秦岭北坡中国林蛙精巢显微结构的年周期变化

用光镜观察了秦岭北坡中国林蛙(Ranachensinensis)精巢显微结构的年周期变化,结合精巢系数的变化探讨其生殖规律。结果显示,秦岭北坡中国林蛙的生精周期属于非连续型。精巢系数的变化与精子发生的活动周期相一致。精子发生从每年5月开始,翌年4月结束,历时1年。生精周期可划分为5个时期。Ⅰ期,精原细胞增殖期,5～7月,精巢系数最小,精原细胞进行有丝分裂;Ⅱ期,精母细胞成熟分裂期,8～9月,精巢系数最大,精原细胞、精母细胞和精子细胞在生精小管内共存;Ⅲ期,精子形成期,9～1 0月,精子细胞变态形成精子;Ⅳ期,成熟精子贮存越冬期,1 1月至翌年2月,成熟精子贮存在生精小管中;V期,精子排放期,翌年3～5月,精巢系数显著下降,成熟精子从生精小管脱离,通过输精管道排出体外。     

乌梢蛇卵巢显微结构的年周期变化

应用光学显微镜观察了乌梢蛇卵巢结构的年周期变化,并结合卵巢形态及卵巢系数的年周期变化探讨了其生殖规律.结果 表明,乌梢蛇的卵巢形态、卵巢系数及卵泡发育均具有较为明显的季节变化.据此认为,乌梢蛇在陕南地区的排卵时间在6月中下旬到7月上旬;乌梢蛇卵泡在不同发育阶段会产生闭锁卵泡或闭锁黄体,其意义可能在于使得体内合成的有限卵黄首先保证少量卵泡得到充分发育并排卵,最终达到延续种族的目的 .     

乌梢蛇精巢间质细胞微细结构与血清 睾酮浓度的相关性

用光镜及透射电镜观察了乌梢蛇(Zaocys dhumnades)精巢间质细胞的显微与超微结构,并利用放射免疫测定法测定了血清中睾酮浓度.结果表明,在一个年生殖周期中,乌梢蛇间质组织所占区域相对大小、间质细胞数量和显微结构均存在较明显的变化;5月份的间质细胞具有发达的管状嵴线粒体、丰富的滑面内质网、大量的脂滴等合成和分泌...     

荒漠沙蜥繁殖生态研究

荒漠沙蜥（Ｐｈｒｙｎｏｃｅｐｈａｌｕｓｐｒｚｅｗａｌｓｋｉｉ）１年繁殖１次,有明显的季节性周期。４月初出蛰时雄性精巢已相当发育,５月其重量和体积最大,６月变小,进入精子发生的晚期,７月降到最小,８月开始回升,１０月中旬入蛰时已接近春季出蛰时水平。１年内仅７月精巢中无精子。雌性出蛰后卵细胞开始发育,４月下旬进入成熟期,６月达高峰,７月下降,８月进入休止期。每雌年产卵１～３枚或１～４枚,平均１．８３（ｎ＝４８,１９８７）和２．１７（ｎ＝４８,１９９３）。特定体长组的生殖率是影响种群年平均生殖率的主要因素。生殖周期与光周期相符,光周期是影响荒漠沙蜥生殖周期的主要气候因子。     

卵胎生硬骨鱼褐菖You精巢的周期发育

研究了卵胎生硬骨鱼褐菖Ｙｏｕ（Ｓｅｂａｓｔｉｓｃｕｓ ｍａｒｍｏｒｄｔｕｓ）的精巢结构和生殖周期。褐菖Ｙｏｕ精巢属于小叶型。每年８～９月,精巢处于精原细胞增殖期。初级精原细胞分裂增殖,产生次级精原细胞。后者和支持细胞组成精小囊。１０月～翌年、月进入精子发生期。精小囊中的生殖细胞进一步发育,逐渐形成精子。２～７月是精子退化吸收期,精巢中仅有初级精原细胞和残余的精子。在生殖季节,精子经由输出管和输精管     

卵胎生硬骨鱼褐菖(鱼良)鲉精巢的周期发育

研究了卵胎生硬骨鱼褐菖(鱼良)鲉(Sebastiscus marmoratus)的精巢结构和生殖周期.褐菖(鱼良)鲉精巢属于小叶型.每年8～9月,精巢处于精原细胞增殖期.初级精原细胞分裂增殖,产生次级精原细胞.后者和支持细胞组成精小囊.10月～翌年1月进入精子发生期.精小囊中的生殖细胞进一步发育,逐渐形成精子.2～7月是精子退化吸收期,精巢中仅有初级精原细胞和残余的精子.在生殖季节,精子经由输出管和输精管运至尿殖突,通过体内受精方式送入雌鱼生殖道.     

中国林蛙婚垫的显微结构变化及其与睾酮的关系

用光镜观察中国林蛙（Rana chensinensis）婚垫显微结构的年周期变化,并对婚垫内的睾酮（T）和雄激素受体（AR）进行免疫细胞化学检测,其结果表明：婚刺的形成是由生发细胞增生、颗粒细胞数量增多和体积增大所致,其消退是由角质细胞包裹的颗粒细胞小体脱落所致。婚腺发育与婚刺形成同步,在林蛙婚配期间婚腺的分泌活动最旺盛。T和AR在颗粒细胞、生发细胞和婚腺内的分布与婚垫显微结构的变化周期一致,说明婚垫的形成与消退受T调控。婚垫发育的变化剧期与精子发生进程和精巢系数具相关性,即婚垫的形态特征可间接反应精巢的发育状况．     

二种寄生蜂寄生抑制小菜蛾精巢生长和精子束形成的比较研究

我们曾发现菜蛾盘绒茧蜂Cotesia vestalis和半闭弯尾姬蜂Diadegma semiclausum寄生严重阻碍小菜蛾Plutella xylostella幼虫的精子发生。本研究着重比较2种蜂寄生对小菜蛾精巢生长和精子束形成的影响, 以探明寄生因子对昆虫生殖调控的作用途径。 采取过寄生和假寄生方法, 对2种蜂各自寄生后的小菜蛾精巢生长体积, 精子发生和形成过程中生精细胞、精子束的显微形态变化进行了比较。 结果表明: 茧蜂和姬蜂寄生均明显降低小菜蛾精子束的数量, 严重阻碍了寄主幼虫的精子发生和精子形成. 姬蜂寄生造成小菜蛾精巢畸形, 而茧蜂则造成小菜蛾精子束畸形, 且茧蜂对小菜蛾精巢生长的抑制程度明显强于姬蜂。过寄生造成寄主寄生性去势程度加剧, 茧蜂和姬蜂过寄生后的小菜蛾精巢体积分别为0.005 mm³和0.008 mm³, 仅为各自只寄生1次后精巢体积的33.1%和36.3%。假寄生后, 发现只有寄生蜂母代物质存在的前提下, 对小菜蛾精巢生长的抑制程度基本模拟了正常寄生时的状态, 说明多分DNA病毒（polydnavirus, PDV）和毒液发挥了主要作用。 由此推断分属姬蜂属PDV和茧蜂属PDV的2类PDV功能基因对小菜蛾精巢生长发育的调控机制可能存在较大差异。     

类雄激素受体在尖唇散白蚁繁殖蚁和工蚁精子发生中的免疫细胞化学定位

为了比较和探讨类雄激素受体 (androgen receptor-like,AR-like)在白蚁生殖品级和非生殖品级精子发生过程中的作用,运用免疫细胞化学方法对尖唇散白蚁Reticulitermes aculabialis繁殖蚁和工蚁精子发生中的AR-like的定位进行了研究。结果显示：在繁殖蚁和工蚁精子发生过程中都有AR-like免疫阳性细胞的分布,均分布于初级精母细胞的细胞质和细胞核中;与繁殖蚁相比,AR-like在工蚁中的表达较弱。结果提示,AR-like的表达与精子发生过程中初级精母细胞的减数分裂有关,雄激素及其受体通过调控精母细胞的第一次减数分裂来影响白蚁精子的发生。虽然工蚁的精巢发育受抑制,但其精子发生和维持具有与繁殖蚁相同的激素调节机制,能形成精子。本研究为工蚁性腺退化不育而根据群体的变化又可以发育为补充繁殖蚁这一特殊的生理功能提供了组织学依据。     

乌梢蛇输精管道的组织学与免疫细胞化学观察

为探讨乌梢蛇(Zaocys dhumnades)输精管道结构与其功能之间的关系,该研究用一般光镜技术观察了乌梢蛇输精管道的显微结构及其年周期变化,并结合免疫细胞化学方法研究了雄激素受体(AR)、雌激素受体(ER)、孕激素受体(PR)和芳香化酶(Ar)在输精管和精巢中精子细胞表达的相关性.为验证该文在乌梢蛇输精管中观察到的大量精子和圆球状结构,用一般光镜技术还观察了黑眉锦蛇(Elaphe taeniura)、赤链蛇(Dinodon rufozonatum)与虎斑颈槽蛇(Rhabdophis tigrina lateralis)的输精管道.结果表明,乌梢蛇的输精管道主要由输出小管、附睾管与输精管构成;8-10月输出小管中有精子,8月—翌年1月附睾管中有精子,全年(除7月外)输精管中有大量精子;在输精管内首次观察到由多个精子细胞构成的圆球状结构,该结构与精巢中精子细胞的AR、ER、PR和Ar累计光密度值之间分别无显著差异.由于在乌梢蛇、黑眉锦蛇及赤链蛇的输精管内圆球状结构均可见精子细胞变态形成精子.因此,建议将蛇类输精管内圆球状结构命名为生精小球(seminiferous spherule).该文认为,蛇类精巢是精子形成的主要部位,而输精管内的生精小球是精子形成的另一个部位;附睾与输精管均可以储存精子,但输精管是精子储存的主要器官.     

Seasonal variation in spermatogenesis in the nine-banded armadillo (Dasypus novemcinctus) from Southeastern Brazil

Nine-banded armadillos living in the southeastern region of Brazil are seasonal breeders. The weight of the testes, diameter of seminiferous tubules, the number of type A spermatogonia and round spermatids at stage 1 of the cycle of the seminiferous epithelium, and volumetric proportions of Leydig cells showed significant variations during the annual reproductive cycle. These parameters reached a peak during the months of November and December when rainfall was plentiful and the number of daily hours of sunlight was at its highest level. In the period of June to August the above parameters were at their lowest values.     

Postnatal sexual development of testis and epididymis in the rabbit: growth and maturity patterns of macroscopic and microscopic markers

We examined the macroscopic variables related to the size of testis and epididymis, and the microscopic variables related to the tissue composition of testis to determine the onset of the male reproductive activity.The present work was carried out using two genetic lines of rabbits showing different reproductive aptitudes to assess the effects of genetic line and birth season on age-related changes of the testes and epididymis.The Caldes and Prat genetic lines showed similar developmental profiles for most of the variables studied. The main changes in the development pattern were observed at younger ages. The Caldes genetic line presented a greater live weight and a smaller testicular volume that the Prat genetic line at any age. No differences in the studied microscopic variables were found between the two genetic lines, except in the variable percentage of seminiferous tubules with presence of lumen.A significant effect of the birth season was found in live weight, testis volume, epididymis volume, percentage of seminiferous tubules with presence of elongated spermatids and diameter of seminiferous tubules. The absolute values and the values relatives to its own value at the adult stage of the variables live weight, testis volume, epididymis volume and in variables related to the functional maturity were lower in animals born in the summer season. Volume growth for both testis and epididymis was delayed in animals born in the summer season.     

Testicular morphological changes during the seasonal reproductive cycle in the bullfrog Rana catesbeiana

Spermatogenesis and steroidogenesis undergo seasonal variations during the reproductive cycle in amphibians. Testicular morphological and morphometric seasonal variations as well as interstitial lipidic inclusions and intralobular glycoconjugates were evaluated during seasonal cycle of Rana catesbeiana. Testes of frogs collected during the annual seasons were weighed for calculation of GSI (Gonadosomatic index). Seminiferous lobule diameters (DSL) and volume densities of seminiferous lobules (VvSL), excretory ducts (VvED), and interstitial tissue (VvIT) were analyzed. Semithin sections were submitted to Periodic Acid-Schiff (PAS) and Alcian Blue (AB) methods for detection of glycoconjugates, while lipidic inclusions were detected by Sudan Black B. GSI showed no significant variations during the year. Since VvED and VvIT increased significantly during summer and were inversely proportional to VvSL, a compensatory effect between the testicular compartments may be related to the maintenance of GSI. During autumn/winter, larger lobular diameters were observed in comparison to spring/summer when spermiogenesis and spermiation were commonly observed. The increased VvIT and the numerous lipidic inclusions in the interstitial cells during summer suggest a relationship between spermiogenesis and steroidogenesis. Besides the structural stability variations occurring in the IT and SL, a possible paracrine interaction between ED and IT should be also involved in the IT development during summer. The presence of PAS and AB-positive globular structures were observed in the seminiferous lobules and excretory ducts. These structures containing acid glycoconjugates appear to be Sertoli cell apical portions, which are accumulated in the lumen of the seminiferous lobules mainly during spermiation.     

Testis morphometry,seminiferous epithelium cycle length,and daily sperm production in domestic cats (Felis catus)

There is very little information regarding the testis structure and function in domestic cats, mainly data related to the cycle of seminiferous epithelium and sperm production. The testis weight in cats investigated in the present study was 1.2 g. Compared with most mammalian species investigated, the value of 0.08% found for testes mass related to the body mass (gonadosomatic index) in cats is very low. The tunica albuginea volume density (%) in these animals was relatively high and comprised about 19% of the testis. Seminiferous tubule and Leydig cell volume density (%) in cats were approximately 90% and 6%, respectively. The mean tubular diameter was 220 microm, and 23 m of seminiferous tubule were found per testis and per gram of testis. The frequencies of the eight stages of the cycle, characterized according to the tubular morphology system, were as follows: stage 1, 24.9%; stage 2, 12.9%; stage 3, 7.7%; stage 4, 17.6%; stage 5, 7.2%; stage 6, 11.9%; stage 7, 6.8%; and stage 8, 11 %. The premeiotic and postmeiotic stage frequency was 46% and 37%, respectively. The duration of each cycle of seminiferous epithelium was 10.4 days and the total duration of spermatogenesis based on 4.5 cycles was 46.8 days. The number of round spermatids for each pachytene primary spermatocytes (meiotic index) was 2.8, meaning that significant cell loss (30%) occurred during the two meiotic divisions. The total number of germ cells and the number of round spermatids per each Sertoli cell nucleolus at stage 1 of the cycle were 9.8 and 5.1, respectively. The Leydig cell volume was approximately 2000 microm3 and the nucleus volume 260 microm3. Both Leydig and Sertoli cell numbers per gram of testis in cats were approximately 30 million. The daily sperm production per gram of testis in cats (efficiency of spermatogenesis) was approximately 16 million. To our knowledge, this is the first investigation to perform a more detailed and comprehensive study of the testis structure and function in domestic cats. Also, this is the first report in the literature showing Sertoli and Leydig cell number per gram of testis and the daily sperm production in any kind of feline species. In this regard, besides providing a background for comparative studies with other fields, the data obtained in the present work might be useful in future studies in which the domestic cat could be utilized as an appropriate receptor model for preservation of genetic stock from rare or endangered wild felines using the germ cell transplantation technique.     

The germ cell development strategy and seasonal changes in spermatogenesis and Leydig cell morphologies of the spiny lizard Sceloporus mucronatus (Squamata: Phrynosomatidae)

The viviparous lizards of the Sceloporus genus exhibit both seasonal and continuous spermatogenesis. The viviparous lizard Sceloporus mucronatus from Tecocomulco, Hidalgo, México, exhibits seasonal spermatogenesis. This study demonstrates the relationship between changes in testis volume, spermatogenesis activity, and Leydig cells during the male reproductive cycle of S. mucronatus. A recrudescence period is evident, which starts in the winter when testicular volume is reduced and climaxes in February, when the greatest mitotic activity of spermatogonia occurs. The testicular volume and Leydig cell index increase gradually during the spring with primary spermatocytes being the most abundant cell type observed within the germinal epithelium. In the summer, the secondary spermatocytes and undifferentiated round spermatids are the most abundant germinal cells. The breeding season coincides with spermiogenesis and spermiation; testicular volume also increases significantly as does the Leydig cell index where these cells increase in both cytoplasmic and nuclear volume. During fall, testicular regression begins with a significant decrease in testicular volume and germinal epithelium height, although there are remnant spermatozoa left within the lumen of the seminiferous tubules. During this time, the Leydig cell index is also reduced, and there is a decrease in cellular and nuclear volumes within these interstitial cells. Finally, during quiescence in late fall, there is reduced testicular volume smaller than during regression, and only spermatogonia and Sertoli cells are present within the seminiferous tubules. Leydig cells exhibit a low index number, their cellular and nuclear volumes are reduced, and there is a depletion in lipid inclusion cytoplasmically.     

Growth response of testis tissue to partial castration in toads, Bufo bufo bufo

The growth response of the remaining intact testis or testis fragments to partial castration was studied as a function of the duration of the postoperative period, the amount of testis mass excised, as well as the functional state of the testes at the time of operation. Excision of about 90% of the testis mass caused a growth response that increased from slight after eight weeks to pronounced after 14 weeks. After 14 weeks the growth response was slight tounilateral excision of 75% of a testie and pronounced to bilateral excision of 75% of each testis. Subtotal castration caused formation of new seminiferous tubules within the remaining testis tissue when the operation was performed early in the annual testis cycle, whereas the growth response late in the cycle was primarily caused by increased spermatogenetic activity within existing tubules. Partial castration stimulated oocyte formation within fragmented testes, but not in a remaining intact testis. Oocyte formation within a testis fragment was independent of the presence of the Bidder's organ.     

The Pineal Gland,but Not Melatonin,Is Associated with the Termination of Seasonal Testicular Activity in an Annual Reproductive Cycle in Roseringed Parakeet Psittacula krameri

The role of the pineal gland and its hormone melatonin in the regulation of annual testicular events was investigated for the first time in a psittacine bird, the roseringed parakeet (Psittacula krameri). Accordingly, the testicular responsiveness of the birds was evaluated following surgical pinealectomy with or without the exogenous administration of melatonin and the experimental manipulations of the endogenous levels of melatonin through exposing the birds to continuous illumination. An identical schedule was followed during the four reproductive phases, each characterizing a distinct testicular status in the annual cycle, namely, the phases of gametogenic quiescence (preparatory phase), seasonal recovery of gametogenesis (progressive phase), seasonal initiation of sperm formation (pre‐breeding phase), and peak gametogenic activity (breeding phase). In each reproductive phase, the birds were subjected to various experimental conditions, and the effects were studied comparing the testicular conditions in the respective control birds. The study included germ cell profiles of the seminiferous tubules, the activities of steroidogenic enzymes 17β‐hydroxysteroid dehydrogenase (17β‐HSD), and Δ⁵3β‐hydroxysteroid dehydrogenase (Δ⁵3β‐ HSD) in the testis, and the serum levels of testosterone and melatonin. An analysis of the data reveals that the pineal gland and its hormone melatonin may play an inhibitory role in the development of the testis until the attainment of the seasonal peak in the annual reproductive cycle. However, in all probability, the termination of the seasonal activity of the testis or the initiation of testicular regression in the annual reproductive cycle appears to be the function of the pineal gland, but not of melatonin.     

The pineal gland, but not melatonin, is associated with the termination of seasonal testicular activity in an annual reproductive cycle in roseringed parakeet Psittacula krameri

The role of the pineal gland and its hormone melatonin in the regulation of annual testicular events was investigated for the first time in a psittacine bird, the roseringed parakeet (Psittacula krameri). Accordingly, the testicular responsiveness of the birds was evaluated following surgical pinealectomy with or without the exogenous administration of melatonin and the experimental manipulations of the endogenous levels of melatonin through exposing the birds to continuous illumination. An identical schedule was followed during the four reproductive phases, each characterizing a distinct testicular status in the annual cycle, namely, the phases of gametogenic quiescence (preparatory phase), seasonal recovery of gametogenesis (progressive phase), seasonal initiation of sperm formation (pre-breeding phase), and peak gametogenic activity (breeding phase). In each reproductive phase, the birds were subjected to various experimental conditions, and the effects were studied comparing the testicular conditions in the respective control birds. The study included germ cell profiles of the seminiferous tubules, the activities of steroidogenic enzymes 17β-hydroxysteroid dehydrogenase (17β-HSD), and Δ⁵3β-hydroxysteroid dehydrogenase (Δ⁵3β- HSD) in the testis, and the serum levels of testosterone and melatonin. An analysis of the data reveals that the pineal gland and its hormone melatonin may play an inhibitory role in the development of the testis until the attainment of the seasonal peak in the annual reproductive cycle. However, in all probability, the termination of the seasonal activity of the testis or the initiation of testicular regression in the annual reproductive cycle appears to be the function of the pineal gland, but not of melatonin.