长吻wei精巢发育的分期及精子的发生和形成

长吻wei精巢的发育分为精原细胞增殖期、精母细胞生长期、精母细胞成熟期、精子细胞出现期、精子完全成熟期和精子退化吸收期。精巢的后1/3不产生也不贮存精子,精子的发生和形成经过精原细胞、精母细胞、精子细胞到精子的一系列过程。精原细胞有两种类型。精子无顶体,有中心粒帽,中片长,核凹窝和线粒体发达,鞭毛具侧鳍。     

锯缘青蟹精巢发育的组织学观察

组织学观察表明,锯缘青蟹（Scylla serrata)精巢发育周期可以分为精原细胞期,精母细胞期,精子细胞期,精子期和休止期5个时期。在划分精巢发育期的基础上,结合生精小管直径的成熟节段比例这2个指标,可以较准确地反映锯缘青解精巢的发育状况。而成熟节段比例可以作为锯缘青蟹精巢发育的表征指标。     

粗糙沼虾精巢发育的组织学

利用光镜技术,对粗糙沼虾精巢发育进行了研究,根据精子发生过程中每种生殖细胞所占的比例和发生的次序,并结合精巢的形态特征,把精巢发育过程分为五个时期,即精原细胞期,精母细胞期,精细胞期,成熟精子期及退化期,精原细胞期,精巢小,透明乳白色,生精小管内的生殖细胞以精原细胞为主;精母细胞期;精巢体积增大,半透明乳白色,主要由处于初级精母细胞的次级精母细胞阶段的生殖细胞组成;精细胞期,精巢体积继续增大,颜色加深,生精小管内的生殖细胞以精细胞为主;成熟精子期,精巢体积可达最大,紫红色,生精小管内充满着成熟的精子,退化期;精巢体积减小,半透明乳白色,生精小管内的成熟精子几乎排空。     

长江江豚精巢发育和组织学特征的研究

性成熟的江豚精巢明显增大,其重量约为成熟前的14倍,结合有关江豚捕捞和野外生态学资料,初步认为长江江豚属多雌性群体,而成熟的雄性个体具有较大的精巢,可能对保证群体的成功繁殖非常重要。根据精巢的组织学特征,可将江豚精巢发育分为胚胎早期、胚胎晚期、成熟前期和成熟期(包括活动期和不活动期),通过对精巢生精小管管径大小和白膜厚度进行分析,认为成熟江豚精巢活动呈季节性变化。     

四平地区六种优势蝗虫精巢发育的动态变化

在吉林省四平地区对6种优势蝗虫进行野外罩养,从成虫出现到死亡期间,对蝗虫精巢发育动态变化进行解剖学测量、统计分析和组织学观察。结果表明,蝗虫成虫刚出现时精巢发育水平较高,精巢长度显著增长但宽度增长差异不显著,随着虫体发育精巢体积达到峰值后出现下降趋势。不同种蝗虫精巢发育具有明显的种间差异,成虫出现时其精巢发育水平依次为长翅素木蝗>黄胫小车蝗>绿牧草蝗>素色异爪蝗>条纹异爪蝗>异翅负蝗,并且各蝗虫类群精巢发育的体积动态变化各不相同,体现出各蝗虫类群精巢生理功能的强弱。组织学观察显示,蝗虫发育不同时期精巢内以不同类型的精母细胞为主,精巢体积增长是精母细胞增长和成熟精子积累的结果,精巢体积下降为交配活动导致的大量精子外排以及其生理机能减退所至。     

柑橘大实蝇精巢、精泵和精泵内骨骼的生长发育状况

【目的】柑橘大实蝇是一种严重为害柑橘类果实的经济害虫。研究其精巢、精泵以及精泵内骨骼生长发育状况,有助于提高柑橘大实蝇人工繁殖效率以及其田间防治效果,为柑橘大实蝇的预测预报及防治提供理论基础。【方法】基于光学显微镜测量恒温和室温条件下柑橘大实蝇雄虫的精巢、精泵以及精泵内骨骼的长度和宽度,并建立其长度、宽度和指数的函数模型,比较恒温和室温2种饲养条件下其雄虫器官发育状况差异。【结果】无论是在恒温还是室温条件下饲养,随着柑橘大实蝇雄成虫日龄的增加,其精巢、精泵以及精泵内骨骼的长度、宽度和指数变化趋势均符合幂函数增长模型。在恒温和室温条件下,其雄虫的精巢宽度、精泵的长度和宽度以及指数、精泵内骨骼宽度均无明显差异。在室温条件下饲养的雄虫的精巢长度[(4.00±0.14) mm]及指数(3.40±0.14)、精泵内骨骼长度[(1.65±0.03) mm]及指数(1.84±0.08)均分别显著高于在恒温条件下饲养的雄虫的精巢长度[(3.75±0.13) mm]及指数(3.19±0.14)、精泵内骨骼长度[(1.61±0.03) mm]及指数(1.77±0.08)。【结论】变温(室温)比恒温更有利于柑橘大实蝇雄虫的精巢和精泵内骨骼的发育,并推荐使用精泵长度推断其雄虫日龄的方法。     

家蚕Fox转录因子在精巢中的表达特征及BmFoxL2在精巢发育中的功能初探

Fox家族蛋白广泛存在于植物以外的物种中,是一类与发育相关的重要转录因子.但是不同Fox基因在鳞翅目昆虫家蚕Bombyx mori精巢中的表达特征,以及BmFoxL2亚家族蛋白在精巢发育中的功能未知.本文检测了家蚕12个BmFox基因在家蚕精巢中的表达量,发现BmFoxL2-2的表达量最高,BmFoxL2-1次之.Bm...     

长吻鮠精巢发育的分期及精子的发生和形成

长吻鮠精巢的发育分为精原细胞增殖期、精母细胞生长期、精母细胞成熟期、精子细胞出现期,精子完全成熟期和精子退化吸收期。精巢的后1/3不产生也不贮存精子,精子的发生和形成经过精原细胞、精母细胞、精子细胞到精子的一系列过程。精原细胞有两种类型。精子无顶体,有中心粒帽,中片长,核凹窝和线粒体发达,鞭毛具侧鳍。     

男性排精后血清睾酮水平的周期性变化

为了解男性排精后可能存在的性激素变化过程,在排精后连续禁欲的情况下,对28人血清睾酮（T）水平进行了两个时段的每天定时检测,检测发现,在排精后连续禁欲的第2-5天,睾酮水平变化不明显;在禁欲的第7天,睾酮水平出现一个明显的高峰,峰值平均提高至底线的145.7%,第7天后如果再继续禁欲,没有再发现明显的变化,排精是这一周期性现象的前提和开始,没有排精就没有这种独特的周期性变化,这些结果说明男性排精会引起睾酮水平的周期性变化,这种变化的形式以禁欲第7天出现一个高峰为标志,这些结果证实了血清睾酮水平这种周期性变化现象的存在以及排精与这一现象之间的联系。     

细鳞鱼精巢超微结构和精子发生

细鳞鱼Brachymystax lenok(Pallas)精巢为叶型;支持细胞(Sertoli cell)和Leydig细胞具有典型内分泌细胞的一些结构特征;A型精原细胞的细胞器是区域性分布,精原细胞线粒体的发育与拟染色质 (chromatoid bodies)有关;生精细胞(spermatogenic cell)核膜孔由均匀排布最终演变为区域性聚集。重复注射绒毛膜促性腺激素(hCG)可促进雄鱼性成熟;精子质量受到多种因素的影响。     

海月水母生长规律及水管系统发育研究

本文对烟台海域海月水母水母体阶段伞径、腕长及体重的生长规律进行了研究,并首次对其生长过程中水管系统的发育进行了观察。结果表明,在人工培养条件下,海月水母体重(W)与伞径(D:15~150㎜)呈幂函数增长;腕长(L)与伞径(D)呈线性关系;伞径生长曲线方程为：Dt = 4×10-6t4-0.0014t3 0.1087t2 0.5079t 9.428 (R2=0.9993)。。海月水母初生碟状体出现主辐管与间辐管,3日龄时碟状体出现从辐管,11日龄时出现环管、分离点。随着水母的生长,伞径增大,水管系统的分离点数与聚合点数逐渐增多,成熟时1/4伞部分离点数最多为66个,聚合点数最多为32个。     

Rat sperm AS-A: subcellular localization in testis and epididymis and surface distribution in epididymal sperm

In this study, we investigated the subcellular compartmentalization of arylsulfatase-A (AS-A) in the testis and epididymis as well as the surface distribution in rat epididymal sperm. Testicular AS-A was compartmentalized specifically to the area underneath the outer acrosomal membrane of the acrosomal granule and to the dorsal aspect of the sperm acrosome. Epididymal AS-A was synthesized in the endoplasmic reticular (ER) network of principal cells and secreted into epididymal lumen as evident by its reactivity in the apical cytoplasm and vesicles therein underneath stereocilia. In clear cells, AS-A reactivity was found throughout the cytoplasmic machineries involved in endocytosis. Surface distribution of AS-A was initially detectable at the concave ridge as early as in sperm of the initial segment (IS). AS-A was additionally localized to the post-acrosomal region in caput (CP), corpus (CO) and cauda (CD) epididymal sperm. The expression levels of surface AS-A gradually increased during sperm transit from IS to CD epididymidis. These results favored the adsorption of AS-A from epididymal fluid onto the sperm surface, rather than shunting from the acrosome as a consequence of capacitation-associated membrane priming.This work was supported by Research Initiate Grant funded by Faculty of Science, Mahidol University to W.W.     

The ultrastructure of the Sertoli cell of the vervet monkey, Chlorocebus aethiops

The ultrastructure of the Sertoli cell of the vervet monkey was studied using both scanning and transmission electron microscopic techniques. SEM micrographs revealed perforated sleeve-like processes which encased mature elongated spermatids which are ready for spermiation. TEM micrographs showed a large Sertoli cell nucleus characterized by many lobes (4–5) and consisting of a homogenous nucleoplasm and a distinctive nucleolus. The nucleus occupies a significant portion of the basal region of the cell. The distribution of chromatin clearly shows high activity of these cells. Lipid droplets and free ribosomes are also found scattered throughout the cytoplasm. Well-developed Golgi apparatus is found in the basal region of the cell. There is phagocytic activity in the Sertoli cells as revealed by the presence of numerous phagosomes. Numerous mitochondria with well-developed tubular cristae are found on the basal side of the nucleus, whereas few mitochondria are located on the apical side of the nucleus. Distinct desmosomes are located between cells. A well-developed smooth endoplasmic reticulum and granular endoplasmic reticulum are frequently found in the cytoplasm of the Sertoli cells. The results of this investigation showed that Sertoli cells of the vervet monkey are almost similar to those of humans and show many similarities with other mammalian species.     

Heligmosomoides polygyrus Venom Allergen-like Protein-4 (HpVAL-4) is a sterol binding protein

Heligmosomoides polygyrus bakeri is a model parasitic hookworm used to study animal and human helminth diseases. During infection, the parasite releases excretory/secretory products that modulate the immune system of the host. The most abundant protein family in excretory/secretory products comprises the venom allergen-like proteins (VALs), which are members of the SCP/TAPS (sperm-coating protein/Tpx/antigen 5/pathogenesis related-1/Sc7) superfamily. There are >30 secreted Heligmosomoides polygyrus VAL proteins (HpVALs) and these proteins are characterised by having either one or two 15?kDa CAP (cysteine-rich secretory protein (CRISP)/antigen 5/pathogenesis related-1) domains. The first known HpVAL structure, HpVAL-4, refined to 1.9?Å is reported. HpVAL-4 was produced as a homogeneously glycosylated protein in leaves of Nicotiana benthamiana infiltrated with recombinant plasmids, making this plant expression platform amenable for the production of biological products. The overall topology of HpVAL-4 is a three layered αβα sandwich between a short N-terminal loop and a C-terminal cysteine rich extension. The C-terminal cysteine rich extension has two strands stabilized by two disulfide bonds and superposes well with the previously reported extension from the human hookworm Necator americanus Ancylostoma secreted protein-2 (Na-ASP-2). The N-terminal loop is connected to alpha helix 2 via a disulfide bond previously observed in Na-ASP-2. HpVAL-4 has a central cavity that is more similar to the N-terminal CAP domain of the two CAP Na-ASP-1 from Necator americanus. Unlike Na-ASP-2, mammalian CRISP, and the C-terminal CAP domain of Na-ASP-1, the large central cavity of HpVAL-4 lacks the two histidines required to coordinate divalent cations. HpVAL-4 has both palmitate-binding and sterol-binding cavities and is able to complement the in vivo sterol export phenotype of yeast mutants lacking their endogenous CAP proteins. More studies are required to determine endogenous binding partners of HpVAL-4 and unravel the possible impact of sterol binding on immune-modulatory functions.     

Do respiratory metabolic rates of the scyphomedusa Aurelia aurita scale isometrically throughout ontogeny in a sexual generation?

We measured the respiration rate of Aurelia aurita payingspecial attention to the relationship between its metabolic ratesand body mass throughout ontogeny of the jellyfish in a sexualgeneration. Two different regression lines between respirationrates and body dry weight were obtained in ephyra to young medusa(bell diameter 4.2–19 mm, 0.07–14 mg dry weight) and medusa(BD17-120 mm, 12-2100 mg DW), at respective temperatures of 10 and15 °C. The cut off point of the metabolic rates was foundat the developmental stage just being metamorphosed into medusashape (BD 12–20 mm). The slope value of medusa respiration ratewas close to isometric scaling (0.9), whereas that of ephyra toyoung medusa was lower (0.6). Ecological implications of allometricscaling in the early developmental stages of ephyrae and metephyraeare discussed.     

一种醇类雄性不育剂对高原鼠兔精子的影响

高原鼠兔(Ochotona curzoniae),隶属于兔形目(Lagomorpha),鼠兔科(Ochotonidae),又名黑唇鼠兔,主要分布于青藏高原及其边缘地带,栖息于海拔4 000 m左右的宽谷草原草甸区(王酉之和胡锦矗,1999),在食物链中扮演着重要的角色,是青藏高原草原生态系统中的关键物种.近年来随着全球变暖、若尔盖湿地水位下降等因素,高原鼠兔在若尔盖湿地繁殖加快,高原鼠兔成了危害草原生态系统的主要害兽(刘少英,2005).1997年,若尔盖湿地高原鼠兔平均种群密度为6 400只/km2(刘少英和冉江洪,1999),据我们2007年的调查显示,平均种群数量上升到25 000只/km2,控制鼠兔数量迫在眉睫.     

精子介导转基因动物的制备

近年来 ,通过显微注射DNA至孵育的卵母细胞原核或外源基因转染后的胚胎干细胞进行转基因动物的生产已取得了令人瞩目的成就。在过去的 1 0年中 ,以精子作载体制备转基因哺乳动物或脊椎动物也取得了一些不同程度的进展。这些技术主要包括 :直接将外源DNA与精子共孵育至成熟 ;提取分离的精子DNA或进行预处理至精子发育成熟 ;以及在辅助受精前分离精子细胞等。此外 ,一些显微注射技术 ,如在输精管内进行体内直接转染雄性生殖细胞 ;将体内转染的雄性生殖细胞植入已分离的雄性生殖细胞 ,再显微注射至受体的睾丸 ,这些技术也逐渐成熟起来。研究表明 ,通过体内、体外转染外源DNA的显微操作技术只需将雄性受体与野生型雌性交配就可产生出转基因的后代个体 ,同时也避免了辅助受精和胚胎操作带来的机械损伤 ,因此具有一定的优势。本文综述了精子介导转基因 (SMGT)技术的发展历程、研究现状及前沿进展。