ABSTRACT. This study was conducted to compare the developmental competence of somatic nuclear transfer (NT) embryos, after either ionomycin or ethanol activation, in locally bred goats. Donor cells were prepared from the ear skin fibroblasts of a female goat. Cells, at passage 3-8, starved by culturing in 0.5% FCS for 4-8 d, were used for NT. Immature oocytes were obtained from FSH-stimulated goats and matured for 22 hr before enucleation and NT. After fusion, the reconstructed embryos were activated with either ionomycin or ethanol followed by culturing in 6-dimethylaminopurine (6-DMAP) and cytochalasin B (CB), for 3 hr. In experiment I, the fuse d NT embryos (n=63, ionomycin and n=68, ethanol treatments, respectively) were cultured in B 2 with a Vero co-culture system and their developmental competence was evaluated through to Day 9. In experiment II, the NT embryos at the 2-4 cell stage on Day 2 derived from each treatment (ionomycin n=46, and ethanol n=37), were transferred into 10 synchronous recipients. There were no significant differences between the NT embryos derived from the ionomycin and ethanol groups, in fusion (86.3% versus 82.9%), cleavage (90.5% versus 82.4%) and for morula/blastocyst development rates (9.5% versus 5.9%). Sixty percent (3/5) of the recipients from ionomycin became pregnant by midterm (2.5 mts) while only 20% (1/5) from ethanol treatment was pregnant by Day 45. The results demonstrate that activation with either ionomycin or ethanol in combination with 6-DMAP-CB treatment does not affect the development of cloned goat embryos. KEY WORDS: activation, developmental competence, goat, nuclear transfer.J. Vet. Med. Sci. 66(12): 1529-1534, 2004 Since the cloned sheep named "Dolly", was produced by transferring nuclei from adult cells into enucleated oocytes [27], there have been many studies carried out to produce other cloned mammals such as mice, cattle, goats, pigs and rabbits [1,5,19,25,26]. The nuclear transfer (NT) technique has been efficiently used for producing transgenic, cloned farm animal offspring. These animals are capable of producing valuable proteins, which could have a marked impact on the pharmaceutical industry [22] [1,4,6,11,32]. There are a few reports on the development of goat oocytes after parthenogenetic activation by treatment with ionomycin and ethanol, both followed by exposure to 6-diethylaminopurine (6-DMAP) [17,18]. Nevertheless, comparison of the development of NT goat embryos with either ionomycin or ethanol, as an activating agent, has not been reported. The objective of this study was to compare the developmental competence in vitro and in vivo of NT goat embryos, after activation, by using either ionomycin or ethanol, both followed by incubation in 6-DMAP-cytochalasin B (CB). MATERIALS AND METHODSUnless otherwise indicated, all chemicals used in this study were obtained from Sigma-Aldrich Company (St. Louis, MO) and the media from Gibco Invitrogen Corporation (Grand Island, NY).Preparation of donor cells: Donor cells were prepared from an ear skin f...

The artificial insemination play an important role in the genetic improvement in goat farming system. The aim of this study was to investigate the effect of cervical application of Hyaluronan (HA) on the fertility in goats after cervical artificial insemination (CAI) using frozen-thawed (F-T semen). Methods: After oestrous synchronisation with progesterone sponges and pregnant mare serum gonadotropin (PMSG) injection, both nulli-and multi-parous goats, were randomly allocated to 2 groups, and were inseminated with 0.25 ml of F-T semen (150 x 10 6 spermatozoa) twice at 52 h and 56 h after sponge removal. Prior to the insemination, goats in Group 1 only were given topical cervical HA application at 48 h after sponge removal. Site of insemination was recorded as os-cervix or intra-cervix or intra-uterus. Pregnancy was tested ultrasonographically 42 days after insemination. The data on pregnancy rates and percentage of animals according to the site of semen deposition were compared by Chi-square analysis. Results: The overall pregnancy rate was significantly (p<0.004) higher in goats with prior application to the cervix with HA (63.3%) than without (36.0%). Same pattern was observed in the pregnancy rates of nulli-and multi-parous goats in both the groups. Percentage of nulliparous goats according to the site of insemination in the HA group did not differ between first and the second insemination. However, in multiparous goats the percentage of animals inseminated intra-cervically was significantly increased (p≤ 0.05) between the first and the second inseminations. Conclusion: The results suggest that significantly higher fertility rate in the "HA goats" compared to the "without HA" group was because of deeper insemination facilitated by topical cervical application of HA. The deeper insemination into the cervical canal increase the rate of fertilisation when the cervical artificially insemination is performed.

The objective of this study was to compare the development to the morula and blastocyst stages, after either cycloheximide (CHX) or ethanol (ETOH) activation, in somatic nuclear transfer (NT) goat embryos derived from 2 sources of oocytes. In vivo- and in vitro-matured oocytes were obtained from FSH-stimulated goats (Native, Saanen, and Native-Saanen crossbred goats). Gonadotropin treatment was performed with a modified program of a previous report (Reggio et al. 2001 Biol. Reprod. 64, 849-856). In vivo-matured oocytes were flushed from the oviduct of donor goats by exposing the reproductive tract via a small ventral laparotomy incision. In vitro-matured oocytes were aspirated and cultured in maturation medium (M199 + 10% FCS, 10 �g mL-1 FSH, 10 �g mL-1 LH, and 1 �g mL-1 17�-estradiol) for 22 h, at 38.5�C in 5% CO2 and air. Donor cells were prepared from ear skin fibroblasts of a female goat (Native breed). Cells, at passage 3-9, starved by culturing in 0.5% FCS for 4-8 days, were used for NT. Matured oocytes were enucleated, and cell-cytoplast couplets (n = 162 in vivo-, and n = 190 in vitro-matured oocyte groups, respectively) were fused by applying 2 DC pulses of 2.2 kV cm-1 for 30 �s. One to 2 h after fusion, fused embryos were either incubated in 10 �g mL-1 cycloheximide plus 5 �g mL-1 cytochalasin B for 5 h (CHX treatment) or in 7% ethanol for 5 min followed by a 4-h incubation in 2 mM 6-dimethylaminopurine plus 5 �g mL-1 cytochalasin B (ETOH treatment). NT embryos were then cultured in B2 medium supplemented with 5% FCS and Vero cells for 9 days. At the end of the culture period, the NT embryos were fixed and stained with Hoechst 33342 (Begin et al. 2003 Theriogenology 59, 1839-1850). The numbers of nuclei were counted under ultraviolet light. Fusion, cleavage, and development rates were compared using chi-square test or Fisher&apos;s exact test. For the in vivo-matured oocyte group, there were no significant differences in fusion rates (78.1% vs. 68.7%), cleavage rates (87.7% vs. 87.0%, based on the numbers of embryos fused) between the CHX and ETOH treatment groups, respectively (P &gt; 0.05). However, the development rates to morula and blastocyst stages of NT embryos derived from either in vivo- or in vitro-matured oocytes were significantly higher in the ETOH group than in the CHX group (in vivo: 15.2% vs. 0%, and in vitro: 7.1% vs. 0%, for ETOH and CHX groups, respectively; P &lt; 0.05). For the in vitro-matured oocyte group, no significant differences were found between the CHX and ETOH groups in fusion rates (78.6% vs. 83.6%; P &gt; 0.05), cleavage rates (80.5% vs. 83.9%: P &gt; 0.05, based on the numbers of embryos fused). NT embryos from the CHX treatment group derived from in vivo- or in vitro-matured oocytes did not develop beyond the 16-cell stage. These results demonstrate that activation with CHX plus cytochalasin B treatment affects the development to the blastocyst stage of cloned goat embryos whether derived from in vivo- or in vitro-matured oocytes. This work was supported by the RGJ PhD program, Thailand Research Fund, and the Bureau of Biotechnology in Animal Production, Department of Livestock Development.