear to be influenced by the method of embryo generation (3.76 ± 0.61 and 3.82 ± 0.62 ng/μl for HMC and in vitro fertilization embryos, respectively). There were no differences in the expression of the mRNA transcripts of genes (GLUT1, OCT4, DNMT1, BAX and BCL2) were analysed by real-time PCR between hand-made cloned and IVF embryos. Pre-treatment of donor cells with oocyte extracts and selection of developmentally competent oocytes through BCB staining for recipient cytoplast preparations may enhance expression of developmentally important genes GLUT1, OCT4, DNMT1, BAX, and BCL2 in hand-made cloned embryos at levels similar to IVF counterparts. These results also support the notion that if developmental differences observed in HMC and in vitro fertilization produced foetuses and neonates are the results of aberrant gene expression during the pre-implantation stage, those differences in expression are subtle or appear after the maternal to zygotic transition stage of development.

Quantitative expression of pluripotency-related genes in parthenogenetically produced buffalo (Bubalus bubalis) embryos and in putative embryonic stem cells derived from them

Parthenogenetically produced embryos and embryonic stem (ES) cells derived from them offer a unique model for investigating the role of transcription factors in embryonic genome activation (EGA), pluripotent lineage specification and in pluripotency and self-renewal of ES cells because of the unique nature of these embryos. There is little information on the quantitative expression of important genes in parthenogenetically produced embryos and in ES cells derived from them. The present study examined the quantitative expression of some important genes in parthenogenetically produced buffalo embryos and in putative parthenogenetic ES cells (pES) cells. The quantitative expression of OCT-4, SOX-2, NANOG, REX-1, FOXD-3 and NUCLEOSTEMIN, which is very low in immature and mature oocytes, and in embryos at 2-, 4- and 8- to 16-cell stage, increases significantly at morula and blastocyst stage. The expression level of TELOMERASE, c-MYC and STAT-3, which is high in immature oocytes decreases during embryonic development followed by either an increase at the morula stage (TELOMERASE) or a low expression level maintained throughout development till blastocyst stage (c-MYC and STAT-3). There is a progressive decline in the expression level of OCT-4, SOX-2, c-MYC, REX-1, NUCLEOSTEMIN, TELOMERASE and STAT-3 during long term culture of pES cells.

Hope for Restoration of Dead Valuable Bulls through Cloning Using Donor Somatic Cells Isolated from Cryopreserved Semen

Somatic cells were isolated from cryopreserved semen of 4 buffalo bulls, 3 of which had died over 10 years earlier, and were established in culture. The cells expressed cytokeratin-18, keratin and vimentin indicating that they were of epithelial origin. The cells were used as nuclear donors for hand-made cloning for producing buffalo embryos. The blastocyst rate and quality, as indicated by apoptotic index, were comparable among embryos produced using cells obtained from fresh or frozen-thawed semen or those obtained from conventional cell sources such as skin. Examination of the epigenetic status revealed that the global level of H3K27me3 but not that of H3K9/14ac and H4K5ac differed significantly (P<0.05) among cloned embryos from different bulls. The relative mRNA abundance of HDAC1, DNMT1, P53 and CASPASE 3 but not that of DNMT3a differed in cells and in cloned embryos. Following transfer of 24 cloned embryos produced from fresh semen-derived cells to 12 recipients, one calf weighing 55 kg, which is now 6 months of age and is normal, was born through normal parturition. Following transfer of 20 embryos produced from frozen-thawed semen-derived cells to 10 recipients, 2 became pregnant, one of which aborted in the first trimester; the calf born was severely underweight (17 kg), and died 12 h after birth. The ability of cells derived from fresh and frozen-thawed semen to produce live offspring confirms the ability of these cells to be reprogrammed. Our findings pave the way for restoration of highly precious progeny-tested bulls, which has immense economic importance, and can also be used for restoration of endangered species.

Global Transcriptome Profiles of Italian Mediterranean Buffalo Embryos with Normal and Retarded Growth

The transcriptome profiles were compared for buffalo embryos with normal growth and embryos with retarded growth on Day 25 after mating. Embryos with retarded growth on Day 25 after mating have a reduced likelihood of undergoing attachment to the uterine endometrium and establishing a pregnancy. Italian Mediterranean buffaloes were mated by AI and on Day 25 underwent trans-rectal ultrasonography to ascertain embryo development. Embryos with an embryonic width (EW)>2.7 mm were classed as normal embryos and embryos with an EW<2.7 mm were classed as retarded embryos. Three buffaloes with embryos of the largest EW (3.7, 3.7 and 3.9 mm) and three buffaloes with embryos of the smallest EW (1.5, 1.6 and 1.9 mm) were slaughtered on Day 27 to recover embryos for transcriptome analysis using a bovine custom designed oligo array. A total of 1,047 transcripts were differentially expressed between embryos with normal growth and embryos with retarded growth. Retarded embryos showed 773/1,047 (74%) transcripts that were down-regulated and 274/1,047 (26%) transcripts that were up-regulated relative to normal embryos; in silico analyses focused on 680/1,047 (65%) of the differentially expressed transcripts. The most altered transcripts observed in retarded embryos were associated with membrane structure and function and with metabolic and homeostasis maintenance functions. Other notable functions altered in retarded embryos were developmental processes and in particular nervous system differentiation and function. Specific biochemical pathways such as the complement cascade and coagulation were also altered in retarded embryos. It was concluded from the findings that buffalo embryos with retarded growth on Day 25 after mating show altered gene expression compared with normal embryos, and some de-regulated functions are associated with attachment to the uterine endometrium.

Expression of apoptosis related genes in buffalo embryos produced through in vitro fertilization and parthenogenetic activation

In present study immature oocytes were obtained from buffalo slaughterhouse ovaries and were subjected to in vitro maturation (IVM) in TCM-199 + 10% FBS + 5 µg/ml pFSH + 0.81 mM sodium pyruvate + 5% buffalo follicular fluid for 24 h in a CO2 incubator (5% CO2, 90–95% relative humidity) at 38.5°C. The maturer oocytes were used for IVF and the cleaved embryos were cultured for 8 days, while the parthenotes were produced with exposure of 7% ethanol, 6- dimethyl aminopurine and cultured for 8 days in mCR2aa medium. The relative abundance of BCL-XL transcripts in immature, matured oocytes; and embryos produced through IVF i.e. 2-cell, 4-cell, 8-16-cell, morula and blastocyst stage were 25.33±0.90, 12.67±1.20, 37.67±0.90, 30.67±0.30, 23.67±0.90, 18.33±0.90 and 27.00±1.20 respectively, while in parthenogenesis these values were 23.67±0.88, 13.67±1.20, 23.67±1.20, 22.34±0.88, 24.34±0.88, 33.67±0.88, 45.34±1.20 respectively. Relative abundance of BAX transcripts by IVF were 23.0±0.60, 0.33±0.10, 4.00±0.60, 5.00±0.60, 0.37±0.06, 13.0±0.66 and 56.7±0.90; and by parthenonenesis were 22.3±0.90, 0.13±0.03, 13.67±0.90, 14.0±0.60, 15.33±0.90, 64.67±2.20 and 55.0±2.10 respectively. In conclusion, expression pattern of apoptosis related genes revealed that incidence of apoptosis was significantly higher in IVF and parthenogenetically produced buffalo embryos at stages like immature oocytes, morula and blastocyst stage than the early cleavage stage embryos.

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.

Treatment of donor cells with trichostatin A improves in vitro development and reprogramming of buffalo (Bubalus bubalis) nucleus transfer embryos

It has been reported that buffalo (Bubalus bubalis) embryos reconstructed by somatic cell nucleus transfer (SCNT) can develop to the full term of gestation and result in newborn calves. However, the developmental competence of reconstructed embryos is still low. Recently, it has been reported that treating donor cells or embryos with trichostatin A (TSA) can increase the cloning efficiency in some species. Thus, the present study was undertaken to improve the development of buffalo SCNT embryos by treatment of donor cells (buffalo fetal fibroblasts) with TSA and explore the relation between histone acetylation status of donor cells and developmental competence of SCNT embryos. Treatment of donor cells with either 0.15 or 0.3 μM TSA for 48 hours resulted in a significant increase in the cleavage rate and blastocyst yield of SCNT embryos (P < 0.05). Meanwhile, the expression level of HDAC1 in donor cells was also decreased (0.4–0.6 fold, P < 0.05) by TSA treatment, although the expression level of HAT1 was not affected. Further measurement of the epigenetic maker AcH4K8 in buffalo IVF and SCNT embryos at the eight-cell stage revealed that the spatial distribution of acH4K8 staining in SCNT embryos was different from the IVF embryos. Treatment of donor cells with TSA resulted in an increase in the AcH4K8 level of SCNT embryos and similar to fertilized counterparts. These results suggest that treatment of donor cells with TSA can facilitate their nucleus reprogramming by affecting the acetylated status of H4K8 and improving the in vitro development of buffalo SCNT embryos. The AcH4K8 status at the eight-cell stage can be used as an epigenetic marker for predicting the SCNT efficiency in buffalos.

Expression pattern of glucose metabolism genes in relation to development rate of buffalo (Bubalus bubalis) oocytes and in vitro–produced embryos

The expression pattern of glucose metabolism genes (hexokinase, phosphofructokinase, glucose-6-phosphate dehydrogenase [G6PDH], lactate dehydrogenase [LDH], and pyruvate dehydrogenase [PDH]) were studied in buffalo in vitro–matured oocytes and in vitro–produced embryos cultured under different glucose concentrations (0 mM, 1.5 mM, 5.6 mM, and 10 mM) during in vitro maturation of oocytes and culture of IVF produced embryos. The expression of the genes varied significantly over the cleavage stages under different glucose concentrations. Developmental rate of embryos was highest under a constant glucose level (5.6 mM) throughout during maturation of oocytes and embryo culture. Expression pattern of glucose metabolism genes under optimum glucose level (5.6 mM) indicated that glycolysis is the major pathway of glucose metabolism during oocyte maturation and early embryonic stages (pre-maternal to zygotic transition [MZT]) and shifts to oxidative phosphorylation during post-MZT stages in buffalo embryos. Higher glucose level (10 mM) caused abrupt changes in gene expression and resulted in shifting toward anaerobic metabolism of glucose during post-MZT stages. This resulted in decreased development rate of embryos during post-MZT stages. High expression of LDH and PDH in the control groups (0 mM glucose) indicated that in absence of glucose, embryos try to use available pyruvate and lactate sources, but succumb to handle the post-MZT energy requirement, resulting to poor development rate. Expression pattern of G6PDH during oocyte maturation as well early embryonic development was found predictive of quality and development competence of oocytes/ embryos.

Proteomic Profiles of the Embryonic Chorioamnion and Uterine Caruncles in Buffaloes (Bubalus bubalis) with Normal and Retarded Embryonic Development1

The aim of this study was to compare the proteome profiles of the chorioamnion and corresponding caruncle for buffalo embryos that had either normal or retarded development on Day 25 after artificial insemination (AI). In experiment 1, embryos that were to subsequently undergo late embryonic mortality had a smaller width on Day 25 after AI than embryos associated with pregnancy on Day 45 after AI. In experiment 2, 25 Italian Mediterranean buffaloes underwent transrectal ultrasonography on Day 25 after AI, and pregnant animals were categorized as one of two groups based on embryonic width: normal embryos (embryonic width > 2.7 mm) and retarded embryos (embryonic width < 2.7 mm). Three buffaloes of each group were slaughtered on Day 27 after AI to collect chorioamnion and caruncle tissues for subsequent proteomic analyses. Two-dimensional difference gel electrophoresis (2D-DIGE) and matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight mass spectrometer analysis were used to ascertain the proteomic profiles. To confirm 2D-DIGE-results, three selected proteins were analyzed by Western blot. The proteomic profiles of the chorioamnion of retarded embryos and the corresponding caruncles showed differences in the expression of several proteins compared to normal embryos. In particular, a down-regulation was observed for proteins involved in protein folding (HSP 90-alpha, calreticulin), calcium binding (annexin A1, annexin A2), and coagulation (fibrinogen alpha-chain) (P < 0.05), whereas proteins involved in protease inhibition (alpha-1-antiproteinase, serpin H1, serpin A3-8), DNA and RNA binding (heterogeneous nuclear ribonucleoproteins A2/B1 and K), chromosome segregation (serine/threonine-protein phosphatase 2A), cytoskeletal organization (ezrin), cell redox homeostasis (amine oxidase-A), and hemoglobin binding (haptoglobin) were up-regulated (P < 0.05).

Developmental Speed Affects the Cryotolerance of In Vitro Produced Buffalo (Babalus Bubalis) Embryos

The aim of this study was to evaluate whether the developmental speed affects the cryotolerance of in vitro produced buffalo embryos. In Experiment 1, abattoir-derived oocytes were in vitro matured, fertilized and cultured. The embryos produced by Say 7 of culture were vitrified at the tight morula (TM), early blastocyst (EBL), blastocyst (BL), expanded-blastocyst (XBL) and hatched-blastocyst (HBL) stage. The embryos were vitrified by cryotop in 16.5% ethylene glycol (EG) and 16.5% dimethyl sulfoxide (DMSO) and 0.5 M sucrose. Embryos were warmed in 0.25 M sucrose for 1 min and then in 0.15 M sucrose for 5 min and cultured in vitro for 24 h, to evaluate post-culture viability. In Experiment 2, ovum pick-up (OPU) was carried out on lactating buffaloes to produce embryos that were vitrified-warmed and transferred into synchronized recipients. The lowest (P<0.01) survival rates were recorded with TM (22.4%) and the highest (P<0.01) with HBL (84.5%), whereas intermediate results were observed with EBL, BL and XBL (54.5, 64.7, 67.9%, respectively). Pregnancy rate on both Days 25 and 45 was significantly higher (P<0.05) for faster (XBL and HBL) developing embryos (75.0% and 62.5%, respectively) than for the slower (TM, EBL and BL) developing counterparts (36.4% and 0, respectively). Interestingly, pregnancies to term were only recorded when HBL were transferred (20%). In conclusion, it was demonstrated that the chronology of development is a major factor affecting the cryotolerance of in vitro produced buffalo embryos.