• Reproductive and Developmental Biology
• /
• v.37 no.1
• /
• pp.17-22
• /
• 2013

Although assisted reproductive technology is very useful to develop novel and therapeutic biomaterials for reproduction, research on molecular mechanism of folliculogenesis in pig is not clear. Therefore, the alteration of gene expression during follicular development in pigs was examined in this study. The expression of folliculogenesis-related genes was quantified in preantral ($250{\sim}300{\mu}m$) and antral (> $300{\mu}m$ in diameter) follicles, and overall gene expression was evaluated by a genome-wide microarray. The microarray results showed that 219 genes were differentially expressed, and of those, 10 and 22 known genes showed higher and less expression at the preantral stage than at antral stages, respectively. Among them, the expression of NR0B1, PPARG, GATA4, and ANXA2 genes related to folliculogenesis was validated by quantitative real-time PCR analysis. The expression of PPARG and GATA4 genes were increased at antral stages, but a significantly stage-specific increase (p<0.05) was only detected in annexin A2 (ANXA2) in antral-stage follicles. The expression of NR0B1 genes was increased at preantral stage and these patterns of gene expression were comparable to the results obtained by microarray analysis. We propose that the systematical regulation of genes supporting specific follicle stage should be employed for improved in-vitro folliculognesis.

• Clinical and Experimental Reproductive Medicine
• /
• v.39 no.1
• /
• pp.10-14
• /
• 2012

The ovarian follicles develop initially from primordial follicles. The majority of ovarian primordial follicles are maintained quiescently as a reserve for the reproductive life span. Only a few of them are activated and develop to an advanced follicular stage. The maintenance of dormancy and activation of primordial follicles are controlled by coordinated actions of a suppressor/activator with close communications with somatic cells and intra-oocyte signaling pathways. Many growth factors and signaling pathways have been identified and the transforming growth factor-beta superfamily plays important roles in early folliculogenesis. However, the mechanism of maintaining the dormancy and survival of primordial follicles has remained unknown for decades. Recently, since the first finding that all primordial follicles are activated prematurely in mice deficient forkhead box O3a, phosphatidylinositol 3 kinase/phosphatase and tensin homolog (PTEN) signaling pathway was reported to be important in the regulation of dormancy and initial follicular activation. With these informations on early folliculogenesis, clinical application can be expected such as in vitro maturation of immature oocytes or in vitro activation of follicles by PTEN inhibitor in cryopreserved ovarian cortical tissues for fertility preservation.

• Clinical and Experimental Reproductive Medicine
• /
• v.32 no.3
• /
• pp.207-216
• /
• 2005

Objective: To understand the crucial requirement for the normal early folliculogenesis, we evaluated molecular as well as physiological differences during in vitro ovarian culture. Among the important regulators for follicle development, anti-Müllerian hormone (AMH) and FSH Receptor (FSHR) have been known to be expressed in the cuboidal granulosa cells. Meanwhile, it is known that c-kit is germ cell-specific and GDF-9 is also oocyte-specific regulator. To evaluate the functional requirement for the competence of normal follicular development, we investigated the differential mRNA expression of several factors secreted from granulosa cells and oocytes between in vivo and in vitro developed ovaries. Materials and Methods: Ovaries from ICR neonates (the day of birth) were cultured for 4 days (for primordial to primary transition) or 8 days (for secondary follicle formation) in ${\alpha}$-MEM glutamax supplemented with 3 mg/ml BSA without serum or growth factors. The mRNA levels of the several factors were investigated by quantitative real-time PCR analysis. Freshly isolated 0-, 4-, and 8-day-old ovaries were used as control. Results: The mRNA of AMH and FSHR as granulosa cell factors was highly increased according to the ovarian development in both of 4- and 8-day-old control. However, the mRNA expression was not induced in both of 4- and 8-day in vitro cultured ovaries. The mRNA expression of GDF-9 known to regulate follicle growth as an oocyte factor was different between in vivo and in vitro developed ovaries. In addition, the transcript of GDF-9 was expressed in the primordial follicles of mouse ovaries. The mRNA expression of c-kit was not significantly different during the early folliculogenesis in vitro. Conclusion: This is the first report regarding endogenous AMH and FSHR expression during the early folliculogenesis in vitro. In conclusion, it will be very valuable to evaluate cuboidal granulosa cell factors as functional marker(s) for normal early folliculogenesis in vitro.

• 대한생식의학회:학술대회논문집
• /
• 1995.05a
• /
• pp.5-7
• /
• 1995

• 대한생식의학회:학술대회논문집
• /
• 2003.06a
• /
• pp.5-6
• /
• 2003

• 대한생식의학회:학술대회논문집
• /
• 2007.11a
• /
• pp.15-22
• /
• 2007

• Clinical and Experimental Reproductive Medicine
• /
• v.48 no.1
• /
• pp.43-49
• /
• 2021

Objective: Exercise is a risk factor for infertility in women. However, research on the effects of different intensities of exercise on folliculogenesis has not yielded clear results. This study was conducted to analyze the effects of differences in the intensity of exercise on folliculogenesis in mice. Methods: Nineteen female BALB/c mice (age, 3-4 months; weight, 13-25 g) were randomly divided into four groups: control, mild exercise, moderate exercise, and high-intensity exercise. The mice in the exercise groups engaged in swimming, with additional loads of 3%, 6%, or 9% of body weight, respectively. There were five swimming sessions per week for 4 weeks, with a gradually increasing duration every week. At the end of the treatment, ovarian extraction was carried out and hematoxylin and eosin staining was performed to identify folliculogenesis. Results: There were significant differences in the number of total follicles between the control and moderate-exercise groups (p=0.036) and between the mild- and moderate-exercise groups (p=0.005). The mean number of primary follicles was higher in the moderate-exercise group than in the mild-exercise group (p=0.006). The mean number of secondary, tertiary, and Graafian follicles did not differ significantly among groups (p≥0.05). However, the number of total follicles and follicles in each phase tended to increase after exercise, especially moderate-intensity exercise. Conclusion: Exercise of different intensities affected the total number of follicles and primary follicles. The number of follicles of each phase tended to increase after exercise. Moderate-intensity exercise had better effects than other intensities of exercise.

• Development and Reproduction
• /
• v.16 no.4
• /
• pp.379-384
• /
• 2012

Lhx8 (LIM homeobox 8) gene encodes a LIM homeodomain transcriptional regulator that is preferentially expressed in germ cells and critical for mammalian folliculogenesis. However, Lhx8 DNA binding sequences are not characterized yet. We aimed to identify and characterize a cis-acting sequence of germ-cell specific transcriptional factor, Lhx8. To identify Lhx8 DNA binding element, Cyclic Amplification of Sequence Target (CAST) Analysis was performed. Electrophoretic Mobility Shift Assay (EMSA) was processed for the binding specificity of Lhx8. Luciferase assay was for the transcriptional activity of Lhx8 through identified DNA binding site. We identified a putative cis-acting sequence, TGATTG as Lhx8 DNA binding element (LBE). In addition, Lhx8 binds to the LBE with high affinity and augments transcriptional activity of luciferase reporter driven by artificial promoter containing the Lhx8 binding element. These findings indicate that Lhx8 directly regulates the transcription of genes containing Lhx8 binding element in oocytes during early folliculogenesis.

• Clinical and Experimental Reproductive Medicine
• /
• v.39 no.3
• /
• pp.95-106
• /
• 2012

It has been revealed that multiple cohorts of tertiary follicles develop during some animal estrous cycle and the human menstrual cycle. To reach developmental competence, oocytes need the support of somatic cells. During embryogenesis, the primordial germ cells appear, travel to the gonadal rudiments, and form follicles. The female germ cells develop within the somatic cells of the ovary, granulosa cells, and theca cells. How the oocyte and follicle cells support each other has been seriously studied. The latest technologies in genes and proteins and genetic engineering have allowed us to collect a great deal of information about folliculogenesis. For example, a few web pages (http://www.ncbi.nlm. nih.gov; http://mrg.genetics.washington.edu) provide access to databases of genomes, sequences of transcriptomes, and various tools for analyzing and discovering genes important in ovarian development. Formation of the antrum (tertiary follicle) is the final phase of folliculogenesis and the transition from intraovarian to extraovian regulation. This final step coordinates with the hypothalamic-pituitary-ovarian axis. On the other hand, currently, follicle physiology is under intense investigation, as little is known about how to overcome women's ovarian problems or how to develop competent oocytes from in vitro follicle culture or transplantation. In this review, some of the known roles of hormones and some of the genes involved in tertiary follicle growth and the general characteristics of tertiary follicles are summarized. In addition, in vitro culture of tertiary follicles is also discussed as a study model and an assisted reproductive technology model.

• Clinical and Experimental Reproductive Medicine
• /
• v.20 no.1
• /
• pp.19-29
• /
• 1993

Plasminogen activator (PA)-plasmin system in follicular fluid is involved in the process leading to follicular rupture at ovulation. It is well known that PA is closely associated with cellular differentiation and tissue remodeling on evidences from the study of normal and malignant tissues. This study was designed to ascertain a potential role of PA in the ovarian folliculogenesis. Immature Sprague-Dawley rats were injected with pregnant mare serum gonadotropin, followed by injection of serine protease inhibitor (SPI; mixture of 1 mol/L benzamidine and 1 mol/L amino-caproic acid) into the unilateral ovarian bursa. In the control study, mechanical effect of bursal injection and contralateral ovarian effect SPI were ruled out. Total antral follicular areas relative to total ovarian cross-sectional areas was siginificantly lower in SPI-injected ovary than in saline-injected ovary. SPI injection decreased the relative antral follicular area by 33 % respectively. Electron microscopic finding of granulosa cell in the atretic follicle showed the presence of pyknotic nucleus, blurring of neucleolemma, degeneration of mitochondria and dilation of endoplasmic reticulum. After induction of ovulation with hCG, the number of oocytes released was significantly decreased in SPI-injected oviduct than in saline-injected oviduct. From above results, author discussed that PA may play a role not only in ovulation but also in some processes of folliculogenesis.