• Korean Journal of Animal Reproduction
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• v.22 no.2
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• pp.119-126
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• 1998

This study was conducted to find out the recovery rate of oocyte according to the different size of follicles from porcine ovaries, and the effect of in vitro maturation of porcine immature oocyte at the different transportation temperature of ovaries from slaughter house. The results obtained were summarized as follows : 1. The number of follicles per ovary was 22.5. The number of A-and B-typed oocytes(type A: cumulus-enclosed oocyte, type-B : corona-enclosed oocyte) per ovary was 2.4. The proportion of A-and B-typed oocytes was 29.6% of the total recovery oocytes. 2. When the immature oocytes were cultured for 36, 40, 44 and 48 h at 5$^{\circ}C$ transportation temperature of ovary, the germinal vesicle breakdown(GVBD) rates of porcine oocytes were 32.5, 28.2, 22.6 and 25.9% respectively. There were no significant differences between all the culture time for GVBD. Especially, most of oocytes were observed to arrest the development beyond germinal vesicle(GV) stage. 3. When the immature oocytes were cultured for 36, 40, 44 and 48 h at $25^{\circ}C$ transportation temperature of ovary, the GVBD rates were 81.0, 90.0, 91.7 and 92.9%, and the maturation (Met-II) rates were 51.2, 78.8, 76.2 and 78.6%, respectively. 4. When the immature oocytes were cultured for 36, 40, 44 and 48 h at 38$^{\circ}C$ transportation temperature of ovary, the GVBD rates were 93.9, 96.5, 96.5 and 95.3%, and the maturation rates were 62.2, 88.4, 84.7 and 86.0%, respectively. 5. The above results showed that the maturation rates of immature oocytes between $25^{\circ}C$ and 38$^{\circ}C$ transportation temperature of ovary did not differ significantly.

• Korean Journal of Veterinary Research
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• v.49 no.3
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• pp.215-220
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• 2009

The prevalence of potentially xenozoonotic viruses in the reproductive tract of female pigs in Korea was investigated by polymerase chain reaction (PCR). These viruses include porcine endogenous retrovirus (PERV), porcine reproductive and respiratory syndrome virus (PRRSV), swine hepatitis E virus (SHEV), porcine lymphotropic herpesvirus (PLHV), and porcine circovirus type 2 (PCV-2). Histopathological examination and PCR analysis were conducted using the ovaries of 70 slaughtered pigs that were collected from 14 farms in Jeju. Histopathologically, infiltrations of mononuclear inflammatory cells around the thick-walled coiled vessels in the ovarian medulla were observed in 15 cases. Based on the PCR method, PERV, PLHV, PRRSV, SHEV, and PCV-2 were detected in 69 (98.6%), 35 (50%), 5 (7.1%), 4 (5.7%), and 1 sample (1.4%), respectively. These results suggest that PERV and PLHV are the major xenozoonotic viruses in the porcine ovary. This study should aid in the development of a monitoring protocol for potential xenozoonotic agents and in the production of germ-free pigs for xenotransplantation.

• Journal of Animal Reproduction and Biotechnology
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• v.37 no.2
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• pp.96-105
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• 2022

The ovary undergoes substantial physiological changes along with estrus phase to mediate negative/positive feedback to the upstream reproductive tissues and to play a role in producing a fertilizable oocyte in the developing follicles. However, the disorder of estrus cycle in female can lead to diseases, such as cystic ovary which is directly associated with decline of overall reproductive performance. In gene expression studies of ovaries, quantitative reverse transcription polymerase chain reaction (qPCR) assay has been widely applied. During this assay, although normalization of target genes against reference genes (RGs) has been indispensably conducted, the expression of RGs is also variable in each experimental condition which can result in false conclusion. Because the understanding for stable RG in porcine ovaries was still limited, we attempted to assess the stability of RGs from the pool of ten commonly used RGs (18S, B2M, PPIA, RPL4, SDHA, ACTB, GAPDH, HPRT1, YWHAZ, and TBP) in the porcine ovaries under different estrus phase (follicular and luteal phase) and cystic condition, using stable RG-finding programs (geNorm, Normfinder, and BestKeeper). The significant (p < 0.01) differences in Ct values of RGs in the porcine ovaries under different conditions were identified. In assessing the stability of RGs, three programs comprehensively agreed that TBP and YWHAZ were suitable RGs to study porcine ovaries under different conditions but ACTB and GAPDH were inappropriate RGs in this experimental condition. We hope that these results contribute to plan the experiment design in the field of reproductive physiology in pigs as reference data.

• Journal of Embryo Transfer
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• v.32 no.3
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• pp.105-109
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• 2017

Autophagy is an intracellular degradation and recycling system. Oocyte maturation is dynamic process, in which various proteins should be synthesized and degraded. In our previous study, we reported the loci of autophagosome and dynamics of autophagic activity in porcine oocytes during in vitro maturation. In this study, we verified loci of autophagosome in porcine follicular cumulus-oocyte complex by detection of microtubule-associated protein 1A/1B-light chain 3 (LC3) which is the reliable marker of autophagosome. Porcine ovary including various sizes of follicles was fixed within 1 hour after collection from slaughterhouse. After fixation, immunohistochemistry was conducted on sliced ovary tissue containing various sizes of follicles by using LC3 antibody. As a result, LC3 signal was clearly detected in both cumulus and oocytes of various sizes of follicles. We also found ring shaped signal which represent autophagosome near oocyte membrane. Most of the signals in oocytes were localized nearby cellular membrane while evenly dispersed in cumulus cells. Therefore, this result suggests that autophagy occurs in porcine COCs (cumulus-oocyte complexes) at follicular stage.

• The Korean Journal of Zoology
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• v.30 no.4
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• pp.351-370
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• 1987

This experiment has been done in order to study the correlation between the ultrastructure changes and the atresia phenomenon of the follicles in porcine ovary. The ovaries were assorted according to the presence or absence of corpus luteum. Thereafter, the follicles were classified into normal, pyknotic, necrotic and cystic groups by atretic characteristics on the histological observation, and then their ultrastructures were examined with an electron microscope. The results were as followings. 1. In normal group, granulosa cells represented the ultrastructural characteristics of protein-synthesizing cells. Since the initiation of atresia, the line structure of granulosa cells showed many of the characteristic features of steroid-secreting cells, followed by gradual pyknosis. 2. In necrotic group of the ovary without corpus luteum, the theca interns became hypertrophic and displayed the ultrastructural features of active steroidsecreting cells. But this phenomenon was not seen in the follicles of the ovary with corpus luteum. 3. Degenerative changes of cumulus cells were similar to those of granulosa cells, and the degenerating oocytes showed the degeneration of cellular organelles, cytoplasmic vacuolization and disappearance of microvilli on the surface. The degeneration of granulosa cells tended to procede that of oocytecumulus complex in the follicles of the ovary having no corpus luteum, but this tendency was reversed in the case of presence of corpus luteum. In conclusion, it may be unable to identi(y the initiation of follicular atresia

• Molecules and Cells
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• v.38 no.4
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• pp.304-311
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• 2015

Most follicles in the mammalian ovary undergo atresia. Granulosa cell apoptosis is a hallmark of follicle atresia. Our previous study using a microRNA (miRNA) microarray showed that the let-7 microRNA family was differentially expressed during follicular atresia. However, whether the let-7 miRNA family members are related to porcine (Sus scrofa) ovary follicular apoptosis is unclear. In the current study, real-time quantitative polymerase chain reaction showed that the expression levels of let-7 family members in follicles and granulosa cells were similar to our microarray data, in which miRNAs let-7a, let-7b, let-7c, and let-7i were significantly decreased in early atretic and progressively atretic porcine ovary follicles compared with healthy follicles, while let-7g was highly expressed during follicle atresia. Furthermore, flow cytometric analysis and Hoechst33342 staining demonstrated that let-7g increased the apoptotic rate of cultured granulosa cells. In addition, let-7 target genes were predicted and annotated by TargetScan, PicTar, gene ontology and Kyoto encyclopedia of genes and genomes pathways. Our data provide new insight into the association between the let-7 miRNA family in granulosa cell programmed death.

• Reproductive and Developmental Biology
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• v.34 no.4
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• pp.283-288
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• 2010

During normal early embryonic development in mammals, the global pattern of genomic DNA methylation undergoes marked. changes. The level of methylation is high in male and female gametes. Thus, we cloned the cDNA of the porcine DNA methyltransferase 1 (Dnmt1) gene to promote the efficiency of the generation of porcine clones. In this study, porcine Dnmt1 cDNA was sequenced, and Dnmt1 mRNA expression was detected by reverse transcription-polymerase reaction (RT-PCR) in porcine tissues during embryonic development. The porcine Dnmt1 cDNA sequence showed more homology with that of bovine than human, mouse, and rat. The complete sequence of porcine Dnmt1 cDNA was 4,774-bp long and consisted of an open reading frame encoding a protein of 1611 amino acids. The amino acid sequence of porcine DNMT1 showed significant homology with those of bovine (91%), human (88%), rat (76%), and mouse (75%) Dnmt1. The expression of porcine Dnmt1 mRNA was detected during porcine embryogenesis. The mRNA was detected at stages of porcine preimplantation development (1-cell, 2-cell, 4-cell, 8-cell, morula, and blastocyst stages). It was also abundantly expressed in tissues (lung, ovary, kidney and somatic cells). Further investigations are necessary to understand the complex links between methyltransferase 1 and the transcriptional activity in cloned porcine tissues.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.11
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• pp.1541-1546
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• 2011

This study was carried out to examine the influence of minimum essential medium (MEM) vitamins supplementation to in vitro maturation medium and in vitro culture medium on the development of porcine embryos. Porcine embryo development was investigated following cultivation in both in vitro maturation and culture medium with the supplementation of MEM vitamins (0, 0.1, 0.2 and 0.4%) using immature oocytes collected from the ovary of prepubertal gilts. Embryo development was observed and the total cell number in each blastocyst generated under the culture conditions was quantified following supplementation of the medium. The embryonic development rate of the blastocyst and hatched blastocyst was higher, but not significantly so, when 0.4% MEM vitamins were supplemented to the in vitro maturation medium of the porcine oocyte. Interestingly, the total number of cells in the blastocyst was significantly higher in the in vitro maturation MEM vitamins supplemented group compared to either the untreated group or the group which had MEM vitamins supplemented to both in vitro maturation and in vitro culture medium simultaneously (p<0.05). Therefore, the supplementation of 0.4% MEM vitamins to the in vitro mature medium has a beneficial effect on the embryonic development of in vitro produced blastocysts derived from the immature porcine oocytes.

• Toxicological Research
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• v.33 no.1
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• pp.49-54
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• 2017

Vitamin D3 is a fat-soluble secosteroid responsible for enhancing intestinal absorption of calcium, iron, and other materials. Vitamin D3 deficiency, therefore, can cause health problems such as metabolic diseases, and bone disorder. Female sex hormones including estrogen and progesterone are biosynthesized mainly in the granulosa cells of ovary. In this study, we isolated granulosa cells from porcine ovary and cultured for the experiments. In order to examine the effect of vitamin D3 on the ovarian granulosa cells, the mRNA and protein levels of genes were analyzed by real-time PCR and Western blot assay. The production of estrogen from the granulosa cells was also measured by the ELISA assay. Genes associated with follicle growth were not significantly altered by vitamin D3. However, it increases expression of genes involved in the estrogen-biosynthesis. Further, estrogen concentrations in porcine granulosa cell-cultured media increased in response to vitamin D3. These results showed that vitamin D3 is a powerful regulator of sex steroid hormone production in porcine granulosa cells, suggesting that vitamin D deficiency may result in inappropriate sexual development of industrial animals and eventually economic loss.

• Clinical and Experimental Reproductive Medicine
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• v.16 no.1
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• pp.35-40
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• 1989

In order to study the follicular atretic mechanism in mammalian ovary, the relationship between pyknotic index (PI) of granulosa cells and the steroid concentrations in the follicular fluid of atretic follicle was investigated. Follicles were isolated from porcine ovary according to their sizes and the reproductive phases. Steroid concentrations were quantified by high-performance liquid chromatography. As PI increased, the concentration of progesterone was significantly increased(p<0.05), whereas testosterone and estradiol showed no significant changes in their concentration. As follicular size was increased, PI of follicular GC in the luteal phase was increased significantly(p<0.05) and the molar ratio of progesterone to testosterone was increased in the follicles of follicular phase. It can be concluded that progesterone accumulated in the follicular fluid as atresia of the follicles was progressed, and that PI of granulosa cells could be used as one of convenient and pratical criteria for the identification of follicular atresia.