• Molecules and Cells
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• 제38권12호
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• pp.1079-1085
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• 2015

Originally, activins were identified as stimulators of FSH release in reproduction. Other activities, including secondary axis formation in development, have since been revealed. Here, we investigated the influence of activin ${\beta}_A$ on the body, including the gastro-intestinal (GI) tract. Initially, the activin ${\beta}_A$ protein was detected in the serum proportional to the amount of pCMV-rAct plasmid injected. The induced level of activin ${\beta}_A$ in muscle was higher in female than male mice. Subsequent results revealed that stomach and intestine were severely damaged in pCMV-rAct-injected mice. At the cellular level, loss of parietal cells was observed, resulting in increased pH within the stomach. This phenomenon was more severe in male than female mice. Consistent with damage of the stomach and intestine, activin ${\beta}_A$ often led to necrosis in the tip of the tail or foot, and loss of body weight was observed in pCMV-rAct-injected male but not female mice. Finally, in pCMV-rAct-injected mice, circulating activin ${\beta}_A$ led to death at supraphysiological doses, and this was dependent on the strain of mice used. Taken together, these results indicate that activin ${\beta}_A$ has an important role outside of reproduction and development, specifically in digestion. These data also indicate that activin ${\beta}_A$ must be controlled within a narrow range because of latent lethal activity. In addition, our approach can be used effectively for functional analysis of secreted proteins.

• 한국발생생물학회지:발생과생식
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• 제22권3호
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• pp.253-262
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• 2018

The spermatogenesis is the process by which spermatozoa are generated in the testes. The spermatozoa travel male reproductive tract during which they meet many substances secreted from reproductive organs. One of the substances is epididymal protease inhibitor (EPPIN) that is involved in the post-testicular maturation including capability of fertilizing the eggs. The expression of EPPIN gene was investigated in various tissues of sexually mature and regressed male Syrian hamsters by reverse transcription polymerase chain reaction (RT-PCR). The EPPIN gene was identified in the testis and epididymis of the male Syrian hamsters and compared to the genes reported previously. There was no expression of EPPIN gene in reproductively and completely regressed testes of Syrian hamster. These results suggest that the expressions of the EPPIN gene are associated with the reproductive capability in the Syrian hamsters.

• 한국발생생물학회지:발생과생식
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• 제23권4호
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• pp.355-365
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• 2019

The morphogenetically matured spermatozoa (sperm) are generated in the testes by the spermatogenesis. They travel male reproductive tract with many substances secreted from the accessory reproductive organs. One of the substances is the semenogelin (SEMG) released from the seminal vesicles that is involved in the post-testicular maturation. The expression of SEMG gene was investigated in seminal vesicle tissues of sexually matured and regressed male Syrian hamsters by reverse transcription polymerase chain reaction (RT-PCR). The SEMG gene was uniquely identified in the seminal vesicles of the matured Syrian hamsters and compared to the genes reported previously. But the expression of SEMG gene was not observed in reproductively and completely regressed testes of Syrian hamsters. These results indicate that the expressions of the SEMG gene are related to the reproductive capability in the male Syrian hamsters.

• 한국가축번식학회지
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• 제10권2호
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• pp.182-187
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• 1986

As a fundamental study to increase the fertility and to modify the sex ratio in cattle, highly motile sperm were separated by bovine serum albumin gradients. The pregnancy rates of Korean native cow and Holstein cow, and the sex ratio between AI and natural mating were also investigated. The results obtained were as follows. 1. First service pregnancy rate of Korean native cow in artificial insemination was higher than that of Holstein. 2. At secondary sex ratio in artificial insemination and natural mating, male ratio in artifical insemination was slightly higher than that in natural mating. 3. The sperm separated from marketed frozen semen using 6%, 10% and 20% bovine serum albumin showed significantly high value in motility, percent of normal sperm and progressive motility as compared with control sperm.

• 한국가축번식학회지
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• 제19권2호
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• pp.141-145
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• 1995

The effect of splenectomy on the concentration of progesterone in pregnant wistar rats showing 4-day regular estrous cycles more than two cycles were investigated. The day after mating with the same male animal was designated day 0 of pregnancy. Splenectomy was conducted on day 0 (early-S), 6 (middle-S) and 13 (late-S) of pregnant rat, respectively. Blood sample were collected at day 1, 7, 14 and 21 of pregnancy. Concentraton of serum progesterone was determined by emzyme-linked immunosorbent assay (ELISA) using specific antibodies and emzyme conjugate(progesterone peroxidase labeled). In normal pregnant rats, serum progesterone concentrations were increased significantly (P<0.05) on day 7 and 14 of pregnancy compared with on day 1 of pregnancy and then dramatically decreased on day 21. However in early and middle splenectomized rats, progesterone concentrations were significantly (P<0.05) decreased on day 7 and 14 of pregnancy compared with same day of normal rats. These observations indicate that luteotropic action and steroidogenesis by corpus luteum of ovary may be regulated by splenocytes in rat.

• 한국발생생물학회지:발생과생식
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• 제16권4호
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• pp.235-251
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• 2012

The reproductive activity in male mammals is well known to be regulated by the hypothalamus-pituitary-gonad axis. The hypothalamic neurons secreting gonadotropin releasing hormone (GnRH) govern the reproductive neuroendocrine system by integrating all the exogenous information impinging on themselves. The GnRH synthesized and released from the hypothalamus arrives at the anterior pituitary through the portal vessels, provoking the production of the gonadotropins(follicle-stimulating hormone (FSH) and luteinizing hormone (LH)) at the same time. The gonadotropins affect the gonads to promote spermatogenesis and to secret testosterone. Testosterone acts on the GnRH neurons by a feedback loop through the circulatory system, resulting in the balance of all the hormones by regulating reproductive activities. These hormones exert their effects by acting on their own receptors, which are included in the signal transduction pathways as well. Unexpected aberrants are arised during this course of action of each hormone. This review summarizes these abnormal phenomena, including various mutations of molecules and their actions related to the reproductive function.

• 한국가축번식학회지
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• 제16권4호
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• pp.335-340
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• 1993

The development of efficient method for the production of transgenic mice has been investigated in our laboratory. This study was conducted to develop the artificial insemination in the mouse. Spermatozoa were collected from the cauda epididymis of ICR males(age:12~15 weeks, Body weight : 30g) and artificially inseminated into the intrauterine via cervix of hormone-primed ICR females(age: 6~8 weeks, body weight: 25g) using the capillary tube, 200~300 $\mu$m in inner diameter. The effect of concentration of sperm(80$\times$104, 40$\times$104, 20$\times$104, 10$\times$104, 5$\times$104, 3$\times$104, 1$\times$104/20${mu}ell$. The artificial insemination was succeeded but fertilization rate was very low(5~15%) compared to the natural mating and 59 normal youngs born from 60 females. Therefore, our findings suggest that it is possible to produce the great number of mice from the same orgin of male by artificial inseminatin. However, the lower pregnancy rate has to be solved to used broadly the artificial insemination in mouse.

• Clinical and Experimental Reproductive Medicine
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• 제39권2호
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• pp.41-45
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• 2012

Transcription factors govern diverse aspects of cell growth and differentiation as major switches of gene expression. Etv5, a member of the E26 transformation-specific family of transcription factors, has many stories to share when it comes to reproduction. Etv5 deficient mice show complex infertility phenotypes both in males and females. In males, the infertility phenotype exhibited by Etv5 deficiency is sexually dimorphic, and it involves both somatic cells and germ cells. In $Etv5^{-/-}$ female mice, the problem is more complicated by hormonal involvement. This review synthesizes old and new information on this versatile transcription factor-from the inadvertent discovery of its role in the testes to its newly discovered role in maintaining spermatogonial stem cells.

• Journal of Plant Biotechnology
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• 제1권1호
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• pp.56-60
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• 1999

Sexual reproduction is an essential process in the propagation of flowering plants. Recent advances in plant cell biology and biotechnology have brought new and powerful methodologies to investigate and manipulate the reproductive processes of angiosperms including agronomically important crop plants. Successful cryopreservation of maize, rye and triticale pollen and young embryos of microspore-and zygote-origine contributes to long term preservation of important plant germ-lines in gene banks. Discovering morphogenetic characteristics of the different developmental pathways taking place in wheat and maize androgenesis in vitro helps to influence the procedure to produce genetically and phenotipically stable homozygous doubled haploid plants for breeding purposes. Detailed ultrastructural and cell-biological studies on the developmental sequences of male and female gametophyte development in wheat, experimental protocols developed to isolate and micromanipulate egg cell protoplasts, make it possible to use plant gametes and the sexual route itself to produce genetically improved organisms. Plant gametes can become useful tools for crop improvement in the near future. Recent achievements by our laboratory in this field are reviewed in the present paper

• ALGAE
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• 제17권3호
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• pp.161-170
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• 2002

The vegetative and reproductive features of Grateloupia filicina (Lamouroux) C. Agardh (Cryptonemiales, Halymeniaceae) from different parts of the Indian Coast were studied. The plants grow in wide range of habitats and showed a lot of morphological variations. The development of the thallus is multiaxial type and the medullary region is composed of irregular, branched and stellate shaped cells. The gametophytic plants are dioecious and the male plants are smaller compared to female plants. The carpogonial branch is two-celled and formed on an a accessory branch system known as ampulla. Cystocarps are spherical to sybspherical with distint ostioles and scattered on the thallus surface. Tetrasporangia are common and tetraspores are either cruciate or decussate. Bisporangia are occasionally encountered. Our study suggests occurrence of two intraspecific taxa of G. filicina i.e.: var. luxurians and var. filinina from India coast.