• Asian-Australasian Journal of Animal Sciences
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• v.17 no.12
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• pp.1652-1656
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• 2004

The aim of this study was to obtain mature ova or embryos at a single cell stage, which can be used in avian transgenesis and nuclear transfer through multiple ovulations, in vitro fertilization and culture. Chicken anterior pituitary extract (CAPE) or acetone-dried chicken anterior pituitary extract (ACAPE) was used to induce multiple ovulations in hens pretreated with pregnant mare' serum gonadotrophin (PMSG). In vitro fertilization of the multiple ovulated ova was performed by inseminating sperm onto the germinal disks in m-Ringer' solution and incubating the ova at 41$^{\circ}C$, 5% $CO_2$ for 10 h in DME-F12 medium containing 20% liquid albumen. The in vitro fertilization process was observed using an environmental scanning electron microscope. When normal laying hens (white Leghorn) were administered daily with PMSG (100 IU), egg laying ceased in most hens within 3 to 8 days. Ovulation began to occur about 7.5 h after injection of CAPE and ACAPE. The number of ovulated ova was 1.00${\pm}$0.00, 2.33${\pm}$0.52 and 2.20${\pm}$0.45, respectively, after receiving 100, 200 and 300 mg CAPE. The number of ovulated ova was 2.00${\pm}$0.00, 2.86${\pm}$0.69 and 3.00${\pm}$1.22, respectively, after receiving 10, 15 and 20 mg ACAPE. The fertilized and cultured ova were able to develop into embryos up to the 32 cell stage. The present experiments demonstrated that multiple ovulations can be induced by CAPE and ACAPE successfully, and the ova resulted from the treatment retained the capability for further fertilization and embryonic development. These data provide new information to support the establishment of an in vitro culture system for future avian transgenesis studies.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.spc1
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• pp.198-202
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• 2006

We investigated the fecundity, egg size, reproductive output, and breeding frequency and season of Neocaridina denticulata denticulata and Latreutes planirostris which inhabit extremely different habitats. The marine shrimp Latreutes planirostris produced more eggs had at a given carapace length than the freshwater shrimp N. d. denticulata. However, N. d. denticulata had a larger egg volume and greater reproductive output than L. planirostris. The monthly gonadosomatic index (GSI) of the freshwater shrimp began to increase in April and reached a maximum in May, suggesting a single breeding period. In contrast, the GSI of the marine shrimp exhibited two breeding peaks: May-June and September. In both shrimps, the regressions between carapace length and ovarian weight were significant at the non-eyed and eyed embryo stages. For both species, an analysis of covariance revealed significant difference between the two regressions in elevation, but not in slope. These results indicate the potential for multiple ovulations within the reproductive season.

• Development and Reproduction
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• v.20 no.2
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• pp.91-99
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• 2016

Lipopolysaccharide (LPS), an endotoxin, elicits strong immune responses in mammals. Several lines of evidence demonstrate that LPS challenge profoundly affects female reproductive function. For example, LPS exposure affects steroidogenesis and folliculogenesis, resulting in delayed puberty onset. The present study was conducted to clarify the mechanism underlying the adverse effect of LPS on the delayed puberty in female rats. LPS was daily injected for 5 days ($50{\mu}g/kg$, PND 25-29) to treated animals and the date at VO was evaluated through daily visual examination. At PND 39, animals were sacrificed, and the tissues were immediately removed and weighed. Among the reproductive organs, the weights of the ovaries and oviduct from LPS-treated animals were significantly lower than those of control animals. There were no changes in the weights of uterus and vagina between the LPS-treated and their control animals. immunological challenge by LPS delayed VO. Multiple corpora lutea were found in the control ovaries, indicating ovulations were occurred. However, none of corpus luteum was present in the LPS-treated ovary. The transcription level of steroidogenic acute regulatory protein (StAR), CYP11A1, CYP17A1 and CYP19 were significantly increased by LPS treatment. On the other hand, the levels of $3{\beta}$-HSD, $17{\beta}$-HSD and LH receptor were not changed by LPS challenge. In conclusion, the present study demonstrated that the repeated LPS exposure during the prepubertal period could induce multiple alterations in the steroidogenic machinery in ovary, and in turn, delayed puberty onset. The prepubertal LPS challenge model used in our study is useful to understand the reciprocal regulation of immune (stress) - reproductive function in early life.

• Clinical and Experimental Reproductive Medicine
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• v.12 no.2
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• pp.71-79
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• 1985

Systemic extrogen therapy promotes multiple preantral follicular development in immature mice. Estrogen pretreated ovaries might therefore be a useful source of cells for in vitro studies of oocytes maturation. Silastic capsules (5.0 mm length; 3.18 mm outer diameter, 1.57 mm inner diameter) filled with diethylstilbesterol were implanted subcutaneously in experimental mice (ICR) for up to 6 days. Ovarian weight and histology in diethylstilbesterol pretreated and control animal were assessed before and after pregnant mare serum gonadotrophin treatment and after human chorionic gonadotrophin. The following results were obtained; 1. Ovarian weight was significantly increased by 6 days of diethylstilbesterol pretreatment. Subsequent ovarian weight gain in response to pregnant mare serum gonadotrophin and human chorionic gonadotrophin was increased. 2. Diethylstilnbesterol pretreatment stimulated the developed healthy preantral follicles. 3. Forty eight hours after pregnant mare serum gonadotrophin treatment, a larger number of the antral follicles which developed in diethylstilbesterol pretreated animals showed signs of atresia, whereas in the control ovaries there was a higher incidence of premature luteinization. 4. Forty eight hours after human chorionic gonadotrophin, numerous corpora lutea and occasional luteinized unruptured follicles were present in both control and diethylstilbesterol ovaries. 5. Ovulation rate, fertilization rate and subsequent preimplantation development in vitro were not adversely affected by diethylstilbesterol pretreatment. However, there was considerable variation in the ovulation rate the number of animals with more than 60 ovulations was greater in the diethylstilbesterol gorup (52.4%) as compared to the control (33.3%).

• Korean Journal of Veterinary Research
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• v.34 no.4
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• pp.881-890
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• 1994

Skim milk progesterone($P_4$) profiles in 74 dairy cows were determind to monitor postpartum ovarian activity by radioimmunoassay. Milk samples were collected from each cow every 5 days from 10 to 90 days postpartum. Signs of estrus were observed twice daily, and status of the ovaries and uterus were examined every 10 days by rectal palpation. Results are summarized as follows: 1. Cows were categorized into five types by the change of skim milk $P_4$ profiles; Type I(normal) : Cyclic changes of skim milk $P_4$ profiles appeared within 20 days postpartum(12 cows, 16.2%), Type II(cycle delayed) : Cyclic changes of skim milk $P_4$ profiles appeared from 21 to 60 days postpartum(39 cows, 52.7%), Type III(cycle ceased with low $P_4$) : Onset of the estrous cycle within 20 days postpartum but ceased later with low levels of $P_4$ (7cows, 9.5%), Type IV(cycle ceased with high $P_4$) : Onset of the estrous cycle within 20 days postpartum but ceased later with high levels(>3.0 ng/ml) of skim milk $P_4$ (4 cows, 5.4%), Type V(acyclicity) : Skim milk $P_4$ concentration remained low(<1.0 ng/ml) until 80 days postpartum(12 cows, 16.2%). 2. Out of the 17 cows classified as the Type III and Type V by skim milk $P_4$ profiles, 13 cows had inactive ovaries and remaining 6 cows had single or multiple follicular cysts in their ovaries by rectal palpation. All 4 cows of Type IV had a persistent corpus luteum in their ovaries. 3. Approximately eighty percent of the cows had begun ovarian activity by 60 days postpartum and 90.6% by 90 days by skim milk $P_4$ profiles, but only 39.2% by 60 days and 71.7% by 90 days had shown visible estrus signs. The mean days from parturition to the first, second and third ovulations determined by skim milk $P_4$ profiles was $28.0{\pm}11.0$, $46.4{\pm}13.3$ and $66.4{\pm}11.5$ days and the visible estrus signs were 9.3%, 38.1%, and 48.6%, respectively. The mean days from parturition to the first visible estrus was $57.2{\pm}15.9$ days. These results indicated that milk $P_4$ profile of each Types by radioimmunoassay can be utilized for monitoring postpartum ovarian and would be useful for the early detection of ovarian dysfunction in dairy cow.