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1.
Synopsis Reproductive biology of the guitarfish,Rhinobatos hynnicephalus, from Xiamen coastal waters is described. Males have two functional testes. Spermatogenic cells in different seminiferous follicles are at different developmental stages while those in the same follicle are at the same stage. The development of claspers suggests that males mature at 380–400 mm TL. Females mature at 390–440mm TL. Both ovaries are functional. The first generation of ovarian eggs reach mature size when 22–24mm in diameter in April or May. The subsequent crop of eggs is ready for ovulation when the intrauterine embryos reach full term. The guitarfish is aplacentally viviparous. Longitudinal folds were observed on the internal wall of the uterus. Gestation takes one year and parturition takes place in June or July. Fecundity ranges from 2 to 9, with the large females usually being more fecund. Of 29 embryos ranging from 52–157mm TL, there were 15 females and 14 males indicating an embryonic sex ratio 1:1.  相似文献   
2.
Copulatory behavior unrelated to conception is sometimes observed in some non-human primates including the Japanese monkey. In the present study, the authors examined whether a mature follicle or a newly formed fresh corpus luteum was observed in the ovaries of female Japanese monkeys which displayed the copulatory behavior unrelated to conception. Post-conception copulatory behaviors were observed in three out of four females usually kept in individual cages in an air-conditioned room, and in two out of three females without infants kept in an outdoor group cage. However, neither a mature Graafian follicle nor a fresh corpus luteum formed newly after conception was observed in any of these females by laparoscopic examinations conducted immediately after termination of the copulatory behavior. In females with infants born in the preceding birth season, copulatory behaviors were observed in three out of four females kept in the outdoor group cage, and in two out of four females in a free-ranging troop. Ovulation was confirmed in one case out of the three kept in the outdoor group cage, but neither a mature follicle nor a newly formed corpus luteum was observed in the remaining four females. These findings suggest that copulatory behavior in the Japanese monkey is not always controlled by the development of a follicle or ovulation in the ovary.  相似文献   
3.
The study was conducted on two consecutive years to determine whether ovulatory activity can be induced in anovulatory goats by exposing them to sexually active bucks for 4, 8, 12 or 16 h per day during 15 consecutive days. In experiment 1, females remained continuously in the experimental pens where they were in contact with males. One group remained isolated from males (controls) and four other groups were exposed to sexually active males for 4, 8, 12 or 16 h per day. In experiment 2, females were taken away to “resting” pens free of male odours between the periods of contact with bucks. They were allocated to 5 groups as in experiment 1. Ovulations were determined by progesterone plasma levels and transrectal ultrasonography. Pregnancy was determined by abdominal ultrasonography. In both experiments, more than 90% of females exposed to the bucks had at least one ovulation during the whole experiment whereas only 11 or 0% (experiments 1 and 2, respectively) did so in the control group (P < 0.001). Furthermore, the proportion of females ovulating did not differ among groups depending on duration of contact with bucks (P > 0.05). In both experiments, pregnancy rates were not affected by the daily duration of contact with males (P > 0.05). To conclude, 4 h of daily contact with sexually active males is sufficient to stimulate ovulatory activity in anovulatory goats and this effect is not due to the presence of olfactory cues from the males remaining in the pens.  相似文献   
4.
Summary The fate of the theca interna after ovulation was studied in ewes, using light and electron microscopic histology and histochemistry. At the time of ovulation the theca interna was incorporated, apparently completely, into the margin of the developing corpus luteum and into the centres of many infoldings of the follicular wall. There was no evidence of degeneration of the more highly differentiated theca interna cells at or following the time of ovulation. Within 24 h of ovulation, cells derived from the theca interna began migrating from their original sites into the deeper, granulosa-derived areas of the luteal tissue. At later stages cells derived from the theca interna remained concentrated in septa derived from the follicular infoldings, but were also widely distributed throughout the luteal tissue. Structural evidence supported the view that the small luteal cells and fibroblasts of the corpus luteum were derived from the theca interna, and the large luteal cells from the membrana granulosa.The authors wish to thank Mrs. Linda Musk and Miss Anneke Veenstra for skilled technical assistanceDeceased on May 4, 1979  相似文献   
5.
Summary The effect of clomiphene citrate on the rabbit ovary was studied in mature nulliparous rabbits pretreated with three consecutive doses ranging from 0.01–10.0 mg/kg per day. With increasing doses a trend of decrease in mean ovarian weight (mg/kg body weight) is observed 2 days after termination of treatment. Five days later a significant increase occurs, which then subsides again to control values on day 12 after termination of treatment. During this period, no matings or injections of luteinizing hormone were performed to trigger ovulation; consequently no ovulations are observed. Folliculogenesis appears as normally; number and morphology of follicles are within normal ranges. No endogenous, spontaneous gonadotropin surges are detected in blood serum up to the 7th day after termination of treatment (2 and 10 mg doses). The surface epithelium of the ovary resembles normal germinal epithelium; however, after treatment with high doses a secretory-like activity is observed, accompanied with ultrastructural changes.Supported by the Deutsche Forschungsgemeinschaft, Special Program on Biology and Clinics of Reproduction. (Grant Be 524/7-7).Visiting Scientist from the Department of Obstetrics and Gynecology, Hadassah University Hospital, Jerusalem, Israel.  相似文献   
6.
The aim of our study was to examine the influence of 3-isobutyl-1-methyl-xanthine (IBMX), an inhibitor of cyclic adenosine monophosphate and cyclic guanosine monophosphate phosphodiesterases, on the reproductive efficiency of gonadotropin-stimulated rabbits (Oryctolagus cuniculus, Leporidae, Lagomorpha). The ovarian cycle and ovulation of control rabbits was induced by pregnant mare serum gonadotropin (PMSG) followed by administration of human chorionic gonadotropin (hCG; first series of experiments) or gonadotropin-releasing hormone (GnRH; second series of experiments). Experimental animals received PMSG and hCG together with IBMX (at 5 or 25 μg/animal) or GnRH together with IBMX (at 50 or 500 μg/animal). After ovulation and mating, in the first series of experiments, animals were killed; the pronuclear-stage eggs were flushed from the oviducts and cultured up to blastocyst cell stage. Numbers of ovarian corpora lutea, ovulated oocytes, and oocyte-derived embryos reaching blastocyst stage were determined. In the second series of experiments, all the animals were kept until parturition, when the pregnancy and birth rate, litter size, and number, viability, and body weight of pups were recorded. IBMX injections at doses of 5 or 25 μg/animal significantly increased the number of ovulations/corpora lutea, harvested zygotes, and embryos derived from these zygotes. Administration of IBMX at doses of 500 μg/animal or 50 μg/animal to nulliparous young animals (4.5 mo of age) significantly increased their pregnancy rate and birth rate, litter size, and litter weight. In multiparous old animals (2 yr of age), IBMX at a dose of 50 μg/animal, but not 500 μg/animal, significantly increased their pregnancy rate and litter size, but not the birth rate, number of pups per female, or litter weight. These data demonstrate that (1) IBMX can enhance the stimulatory effect of GnRH/gonadotropins on rabbit ovulation, oocyte maturation, embryo yield and development, pregnancy and birth rate, and number, viability, and body weight of pups; (2) nulliparous young females (4.5 mo of age) are more sensitive to IBMX treatments than the multiparous old animals (2 yr of age); and (3) cyclic nucleotides-dependent intracellular mechanisms are involved in control of rabbit reproductive functions and IBMX, an activator of these mechanisms, can be a stimulator of reproduction and fertility.  相似文献   
7.
山羊发情后期三种不同超排方法的比较   总被引:1,自引:0,他引:1  
目的 研究在山羊发情后期三种不同超排方法的超排效果。方法 实验以 2 0只本地山羊为实验材料 ,以氯前列烯醇二次注射法进行同期发情 ,研究了于发情后期 (发情结束后第 2天 )进行 3种不同的超排方法 (对照组 :3 0 0IUFSH 6次减量法 ,F -pvp组 :3 0 0IUFSH溶于 3 0 %PVP一次注射 ,F -pmsg组 :先注射 2 0 0IUFSH ,2 4h后结合 3 3 0IUPMSG一次注射法 )的超排效果。结果 二次注射氯前列烯醇在 60h内同期率为 80 % (16 2 0 ) ,3种超排方法平均获黄体数分别为 9 75± 4 65,11 75± 8 3 4 ,11± 9 13 ;平均获可用胚数分别为 7± 2 94,8± 5 48,7 5± 5 80 ;胚胎回收率分别为 62 16% ,68 0 8% ,61 3 6%。t检验证明实验组 (F pvp组和F pmsg组 )平均获黄体和平均可用胚与对照组差异有显著性 (P <0 0 5) ,而胚胎回收率 (卡方检验 )差异无显著性 (P >0 0 5)。结论 山羊发情周期的发情后期进行超排能取得很好的卵巢反应 ,而且FSH一次注射法 (溶于 3 0 %PVP或 2 4h后结合少量PMSG)与多次减量法的超排效果一致 ,这表明 ,在山羊发情后期使用FSH一次注射的超排方法有可能作为一种简化的体内生产胚胎的方法加以进一步开发和应用  相似文献   
8.
In Callithrix jacchus the urinary excretion of hydroxypregnanolone (5 alpha-pregnane-3 alpha, 7 alpha-diol-20-one) shows a luteal rise during the ovulatory cycle. This progesterone metabolite can therefore be used as an indication of ovulation, implantation, and subsequently for the persistence of the pregnancy. The excretion can be monitored by high performance thin-layer chromatography (HPTLC) and postchromatographic derivatization after enzymatic hydrolysis of the conjugate. Profiles of urinary hydroxypregnanolone levels are presented and correlated with luteinizing hormone excretion. The method is noninvasive and therefore suited for long-term studies in these monkeys.  相似文献   
9.
The continuous, subcutaneous infusion of native GnRH into seasonally anovulatory mares stimulates the synthesis and secretion of LH without pituitary refractoriness, offering opportunities to markedly accelerate the timing of ovulation within the operational breeding season. Herein, we tested the hypothesis that ovarian cycles induced in winter anovulatory mares using continuous administration of native GnRH for 28 days, beginning in either early February or early March (North America) would not revert to an anovulatory state after treatment withdrawal. Anovulatory mares received sham pumps (control) or native GnRH (100 μg/h) for 28 days beginning from February 2 or 3 (GnRH-Feb) or March 2 or 3 (GnRH-Mar). Mean concentrations of LH were five- to seven-fold greater during February in the GnRH-Feb group compared with control and GnRH-Mar groups through February and ending on March 2 or 3. However, concentrations of LH returned to the winter baseline within 3 to 11 days after pump removal and all GnRH-Feb mares failed to remain cyclic after treatment withdrawal. Correspondingly, during March, concentrations of LH in the GnRH-Mar group were greater (P < 0.001) than in the control and GnRH-Feb groups during the 28-day treatment period. Follicular growth and frequency of ovulation (6/10 GnRH-Feb; 9/10 GnRH-Mar, 1/11 controls, respectively) were greater (P < 0.01) in GnRH-treated mares. Ovulatory cycles continued in five of nine GnRH-Mar mares that ovulated, with interovulatory intervals of 15 to 24 days; whereas, three of nine mares had extended (33–42 days) interovulatory intervals and one of nine mares had a persistent CL after cessation of treatment. In summary, continuous administration of native GnRH for 28 days, beginning in early February or March, elevated circulating LH adequately to stimulate follicular growth and ovulation up to 60 days earlier than in untreated controls. However, if continuous, subcutaneous infusion of GnRH is selected as the only pharmacologic or managerial intervention, and mares are not pregnant, treatment must be continued at least until the end of March. This will improve the likelihood of a normal interovulatory interval after treatment withdrawal.  相似文献   
10.
催产时鳝卵磷酸酶活性的变化及其与排卵的关系   总被引:2,自引:0,他引:2  
本实验采用Gomori组织化学法和磷酸苯二钠法,分别检测黄鳝卵ALP、ACP的细胞定位和活性变化。结果表明,催产后72h,ALP活性显著高于临近注射时(Oh),催产后48h和96h(p<0.05);临产前(催产后96h),ACP活性极显著高于试验组其它各时程(p<0.01)。提示ALP和ACP活性增强与卵母细胞成熟、排放有直接关系。本研究为探索排卵机制提供资料。  相似文献   
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