• Proceedings of the Korean Society of Toxicology Conference
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• 2001.05a
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• pp.164-164
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• 2001

This study investigated expression pattern of PHGPx gene in male rat reproductive organs exposed to 17$\beta$-estradiol. First, in view of quantitative change, the exposure to 17$\beta$-estradiol for 1 week increased PHGPx mRNA level in testis and prostate. PHGPx mRNA level in epididymis decreased weakly as compared to control group.(omitted)

• Development and Reproduction
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• v.22 no.3
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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.

• The Korean Journal of Zoology
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• v.36 no.1
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• pp.51-66
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• 1993

한국산 관박쥐(Rhinolophusfemmequinum koran의 웅성생식 pattern을 알아보기 위하여, 1년 주기를 통한 정소상체 이부로의 정자유입, 정자저장 및 정자소멸에 따른 상피세포와의 상관관계를 조사하여, 다음과 같은 결론을 얻었다. 정소로부터 정자유입과 정자저장 및 정자소멸에 관련하여 볼때, 정소상체 미부는 2단계의 정화기간(cleaning time)을 가진다. 첫째로, 동면 각성시기인 4월부터 6월까지는 오래된 저장정자를 파괴시켜 새로운 정자를 받아들이기 위한 준비단계로서 둘째로, 정차과정은 7월에서 8월까지 계속되는[tl 이는 7월부터 새로운 정자와 함께 유임된 기형 정자세포,기형 정자 및 기타 잔여 노페물질을 제거하여 성숙된 정자만을 보유함으로서 곧 교미기를 맞이하기 위한 준비단계로서 정화기간을 가진다. 따라서, 1년 주기를 통한 정소상체 이부의 정화기간은 동면 각성기인 4월부터 8월까지 약 5개월에 걸쳐 이루어진다. 한편, 교미가 끝난 11월부터 동면기를 거쳐 동연 각성기 전까지의 긴 기간동안에 정소상체 미부내의 저장된 정자는 급격한 변화를 가져오지 않았다. 이는 동면동안의 낮은 물질대사율과 관련이 있다고 생각된다. 이상의 결과로 미루어 보아 정자유입, 정자저장 및 정자소멸에 따른 정소상체 미부의 조직변화는 정소상체 미부내 상피세포의 분비 및 흡수의 조절작용에 의해 변학되는것이라 여겨진다.

• Journal of Forest and Environmental Science
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• v.32 no.2
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• pp.113-119
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• 2016

The long lived iteroparous conifers produce male and female gametophyte for hundreds of years once they reach the reproductive stage, however, the production of seed is not frequent. This phenomenon of infrequent seed production in conifers is yet to be understood. An attempt to study this change in cone production in Cedrus deodara of Western Himalayas -a species reported to be mainly monoecious and rarely dioecious has been made. The observations recorded on selected trees of flowering/fruiting stage for four years at four different locations have shown the species to be dioecious with higher percentage of female trees during good seed year but with no definite or predictable pattern of reproduction in the trees. A decline in production of female trees was witnessed at all but one location immediately year after reaching the maximum (good seed year). The phenomenon of seed production has been observed to be cyclic and site specific. A change in the sexual behavior of the trees from male to female or vice-versa, male or female turning monoecious or vegetative and vegetative coming to reproductive was unpredictable.

• Journal of fish pathology
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• v.16 no.2
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• pp.111-118
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• 2003

Androgen plays an important role in the regulation of gonadotropin production in vertebrates . We have investigated the transcriptional pattern of androgen receptor (AR) in a variety of tissues in maturing male and female goldfish by RT-PCR. Specific primer for AR was designed based on goldfish AR gene from the GenBank (accession number AY090897). AR was shown 10 be maturity- and tissue-dependent gene expression pattern in goldfish. In immature male goldfish, significantly higher transcript level of AR was observed in the pituitary und testis , compared [0 brain and liver. Mature male goldfish showed a similar expression pattern to immature male goldfish. Interestingly. when compare to male goldfish, female goldfish showed AR mRNA expression that was found 10 be weak in pituitary, and very low expression in brain. They could not be found 10 have expression in any other tissues. Taken together. the- transcriptional analysis of AR depending on the tissue, sex. and maturity of a goldfish provides the opportunity for the study of goldfish reproductive physiology ,The results provided for the first time a comparison of the tissue distribution of AR mRNA in sexually maturating male and female goldfish.

• Korean Journal of Ichthyology
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• v.12 no.3
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• pp.192-202
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• 2000

Reproductive biology of the slimy, Leiognathus nuchalis was investigated by means of histological methods. Sex ratio was 1.81 : 1 in female to male. Developmental pattern of oocytes was group-synchronous. Testicular structure was restricted spermatogonial testis-type of tubular testis. The size of first group maturity is 7.5 cm in total length. Gonadosomatic index(GSI) of female was the highest in July(12.83) and the lowest in September(1.08). GSI of male was the highest in June(19.0) and the lowest in October(0.24). Hepatosomatic index(HSI) of female showed to be positively correlated with GSI. Thoracic spot index(TSI) showed to be the minimum value from May to July when the maturation and ripe season of gonad. Reproductive cycle of female could be classified into the growing(March~May), maturation(May~June), ripe and spent(June~August), recovery(August~November), and resting stage(November~March). Reproductive cycle of male could be classified into the multiplicative and growing(January~April), maturation(April~May), ripe and spent(June~August), recovery(August~October), and resting stage(October~December).

• Korean Journal of Ecology and Environment
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• v.33 no.4 s.92
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• pp.395-404
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• 2000

The gonadosomatic index (GSI), hepatosomatic Index (HSI), egg size distribution, gonad development and reproductive characteristics of venus fish, Aphyocypris chinensis, were examined during March 1997- March 1998 in agricultural waterways of the Sedo-myun, Puyo county, Chungnam Province, Korea. Annual reproductive cycle was classified into the following five successive phases by monthly changes in GSI and the characteristics of ovary: quiescent phase (January- February), secondary growing and mature phase (March-May), ripe and spawning phase (June-July), degenerating and resting phase (August-September) and primary growing phase (October-December). The hepatosomatic index (HSI) showed clear seasonal pattern with two separate peaks. However, it exhibited a negative correlation to changes of GSI values. The regression analysis suggested that fecundity showed a strong positive linear relationship ($r^2\;=\;0.91$, n = 34) with body weight. The sex ratio of female to male was 1.4 : 1 in the natural population during the study. The minimum reproductive size of female and male venus fish was 38 mm and 33 mm in fork length, respectively.

• The Korean Journal of Zoology
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• v.36 no.1
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• pp.36-50
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• 1993

한국산 관박쥐(Rhinolophusfewmequinum Jroma의 웅성생식 pattern을 알아보기 위하여 정소의 형태변화와 세정관 정상피의 1년주기를 조사하여 다음과 같은 결론을 얻었다. 정자형성은 5월에 시작되어 10월말에 완료되었다. 7월초부터 10월중순까지는 정자변태과정이며, 정자형성과정의 활성도가 가장 높은 달은 8월 중순경이었다. 또한 교미가 끝난 11월경부터 세정관내에는 미성숙한 정자세포가 Sertoli cell의 식작용과정의 일환으로 포식되어졌고, 91년 12월부터 92년 1월, 2월, 3월, 그리고 동면각성기인 4월의 실험군에서도 역시 점진적으로 식작용 과정을 관찰할 수 있었다. 교미가 끝난 후의 세정관 내에는 새로운 정자를 만들기 위한 준비단계로서 미성숙된 정자들이 Sertoli cell의 식작용에 의해 정화(cleaning)되므로 이 기간을 정화기간(cleaning time)이라 볼 수 있다. 따라서 정소내 세정관의 1년 주기를 볼 때 정화기간은 동면 개시기인 11월부터 익년 4월까지 약 6개월에 걸쳐 이루어 진다. 이상의 결과로 볼때, 정자형성은 동면각성 직후부터 시작하여 10월경에 완료되며 교미개시기에는 정지되고, 동면기 동안 정자형성이 일어나지 않는 점으로 보아 한국산 관박쥐는 'Pipistnfluspottem'에 속한다고 할 수 있다.

• Development and Reproduction
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• v.16 no.1
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• pp.53-58
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• 2012

Circadian rhythmicity (e.g. secretory pattern of hormones) plays an important role in the control of reproductive function. We hypothesized that the alteration of feeding pattern via meal time shift/restriction might disrupt circadian rhythms in energy balance, and induce changes in reproductive activities. To test this hypothesis, we employed simple animal model that not allowing $ad$ $libitum$ feeding but daytime only feeding. The animals of $ad$ $libitum$ feeding group (Control) have free access to food for 4 weeks. The day feeding (=reverse feeding, RF) animals (RF group) have restricted access to food during daytime (0900-1800) for 4 weeks. After completing the feeding schedules, body weights, testis and epididymis weights of animals from both group were not significantly different. However, the weights of seminal vesicle (control : RF group = $0.233{\pm}0.014g$ : $0.188{\pm}0.009g$, $p$<0.01) and prostate (control : RF group = $0.358{\pm}0.015g$ : $0.259{\pm}0.015g$, $p$<0.001) were significantly lower in RF group animals. The mRNA levels of pituitary common alpha subunit ($C{\alpha}$; control : RF group = $1.0{\pm}0.0699$ AU : $0.1923{\pm}0.0270$ AU, $p$<0.001) and $FSH{\beta}$ (control : RF group = $1.0{\pm}0.1489$ AU : $0.5237{\pm}0.1088$ AU, $p$<0.05) were significantly decreased in RF group. The mRNA levels of ACTH were not significantly different. We were unable to find any prominent difference in the microstructures of epididymis, and there were slight alterations in those of seminal vesicles after 4 weeks of reversed feeding when compared to control samples. The present study demonstrates that the shift and/or restriction of feeding time could alter the pituitary gonadotropin expression and the weights of seminal vesicle and prostate in rats. These data suggest the lowered gonadotropin inputs may decrease androgen secretion form testis, and consequently results in poor response of androgen-dependent tissues such as seminal vesicle and prostate.

• Journal of Forest and Environmental Science
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• v.38 no.4
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• pp.275-283
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• 2022

A study was designed to investigate the pattern of sexual dimorphism in a plantation of Garcinia kola. Twenty trees were randomly selected for the study and have been observed to flower regularly. A total of 100 inflorescence were randomly collected from the crown of each tree and 500 flowers randomly assessed within the period of four (4) flowering seasons. Floral sex assessment was done visually and with a hand magnifying lens; floral morphometric measurements (i.e. pedicel and perianth length and breadth), inflorescence length, and breadth) was taken using a veneer caliper; number of flowers per inflorescence and inflorescence per twig was counted; while, data analysis was conducted on excel using analysis of variance and pairwise t-test comparison. Four floral sexes were identified in the G. kola plantation studied which were unisexual male flowers, unisexual female flowers, cosexual unisexual male flowers, and cosexual hermaphrodite flowers. Three tree sexes were identified viz: inconstant male, invariant female, and cosexual trees. The plantation was significantly sexually dimorphic in floral sex and phenotypic traits (i.e. pedicel and perianth size), and as well as sexually dimorphic in tree sex and reproductive phenotypic traits (i.e. inflorescence size, number of inflorescences per twig, and number of flower bud per inflorescence). The sexual system of the plantation was therefore trioecious with features suggestive of evolving dioecy through the gynodioecious pathway.