Lnc5926 is essential for early embryonic development in goats through regulation of ZSCAN4 and EIF1AX

Long noncoding RNAs (lncRNAs) are abundant in mammalian genomes and have been found to play important roles in many biological events. However, the mechanism by which lncRNAs regulate embryonic development remains to be fully elucidated. Here, we investigated the function of the lncRNA, TCONS_00135926 (referred to as lnc5926), through knockdown and overexpression experiments in goat early embryos. Lnc5926 expression at the eight-cell embryonic stage was significantly higher than that at other stages, which was consistent with the pattern of embryonic genome activation (EGA) gene expression. The blastocyst rate after lnc5926 knockdown in eight-cell embryos was significantly lower than that in the control group (0.2% vs. 17.1%, p < 0.05), whereas the cleavage rate was not affected (71.9% vs. 75.1%, p ˃ 0.05). After knockdown or overexpression of lnc5926 in embryos, we measured expression levels of the potential target genes, STAM, HACD1, UBL5, MIOX, ELF1, and the key EGA genes, ZSCAN4 and EIF1AX. Only ZSCAN4 and EIF1AX were significantly downregulated after lnc5926 knockdown, and this effect was reversed by lnc5926 overexpression. We conclude that lnc5926 plays an essential role in early embryonic development in goats by regulating expression of EGA-associated genes.

Development of Standardized Fetal Progenitor Cell Therapy for Cartilage Regenerative Medicine: Industrial Transposition and Preliminary Safety in Xenogeneic Transplantation

Diverse cell therapy approaches constitute prime developmental prospects for managing acute or degenerative cartilaginous tissue affections, synergistically complementing specific surgical solutions. Bone marrow stimulation (i.e., microfracture) remains a standard technique for cartilage repair promotion, despite incurring the adverse generation of fibrocartilagenous scar tissue, while matrix-induced autologous chondrocyte implantation (MACI) and alternative autologous cell-based approaches may partly circumvent this effect. Autologous chondrocytes remain standard cell sources, yet arrays of alternative therapeutic biologicals present great potential for regenerative medicine. Cultured human epiphyseal chondro-progenitors (hECP) were proposed as sustainable, safe, and stable candidates for chaperoning cartilage repair or regeneration. This study describes the development and industrial transposition of hECP multi-tiered cell banking following a single organ donation, as well as preliminary preclinical hECP safety. Optimized cell banking workflows were proposed, potentially generating millions of safe and sustainable therapeutic products. Furthermore, clinical hECP doses were characterized as non-toxic in a standardized chorioallantoic membrane model. Lastly, a MACI-like protocol, including hECPs, was applied in a three-month GLP pilot safety evaluation in a caprine model of full-thickness articular cartilage defect. The safety of hECP transplantation was highlighted in xenogeneic settings, along with confirmed needs for optimal cell delivery vehicles and implantation techniques favoring effective cartilage repair or regeneration.

Using WGCNA (weighted gene co-expression network analysis) to identify the hub genes of skin hair follicle development in fetus stage of Inner Mongolia cashmere goat

OBJECTIVE

Mature hair follicles represent an important stage of hair follicle development, which determines the stability of hair follicle structure and its ability to enter the hair cycle. Here, we used weighted gene co-expression network analysis (WGCNA) to identify hub genes of mature skin and hair follicles in Inner Mongolian cashmere goats.

METHODS

We used transcriptome sequencing data for the skin of Inner Mongolian cashmere goats from fetal days 45-135 days, and divided the co expressed genes into different modules by WGCNA. Characteristic values were used to screen out modules that were highly expressed in mature skin follicles. Module hub genes were then selected based on the correlation coefficients between the gene and module eigenvalue, gene connectivity, and Gene Ontology (GO)/Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. The results were confirmed by quantitative polymerase chain reaction (qPCR).

RESULTS

Ten modules were successfully defined, of which one, with a total of 3166 genes, was selected as a specific module through sample and gene expression pattern analyses. A total of 584 candidate hub genes in the module were screened by the correlation coefficients between the genes and module eigenvalue and gene connectivity. Finally, GO/KEGG functional enrichment analyses detected WNT10A as a key gene in the development and maturation of skin hair follicles in fetal Inner Mongolian cashmere goats. qPCR showed that the expression trends of 13 genes from seven fetal skin samples were consistent with the sequencing results, indicating that the sequencing results were reliable.n.

Aberrant DNA and histone methylation during zygotic genome activation in goat cloned embryos

In somatic cell nuclear transfer (SCNT) embryos, developmental defects first appear at the time of zygotic genome activation (ZGA), a process that is under the control of DNA and histone methylation. However, dynamics of 5-mC and 5-hmC during ZGA differ between porcine and bovine SCNT embryos, and histone methylation during ZGA in goat SCNT embryos remains poorly understood. Therefore, in the present study, we investigated the dynamic changes of 5-mC, 5-hmC, H3K4me2/3, and H3K9me3, as well as the expression of key genes related to these epigenetic modifications, during ZGA in goat cloned embryos. Compared with the IVF embryos, the 5-mC signal intensity was significantly increased at the 2- and 4-cell stage SCNT embryos, and the H3K4me3 and H3K9me3 signal intensity was significantly increased at 2- to 8-cell stage SCNT embryos, while the 5-hmC and H3K4me2 signal intensity was significantly lower at the 4- and 8-cell stage SCNT embryos. Of note, the H3K9me3 level was also significantly higher, whereas H3K4me3 signal intensity showed no statistical difference in the pronuclear stage SCNT embryos. Moreover, the expression of TET2, DNMT3B, KDM4A, SUV39H1, G9A, and SETDB1 was significantly increased, while the expression of UHRF1, PCNA, KDM4B, KDM4D, KDM5A, KDM5B, and KDM5C was significantly decreased at the 8-cell stage SCNT embryos. Our data revealed aberrant DNA and histone methylation during ZGA in goat cloned embryos. We further inferred that the abnormally higher level of 5-mC, H3K4me3, and H3K9me3 might serve as epigenetic barriers of the reprogramming and modifying these aberrant modifications might be a promising strategy to improve cloning efficiency in goat.

Effects of abundances of OCT-4 mRNA transcript on goat pre-implantation embryonic development

Unlike in mice, the function of pluripotent markers in early embryonic development of domestic animals remains to be elucidated and this may account for the failure to establish embryonic stem cell lines for these species. To study the functions of the OCT-4 protein which has important actions in maintenance of pluripotent and self-renewal processes during early embryonic development, there was induced reduction in relative abundance of OCT-4 mRNA transcript during goat early embryonic development by using RNA interference techniques. The injection of OCT-4 siRNA into goat IVF presumptive zygotes resulted in a decrease in the relative abundance of OCT-4 mRNA transcript; however, there was development of these embryos to the blastocyst stage at the same rate as there was in the control group. The blastocysts from the treated groups had a similar number of TE, ICM, and total cells compared to those from the control group. Although there was a greater relative abundance of NANOG, REX1, and CDX2 mRNA transcript in the embryos injected with siRNA at the 8-16 cell stage, the relative transcript abundances were similar for the control and treatment groups at the blastocyst stage. The relative abundance of SOX2 mRNA transcript was similar for the treatment and control group. It, therefore, is concluded that inhibition of abundances of OCT-4 mRNA transcript to about 20 % of that of the untreated control group did not affect blastocyst formation rate in goats. The functions of OCT-4 in maintaining ICM and TE integrity, however, remains to be assessed.

Transcriptome profiling reveals transcriptional and alternative splicing regulation in the early embryonic development of hair follicles in the cashmere goat

The undercoat fiber of the cashmere goat, from the secondary hair follicle (HF), possesses commercial value. However, very few studies have focused on the molecular details of primary and secondary HF initiation and development in goat embryos. In this study, skin samples at embryonic day 45, 55, and 65 (E45, E55, and E65) were collected and prepared for RNA sequencing (RNA-seq). We found that the HF probably initiated from E55 to E65 by analyzing the functional pathways of differentially expressed genes (DEGs). Most key genes in canonical signaling pathways, including WNT, TGF-β, FGF, Hedgehog, NOTCH, and other factors showed clear expression changes from E55 to E65. We, for the first time, explored alternative splicing (AS) alterations, which showed distinct patterns among these three stages. Functional pathways of AS-regulated genes showed connections to HF development. By comparing the published RNA-seq samples from the E60, E120, and newborn (NB) stages, we found the majority of WNT/β-catenin signaling genes were important in the initiation of HF development, while other factors including FOXN1, GATA3, and DLX3 may have a consistent influence on HF development. Our investigation supported the time points of embryonic HF initiation and identified genes that have potential functions of embryonic HF initiation and development. We further explored the potential regulatory roles of AS in HF initiation, which extended our knowledge about the molecular mechanisms of HF development.

Determination of the gestational age through ultrasound measurements of some uterine and foetal parameters in Bulgarian local goats

The aim of the current study was to determine the gestational age in goats through the measurement of some foetal and uterine structures. Twenty-four pregnant Bulgarian local goats were submitted to ultrasound foetometry by transrectal and transabdominal approaches. Ultrasound measurement of studied parameters was done at 7-day intervals during the first trimester of gestation (days 21-49) and at 14-day intervals between gestation days 49 and 133. Associations of foetometry data with foetal age were investigated by linear (y = a + bx), quadratic (y = ax²  + bx + c) and exponential (y = axⁿ ) equations. According to the results, some biometric parameters (uterine lumen diameter, crown-rump length, trunk diameter, biparietal diameter, foetal aortic diameter) exhibited a stronger correlation to gestational age (R²  ≥ 0.90) and lower standard error of the estimate (SEE ≤ 8) as compared to foetal eye orbit diameter, and outer and inner placentome diameters (R²  ≤ 0.90; SEE ≥ 8). Each of these biometric parameters could be measured in different periods of gestation, thus allowing for monitoring and determination of foetal age at almost all stages of pregnancy.

Differential expression pattern of key regulatory developmental genes in pre-implant zona free cloned vs in vitro fertilized goat embryos

The success of Somatic cell nuclear transfer (SCNT) primarily depends on the extent of reprogramming of donor cells genome. The error of reprogramming may lead to inappropriate expression of embryonic genes at any stage of development. Under the present study the relative expression of different genes related to pluripotency (Oct-4 and Nanog), growth factors (IGF-2 and IGF-2R) and DNA methyltransferase gene (Dnmt-1) was evaluated in SCNT embryos at 8-16 cells, morula and blastocyst stages as compared to IVF group. In SCNT, significantly higher degree of relative expression was observed for Oct-4 in morula (1.41) and blastocysts (1.14) as compared to 8-16 cells (referral stage) whereas in IVF, a lower expression was observed at morula (0.82) stage. The expression of Nanog in SCNT embryos was increased significantly in morula (2.23) and decreased subsequently in blastocyst (0.56), whereas it was increased significantly from 8 to 16 cells to morula (1.62) and blastocyst (4.5) of IVF group. The IGF-2 and IGF-2R showed significantly higher expression rates in morula and blastocysts of SCNT (6.56, 5.90 and 1.11, 1.4) and IVF (8.69, 8.25 and 2.96, 3.91) embryos, respectively as compared to referral stage. The expression of Dnmt-1 was significantly higher in SCNT morula (1.29) and blastocyst (1.15) however in IVF, it was similar in 8-16 cells stage and morula but, higher in blastocyst (1.58). The dissimilar pattern of gene expression of SCNT might be a consequence of incomplete reprogramming of donor nucleus which resulted into lower blastocyst rate of SCNT as compared to IVF embryos.

Comparative Transcriptome Analysis of Fetal Skin Reveals Key Genes Related to Hair Follicle Morphogenesis in Cashmere Goats

Cashmere goat skin contains two types of hair follicles (HF): primary hair follicles (PHF) and secondary hair follicles (SHF). Although multiple genetic determinants associated with HF formation have been identified, the molecules that determine the independent morphogenesis of HF in cashmere goats remain elusive. The growth and development of SHF directly influence the quantity and quality of cashmere production. Here, we report the transcriptome profiling analysis of nine skin samples from cashmere goats using 60- and 120-day-old embryos (E60 and E120, respectively), as well as newborns (NB), through RNA-sequencing (RNA-seq). HF morphological changes indicated that PHF were initiated at E60, with maturation from E120, while differentiation of SHF was identified at E120 until formation of cashmere occurred after birth (NB). The RNA-sequencing analysis generated over 20.6 million clean reads from each mRNA library. The number of differentially expressed genes (DEGs) in E60 vs. E120, E120 vs. NB, and E60 vs. NB were 1,024, 0 and 1,801, respectively, indicating that no significant differences were found at transcriptomic levels between E120 and NB. Key genes including B4GALT4, TNC, a-integrin, and FGFR1, were up-regulated and expressed in HF initiation from E60 to E120, while regulatory genes such as GPRC5D, PAD3, HOXC13, PRR9, VSIG8, LRRC15, LHX2, MSX-2, and FOXN1 were up-regulated and expressed in HF keratinisation and hair shaft differentiation from E120 and NB to E60. Several genes belonging to the KRT and KRTAP gene families were detected throughout the three HF developmental stages. The transcriptional trajectory analyses of all DEGs indicated that immune privilege, glycosaminoglycan biosynthesis, extracellular matrix receptor interaction, and growth factor receptors all played dominant roles in the epithelial-mesenchymal interface and HF formation. We found that the Wnt, transforming growth factor-beta/bone morphogenetic protein, and Notch family members played vital roles in HF differentiation and maturation. The DEGs we found could be attributed to the generation and development of HF, and thus will be critically important for improving the quantity and quality of fleece production in animals for fibres.

A study on embryonic death in goats due to Nicotiana glauca ingestion

Numerous plants are known to be teratogenic in livestock. In addition to causing malformations, several plants can also cause embryonic death. These losses decrease the reproductive efficiency of animals exposed to these plants. The aim of this study was to determine if teratogenic plants such as lupines or tobaccos cause embryonic losses. A goat model using the plant Nicotiana glauca was used in this study, as this model has been used to characterize the mechanism of Lupinus, Conium, and Nicotiana-induced terata. Four groups of goats were dosed from gestational day 1-10, 11-20, 21-30, and 31-40. Goats were evaluated via ultrasound imaging for pregnancy after completion of the dosing regimen and kids were evaluated for malformations at the time of parturition. Overall, there was no evidence from this study that N. glauca (anabasine) at this dose (2 g/kg/day) would cause embryonic losses in goats. However, the dose of N. glauca used in this study was at the lower threshold that would be expected to produce terata. Therefore it is possible that higher doses of anabasine could cause embryonic loss. Further work is also needed to characterize the kinetic profile of anabasine, and other teratogenic alkaloids, in the fetal compartments.

In vitro development of goat-sheep and goat-goat zona-free cloned embryos in different culture media

The gradual decline in the genetic diversity of farm animals has threatened their survival and risk of their extinction has increased many fold in the recent past. Endangered species could be rescued using interspecies embryo production. The objective of this study was to investigate the effect of three different culture media on the development of Handmade cloned intraspecies (goat-goat) and interspecies (goat-sheep) embryo reconstructs. Research vitro cleave media (RVCL) yielded higher cleavage and morula-blastocyst development in intraspecies and interspecies nuclear transfer groups compared with G1.G2 and modified synthetic oviductal fluid (mSOFaaci). Cleavage frequency of intraspecies cloned embryos in RVCL, mSOFaaci, and G1.G2 did not differ significantly (87.12%, 82.45%, and 92.52%, respectively). However, the morula/blastocyst frequency in RVCL was greater in mSOFaaci and G1.G2 (51.18% vs. 38.28% vs. 36.50%, respectively). Cleavage and morula/blastocyst frequency in interspecies cloned embryos was greater in RVCL than in mSOFaaci and G1.G2 (76.14% and 42.3% vs. 65.9% and 38.3% vs. 58.56% and 33.1%, respectively). Goat oocytes were parthenogenetically activated and cultured in RVCL, mSOFaaci, and G1.G2 and kept as control. Cleavage and morula/blastocyst frequency in this group was greater in RVCL than in mSOFaaci and G1.G2 (89.66% and 65.26% vs. 85.44% and 48.05% vs. 86.58% and 42.06%, respectively). Conclusively, the results suggest that not only can the interspecies embryos of goat be produced using sheep oocytes as donor cytoplast but also the percentages can be improved by using RVCL media for culturing of the embryos.

[Cloning goat producing human lactoferrin with genetically modified donor cells selected by single or dual markers]

We compared the efficiency of cloning goat using human lactoferrin (hLF) with genetically modified donor cells marked by single (Neo(r)) or double (Neo(r)/GFP) markers. Single marker expression vector (pBLC14) or dual markers expression vector (pAPLM) was delivered to goat fetal fibroblasts (GFF), and then the transgenic GFF was used as donor cells to produce transgenic goats. Respectively, 58.8% (20/34) and 86.7% (26/30) resistant cell lines confirmed the transgenic integration by PCR. Moreover, pAPLM cells lines were subcultured with several passages, only 20% (6/30) cell lines was observed fluorescence from each cell during the cell passage. Somatic cell nuclear transfer using the donor cells harbouring pBLC14 or pAPLM construct, resulting in a total of 806 reconstructed embryos, a pregnancy rate at 35 d (53.8%, 39.1%) and 60 d (26.9%, 21.7%), and an offspring birth rate (1.9%, 1.4%) with 5 and 7 newborn cloned goats, respectively. Transgene was confirmed by PCR and southern-blot in all cloned offspring. There were no significant differences at the reconstructed embryo fusion rates, pregnancy rates and the birth rate (P > 0.05) between single and double markers groups. The Neo(r)/GFP double markers could improve the reliability for accurately and efficiently selecting the genetically modified donor cells. No adverse effect was observed on the efficiency of transgenic goat production by SCNT using somatic cells transfected with double (Neo(r)/GFP) markers vector.

Umbilical artery doppler sonography in Saanen goat fetuses during singleton and multiple pregnancies

The objective of this study was to evaluate the blood flow from the umbilical artery (UA) in healthy pregnant goats. Doppler sonography examinations were performed every two weeks in Saanen goats with a singleton (n = 5) or multiple (n = 4) pregnancy from 40 to 145 days of gestation. Fetal heart rates (FHR), pulsatility index (PI), and resistance index (RI) were recorded from the mid-cord site of the free-floating umbilical cord. FHR decreased gradually as the pregnancy progressed and significantly decreased during the last two examinations of all fetuses (P < 0.05). The mean PI level was dramatically different (P < 0.05) until 85 days of gestation, after which it reached a plateau level until parturition. Similar to PI, RI decreased by 85 days of gestation (P < 0.05), and decreased again by 130s gestation. No reverse or absent end-diastolic flow were observed in fetuses during any examinations. When comparing singleton and multiple pregnancies, there were no significant differences in UA pulsatility or resistance in fetuses seen. The middle of the second trimester was observed to be a threshold stage for indices in the pattern of caprine pregnancy. In conclusion, this work provides additional values that might be useful when evaluating singleton and multiple pregnancies, and may be evaluated in further studies regarding fetal monitoring.

Studies on the development of omasum in West African dwarf goats (Capra hircus)

This work studied the sequential morphological changes of omasum in foetuses, neonates and adult West African Dwarf (WAD) goats by gross and light microscopic methods. The mean omasal volume was 1.37 +/- 0.36, 4.2 +/- 0.4, 8.7 +/- 6.9 and 60.1 +/- 8.6 ml for gestation day 87 and 146 foetuses, neonates and adults respectively. Grossly the mucosa exhibited longitudinally oriented primary, secondary, tertiary and quartnery laminae with smooth surface in foetuses and numerous papillae in the adults. Microscopically it was lined by stratified squamous epithelium which was divided into larger lighter luminal and smaller darker basal zones in gestation day 60 foetuses. The core of the laminae contained extension of the inner muscular tunic. The basal zone developed lateral evaginations (corial papillae) into the lighter zone of the laminae in gestation day 106 foetuses. By term these corial papillae approached the luminal surface. The papillae emerged above the luminal surface in 4 week old neonates. The papillae were fully developed in adult goats. The mean papillary height and width were -205.1 +/- 34.0, 67.0 +/- 9.6; 235.0 +/- 86.5, 185.0 +/- 42.3 and 570.3 +/- 60.0, 290.1 +/- 66.3 microm for foetuses, neonates and adult goats. The inner circular layer was thicker than the outer longitudinal layer of the muscular tunic. The central muscular layer of the laminae originated from the inner circular layer with attachment to the outer muscular layer in adults. This attachment could be adaptation for better anchorage and muscular contraction of the laminae in WAD goats.

Goat MII ooplasts support preimplantation development of embryos cloned from other species

The preimplantation development competences of somatic cell nuclear transfer (SCNT) embryos reconstructed with enuleated goat (Capra hircus) Metaphase II (MII) oocytes matured in vivo and whole cells derived from adult fibroblasts of several mammalian species (goat, boer goat, bovine, tahr, panda) and human patient were evaluated. Results obtained from our experiments revealed that these reconstructed SCNT embryos could complete preimplantation development to form blastocysts. The fusion rate and blastocyst rate of intra-species SCNT embryos (Capra hircus as control) was 78.67 (557/708); 56.29% (264/469), that of sub-species or inter-species SCNT embryos were: boer goat 78.18% (541/692); 33.90% (40/118), bovine 70.53% (146/207); 22.52% (25/111), tahr 53.51% (61/114); 5.26% (3/570), panda 79.82% (1159/1452); 8.35% (75/898) and human 68.76% (317/461); 5.41% (16/296), respectively. It is concluded that (1) there are no relationships between fusion rate and relativeness of the recipient cytoplasm to nucleus donor cells, (2) cytoplast of the goat MII oocyte can support the preimplantation development of SCNT embryos reconstructed with nucleus from other species, (3) the blastocyst rate of close relative inter-species SCNT embryos is higher than that of distant relative inter-species SCNT embryos.

Total RNA and protein content, Cyclin B1 expression and developmental competence of prepubertal goat oocytes

The aim of this study was to examine the relationship between the developmental competence of oocytes and their total RNA and protein contents, and the level of Cyclin B1 transcription. Ovaries from prepubertal goats were collected from a slaughterhouse. Oocytes were recovered by slicing and those with two or more layers of cumulus cells and homogenous cytoplasm were matured in vitro (20-25 oocytes per drop) for 27 h. Both before and after IVM, samples of oocytes were denuded and categorised into four group treatments by diameter (<110 microm, 110-125 microm, 125-135 microm; >135 microm), separated into sub-groups of 10 oocytes per treatment-replicate and stored in liquid nitrogen until total RNA content analysis by spectophotometry, total protein content analysis by a colorimetric assay and Cyclin B1 transcription analysis by RT-PCR. For the study of developmental competence, the rest of the matured oocytes were fertilised in vitro in groups of 20-25 for 24 h. Presumptive zygotes were denuded, sorted into the four categories of diameter noted above, and placed into culture drops in groups of 18-25 for in vitro culture. Cleavage rate was evaluated at 48 hpi and embryo development at 8 d post-insemination. There were four replicates of each treatment for each assay or evaluation point of the experiment. There were no significant differences between the size categories of oocytes at collection in total RNA content, total protein content and Cyclin B1 mRNA. There were significant differences (P<0.05) in the expression of Cyclin B1 before IVM with oocytes in the >135 mm diameter category having the highest value for this variant. There were no significant differences in these characteristics between the categories of oocyte diameter after IVM except in respect of total RNA content, which was lower for the largest size of oocytes (>135 microm; mean+/-S.D.=12.3+/-1.84 ng/oocyte) than the other three size groups (19.2+/-1.38-22.1+/-4.44 ng/oocyte; P<0.05). Significant differences (P<0.05) in cleavage rate were observed between the different oocyte size categories (<110 microm, 3.0%; 110-125 microm, 32%; 125-135 microm, 50%; >135 microm, 73%). Only oocytes >125 microm diameter developed to the blastocyst stage (125-135 microm, 7%; >135 microm, 10%). This study showed that the RNA content and the Cyclin B1 RNA expression of prepubertal goat oocytes, and their development to embryos varied between the different size categories of the oocytes.

Production of transgenic goat (Capra hircus) with human Granulocyte Colony Stimulating Factor (hG-CSF) gene in Brazil

In order to produce transgenic goats with hG-CSF, a total of 24 adult Saanen and 48 adult undefined breed goats were used as donors and recipients, respectively. Donors were estrus-synchronized with vaginal sponges and superovulated by a treatment with 200 mg FSH given twice daily in decreasing doses over 3 days starting 48 h before sponge removal. Ovulation was induced by injecting 100 microg GnRH 36 h after sponge removal. The recipients also received an estrus synchronization treatment. Donors were mated with fertile Saanen bucks and, approximately 72 h after sponge removal, zygotes were recovered surgically by flushing oviducts. The recovered zygotes were briefly centrifuged to a reliable visualization of the pronuclei. The DNA construct containing hG-CSF gene flanked by goat and bovine alphas1-casein sequences was injected into pronuclei of 129 zygotes. The microinjected embryos (3-6 per female) were transferred to 27 recipients. Ten recipients became pregnant and 12 kids were born. One transgenic male founder was identified in the group of kids. This is the first report of a birth of a transgenic goat in Latin America.

Day 0 Protocol: Superstimulatory treatment initiated in the absence of a large follicle improves ovarian response and embryo yield in goats

A new superstimulatory protocol (Day 0 Protocol) to initiate FSH treatment in the absence of a large follicle was compared to a traditional protocol in goats. The Day 0 Protocol (n=44) consisted of pre-treatment with progesterone and eCG to synchronize ovulation and the emergence of Wave 1, with FSH starting 84 h after the end of progesterone exposure (i.e., soon after ovulation). The traditional protocol (n=46) consisted of 11 d of progesterone exposure, with FSH treatment beginning 2 d before the end of progesterone exposure. Treatment with FSH was initiated in the absence of a large follicle in 37/44 and in 6/46 goats in the Day 0 Protocol and traditional protocol, respectively (P<0.01). There was more CL in the Day 0 Protocol than in the traditional protocol (breeding season: 9.6+/-0.6 and 6.3+/-0.8, P<0.05; non-breeding season: 14.3+/-1.5 and 10.7+/-1.5; P<0.05). More Grades 1 and 2 embryos were recovered in the Day 0 Protocol than in the traditional protocol (breeding season: 4.8+/-0.7 and 1.8+/-0.5, P<0.05; non-breeding season: 5.6+/-1.1 and 3.5+/-0.7, P=0.07). Similarly, the proportion of embryos that were Grades 1 and 2 was higher for the Day 0 Protocol than for the traditional protocol (breeding season: 81/114, 71%, versus 16/43, 37%, P<0.05; non-breeding season: 118/203, 58% versus 95/205, 46%, P<0.05). In summary, the Day 0 Protocol, was effective in initiating superstimulatory treatment in the absence of a large follicle, and compared to the traditional protocol, induced a higher ovulation rate and better embryo yield in goats.

Effect of coculture with oviduct epithelial cells on viability after transfer of vitrified in vitro produced goat embryos

This study evaluates the effect of coculture with goat oviduct epithelial cells (GOEC) on the pregnancy rate, embryo survival rate and offspring development after direct transfer of vitrified/thawed caprine in vitro produced (IVP) embryos. Oocytes were recovered from slaughterhouse goat ovaries, matured and inseminated with frozen/thawed capacitated semen, and presumptive zygotes were randomly cultured in synthetic oviduct fluid (SOF) (n=352) or GOEC (n=314). The percentage of cleaved embryos reaching the blastocyst stage was 28% and 20% in SOF and GOEC, respectively (P<0.05). Overall, 26 blastocysts of SOF were transferred freshly in pairs to recipient goats, whereas 58 of SOF and 36 of GOEC were vitrified and transferred directly in pairs to recipient goats after thawing without removal of cryoprotectants or morphological evaluation. The kidding rate was 92% for SOF fresh, 14% for SOF vitrified (P<0.001) and 56% for GOEC vitrified (P<0.05); the difference was also significant between vitrified groups (P<0.01). The embryo survival rate was 62% for SOF fresh, 9% for SOF vitrified (P<0.001) and 33% for GOEC vitrified (P<0.05) with a significant difference between vitrified groups (P<0.01). The results showed that the coculture of IVP goat embryos with GOEC significantly improves the pregnancy and embryo survival rates and leads to the birth of healthy offspring. However, further research using more defined GOEC coculture is required to confirm its capacity to increase the success rate of IVP embryo technology in goat.

Isolation and propagation of keratinocytes derived from Cashmere goat fetus

The study was conducted to isolate epidermal keratinocytes from Cashmere goat fetus with the aim to develop suitable conditions for keratinocyte cultivation and propagation. The methods developed for keratinocyte culture include (i) use of a feeder-layer of mitotically inactivated fibroblasts obtained from goat and mouse fetal skin, (ii) use of a substrate such as collagen IV, or (iii) without use of any substrate. Epidermal cell removal was established by enzymatically separating keratinocytes from 12 to 16 weeks aged fetal skin tissues treated with 0.125% trypsin solution overnight at 4 degrees C. The cells were maintained in all culture conditions with serum containing medium. Keratinocyte multiplication and proliferation were comparable in different culture conditions and the improved cellular attachment and growth have been obtained in cultures on feeder layers. Colony forming keratinocytes on feeder layer were heterogeneous in their growth potential. In feeder free conditions, high cellular density was required at plating for sub-cultivation as their poor attachment in culture dishes. This study reports the comparative efficacy of different culture conditions for keratinocyte isolation and in vitro propagation originating from Cashmere goat fetus.

Effects of oocyte quality, semen donor and embryo co-culture system on the efficiency of blastocyst production in goats

The aim of the study was to determine whether the selection of immature oocytes by a combination of cumulus-oocyte-complexes (COCs) morphology and staining with brilliant cresyl blue (BCB) would be helpful in selecting developmentally competent oocytes, and thereby increase the efficiency of blastocyst production from ovarian oocytes of FSH-primed, adult goats. In a second experiment the interaction between oocyte quality and semen donor was assessed. In a third experiment the usefulness of Vero cells for co-culture with goat embryos was investigated. In the pool of morphologically normal COCs recovered from ovaries following slicing (21.9+/-11.0), the mean rate of COCs classified as BCB+ was 85.6%, and the BCB- was approximately 11%. Oocytes classified as grade 1 and BCB+ exhibited the highest developmental competence (P<0.001) after in vitro maturation and fertilization compared with oocytes of grade 1 BCB- and grade 2 BCB+ or BCB-. There were no significant differences in developmental competence in grade 2 oocytes, regardless of BCB coloration. No significant differences in embryo cleavage and blastocyst formation rates among three bucks were observed when morphologically normal, BCB+ oocytes were used. For all tested bucks, differences in embryo production efficiency were related only to the oocyte quality. Similar blastocyst rates were developed from embryos co-cultured with goat oviduct epithelial cells (34.3%) and with Vero cells (33.3%). These results show that the most important criterion for selection of COCs before maturation is the visual assessment of morphological features. Staining with BCB of COCs recovered from adult goats does not enhance efficiency of selection of developmentally competent oocytes for IVF.

Goat PRND expression pattern suggests its involvement in early sex differentiation

Expression of the goat prion protein gene locus was assessed by reverse transcriptase-polymerase chain reaction on testes and ovaries at various developmental stages. A weak and stochastic expression of the PRNP and PRNT genes was observed. For PRNT, it is consistent with the detected deletions of two single nucleotides within its open reading frame in ruminant genes. PRND was expressed in both tissues at all stages. Whereas its expression is constant in the ovaries, it increases in testes between 36 and 46 days postcoitum (dpc) and remains high thereafter. In testes, Doppel was found in the nucleus of germinal cells and in the cytoplasm of Leydig cells at 44 dpc. It was detected in the cytoplasm of Leydig cells and of some Sertoli and germinal cells at 62 dpc. In the ovaries, it was observed in the nucleus of germinal cells at 44 dpc and mainly in their cytoplasm at 62 dpc. This expression pattern was shown to parallel that of C-kit and suggests Doppel involvement in early testis differentiation.

Qualitative and quantitative analysis of goat ovaries, follicles and oocytes in view of in vitro production of embryos

Goat ovaries were collected from the slaughterhouse and categorized as right, left, corpus luteum (CL)-present and -absent group and evaluated on the basis of weight (g), length (cm), width (cm), number of follicles, follicles aspirated and number and state of cumulus-oocyte-complexes (COCs). Comparatively higher weight [(0.66+/-0.02) vs (0.64+/-0.02) g], length [(1.17+/-0.02) vs (1.11+/-0.02) cm] and width [(0.77+/-0.02) vs (0.74+/-0.02) cm] were found in right ovaries than those of left. On the other hand significantly (P<0.05) higher weight [(0.71+/-0.03) vs (0.64+/-0.01) g] and width [(0.76+/-0.03) vs (0.75+/-0.01) cm] were found in CL-present group than those of CL-absent group of ovaries. The left ovaries contained comparatively higher number of normal COCs [(1.06+/-0.09) per ovary] than right ovaries [(1.03+/-0.10) per ovary] and the similar trend was found in total number of follicles [(4.51+/-0.25) vs (4.30+/-0.23) per ovary] and follicles aspirated [(2.55+/-0.14) vs (2.52+/-0.12) per ovary]. But the total COCs per ovary was almost similar in both ovaries [right and left: (1.85+/-0.12) and (1.85+/-0.11) per ovary, respectively]. Higher number of total COCs [(1.87+/-0.09) vs (1.76+/-0.16) per ovary], total number of follicles [(4.45+/-0.19) vs (4.16+/-0.37) per ovary], follicles aspirated [(2.55+/-0.10) vs (2.48+/-0.21) per ovary] and normal COCs [(1.12+/-0.07) vs (0.76+/-0.14) per ovary] were found in CL-absent group than those of CL-present group of ovaries.

[Optimization of culture measure for bovine-bovine and goat-bovine cloned embryos in vitro]

This study is conducted to explore an effective culture method for supporting the embryo development. The cattle fetal ear fibroblasts and the goat fetal ear fibroblasts are transplanted into the enucleated cattle oocytes separately by oocyte intraplasmic nuclear injection method to construct bovine cloned embryos and goat-bovine cloned embryos. The embryos are first cultivated in modified charles rosenkrans 2 amino acid medium (mCR2aa) and modified synthetic oviduct fluid medium (mSOF) separately. Then BSA (8 mg/mL) or FBS (10%) can be added to mSOF according to the different culture period. The supplements and orders, added during the first three days and after three days are as follow: BSA and BSA, BSA and FBS, FBS and BSA, FBS and FBS. On the basis of the cleavage rate, 8/16-cell rate, blastocysts rate and total cell number of blastocysts, the best culture way can be screened out.

RESULT

First, cleavage rate, 8/16-cell rate, blastocysts rate and total cell number of blastocysts, cultivated in mSOF solution are all higher than those cultivated in mCR2aa( P < 0.05). Second, the cleavage rate and 8/16-cell rate, adding BSA and FBS into mSOF, are in turn 79.8% +/- 7.1%, 49.7% +/- 3.5%, 21.5% +/- 1.8%, and 115.2 +/- 4.3 in bovine cloned embryo, and 40.1% +/- 6.3%, 29.2% +/- 2.0%, 13.4% +/- 2.1% and 100.1 +/- 3.0 in goat-bovine cloned embryo, which are significant higher than other culture groups (P < 0.05).

CONCLUSION

The goat-bovine cloned embryo can be cultivated by the optimized culture measure of bovine cloned embryo. The best culture ways of bovine cloned embryo and goat-bovine cloned embryo are all to use mSOF supplemented BSA in the first three days and then use mSOF supplemented FBS in the next five days.

Early fetal sexing of Saanen goats by use of transrectal ultrasonography to identify the genital tubercle and external genitalia

OBJECTIVE

To define the optimum period for sexing of Saanen goat fetuses by use of transrectal ultrasonography.

ANIMALS

82 Saanen goats pregnant with 124 fetuses.

PROCEDURES

Fetal sexing was performed on the basis of the final location of the genital tubercle or identification of external genitalia. In experiment 1, fetuses (n = 78) were monitored every 48 hours from days 40 to 60 of gestation, whereas for experiment 2, 46 fetuses were examined only once between days 47 and 77 of gestation.

RESULTS

For experiment 1, accuracy of fetal sexing was 20 of 20 (100%) for a single fetus, 39 of 42 (92.8%) for twin fetuses, and 10 of 16 (62.5%) for triplet fetuses. Diagnostic accuracy was significantly lower for triplet fetuses than that for single or twin fetuses. Final location of the genital tubercle was detected between 45 and 55 days of gestation (mean +/- SEM, 48.9 +/- 1.8 days). For experiment 2, accuracy of fetal sexing for a single fetus (24/24 [100%]) was significantly higher than the accuracy for twin fetuses (16/22 [72.7%]). Considering all fetuses that were born, accuracy of diagnosis was 69 of 78 (88.4%) for experiment 1 and 40 of 46 (86.9%) for experiment 2. Accuracy did not differ significantly between experiments.

CONCLUSIONS AND CLINICAL RELEVANCE

Real-time ultrasonography after day 55 of gestation is a suitable method for determination of sex of Saanen goat fetuses by observation of the genital tubercle or identification of external genitalia.

In Vitro Fertilization and Development of OPU Derived Goat and Sheep Oocytes

The recent upgrade in IVP technology seen in cattle can be adapted to embryo production in small ruminants to overcome limitations exhibited by surgical procedures on preserving the reproductive potential of donors and the efficiency of embryo production. The aim of the present study was to assess the current procedures used in cattle for the production of IVP embryos in goats and sheep based on laparoscopic-aided ovum pick-up (LOPU) supplied oocytes. Sexually matured goat and sheep donors were treated during the breeding season with FSH and subjected to laparoscopic-guided follicular puncture under general anaesthesia. The collected cumulus-oocyte complexes were matured in medium 199 and fertilized by frozen-thawed spermatozoa using Talp medium supplemented with heparin and oestrus-sheep serum. Cleaved ova were either cultured in sheep in vitro fertilization medium plus amino acids or transferred to sheep oviducts. Blastocyst rate, hatching rate and development rate up to term were used as markers of embryo function. The results obtained for goat and sheep involving 30 and 35 donors respectively (10 and 9 LOPU sessions) were 81.2% and 85.2% of oocyte collection rate; 88.3% and 98.6% oocyte incubation rate; 85.6% and 76.0% fertilization rate; 82.4% and 93.4% of cleavage rate; 50.0% and 61.5% IVP blastocyst rate; 42.1% and 45.5% blastocyst rate in oviducts; 73.0% and 66.7% embryo survival up to term, respectively. The results are comparable to those obtained in small ruminants and in bovines suggesting that requirements for embryo production and development are similar.

Vitrification of Boer Goat Morulae and Early Blastocysts by Straw and Open-Pulled Straw Method

The aim of this study was to investigate the effects of different vitrification solutions [EFS30 or EFS40 contains 30% (v/v) ethylene glycol (EG), 40% (v/v) EG; EDFS30 or EDFS40 contains 15% (v/v) EG and 15% (v/v) dimethyl sulfoxide (DMSO), 20% (v/v) EG and 20% (v/v) DMSO], equilibrium time during vitrification (0.5-2.5 min) and vitrification protocols [one-step straw, two-step straw and open-pulled straw (OPS)] on in vivo development of vitrified Boer goat morulae and blastocysts after embryo transfer. In the one-step straw method, the lambing rates of vitrified embryos in EFS30 (37.5%), EFS40 (40.5%) or EDFS30 (38.2%) group were similar to that of fresh embryos (57.5%) and conventional freezing method (46.7%) when the equilibrium time was 2 min. In the two-step straw method, the highest lambing rate was obtained when embryos were pretreated with 10% EG for 5 min and then exposed to EFS40 for 2 min (51.4%), showing similar lambing rates compared with fresh embryos (56.1%) or the embryos cryopreserved by conventional freezing method (45.2%). In the OPS method, the lambing rate in EFS40, EDFS30 or EDFS40 groups were similar to that (57.1%) of fresh embryos, or to that (46.0%) of embryos cryopreserved by conventional freezing method. The highest lambing rate (51.4%) of the group of OPS was obtained when the embryos were vitrified with EDFS30. In conclusion, either the two-step straw method in which embryos were pretreated in 10% EG for 5 min and then exposed to EFS40 for 2 min, or the OPS method in which embryos were pretreated in 10% EG + 10% DMSO for 30 s and then exposed to EDFS30 for 25 s was a simple and efficient method for the vitrification of Boer goat morulae and blastocysts.

Effect of oocyte diameter on meiotic competence, embryo development, p34 (cdc2) expression and MPF activity in prepubertal goat oocytes

The aim of this study was to analyze the relationship between oocyte diameter, meiotic and embryo developmental competence and the expression of the catalytic subunit of MPF, the p34(cdc2), at mRNA, RNA and protein level, as well as its kinase activity, in prepubertal (1-2 months old) goat oocytes. MPF is the main meiotic regulator and a possible regulator of cytoplasmic maturation; therefore, it could be a key factor in understanding the differences between competent and incompetent oocytes. Oocytes were classified according to oocyte diameter in four categories: <110, 110-125, 125-135 and >135 microm and matured, fertilized and cultured in vitro. The p34(cdc2) was analyzed in oocytes at the time of collection (0 h) and after 27 h of IVM (27 h) in each of the oocyte diameter categories. The oocyte diameter was positively related to the percentage of oocytes at MII after IVM (0, 20.7, 58 and 78%, respectively) and the percentage of blastocysts obtained at 8 days postinsemination (0, 0, 1.95 and 12.5%, respectively). The expression of RNA and mRNA p34(cdc2) did not vary between oocyte diameters at 0 and 27h. Protein expression of p34(cdc2) increased in each oocyte category after 27 h of maturation. MPF activity among diameter groups did not vary at 0h but after IVM there was a clear and statistically significant increase of MPF activity in the biggest oocytes.

Quantitative analysis of mitochondrial RNA in goat–sheep cloned embryos

Mitochondria are the key generators of cellular ATP, and contain extranuclear genome-mitochondrial DNA (mtDNA). In the process of nuclear transfer (NT), heteroplasmic sources of mtDNA from a donor cell and a recipient oocyte are mixed in the cytoplasm of the reconstituted embryo. Previous studies showed inconsistent patterns of mtDNA inheritance in offspring and early fetuses generated through interspecies NT. The quantitative analysis of mitochondrial RNA (mtRNA) in interspecies cloned embryos is useful for better understanding the fate of two types of mitochondria. The components of nicotinamide adenine dinucleotide (NADH) dehydrogenase were coded by both nuclear DNA (nDNA) and mtDNA. The Subunit 1 (ND-1) is one of seven NADH dehydrogenase subunits coded by mtDNA. In present study, using real-time and reverse-transcription PCR, the copy number of species-specific ND-1 mRNA was examined in goat-sheep cloned embryos of various developmental stages, and was applied to evaluate the expression pattern of species-specific mtDNA. The results of showed that (1) the expression of mtDNA derived from goat fetal fibroblast (GFF) decreased from 1-cell stage (immediately after fused) to 2-cell stage, and could not be detected from 4-cell stage onward to blastocyst stage; (2) the expression of mtDNA derived from sheep oocyte was roughly constant from 1-cell stage to the 8-cell stage, increased gradually from 16-cell stage, and sharply at morula and blastocyst stage. Moreover, we strongly argued a mechanism, that is GFF-derived mitochondria were degraded for the depression of bioenergetic functions, and then selectively eliminated during the embryogenesis of goat-sheep cloned embryos.

Effect of cytoplast on the development of inter-subspecies nuclear transfer reconstructed goat embryo

The aim of this study was to investigate effect of cytoplast on the development competence of reconstructed embryos derived from inter-subspecies somatic cell nucleus transfer (SCNT). First, the development potency of reconstructed embryos produced by transferring Boer goat fibroblast cell nucleus of different ages into enucleated Sannen goat ova was evaluated in order to determine which age of nuclear donor is favorable for the reconstructed embryos development. Secondly, the another component of reconstructed embryos, "cytoplast," was evaluated by comparing the effect of ovum cytoplast derived from Sannen male symbol x Boer female symbol descendant on the reconstructed embryos development to that of Sannen goat ovum cytoplast. The results revealed that the development rate of the reconstructed embryos derived from 2 months old Boer goat somatic cells was the highest, their gestation rate was up to 50%, and one viable male offspring was obtained. The cytoplast derived from the crossbreeding goats improves the development competence of reconstructed embryos, which birth rate was 5.5%. The genetic identification of offspring by using PCR-SSCP analysis confirmed that these cloned kids were derived from the donor. The results above reveal that the cytoplast of Sannen goat ovum could induce the dedifferentiation of somatic cell nuclei derived from Boer goat, but the reprogramming process of these reconstructed embryos seems incomplete, probably due to some incorrect processes happened after implantation. Relatedness components of nucleus donor in cytoplast of the crossbreeding goat may be helpful to induce the dedifferentiation of somatic cell nuclei completely and improve the development competence of the reconstructed embryos.

Embryo development of prepubertal goat oocytes fertilised by intracytoplasmic sperm injection (ICSI) according to oocyte diameter

The aim of this study was to evaluate embryo development of prepubertal goat oocytes fertilised by ICSI according to their diameter. Three experiments were carried out to achieve this objective. In all experiments, oocytes were matured in TCM199 supplemented with hormones, cysteamine and serum for 27 h at 38.5 degrees C. In Experiment 1, we studied the nuclear stage of goat zygotes produced by conventional ICSI and IVF using 20 nM ionomycin plus 10 microM heparin as sperm treatment. A group of Sham-injected oocytes was used as control. Results showed differences in the percentage of 2 PN (zygotes with male and female pronuclei) between ICSI, IVF and Sham (40.9, 26.6 and 3.0%, respectively; P<0.05). In Experiment 2, we evaluated the embryo development of prepubertal goat oocytes produced by ICSI and IVF after 192 h of culture in SOF medium. The percentage of morulae plus blastocysts obtained was higher in the ICSI than in the IVF group (13.4 and 5.1%, respectively; P<0.05). In Experiment 3, IVM-oocytes were classified in four groups depending on their diameter (Group A: <110 microm; Group B: 110-125 microm; Group C: 125-135 microm; Group D: >135 microm), fertilised by ICSI and cultured for 192 h. Results showed a positive correlation between oocyte diameter and embryo development (morulae+blastocysts: Group A: 0%; Group B: 6.2%; Group C: 46.4% and Group D: 33.3%). In conclusion, sperm treatment with ionomycin plus heparin using the conventional ICSI protocol improved fertilisation rates in comparison to IVF. Oocytes smaller than 125 microm were unable to develop up to blastocyst stage.

Magnesium sulfate exposure increases fetal blood flow redistribution to the brain during acute non-acidemic hypoxemia in goats

BACKGROUND

It is still controversial that intrapartum exposure to magnesium may or may not reduce brain damage in premature infants in human and animal models.

AIMS

We investigated the effect of hypoxemia alone under magnesium exposure on fetal cardiovascular changes in chronically catheterized goat fetuses.

STUDY DESIGN

We performed a 3-day experimental protocol with control (10% glucose) on day 1, recovery on day 2, and magnesium on day 3. Magnesium sulfate was directly infused to fetuses in a bolus dose of 270 mg/kg followed by 80 mg/kg/h. Hypoxemia was induced by maternal inhalation of nitrogen gas on day 1 and on day 3. Cerebral blood flow was measured by colored microsphere techniques. Repeated measure ANOVA and Bonferroni's/Dunn's test were used for comparison.

SUBJECTS

Six Japanese Saanen goats at 0.85 gestation.

OUTCOME MEASURES

Fetal heart rate, blood pressure, and cerebral blood flow.

RESULTS

Ionized magnesium concentrations were significantly increased. Fetal PO2 decreased significantly from 30 mmHg to 14 mmHg without acidemia. Magnesium exposure significantly attenuated hypoxemia-induced bradycardia but did not affect blood pressure. Hypoxemia significantly increased fetal brain blood flow from the pre-hypoxic levels on day 1. Magnesium exposure further increased hypoxemia-induced brain blood flow on day 3, but statistical significance was limited to the cerebral cortex.

CONCLUSION

In near-term, initially healthy goat fetuses, brain blood flow during acute hypoxemia was significantly increased with magnesium sulfate exposure.

Improved vitrification method allowing direct transfer of goat embryos

The aim of this study was to design a vitrification method suited to field embryo transfer experiments in goat. In a first experiment, a standard vitrification protocol, previously designed for sheep embryos was compared to slow freezing of goat embryos. No significant difference was observed on kidding rate (48% versus 69%, respectively), nor on embryo survival rate (35% versus 45%). Second experiment: all embryos were vitrified. After warming, embryos were either transferred directly (direct transfer), or after in vitro dilution of the cryoprotectants (conventional transfer). The kidding rate was not affected by the transfer method (38% versus 23%, respectively). However, embryo survival rate tended to be higher after direct transfer (26% versus 14%). Third experiment: OPS vitrification was compared to standard vitrification. The kidding rate was not affected (22% versus 39%, respectively), but the embryo survival rate was lower after OPS (14% versus 28%). Fourth experiment: 0.4M sucrose was added with cryoprotectants in vitrification. The kidding rate after direct transfer was significantly enhanced after addition of sucrose (56% versus 27%, respectively), whereas embryo survival rate was not significantly affected (32% versus 18%). Fifth experiment: vitrification with sucrose supplementation was compared to slow freezing. No significant difference was observed after direct transfer on kidding rate (52% versus 31%, respectively), but embryo survival rate tended to be higher after vitrification (34% versus 21%). In conclusion, our results indicate that addition of 0.4M sucrose in association with direct transfer improves significantly the viability of goat vitrified embryos.

Developmental expression of pluripotency determining factors in caprine embryos: Novel pattern of NANOG protein localization in the nucleolus

Transcription factors, POU5F1/OCT4 and NANOG, whose expression is restricted to the inner cell mass (ICM) in mouse and human blastocysts, are used to characterize undifferentiated embryonic stem cells (ESC) in vitro. However, POU5F1 may not be a useful marker in domestic animals due to its expression in both ICM and trophectoderm (TE), while NANOG mRNA and protein expression have only been described fully in mice. In an effort to identify ESC markers for domestic animals, expression patterns of NANOG, POU5F1, and the cell surface markers (SSEA1, SSEA4, TRA-1-60, TRA-1-81) were examined in preimplantation goat embryos, a species that has proven to be a superior choice for the production of transgenic proteins in milk (biopharming). Our results indicate that while goat embryos express POU5F1, SSEA1, and SSEA4 proteins, their expression is not strictly restricted to the ICM. In a unique staining pattern, NANOG protein was localized to the nucleoplasm and nucleoli in ICM cells, but was localized strictly to nucleoli in TE. This pattern may reflect down-regulation of protein by sequestration/degradation utilizing a nucleolar mechanism known to operate in stem cells. Furthermore, NANOG mRNA in TE was also significantly down-regulated as compared with that in ICM. Taken together, this novel expression pattern of NANOG in goat preimplantation embryos suggests that NANOG could serve as marker of pluripotency in goats and may be useful in derivation and characterization of caprine ESC. This study is the first to characterize both NANOG mRNA and protein expression in any species other than the mouse.

Birth of live Spanish ibex (Capra pyrenaica hispanica) derived from artificial insemination with epididymal spermatozoa retrieved after death

As a consequence of increasing limitations to maintaining genetic variability in endangered wildlife species, methods of assisted reproduction widely used in domestic animals are being applied to nondomestic species. However, practical efforts have met limited success to date. The Spanish ibex (Capra pyrenaica hispanica) is a wild caprine originating exclusively in the mountains of Spain. This study was designed to evaluate the fertilizing capability of cryopreserved Spanish ibex epididymal spermatozoa recovered postmortem. For this purpose, we have previously evaluated the effect of time elapsed between death and sperm recovery on spermatic parameters, and the fertilization ability of frozen-thawed spermatozoa using heterologous in vivo fertilization by intrauterine insemination in domestic goat (Capra hircus). The time of death significantly affected most sperm quality parameters (motility, viability and intact acrosomes). The fertility obtained by heterologous artificial insemination was 18.7%, and only goats inseminated with spermatozoa recovered within 8h after death became pregnant. Our findings showed that heterologous in vivo fertilization is a useful method to evaluate the fertilizing capacity of sperm samples in rare or wild species. Sperm samples, with verified fertilization ability in the previous trial, were used to inseminate a total of six ibex females. Inseminations resulted in one pregnancy. The study demonstrated for the first time the feasibility of applying artificial insemination in Spanish ibex.

Factors derived from mouse embryonic stem cells promote self-renewal of goat embryonic stem-like cells

Goat embryonic stem (ES)-like cells could be isolated from primary materials-inner cell masses (ICMs) and remain undifferentiated for eight passages in a new culture system containing mouse ES cell conditioned medium (ESCCM) and on a feeder layer of mouse embryo fibroblasts (MEFs). However, when cultured in medium without mouse ESCCM, goat ES-like cells could not survive for more than three passages. In addition, no ES-like cells could be obtained when ICMs were cultured on goat embryo fibroblasts or the primary materials-whole goat blastocysts were cultured on MEFs. Goat ES-like cells isolated from ICMs had a normal karyotype and highly expressed alkaline phosphatase. Multiple differentiation potency of the ES-like cells was confirmed by differentiation into neural cells and fibroblast-like cells in vitro. These results suggest that mouse ES cells might secrete factors playing important roles in promoting goat ES-like cells' self-renewal, moreover, the feeder layers and primary materials could also influence the successful isolation of goat ES-like cells.

The effect of electrical field strength on activation and development of cloned caprine embryos

The activation procedure used in nuclear transfer (NT) is one of the critical factors affecting the efficiency of animal cloning. The purpose of this study was to compare the effect of two electrical field strengths (EFS) for activation on the developmental competence of caprine NT embryos reconstructed from ear skin fibroblasts of adult Alpine does. The NT embryos were obtained by transfer of the quiescent fibroblasts at the fourth passage into the enucleated metaphase II (M II) oocytes. Four to five hours after electrical fusion, the NT-embryos were activated by EFS either at 1.67 or at 2.33 kV/cm and immediately incubated in 6-DMAP (2 mM) for 4 h. The cleavage rate of the NT-embryos activated with 2.33 kV/cm was greater than that activated with 1.67 kV/cm after in vitro culture for 18 h (65.6% versus 19.6%, p < 0.001). No pregnancy was found in 14 recipient does after transferring 51 NT embryos at 1-2 cell stages activated with 1.67 kV/cm. In contrast, two of the seven recipients were pregnant and gave birth to three kids after transferring 61 NT embryos at 1-2 cell stages activated by 2.33 kV/cm. The birth weights of three cloned kids were within the normal range of Alpine goats. However, one kid died 1h after birth while the remaining two are still healthy. DNA analysis by polymerase chain reaction (single-strand conformation polymorphism, SSCP) confirmed that the three kids were genetically identical to the nuclear donor.

Ovulatory response and embryo yield in Jakhrana goats following treatments with PMSG and FSH

Superovulatory response and embryo production efficacy were investigated in adult (age 2-4 years, average body weight: 27-43 kg) cycling Jakhrana goats (n = 15) under semi-arid environmental conditions of India by administering different superovulatory regimens. Goats were reared under semi-intensive system of management in established farm conditions. To synchronize oestrus, a luteolytic dose of carboprost tromethamine (Upjohn, UK) was administered intramuscularly to all does at the dose rate of 5 microg per kg body weight in a double dose schedule with an interval of 11 days. For superovulation, 750 IU of PMSG (Folligon, Intervet, Boxmeer, Holland) per goat was administered intramuscularly 24 h before administering a second dose of luteolytic agent in five does (treatment 1). FSH (Sigma, St. Louis, MO, USA) 12.50 IU per goat was administered intramuscularly in a decreasing daily dose schedule (2.50, 2.50; 1.875, 1.875; 1.25, 1.25; 0.625, 0.625) at 12 h intervals over four days, initiated 48 h before administering second dose of carboprost tromethamine in 5 does (treatment 2). FSH (Super-Ov, Ausa Intern, USA) was administered at a uniform dose rate of 8.33 units per goat intramuscularly at 24 h intervals over three consecutive days (total dose was 25 units), initiated 48 h before administering a second dose of carboprost tromethamine in 5 does (treatment 3). To synchronize ovulation in responders, human chorionic gonadotrophin (hCG, Chorulon, Intervet) was injected intramuscularly at a dose rate of 500 IU in each goat on the day of oestrus appearance. Goats were laparotomized 72-82 h following the onset of synchronized oestrus and their genitalia were flushed using a standard collection procedure. Variability (p > 0.05) in superovulatory response (number of established corpora lutea) was observed: FSH (Sigma), 11.8 +/- 2.9; FSH (Super-Ov), 11.6 +/- 4.5; PMSG (Intervet), 8.4 +/- 2.3. A similar pattern was reflected in mean embryo and transferable embryo recovery, respectively (p > 0.05): FSH (Sigma), 8.0 +/- 1.8, 5.2 +/- 1.7; FSH (Super-Ov), 6.6 +/- 2.4, 5.4 +/- 2.4; PMSG, 5.8 +/- 1.9, 3.8 +/- 2.2. In PMSG-treated does, comparatively more unfertilized ova or retarded embryos were recovered than in FSH-treated does. The superiority of FSH preparations over PMSG was reflected in terms of total and transferable embryo production (p > 0.05). On average, five transferable embryos (excellent and good quality) were recovered per doe treated with FSH of either source. The mean ova/embryo recovery was satisfactory (55-68%). Results indicated that Jakhrana goats can be superovulated for embryo production using FSH of either source to augment productivity.

Comparison of cell proliferation index in equine and caprine embryos using a modified BrdU incorporation assay

The measurement of cell proliferation and cell viability using 5'bromo-2'deoxy-uridine (BrdU) labelling has been described in several cell types and species. The aim of this study was to adapt this technique to equine embryos and to compare the index of DNA replication (S-phase) between equine and caprine embryos. Seventeen equine embryos were recovered at day 6.5 post-ovulation and 20 caprine embryos were recovered at day 7 after the onset of estrus. Equine embryos were incubated during 1h at 39 degrees C in PBS containing 1mM of BrdU. Embryos were then treated in 0.05% trypsin during 15 min at 39 degrees C to permeabilise the capsule, and then embryos were rinsed in PBS containing 10% of foetal calf serum. After washing, embryos were immediately fixed in 2.5% paraformaldehyde with 0.3M NaOH during 15 min at ambient temperature. The S-phase was detected by immunocytochemistry technique. In caprine embryos, BrdU was visualised by the same technique but without the trypsin treatment. The percentage of cells (+/-S.E.M.) with BrdU incorporated into newly synthesised DNA strands was significantly higher in equine embryos (74+/-1) than in caprine (38+/-2). Our results demonstrated that BrdU incorporation assay can be used in equine embryos. This assay allows the determination of the proliferation index of live cells and could be used as an additional tool for evaluating the viability of embryos. The high percentage of cells incorporating BrdU during 1h of incubation with BrdU suggests that in comparison with the caprine embryos the cellular activity of proliferation is more intense in equine embryos and suggests that the cellular cycle is shorter in equine embryos.

Metabolism, protein content, and in vitro embryonic development of goat cumulus-oocyte complexes matured with physiological concentrations of glucose andL-lactate

No information is available concerning how the maturation environment controls the metabolism of goat oocytes. The objectives of this experiment were to: (1) Determine the concentrations of glucose, lactate, and pyruvate in caprine follicular fluid; and (2) Investigate the effects of physiological concentrations of glucose and lactate in the in vitro maturation (IVM) medium on the metabolism (glycolysis and pyruvate oxidation), protein content, and developmental competence of caprine oocytes and cumulus-oocyte complexes (COCs). Abattoir-derived COCs were matured for 18-20 hr in a defined, SOF-based medium containing 0.75, 1.5 (follicular fluid = 1.4 mM), or 3.0 mM glucose, and 3.0, 6.0 (follicular fluid = 7.1 mM), or 12.0 mM L-lactate. The protein content of oocytes and COCs was not affected (P > 0.05) by the concentration of glucose and lactate in the maturation medium. Increasing glucose and lactate decreased (P < or = 0.05) glycolytic activity of oocytes, without affecting (P > 0.05) pyruvate oxidation. In COCs, increasing glucose concentrations tended (P = 0.07) to decrease glycolysis. When metabolic activity was corrected for protein content (pmol/microg protein/3 hr), increasing glucose or lactate concentrations in the medium decreased (P < or = 0.05) pyruvate oxidation in oocytes, but increased (P < or = 0.05) pyruvate oxidation in COCs. Embryonic development (cleavage and blastocyst development, hatching, and cell number) was not affected (P > 0.05) by the glucose and lactate concentrations tested. These results indicate that concentrations of glucose and lactate in the medium have cell type-specific effects on metabolism of oocytes and COCs, but do not affect developmental competence within the range of concentrations tested.

Comparison between intracytoplasmic sperm injection and in vitro fertilisation employing oocytes derived from prepubertal goats

The objective of this study was to compare the embryo development of prepubertal goat oocytes after ICSI and IVF procedures. Three experiments were carried out to achieve this objective. (1) An analysis of the efficiency of ICSI with or without chemical stimulation (5 microM ionomycin for 5 min and 2 mM 6-DMAP for 4 h). In this experiment, Sham and parthenogenetic oocyte groups were used as controls. (2) According to the results from experiment 1, we investigated the nuclear stage of zygotes obtained with ICSI and IVF, and their further embryo development. (3) We compared two embryo culture media (G1.3/G2.3 and TCM199 with granulosa cells) on the embryo development of zygotes obtained from ICSI and IVF procedures. Experiment 1 demonstrated that prepubertal goat oocytes needed additional chemical stimulation, after conventional ICSI, to form zygotes with male and female pronuclei (2PN). Experiment 2 showed that significantly higher percentages of -zygotes were found in ICSI-oocytes than IVF-oocytes (40.0 and 25.1%, respectively; P < 0.005). The percentage of embryos obtained and developed beyond the 8-cell stage was significantly higher for ICSI than for IVF and parthenogenetic embryos (22.8, 10.3 and 3.8%, respectively; P < 0.05). Experiment 3 showed that G1.3/G2.3 medium improved the embryo development of ICSI- and IVF-oocytes compared to co-culture with granulosa cells in TCM medium. The highest percentage of embryo development beyond 8-16 cells was found in ICSI-oocytes cultured in G1.3/G2.3 medium. However, a reduced number of morulae were found in this study.

Transfer of an expression YAC into goat fetal fibroblasts by cell fusion for mammary gland bioreactor

Yeast artificial chromosomes (YACs) as transgenes in transgenic animals are likely to ensure optimal expression levels. Microinjection of YACs is the exclusive technique used to produce YACs transgenic livestock so far. However, low efficiency and high cost are its critical restrictive factors. In this study, we presented a novel procedure to produce YACs transgenic livestock as mammary gland bioreactor. A targeting vector, containing the gene of interest-a human serum albumin minigene (intron 1, 2), yeast selectable marker (G418R), and mammalian cell resistance marker (neo(r)), replaced the alpha-lactalbumin gene in a 210kb human alpha-lactalbumin YAC by homogeneous recombination in yeasts. The chimeric YAC was introduced into goat fetal fibroblasts using polyethylene glycol-mediated spheroplast fusion. PCR and Southern analysis showed that intact YAC was integrated in the genome of resistant cells. Perhaps, it may offer a cell-based route by nuclear transfer to produce YACs transgenic livestock.

Isolation, identification and characterization of secretory proteins of IVMFC embryos and blood circulation of estrus and early pregnant goat

The aim of the present study was to isolate, identify and characterize the secretory proteins of IVM oocytes and IVMFC embryos to evaluate its immunogenecity. and identify of such proteins if any, in blood circulation of estrus and early pregnant goats. Oocytes were matured in TCM-199 with 1 microg/ml, estradiol-17beta; 0.5 microg/ml, FSH; 100 IU/ml, LH and 10% FCS on granulosa cell monolayer. After 18 hr of maturation, oocytes were further cultured in maturation medium containing 3 mg/ml polyvinyl alcohol (PVA) without serum and BSA for 12 hr and medium was collected. The IVF embryos of 4-8 cell stage were cultured in medium containing PVA without serum and BSA. Embryo culture medium was collected after 24 hr of culture and was pooled. The proteins were analyzed on SDS-PAGE (12.5%). Four secretory proteins of oocytes with approximately molecular weight of 45, 55, 65 and 95 kDa and three secretory proteins of embryos 45, 55 and 65 kDa were obtained on SDS-PAGE in silver staining. The protein profile of midluteal, estrus and early pregnant goat serum was similar and no variation was observed among the proteins on SDS-PAGE. Two secretory proteins of 55 and 65 kDa of both IVM oocytes and IVMFC embryos were observed on Western analysis. None of such proteins was observed in midluteal, estrus and early pregnant goat serum on western blotting. It can be concluded that IVM oocytes and IVMFC embryos secrete proteins in medium and two of them can develop antibody. The proteins secreted from embryos till morula stage was similar to that of oocytes. None of these oocyte/embryo released proteins were observed in blood circulation of estrus and early pregnant goats.

In utero transplantation of human hematopoetic stem cells into fetal goats under B-type ultrasonographic scan: an experimental model for the study of potential prenatal therapy

OBJECTIVE

Using fetal goats as animal models, to establish the methodology of in utero transplantation of human hematopoeitic stem cell (HSC) under B-scan ultrasonographic guidance for prenatal therapy.

STUDY DESIGN

Human HSC were directly injected into the peritoneal cavities of the recipient fetal goats at 45-55 days of gestation (term: 145 days) under the guidance of B-type ultrasound scan. After birth, the peripheral blood was collected for fluorescence assisted cell sorting (FACS), quantitative real-time PCR and fluorescence in situ hybridization (FISH) to detect and analyze the presence of human cells in the recipients.

RESULTS

The 32 recipients were born alive except one miscarriage. To test for the presence of human-goat chimeras, cells from 13 randomly selected transplanted goats were collected. FACS analyses showed the presence of human cells in all the transplanted goats tested. The average proportion of CD34+ cells and GPA+(glycophorin A) cells in the peripheral blood were 1.34 +/- 1.10% and 2.80 +/- 2.10%, respectively. No CD34+ or GPA+ cells were found in the non-transplanted goats tested. The results of the quantitative real-time PCR in three engraftment goats were 1.2 x 10(4), 2.9 x 10(4), and 3.2 x 10(4) copies of human GPA DNA per mug of genomic DNA. FISH experiments showed that cells containing human specific alpha-satellite DNA sequence were present in the peripheral blood of the transplanted goats.

CONCLUSIONS

The method described herein is safe and reliable, with low miscarriage risk and high chimerism rate. This approach may provide a promising animal model for potential prenatal treatment.

Differences in the incidence of apoptosis between in vivo and in vitro produced blastocysts of farm animal species: a comparative study

The occurrence of pregnancies and births after embryo transfer (ET) of in vivo produced embryos is generally more successful compared to that of embryos produced in vitro. This difference in ET success has been observed when embryos of morphological equal (high) quality were used. The incidence of apoptosis has been suggested as an additional criterion to morphological embryo evaluation in order to assess embryo quality and effectively predict embryo viability. In this study, equine, porcine, ovine, caprine and bovine in vivo and in vitro produced morphologically selected high quality (grade-I) blastocysts were compared for the occurrence of apoptosis in blastomeres. The total number of cells per embryo and the number of cells with damaged plasma membranes, fragmented DNA and fragmented nuclei per embryo were assessed in selected blastocysts by combining Ethidium homodimer (EthD-1), terminal dUTP nick end labeling (TUNEL) and Hoechst 33342 staining. In general, the level of blastomere apoptosis was low. A higher level of apoptosis was observed in in vitro produced equine, porcine and bovine blastocysts compared to their in vivo counterparts. Interestingly, 4 of the initially selected 29 bovine in vitro produced blastocysts exhibited extensive signs of apoptosis affecting the inner cell mass (ICM), which is not compatible with a viable conceptus. Repeated occurrence of this observation may explain the lower ET outcome of in vitro produced bovine embryos compared to in vivo produced embryos. It is concluded that, although in morphologically high quality blastocysts of several farm animal species a significant difference exists in the percentages of apoptotic cells between in vivo and in vitro produced embryos, the incidence of apoptosis at the blastocyst stage is at such a low level that it cannot reflect the substantial differences in embryo viability that have been described between in vivo and in vitro produced blastocysts following ET.

Effect of serum concentration, method of trypsinization and fusion/activation utilizing transfected fetal cells to generate transgenic dairy goats by somatic cell nuclear transfer

This work was performed within a commercial nuclear transfer program to investigate different methods for synchronizing donor cell cycle stage, for harvesting donor cells, and for fusion and activation of reconstructed caprine embryos. Primary fetal cells isolated from day 35 to day 40 fetuses were co-transfected with DNA fragments encoding both the heavy and light immunoglobulin chains of three different monoclonal antibodies and neomycin resistance. Four neomycin resistant cell lines for each antibody were selected, expanded, and aliquots were both cryopreserved for later use as karyoplast donors or used for further genetic characterization. Transfected fetal cells were cultured in 0.5% FBS to synchronize G0/G1 cell cycle stage cells, then re-fed with 10% FBS prior to use to allow donor cells to re-enter the cell cycle. Alternatively, transfected fetal cells were grown to confluence in 10% FBS to induce contact inhibition to synchronize G0/G1 cell cycle stage cells. Adherent monolayers of transfected fetal donor cells were harvested by either partial or complete trypsinization. Donor cells were simultaneously fused and activated with enulceated in vivo produced ovulated oocytes from superovulated does. Half of the fused couplets received an additional electrical activation pulse and non-fused couplets were re-fused. Four live offspring were produced from 587 embryos generated from cell lines cultured in 0.5% FBS, while one live offspring was produced from 315 embryos generated from cell lines cultured in 10% FBS (0.7% versus 0.3% embryos transferred, respectively, P > 0.05). Five offspring were produced from 633 embryos generated from cell lines harvested by partial trypsinization (0.8% embryos transferred), and no offspring were produced from 269 embryos generated from cell lines harvested by complete trypsinization. Four live offspring were produced from 447 embryos generated from re-fused couplets, and one live offspring was produced from 230 embryos generated from fused couplets that received an additional electrical activation pulse (0.9% versus 0.4% embryos transferred, respectively, P > 0.05). These results suggest that low-serum culture of transfected goat fetal cells and harvest by partial trypsinization may be more efficient methods for generating transgenic goats by somatic cell nuclear transfer. In addition, re-fusion of non-fused couplet or an additional activation step was successful for producing live offspring.

Positional cloning of the PIS mutation in goats and its impact on understanding mammalian sex-differentiation

In goats, the PIS (polled intersex syndrome) mutation is responsible for both the absence of horns in males and females and sex-reversal affecting exclusively XX individuals. The mode of inheritance is dominant for the polled trait and recessive for sex-reversal. In XX PIS-/- mutants, the expression of testis-specific genes is observed very precociously during gonad development. Nevertheless, a delay of 4-5 days is observed in comparison with normal testis differentiation in XY males. By positional cloning, we demonstrate that the PIS mutation is an 11.7-kb regulatory-deletion affecting the expression of two genes, PISRT1 and FOXL2 which could act synergistically to promote ovarian differentiation. The transcriptional extinction of these two genes leads, very early, to testis-formation in XX homozygous PIS-/- mutants. According to their expression profiles and bibliographic data, we propose that FOXL2 may be an ovary-differentiating gene, and the non-coding RNA PISRT1, an anti-testis factor repressing SOX9, a key regulator of testis differentiation. Under this hypothesis, SRY, the testis-determining factor would inhibit these two genes in the gonads of XY males, to ensure testis differentiation.

Viable transgenic goats derived from skin cells

The current study was undertaken to evaluate the possibility of expanding transgenic goat herds by means of somatic cell nuclear transfer (NT) using transgenic goat cells as nucleus donors. Skin cells from adult, transgenic goats were first synchronized at quiescent stage (G0) by serum starvation and then induced to exit G0 and proceed into G1. Oocytes collected from superovulated donors were enucleated, karyoplast-cytoplast couplets were constructed, and then fused and activated simultaneously by a single electrical pulse. Fused couplets were either co-cultured with oviductal cells in TCM-199 medium (in vitro culture) or transferred to intermediate recipient goat oviducts (in vivo culture) until final transfer. The resulting morulae and blastocysts were transferred to the final recipients. Pregnancies were confirmed by ultrasonography 25-30 days after embryo transfer. In vitro cultured NT embryos developed to morulae and blastocyst stages but did not produce any pregnancies while 30% (6/20) of the in vivo derived morulae and blastocysts produced pregnancies. Two of these pregnancies were resorbed early in gestation. Of the four recipients that maintained pregnancies to term, two delivered dead fetuses 2-3 days after their due dates, and two recipients gave birth to healthy kids at term. Fluorescence in situ hybridization (FISH) analysis confirmed that both kids were transgenic and had integration sites consistent with those observed in the adult cell line.

Cysteamine, glutathione and ionomycin treatments improve in vitro fertilization of prepubertal goat oocytes

The aim of this study was to improve in vitro embryo development of prepubertal goat oocytes by studying the effect of adding cysteamine to in vitro maturation medium, glutathione (GSH) to in vitro fertilization medium and ionomycin to the sperm capacitation medium. In experiment 1, we analysed the effect of 1 mM GSH added to fertilization medium of oocytes matured with 400 μM cysteamine. The control group were oocytes without cysteamine and GSH. In experiment 2, oocytes matured and fertilized in the presence of 400 μM cysteamine and 1 mM GSH, respectively, were inseminated with spermatozoa treated with ionomycin or heparin. In experiment 1, the percentages of total and normal fertilized oocytes were significantly higher for oocytes supplemented with cysteamine and GSH (40.26% and 30.20%, respectively) than for oocytes from the control group (16.66%, and 10.61%, respectively). The percentage of total embryos obtained after 7 days of culture was significantly higher in the group supplemented with cysteamine and GSH (30.62%) than in the control group (8.09%) . In experiment 2, percentages of total and normal fertilized oocytes were significantly higher for the group of spermatozoa capacitated with ionomycin (52.21% and 37.17%, respectively) than with heparin (38.62% and 28.35%, respectively). After 7 days of culture, total embryo rate was significantly higher in the group of sperm capacitated with ionomycin (44.91%) than with heparin (38.69%) . However, the percentage of embryos developed to the blastocyst stage was not affected by any of the treatments studied.