• Asian-Australasian Journal of Animal Sciences
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• v.13 no.3
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• pp.292-299
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• 2000

Forty-four Javanese thin-tail ewes were used to study the effect of superovulation prior to mating and of ration quality on lamb birth weight at parturition. Twenty-two ewes weaning at least one lamb were used to measure lamb preweaning growth. Prior to mating, the experimental ewes were injected twice with prostaglandin, with an 11 d interval between injections to synchronize the estrous cycle. At the last prostaglandin injection, 24 ewes were also injected with 700 IU of pregnant mare serum gonadotropin (PMSG) to stimulate superovulation and the remainder were injected with saline as control. During pregnancy and lactation, the experimental ewes were fed either on a low (12% CP and 65% TDN) or a high (15% CP and 75% TDN) quality ration. During lactation, the milk was collected twice a day and was refed to the lambs by bottle feeding immediately after collection. Superovulation or ration quality as a main factor did not significantly affect lamb birth weight. Litter size significantly affected lamb birth weight (p<0.05), and there was an interaction of superovulation and litter size. Nonsuperovulated ewes giving birth to multiple lambs had significantly lower average lamb birth weight (1.34 kg) as compared to those giving birth to a single lamb (1.97 kg) (p<0.05). However, superovulated ewes giving birth to multiple lambs had no significant difference in average lamb birth weight (1.68 kg) as compared to those giving birth to a single lamb (1.91 kg) (p>0.05). Superovulation of ewes prior to mating resulted in a significant improvement in lamb birth weight in the multiple litter size, without significant effect on average preweaning daily gain (p=0.07). Superovulation had a promising use in improving animal production through improvement of prenatal growth during pregnancy and milk production during lactation.

• Korean Journal of Animal Reproduction
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• v.10 no.1
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• pp.58-65
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• 1986

The results from a survery on the reproduction of a, pp.oximately 500 dairy cows raised in four different farming areas including Cheju city, Jochun, Hallim and Sung-up are summarized as follows; 1. At the occurrence of first estrus, the average age of the heifers was 15.1 months (330 Kg/B.W.), and at first conception 18.0 months (354Kg/B.W.). There was no regional differences. 2. The average interval of the estrous cycle was 20.4 days. And the repetition of esturs after unsuccessful insemination occurred on an average of 1.6 times, especially 2.0 times in the herds of the Jochun district. 3. The ages at the first calving were similar to the data recorded for the domestic mainland's herds at 27.1 months. But some regional differences were recognized within the four districts: i.e. 28.6 (Cheju city), 27.4(Jochun), 27.1(Hallim) and 25.3 months (Sung-up). There was no significant differences in sex ratio of newborns at 50.4%(♂) and 49.6%(♀). 4. The intervals of esturs recurrence and the following conception after calving were 80.0 and 95.8 days respectively. In the followsing conception intervals after cavling, 90.6-97.4 days were average for the herds of Cheju city and Jochun districts, 62.4-69.7 days for those of Hallim and Sung-up districts. 5. The average gestation period was 279.8 days, and was almost identical in the four districts. 6. The calving intervals was 377.7 days in average, and it was shorter than the data recorded for the domestic mainland's herds. Also it was reduce gradually according to the calving frequency.

• Reproductive and Developmental Biology
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• v.42 no.2
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• pp.7-12
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• 2018

In this review, we have tried to summarize the evidence and molecular characterization indicating that $20{\alpha}$-hydroxysteroid dehydrogenase ($20{\alpha}$-HSD) is a group of the aldo-keto reductase (AKR) family, and it plays roles in the modulation and regulation of steroid hormones. This enzyme plays a critical role in the regulation of luteal function in female mammals. We have studied the molecular expression and regulation of $20{\alpha}$-HSD in cows, pigs, deer, and monkeys. The specific antibody against bovine $20{\alpha}$-HSD was generated in a rabbit immunized with the purified recombinant protein. The mRNA expression levels increased gradually throughout the estrous cycle, the highest being in the corpus luteum (CL) 1 stage. The mRNA was also specifically detected in the placental and ovarian tissues during pregnancy. The $20{\alpha}$-HSD protein was intensively localized in the large luteal cells and placental cytotrophoblast villus, glandular epithelial cells of the endometrium, syncytiotrophoblast of the placenta, the isthmus cells of the oviduct, and the basal part of the primary chorionic villi and chorionic stem villus of the placenta and large luteal cells of the CL in many mammalian species. Further studies are needed to determine the functional significance of the $20{\alpha}$-HSD molecule during ovulation, pregnancy, and parturition. This article will review how fundamental information of these enzymes can be exploited for a better understanding of the reproductive organs during ovulation and pregnancy.

• Biomedical Science Letters
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• v.25 no.1
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• pp.107-112
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• 2019

The corpus luteum (CL) is composed to various cells, such as luteal steroidogenic cells (LSCs), luteal thecal steroidogenic cells (LTCs), luteal endothelial cells (LECs), fibroblast, immune cells and blood cells. The life span of CL is controlled by proliferation and apoptosis of luteal cells. Therefore, this study investigated apoptotic factors in luteal cells derived from bovine CL. The CL tissues were collected from bovine ovaries and luteal cells were isolated from middle phase CL. Then, LTCs and LECs were separated according to cellular morphology from LSCs. The expression of Bax, Bcl-2, Fas and tumor necrosis factor 1 receptor (TNF1R) mRNA and protein were analyzed using quantitative RT-PCR and western blot. Results show that, Bax and TNFR1 mRNA expression were significantly increased at late group than early and middle groups, otherwise Bcl-2 were significantly decreased at late group than early group (P<0.05). Fas mRNA expression were significantly decreased in middle group compared to early and late groups (P<0.05). In addition, Bax and Bcl-2 mRNA in LTCs was lower than LSCs, Fas mRNA was higher than LSCs. The Bcl-2 protein expression was lower at LTCs than LSCs, especially Fas protein in LTCs was significantly lower than LSCs and LECs (P<0.05). Otherwise, TNFR1 protein of LTCs were similar with LSCs but higher compared with LECs. In conclusion, we suggest that the results may help understanding of apoptosis ability in luteal cells according to cell type during CL regression of estrous cycle.

• Animal Bioscience
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• v.37 no.8
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• pp.1377-1386
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• 2024

Objective: Embryonic interferon-tau (IFNT) and progesterone affect expression of interferon-stimulated genes (ISGs), progesterone receptor (PGR) and progesterone-induced blocking factor (PIBF) in the ovine thyroid. Methods: Thyroids of ewes were sampled at day 16 of nonpregnancy, days 13, 16, and 25 of pregnancy, and real-time quantitative polymerase chain reaction assay, western blot and immunohistochemistry were used to detect expression of ISGs, PGR, and PIBF. Results: Free ISG15 protein was undetected, but ISG15 conjugated proteins upregulated at day 16 of pregnancy, and expression levels of ISG15 conjugated proteins, PGR isoform (70 kDa), PIBF, interferon-gamma-inducible protein 10 and myxovirusresistance protein 1 peaked, but expression level of signal transducer and activator of transcription 1 was the lowest at day 16 of pregnancy. In addition, the expression levels of PGR isoform (70 kDa) and signal transducer and activator of transcription 1 (STAT1) decreased, but levels of PGR isoform (43 kDa), 2',5'-oligoadenylate synthetase, IP-10 and MX1 increased at day 25 of pregnancy comparing with day 16 of the estrous cycle. Conclusion: Early pregnancy affects expression of ISGs, PGR, and PIBF in maternal thyroid through IFNT and progesterone, which may regulate thyroid autoimmunity and thyroid hormone secretion in ewes.

• Current Research on Agriculture and Life Sciences
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• v.6
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• pp.181-186
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• 1988

This experiment was conducted to examine the $PGF{2{\alpha}}$-induced changes in concentrations of ovarian and pituitary hormones of Korean native goats. Each goats received two injections of $PGF{2{\alpha}}$ (5mg each ; 3 hours apart) on day 10 of the estrous cycle. Jugular venous blood samples were collected at 0, 3, 6, 12, 24, 48 and 72 hours postinjection for quantification of LH, FSH, prolactin, progesterone and estradiol-$17{\beta}$. The results were summarized as follows ; The blood serum concentration of progesterone was decreased from pretreatment level of $4.15{\pm}1.8ng/ml$ to $2.52{\pm}1.2ng/ml$ (about 60%) within 3 hours and to $0.81{\pm}0.3ng/ml$ at 12 hours of the $PGF{2{\alpha}}$ injection. After 12 hours, the concentrations of progesterone were less than 1.02ng/ml by 72 hours postinjection. The concentrations of estradiol-$17{\beta}$ following treatment increased (p < 0.05) over the 72 hours. Initial concentration of LH was $3.0{\pm}0.3{\mu}IU/ml$. After treatment with $PGF{2{\alpha}}$, concentrations of LH increased within 12 hours but declined 12 and 72 hours from $4.1{\mu}IU/ml$ to $2.5{\mu}IU/ml$. Prior to administration of $PGF{2{\alpha}}$, mean concentration of FSH was $3.5{\pm}0.5{\mu}IU/ml$. Concentrations of FSH declined over time in goats treated with $PGF{2{\alpha}}$ on day 10 postestrus. The mean prolactin concentrations in the blood serum after $PGF{2{\alpha}}$ treatment were not significantly different from those of the pretreatment. It is concluded that the initial increase in LH is dependent on a decrease in serum progesterone and differences in patterns of secretion of gonadotropins might be caused by differences in progesterone or progesterone-estradiol ratio when luteal regression is induced on day 10 of the estrous cycle.

• Journal of Embryo Transfer
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• v.21 no.3
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• pp.207-216
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• 2006

Vaginal cytology was examined in 12 Shih-tzu bitches to establish the accurate basic data for estimate to the optimal mating time and ovulation time. The mean duration of proestrus and estrus were $9.09{\pm}0.83\;(mean{\pm}SD)$ days and $7.36{\pm}0.47$ days in pregnant bitches. The gestational length in the 12 pregnant bitches was $65.2{\pm}0.5$ days in pregnant bitches when Day 0 was timed from the first day of male acceptance. Characteristic features of vaginal cytology during the estrous cycle were the high proportion of large intermediate cell, superficial cell, anuclear cell and erythrocyte in proestrus, superficial cell, anuclear cell and erythrocyte in estrus, and parabasal cell, small and large intermediate cell and leukocyte in diestrus, respectively. Cornification index (CI) was the high proportion in proestrus and estrus, then it decreased in diestrus and anestrus. When Day 0 was timed from the day of the first male acceptance, the CI peak was Day 2 and maintained above 80% between Day -4 and Day 6 during 11 days, and above 90% between Day -1 and Day 5 during 7 days. In relationship between CI and reproductive hormones, CI showed peak at the first day after plasma estradiol-$17{\beta}$ concentration peak and plasma progesterone concentration was first increased above 4.0 ng/ml at Day 0 which was the first day after CI peak. In conclusion, ovulation in Shih-tzu bitches occurred at the first day after CI peak. Vaginal cytology is the simple and reliable method for estimating estrous cycle, optimal breeding time and ovulation time in Shih-tzu bitches.

• Journal of Embryo Transfer
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• v.21 no.2
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• pp.147-156
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• 2006

The objective of this study was to supply excellent genetic resources to livestock farms by transferring embryos produced by genetically superior Korean cows (Hanwoo). Eighty Hanwoo donors were superovulated with gonadotropin ($Folltrpin^(R)\;or\;Antorin^(R)$) for 4 days combined with or without progesterone releasing intravaginal device (CIDR) insertion. The collected fresh or frozen-thawed embryos were transferred to 226 farm recipients. In this study, the effect of CIDR insertion in combination with gonadotropin ($Folltrpin^(R)$) treatments initiated at the random stage of estrous cycle on embryo production was evaluated and compared to conventional superovulation protocol. Moreover, the effect of gonadotropin ($Antorin^(R)$) dose in CIDR-treated Hanwoo donors on the embryo yield was determined. In addition, the effects of embryos (fresh vs. frozen-thawed), embryo transfer person, seasons and farms on the pregnancy rate were evaluated. In Hanwoo donors, CIDR insertion in combination with $Folltrpin^(R)$ treatments regardless of estrous detection resulted in increased numbers of total ova (6.5 vs. 5.8) and transferable embryos (3.9 vs. 3.2) compared to the conventional superovulation protocol (p<0.01). In CIDR-treated Hanwoo donors, the higher dose of $Antorin^(R)$ (36 vs. 28 mg) resulted in the increased number of transferable embryos (8.3 vs. 5.4, p<0.05). The embryos (fresh 43.9% vs. frozen-thawed 23.1%) and embryo transfer person (53.9 vs. $0{\sim}16.7%$) significantly affected the pregnancy rate after embryo transfer (p<0.01). These results suggest that CIDR-based superovulation protocol may be effectively used for production of superior Hanwoo embryos and, multiple ovulation and embryo transfer in Hanwoo might be effectively applied for livestock improvement if pregmancy rate with frozen-thawed embryos and embryo transfer skill would be improved.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.18 no.3
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• pp.224-238
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• 2008

The aim of this study is to confirm the physicochemical property and hazard of thinner (012), which is a diluent of enamel paint used for floor coating for waterproofing and oil painting for the outer wall. The literatures of physicochemical property and hazard of thinner were surveyed and its physicochemical property were evaluated. And then, the inhalation toxicity of thinner affecting the central nervous system and reproductive organs in rats were examined by subchronic (6 h./day. 5 days/ week for 13 weeks) inhalation test. 1) According to the 13-week subchronic inhalation test, there were no significant changes in clinical test and body weight. However, a significant evidence of toxicity was observed in the hematological test and organ weight such as heart, kidney, liver and brain (p<0.01) in the 200 ppm and 1,000 ppm exposure groups in a dose response manner. In the histopathology analysis, there were no significant evidence of toxicity. Therefore, thinner was not classified as an organ targeted toxic agent. In case of Harmfulness, it could be classified as a chronic toxic agent 3($500 ppm/4hr, rat). 2) The reproductive toxicity such as extension of the period of estrous cycle, reduction of serum estradiol concentration and increase of frequency of the abnormal sperm was observed in the 1,000 ppm exposed animals. 3) The result of the physicochemical property of the test material showed that the specific gravity was 0.793, boiling point $155.8^{\circ}C$, steam pressure 2.1 kPa, ignition point $34.5^{\circ}C$, and spontaneous ignition point $280^{\circ}C$. The endothermic and exothermic values were 371.4 J/g and 159.1 J/g. respectively. The explosion limit was 214 mg/l. These data showed that thinner could be classified as an explosion agent level 1.2 and ignitive liquid agent 3 ($23-60^{\circ}C$) according to the notification No. 2008-1 of the Labor Ministry, "Classifying Standard of Chemical Materials."

• Development and Reproduction
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• v.4 no.1
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• pp.45-52
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• 2000

Membrane type matrix metalloproteinases(MT-MMPs) have been suggested to play an important role during structural remodeling of various tissue. Expression patterns of MT1-MMP and MT2-MMP mRNAs were investigated in oocytes, embryos, ovary and oviduct of mouse during their differentiation or periovulatory period using RT-PCR technique. Both cDNA products of MT1- and MT2-MMP of immature oocytes were barely discernable with a minimum amount but the expressions were distinct in mature oocytes regardless that they were matured in vivo or in vitro. MT2-MMP was not expressed by 2-cell embryos but was expressed by 4-cell stage embryos. From the morula stage untill hatched blastocyst stage, embyos showed intesnse expression of MT2-MMP with a sudden increase at blastocyst stage. While mouse ovarian tissues showed both expression of MT1- and MT2-MMP, there was no stage-specific difference throughout the estrous cycle. Mouse oviducts also exhibit constant amount of both MT1- and MT2-MMP expressions throughout periovulatory period, i.e., before or after ovulation. These observations lead to suggest that the differential expressions of maternal MT1- and MT2-MMP during meiotic resumption of mouse oocytes and embryonic expression of MT2-MMP particularly at blastocyst stage might play a role in the differentiation of mouse oocytes and／or embryos. The precise function of MT1- and MT2-MMP with regards to their participation in the remodeling of ovarian and oviductal tissues remains in a question.