• 한국발생생물학회지:발생과생식
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• 제17권2호
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• pp.87-97
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• 2013

The seminiferous epithelium cycle and developmental stages of spermatids in Clethrionomys rufocanus were observed under a light microscope. The seminiferous epithelium cycle was divided into 8 stages. Type Ad spermatogonia appeared through all stages. Type Ap, In, and B spermatogonia appeared in stages I, II, III, and IV. In the first meiosis prophase, the leptotene spermatocytes appeared from stage V, the zygotene spermatocytes in stages I, VI, VII, VIII, the pachytene spermatocytes from stages II to VI, the diplotene spermatocytes in stage VII. The meiotic figures and interkinesis spermatocytes were observed in stage VIII. Developing spermatids were subdivided into 10 steps, based on the morphological characteristics such as the acrosome formation changes in spermatozoa, nucleus, cytoplasm, and spermiation changes. The C. rufocanus spermatocytogenesis and spermiogenesis results displayed similar results with Apodemus agrarius coreae and A. speciosus peninsulae. Considering all the results, the spermatogenesis may be useful information to analyze the differentiation of spermatogenic cells and the breeding season.

• Asian-Australasian Journal of Animal Sciences
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• 제20권5호
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• pp.701-705
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• 2007

Seven rc mutant and seven normal male birds (Rhode Island Red suie, RIR) were used in this study to determine the effects of rc mutation on semen characteristics, testosterone profile and spermatogenic tissues. All birds were randomly selected at week 12 of age and housed in individual cages and were fed and watered ad libitum. The birds were exposed to a 14L:10D light cycle during experiment. Semen were collected at weeks 22 to 23 from each bird twice a week and evaluated for semen volume (SV), sperm concentration (SC), total sperm count (TSC), percent of sperm motility (%SM), dead sperm (%DS), and sperm metabolic activity (SMA). To determine the testosterone concentration (TC) in plasma, blood was collected at weeks 12, 16 and 18. Testicular tissue were collected, processed and evaluated for semineferous tubule diameter (STD), round spermatid number (RSN), percent elongated sperm (%ES) and semineferous tubules length (STL). Body weight (BW), comb weight (CW) and testes weight (TW) were weighted at the end of experiment (week 23). The SV, TSC and %SM were significantly higher in normal birds but the %DS was higher in blind birds (p<0.05). The SC did not differ significantly between the two groups but its value was higher in normal birds. The sperm metabolic activity in the first h of collection did not differ significantly between the two groups but after 24 h, the level of SMA in normal group was significantly higher (p<0.05). The level of TC did not differ significantly between the two genotype groups but normal birds had higher TC in all collections except the last one. The STD, RSN, %ES and STL in normal birds were higher when compared to blind birds but the differences were insignificant except for ES percent. The BW, CW and TW between the two groups did not differ significantly but the weights were higher in normal group compared to blind birds. Statistical analysis of semen characteristics, testosterone profile and histological factors were indicated detrimental effects of rc mutation in prepubertal RIR blind male birds due to lack of light.

• Animal cells and systems
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• 제5권1호
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• pp.37-44
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• 2001

Gonadal development, reproductive cycle, gonad index, meat weight rate, and first sexual maturity of the top shell, Omphalius rusticus were Investigated monthly by histological observations. Specimens were collected from the west coast of Korea during the period from January to December in 1999. O. rusticus is dioecious and oviparous. The gonad is widely situated on the surface of the digestive g1and located in the posterior spiral meat part in the shell. The ovary and the testis were composed of a number of oogenic follicles and several spermatogenic follicles, respectively. Ripe oocytes were approximately 120-130 $\mu$m in diameter. The meat weight rate peaked in June (27.7%), and then rapidly decreased in September (19.5%). Monthly changes in the gonad index in both sexes reached the maximum in June, and then sharply decreased in September. Percentages of first sexual maturity of female and male snails ranging from 9.0 to 9.9 mm in shell heights were 58.3% and 54.5%, respectively, and 100% in those over 11.0 mm in both sexes participated in reproduction. Reproductive cycle of this species can be categorized into five successive stages: in females, early active (October to April), late active (December to June), ripe (April to September), spawning (July to September) and recovery (September to January): in males, early active (November to March), late active (December to June), ripe (April to September), spawning (July to September) and recovery (September to December). Gonadal development, gametogenesis, reproductive cycle, and spawning were closely related to the seawater temperature.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2003년도 학술발표대회 발표논문초록집
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• pp.96-96
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• 2003

Nek2 (NIMA-related protein) is a mammalian cell cycle-regulated kinase that involves in chromosome condensation and centrosome regulation and NuMA (nuclear mitotic apparatus protein) is involved in spindle assembly during a cell cycle. The cellular distribution and organization of the centrosomal components is completely unknown during fertilization and embryonic development. We examined distribution of two well-known centrosomal proteins, Nek2 and NuMA in mouse gametes and embryos to get an insight in the reorganization of centrosomal proteins during germ cell development and early fertilization. Spermatogenic cells, gametes, and embryos were analyzed with anti-Nek2 or -NuMA antibodies by immunological assay, RT-PCR, and overexpression through gene transfection. Mitotically or meiotically active spermatogenic cells were intensively stained with these antibodies in both centrosomes and cytoplasm, whereas the oocytes showed different staining patterns depending on the meiotic stages. During maturation, GV, GVBD, and MI stage were clearly stained with NuMA antibody in the nucleus or cytoplasm at MII. Also, Nek2 was detectable in cytoplasm as scattered spots or chromosome associated at MII. In early developmental embryo, NuMA was detected in nucleus of each blastomere, while Nek2 was detected in cytoplasm. In contrast to previously reported results, Nek2 and NuMA were detected in both decondensing head, and the centriole of demembranated and decondensed sperm or whole body of trypsin-treated sperm for Nek2. During meiotic progress in oocytes, transcripts levels were the highest in MI stage and then downregulated in MII. Also, it shows dramatically change in early developmental embryos, firstly, it was increased until 4 cell stage and reduced in 8 cell stage, and finally, transcript levels were upregulated until blastoscyst. This finding suggests that cnetrosomal component may play an important role in reorganizing of functional centrosome during fertilization process and subsequent development.

• Animal cells and systems
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• 제3권4호
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• pp.375-383
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• 1999

Gonadal development, gametogenesis, reproductive cycle, and first sexual maturity of Reishia clavigera were investigated monthly from July 1998 to June 1999 through cytological and histological observations. R. clavigera had separate sexes, and was an internal fertilizer. The ma1e penis was located near the two tentacles. The ovary and testis were composed of a great number of oogenic lobules and spermatogenic tubules, respectively. The size of ripe oocyte ranged from 130 to 140 ${\mu}$m in diameter. The peripheral cytoplasm of the germinal vesicle of the ripe oocyte in many cases were surrounded by smaller yolk granules, while the eccentric cytoplasm was occupied with larger ones. The reproductive cycle of R. clavigera could be classified into five successive stages: early active, late active, ripe, spawning, and recovery. Spawning of females occurred from early July to August when the seawater reached above 24.8$^{\circ}C$. Spawning of males occurred from early June to August in the water above 22.8$^{\circ}C$. Minimum size for sexual maturity of both sexes was above 10.0 mm in shell height. Each egg capsule was a cylinder or spindle in shape, 4-6 mm in length and 1-2 mm in width. Colors of newly spawned egg capsules showed yellowish white or pale yellow, while those with veliger larvae showed pale black, and released larvae or dead egg capsules showed black violet. The fecundity in an egg capsule ranged from 70 to 91 eggs (mean＝80.28 eggs).

• 한국패류학회지
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• 제29권1호
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• pp.65-76
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• 2013

We investigated the gametogenic cycle and spawning seasons of the male Chlamys (Azumapecten) farreri nipponensis by qualitative and quantitative analyses, and also the size at 50% of group sexual maturity was calculated by the data of first sexual maturity. In this study, the male gametogenic cycle of this species by qualitative analysis was divided into five successive stages: early active stage (January to March), late active stage (March to April), ripe stage (April to August), partially spawned stage (July to September), and spent/inactive stage (August to January). The male gametogenic cycle showed similar patterns with monthly changes in the gonadosomatic index and condition index. Particularly, spawning in male scallop occurred once a year from July to September, unlike the spawning period of this species (from June to August) reported by the previous researchers. In quantitative statistical analysis using an image analyzer system, the patterns of monthly changes in the percent (%) of the areas occupied by spermatogenic stages to the testis areas in males showed a maximum in June, and then sharply dropped from July to September, 2006. From these data, it is apparent that the spawning season of C. (A.) farreri nipponensis occurred once per year from July to early September, indicating a unimodal gametogenic cycle during the year. Shell heights at 50% of group sexual maturity (RM50) fitted to an exponential equation were estimated to be 49.90 mm in males (considered to be one year old), and it was 100% for male scallops over 61.0 mm (considered to be two years old).

• 한국수산과학회지
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• 제37권5호
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• pp.385-392
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• 2004

Gonadal development, gametogenesis, reproductive cycle, gonad index, and flesh weight rate of the murex shell (Ocenebra japonica) collected from the rocky intertidal zone of Buan-gun, Jeollabuk-do, Korea were investigated by means of histological method from January to December 2002. O. japonica had separate sexes, and was oviparous. The gonad was widely situated on the surface of the digestive gland located in the rear of the spiral flesh part in the shell. The male penis was located near the two tentacles. The ovary was composed of a number of oogenic follicles, and the testis was composed of several spermatogenic tubules. The size of ripe oocyte was approximately $140{\mu}m$ in diameter. The gonad index (GI) began to increase in March $(33.24{\pm}2.33)$ and reached the maximum in June $(47.77{\pm}1.90)$ Thereafter, the values decreased from July $(45.12{\pm}3.60)$ to October $(19.32{\pm}2.91)$. The flesh weight rate (FWR) began to increase in January $(25.93{\pm}1.32)$ and reached the maxium in May $(31.78{\pm}1.09)$ Thereafter, the values decreased from June $(31.50{\pm}0.66)$ to October $(24.09{\pm}1.60)$. The reproductive cycle could be classified into five successive stages: early active (October to April), late active (January to June), ripe (May to September), spawning (July to September) and recovery (September to February). The reproductive cycle was closely related to the seawater temperature.

• 한국발생생물학회지:발생과생식
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• 제2권1호
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• pp.89-99
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• 1998

본 연구는 미성숙 혹은 성숙된 3년생 무지개 송어(Oncorhynchus mykiss) 수컷 150마리의 뇌하수체와 정자형성세포의 형태적인 변화를 조사하기 위해서 실시되었다. 3월부터 그 이듬해 2월까지 번식주기에 따라 광학현미경, 투과 및 주사전자현미경으로 정자 형성과 정자완성시기의 미세구조적 변화를 연구하였다. 뇌하수체 호르몬 분비세포의 성숙은 휴지기 (3월부터 8월까지), 정자형성기 (9월부터 11월가지), 번식기 (12월부터 2월까지)의 3가지 시기로 구분되었다. 뇌하수체 호르몬 분비세포의 미세구조가 변하는 추세는 정소의 주기적 변화와 대체적으로 일치하였다. 정자형성초기에는 여러 단계의 세포군이 하나의 세정관안에 위치해 있었다. 정원세포로부터 정자세포까지 사류ㅕ볼 때 핵과 세포질의 크기는 각 발달단게마다 점진적으로 감소하였다. 제2차 정모세포 및 정자세포의 세포질 외측에 작은 크기의 미토콘드리아가 확인되었다. 정자세포의 2개의 미토콘드리아는 세포질의 한쪽에 위치하면서 길게 늘어지기 시작하였다. 정자의 경우, 핵의 크기가 감소하였고, 핵막과 세포질막은 두부의 핵과 근접해 있었따. 2개의 미토콘드리아는 다른 척추동물과 달리 그 수가 적었고, 축사로부터 분리되어 있었다. 무지개송어의 축사구조는 축추동물의 전형적인 "9+2"형을 나타내었다. 투과 및 주사전자현미경으로 여러 단계의 정자형성세포들을 관찰한 결과 그 두부의 크기와 형태의 구체적인 차이를 확인할 수 있었다.확인할 수 있었다.

• 한국양식학회지
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• 제14권2호
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• pp.73-79
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• 2001

Testicular development of the male African lungfish, Protopterus annectens (Owen) was investigated histologically. The testis was found to be an elongated structure that possessed two distinct portions: an anterior spermatogenic part that was made up of a system of testicular tubules and a posterior vesicular part that invaded the kidney tissue. Spermatogenesis can be divided into five stages; primary spermatogonia, secondary spermatogonia, spermatocyte, spermatids and spermatozoa. Based on the gonadosomatic index (GSI) and histological changes observed, the reproductive cycle can be divided onto four distinct stages: resting and quiescent (December to February), growing (March to June) ripe and spent (July to August) and postspawning (September to November). The GSI was the maximum on July when reproductive cells were mature, ripe and ready for spawning; and the minimum in August after fish spawned.

• 한국동물학회지
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• 제36권4호
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• pp.580-587
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• 1993

북방산개구리의 성체 수컷들 년중 채집하여 gonadosomatic index(GSI)와 정자형성과 정 및 정소내 testosterone양의 변화를 조사하였다 정자형성은 8월에 시작되어 9월에 가장 활발하게 진행되었으며 이때 GSI도 가장 높았고 세정관의 단면적도 가장 넓었다 번식기(2월) 이후 일정기간 동안에는(3월-7월) 정자형성이 정지되었으며, GSI나 세정관의 단면적도 최저치를 나타내었다. 정소내 testosterone양은 11월부터 급격히 증가하여 2월에 가장 높았으며 3월부터 급격히 감소되어 10월 까지 매우 낮은 농도를 유지하였다. Interstitial cell의 수도 동면기간이 찰동기 보다 훨씬 많았으며 핵의 크기도 동면기간이 훨씬 컷다. 따라서 testosterone의 생성 증가와 interstitial cell의 활성화가 일치함을 알 수 있었다. 본 결과들은 북방산개구리의 정 소에서는 정자형성과정이 불연속적으로 일어난다는 것과 2월 이후에는 testosterone의 양이 급격히 줄어드는 것으로 보아 이 개구리의 번식기가 2월임을 확인해 주고 있다.