• Title/Summary/Keyword: reproductive cycle

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Reproductive Ecology and Parasite of the Venus Clam, Cyclina sinensis (Gmelin), on the West Coast of Korea 1 Reproductive Ecology (한국 서해산 가무락조개, Cyclina sinensis의 번식생태 및 기생충에 관한 연구 1. 번식생태)

  • 김용호;정의용;김영길
    • The Korean Journal of Malacology
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    • v.16 no.1_2
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    • pp.35-41
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    • 2000
  • We investigated the gonad index (GI), gonadal development, the reprodutive cycle and first sexual maturity of the venus clam, Cyclina sinensis by histological observation. Samples were collected from the intertidal zone of Komso Bay, Chollabuk-do, west coast of Korea, from April 1998 to March 1999. This clam is dioecious and oviparous. Monthly changes in the gonad index (GI) showed a similar pattern to the reproductive cycle. Ripe oocytes are about 90-100 ㎛ in diameter. The spawning period was between early July to September, and the main spawning occurred between July and August when the sea water temperature was over 20$\^{C}$ The reproductive cycle of this species can be divided into five successive stages: early active stage (February to April), late active stage (March to June), ripe stage (April to August), partially spawned stage (July to October), and spent / inactive stage (September to February). Percentages of first sexual maturity of female and male clams measuring 26.1-30.0 ㎜ in shell length were 53.3% and 62.5%, respectively, and 100% for the clams > 41.0 ㎜. It is assumed that both sexes begin reproduction at about two years age.

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Sexual Maturity and Reproductive Cycle of Starry Flounder Platichthys stellatus Cultured in Indoor Tank (실내 사육한 강도다리 Platichthys stellatus의 성성숙과 생식주기)

  • Lim, Han-Kyu;Byun, Soon-Gyu;Lee, Jong-Ha;Park, Sang-Un;Kim, Yi-Cheong;Han, Hyoung-Kyun;Min, Byung-Hwa;Lee, Bea-Yik
    • Journal of Aquaculture
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    • v.20 no.4
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    • pp.212-218
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    • 2007
  • Reproductive biology (sexual maturity and reproductive cycle) of starry flounder Platichthys stellatus were examined by histological methods. From March 2004 to February 2005, 144 females and males were sampled. Gonadosomatic index (GSI) of female and male were peaked in May and February, respectively. Monthly changes of hepatosomotic index (HSI) showed a negative correlationwith those of the GSI. Changes of condition factor (CF) in female were correlated with gonad maturation, while that of male were no difference all the year round. Based on monthly GSI and gonadal development the reproductive cycle of starry flounder could be divided into four stages: growing stage (September to November), maturation stage (September to February), ripe and spent stage (March to May), and recovery and resting stage (June to August). Biological minimum size of female was 1,074 g. The relationship between fecundity (F) and body weight (BW) of the fish was expressed as $F\;=\;455.86BW^{1.2006}$.

Effects of early prepubertal exposure to bisphenol A on the onset of puberty, ovarian weights, and estrous cycle in female mice

  • Nah, Won-Heum;Park, Mi-Jung;Gye, Myung-Chan
    • Clinical and Experimental Reproductive Medicine
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    • v.38 no.2
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    • pp.75-81
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    • 2011
  • Objective: Bisphenol A (BPA) is a chemical used extensively to manufacture plastics and epoxy resin liners for food and beverage cans. BPA, with properties similar to estrogen, has endocrine-disrupting effects. In the present study, we examined the effects of early prepubertal BPA exposure on the onset of puberty and reproductive parameters such as estrous cycle and reproductive organ weights in female mice. Methods: Female mice were injected subcutaneously at postnatal day (PND) 8 with BPA (0.1, 1, 10, 100 mg/kg) in sesame oil or with sesame oil alone. Body weight was measured from PND 10 to 70. Vaginal opening and estrous cycle were monitored from PND 20 to 29. Animals were sacrificed at PND 25, 30, and 70, and the ovary and uterus weights were measured. Results: Early prepubertal exposure to BPA (10 and 100 mg/kg) significantly decreased body weight from PND 18 to 30. BPA treated mice at testing dose levels showed early opening of the vagina compared to the control group. The number of estrous cycle and days of estrus were significantly decreased in high dose (100 mg/kg) BPA treated mice. The ovary weight at PND 25 and 30 was significantly decreased in all BPA treatment groups. Conclusion: Early prepubertal exposure to BPA accelerated the onset of puberty but decreased reproductive parameters in female mice.

Histological Observations of the Female Reproductive Cycle of Honeycomb Grouper, Epinephelus merra in Chuuk (Chuuk에 서식하는 Honeycomb Grouper, Eplinephelus merra 암컷의 생식주기)

  • Song Young Bo;Park Yong Ju;Takemural Akihiro;Kim Han Jun;Choi Myun Sik;Choi Young Chan;Lee Young Don
    • Development and Reproduction
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    • v.7 no.1
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    • pp.23-28
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    • 2003
  • The seasonal reproductive cycle of the female honeycomb grouper, Epinephelus merra, inhabiting Chuuk was examined by histological observations of the ovaries. The gonadosomatic index (GSI) began to increase in February and peaked in March. Histological observations revealed many oocytes laden with yolk in the ovaries from March to April. From June to January, the ovaries were occupied by immature oocytes. These results suggest that the reproductive season of E. merra in Chuuk is from March through April.

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Seasonal Changes in the Ovary of the African Lungfish Protopierus annectens (Pices : Sarcopterygii) in the Flood Plains of River Niger in Etsako East Local Government Area of Nigeria

  • Onyedineke, Nkechi E.;Otuogbai, Timothy;Elakhame, Luckey A.;Erekaife, Joyce O.
    • Journal of Aquaculture
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    • v.15 no.1
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    • pp.43-48
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    • 2002
  • We investigated the gonadosomatic index (GSI), germ cell development, reproductive cycle of the Afriean lungfish Protorierus annecteus (Owen) by histological observations and morphometric data. Samples were collected from the river Orie and its flood of Nigeria, from January to December 2000. The fish is dioecious and oviparous. Monthly changes in the gonadosomatic index (GSI) showed a similar pattern to change in the mean oocyte diameter and the reproductive cycle. The reproductive period occurred from March to July-August; the spawning period was once a year between truly and August, and the main spawning occurred in August when active and voracious feeding occurred during the rainy season. In the resting (dormant) stage after spawning, fish stopped feeding and aestivated during the dry season from December to February. The reproductive cycle of the species can be divided into five successive stages, quiescent stage (March to April), developing/maturing stage (April to lune), ripe/spawning stage (July to August), post-spawning stage (September to November), and resting (dormant) stage (December to February).

Ovarian Development and Reproductive Cycle of the Female Red Tongue Sole, Cynoglossus joyneri (Teleostei: Cynoglossidae) (참서대 (Cynoglossus joyneri) 암컷의 난소발달 및 생식주기)

  • LEE Jung Sick;KIM Sung Yeon;MA Kyung Hwa;HUH Sung Hoi
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.33 no.6
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    • pp.554-558
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    • 2000
  • Reproductive biology of the female red tongue sole, Cynoglossus joyneri was investigated by means of histological methods. Gonadosomatic index (GSI) was the highest in June. Developmental pattern of oocytes was group-synchronous. Egg stalk and yolk nucleus were observed in the early growing oocytes. Reproductive cycle could be classified into the growing ($February{\~}May$), maturation ($May{\~}June$), ripe and spent ($June{\~}August$), and recovery and resting ($August{\~}February$). The absolute fecundity per individual ($TL 28.1{\~}30.8 cm$) was 2,197 and relative fecundity per g body weight was 18.0.

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Effect of Crotalaria juncea seed extracts on the estrous cycle and ovarian activity in albino mice

  • Malashetty, Vijaykumar B.;I., Sangamma;A., Sharanabasappa;Patil, Saraswati B.
    • Advances in Traditional Medicine
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    • v.4 no.2
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    • pp.77-81
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    • 2004
  • Petroleum ether, benzene and alcohol extracts of seeds of C. juncea administered orally at the dose level of 25mg/100g body weight to adult female mice for 30 days, resulted in irregular estrous cycle with prolonged estrus and metaestrus and reduced diestrus and proestrus during the experimental period. Histological studies of the ovary indicate increases in the number of atretic follicles but decreases in the number of developing follicles, Graafian follicles and corpora lutea. The total cholesterol content of the ovary is increased, whereas ascorbic acid content is decreased. The weight of the uterus and its micrometric measurement in all experimental mice are increased significantly. The alcoholic extracts showed estrogenic activity in immature mice by early opening of the vagina, premature cornification of the vaginal epithilium and increases in uterine weight. However, alcohol extract of seeds of C. juncea was more effective in causing these changes compared to other extracts. After subjecting to preliminary phytochemical screenings alcohol extract showed positive; test for alkaloids, steroids, glycosides, flavones, phenols and tannins.

Reproductive Biology of the Pen Shell, Atrina(Servatrina) pectinata on the Boryeong Coastal Waters of Korea

  • Chung, Ee-Yung;Baik, Seong-Hyeon;Ryu, Dong-Ki
    • The Korean Journal of Malacology
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    • v.22 no.2
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    • pp.143-150
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    • 2006
  • The gonad index, condition index, reproductive cycle and spawning of the pen shell Atrina (Servatrina) pectinata were investigated using samples from the subtidal zone of Nokdo on the Boryeong coastal waters of Korea. Samples were collected monthly by SCUBA divers for one year from January to December, 2001. A. (Servatrina) pectinata is dioecious and oviparous. The spawning season of this species occurred once a year from June to August, with the main spawning occurring between June and July when the seawater temperature was around $20^{\circ}C$. Ripe oocytes were about 60-65 ${\mu}m$ in diameter. The reproductive cycle of this species could be classified into five successive stages; early active stage (November to March), late active stage (February to May), ripe stage (April to July), partially spawned stage (June to August), and spent/inactive stage (August to October). Monthly changes in the gonad index reached a maximum (4.6) in May (ripe stage), thereafter, the GI values gradually decreased from June to August when spawning occurred continuously. Therefore, monthly changes in the GI values showed a similar pattern to the gonadal phase. The condition index (CI) of the meat part without the posterior adductor muscle reached the maximum in June (ripe and partially spawned stage) and the minimum in September (spent/inactive stage), Accordingly, monthly changes in the condition indice of the meat part without the posterior adductor muscle coincided with the gonadal phases.

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Reproductive Cvcle-related Changes in GnRH Immunoreactivitv in the Brains of Three Congeneric Species of Frog. (3종의 개구리 뇌에서 생식주기에 따른 GnRH 면역반응성의 변화)

  • 임욱빈;김정우
    • The Korean Journal of Zoology
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    • v.37 no.3
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    • pp.311-317
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    • 1994
  • Seasonal variations of GnRH were investigated by immunohlstochemicsl technique in three species of frog, Rona niEromaculutu, R. dvbowskii 8nd R. mgosa with different ovulation period in order to examine the relationship between GnRH expression and reproductive function. In all three species of frog, the intensity of GnRH immunoreactivitv and the number of GnRH neurons in the brawn were relatively high in frogs at the pre-ovulation period and markedly increased at the ovulation period. Those were then decreased after ovulation and further lowered during early hibernation period. These results indicate that GnRH experssion is closely related to specific phases of annual reproductive cycle in frog.

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COVID-19 (SARS-CoV-2) mRNA vaccination does not affect basal sex hormone levels (follicle-stimulating hormone, luteinizing hormone, estradiol) in reproductive-age women

  • Haeng Jun Jeon;Woo Sik Lee;Ji Eun Park;Ji Young Hwang;Ji Won Kim
    • Clinical and Experimental Reproductive Medicine
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    • v.51 no.2
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    • pp.151-157
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    • 2024
  • Objective: People vaccinated with the coronavirus disease 2019 (COVID-19) (severe acute respiratory syndrome coronavirus-2 [SARS-CoV-2]) mRNA vaccine have reported experiencing various adverse effects. For instance, reproductive-age women have presented with complaints of abnormal uterine bleeding or menstrual cycle changes. We speculated that differences in basal sex hormone levels before and after vaccination may be present in women who experienced irregular bleeding or menstrual cycle changes; thus, this study aimed to investigate the differences in basal sex hormone levels of women before and after two doses of SARS-CoV-2 mRNA vaccination. Methods: This retrospective study included patients who received SARS-CoV-2 mRNA vaccines between January 2021 and February 2022 at a single center. In an outpatient setting, patients were queried regarding their menstrual cycle, the date of SARS-CoV-2 mRNA vaccination, vaccination type, and vaccination side effects. Differences in basal hormone levels (menstrual cycle days 2-3, follicle-stimulating hormone [FSH], luteinizing hormone [LH], and estradiol) before and after vaccination were compared. Results: Among the 326 patients, patients with no laboratory records of the hormones were excluded. The median time interval between SARS-CoV-2 mRNA vaccination and the laboratory test day was 79 days (interquartile range, 44 to 127). A comparative analysis of these hormones before and after vaccination revealed no significant differences. Subgroup analyses based on age and reported adverse events also found no statistically significant differences. Conclusion: This study showed no significant differences in basal hormone levels (FSH, LH, and estradiol) before and after SARS-CoV-2 mRNA vaccination.