超低温保存存前后太平洋牡蛎精子（Crassostrea gigas（Thunberg）超微结构观察

应用扫描电镜和透射电镜技术，研究超低温冷冻前后太平洋牡蛎精子形态与超微结构。结果发现，受伤精子被膜肿胀、皱褶、破裂；顶体变形、囊泡化、顶体膜肿胀，局部断裂；核膜肿胀，破裂，核空泡化；线粒体嵴变形、消失，基质电子密度降低，结构模糊；精子鞭毛被膜膨胀，鞭毛自精子基部或主、末段断裂。结果表明，超低浊冷冻和升温解冻，对牡蛎精子的膜结构损伤严重，导致精子活力和受精能力下降。     

海金沙(Lygodium japonicum)游动精子的形态发生及多层结构的研究

海金沙（Ｌｙｇｏｄｉｕｍ　ｊａｐｏｎｉｃｕｍ）精子发生过程中多层结构由生毛体发育而成,其结构与其他薄囊蕨亚纲植物相似．刚形成的多层结构由微管带和片层组成,微管带由平行排列的微管组成,片层由电子致密盘组成,无明显分层．多层结构形成后不久即转向近核侧,片层下部与一椭圆形线粒体相连而微管带贴于核膜上．随着微管带沿核膜伸长并增加微管数目,微管带逐渐包围核,核发生变形．成熟精子成３周半螺旋,核位于后部２周半而片层及所连大线粒体位于头部１周半螺旋,微管带是唯一贯穿整个细胞的结构．精子成熟后片层明显分为３层．精子头部尚有鞭毛带、嗜锇冠、额外微管带等结构存在．成熟精子中细胞质减少,仅剩大量淀粉粒、线粒体和小泡,淀粉粒位于精子后部而线粒体多依附于微管带上,核、淀粉粒、线粒体在精子后部常紧挨在一起形成一种有序的排列．     

大黄鱼精子冷冻复苏后活力和超微结构的变化

大黄鱼精子以甘油为冷冻保存剂,经冷冻-解冻复苏后观察精子的活力和超微结构变化,并进行人工授精,观察冻精的受精能力.实验结果表明,冷冻精子的活力较高(83.1±6.2)%.大部分冷冻精子结构完整,进行人工授精可以获得较高的受精率(71.5±11.6)%.与鲜精对照组比较,仍存在差异(P<0.05).部分冷冻-解冻后的精子结构出现异常,畸形率达到29.3%(P<0.01).较常见的异常是精子质膜膨胀或破损,核膜消失,染色质解体,线粒体嵴消失,轴丝断裂成许多段等.冷冻精子结构异常可能是冻精解冻复苏后精子活力和受精力下降的主要原因.     

牛精子体外获能后的超微结构变化

用肝素 咖啡因作获能剂对牛冷冻 解冻精子进行体外获能处理 ,体外培养 1h ,在透射电镜下观察精子获能后的超微结构变化。结果表明 :(1)牛精子顶体内膜和外膜均为双层膜结构 ;(2 )精子获能后顶体囊泡化的形成有多种形式 :质膜与顶体外膜融合 ,双层顶体外膜自身融合 ,顶体外膜内陷或外突打褶 ,双层顶体内膜自身融合 ,顶体内膜外突打褶形成囊泡 ;而且在同一精子的顶体反应中可同时出现多种囊泡化形式 ;(3)精子获能后 ,头部无顶体覆盖的核后区核膜膨胀 ,并与膨胀的质膜融在一起 ;(4 )精子获能后 ,尾部质膜膨胀 ,且主段质膜比中段质膜膨胀明显 ,这可能与超激活运动有关。     

中国对虾精子发生过程内质网的变化

利用透射电镜观察了中国对虾精子发生过程及纳精囊中的精子内质网变化特征,精原细胞内质网囊泡较多,内质网较少,初级精母细胞内质网囊泡较多,在细胞核一侧有１－３个内质网囊泡团,粗面内质网折叠于细胞核的一侧,环状片层体２个,次级精母细胞内质网囊泡较少,早期的精细胞细胞核周期出现与核膜平行的环核内质网,中期的精细粗面内质网形成光滑内质网。后期精细胞光滑内质网折叠或盘曲,雄虾体内的精子主体部上方内质网发达。而雌性纳精囊中精子的内质网浓缩为团块状或颗粒状。     

18-碳酸-3,4-呋喃二酯对小鼠精子超微结构的影响

研究了18-碳酸-3,4-呋喃二酯对昆明小鼠精子超微结构的影响.处死10只健康有生育力的雄性小鼠,取睾丸组织,获取具有高活力的精子悬浮液,测定18-碳酸-3,4-呋喃二酯的瞬间杀精活性;然后将经过处理的精子团块固定在2.5%的戊二醛溶液中,电镜观察.结果表明,18-碳酸-3,4-呋喃二酯的瞬间杀精浓度为4 g·L^-1.在电镜下,精子头部顶体与核膜被破坏,在核质膜周边形成大小不一的虫蚀状缺痕,严重者,细胞核膜破裂/缺损,核染色质不均匀,呈颗粒样改变,有空泡形成.由此可见,18-碳酸-3,4-呋喃二酯有很强的体外杀精作用.     

凡纳滨对虾精子超微结构及遗传失活的研究

本文研究使凡纳滨对虾精子遗传失活的方法,用波长365nm和照射距离10.5cm的不同剂量紫外线照射凡纳滨对虾精液稀释液或精荚,然后进行人工授精。结果表明,新鲜精液稀释液在0~20s照射范围内,受精作用都仍能正常发生,与卵子人工体外授精仍可获得5%的平均受精率,但胚胎在孵化前死亡;新鲜精荚在5~10min照射范围内,采用精液移植授精法可获得20%的平均受精率和3%的平均幼体孵化率。精子在2×105个/cm2的条件下,精液稀释液厚度2cm,经30s以上紫外线照射后,精子染色体可完全失活,而精荚经20min以上紫外照射后,精子染色体亦可完全失活。应用透射电镜对正常和不同时间紫外辐射的凡纳滨对虾精子形态和超微结构进行观察,结果发现,凡纳滨对虾正常精子系单一棘突类型,主要由前端棘突、中间帽状体和后主体部构成,精子无尾部,不主动运动。紫外辐射凡纳滨对虾新鲜精液稀释液10~20s的精子形态和超微结构与正常活精子无明显变化。紫外辐射30s的精子表现为顶体和棘突形态正常,而染色质散乱,后主体部壁变薄;紫外辐射60s时精子就出现明显的受损状态,主要表现为细胞核变形,核区缩小,核膜受损部分破裂,染色质散乱甚至溢出,后主体部或前部胞壁加厚、膜表面皱缩、底部凹陷,顶体部局部受损,细胞质带囊泡化,双层膜肿胀,膜间腔增大。     

罗氏沼虾精子发生的超微结构

应用透射电镜技术，研究了罗氏沼虾精子发生的全过程．观察表明：精原细胞较大，近卵圆形，核大而圆，染色质分散．初级精母细胞比精原细胞略小，染色质凝聚成块状，散布于核质中．次级精母细胞呈多边形，染色质致密，核膜双层，细胞质和核质问通过核孔进行物质交换．精细胞近圆形或多边形，染色质较密集地均匀分布，胞质较丰富，有线粒体、游离核糖体和内质网分布．精子分化早期，染色质向胞核的一侧移动，随着分化的进行，精细胞核逐渐拉长，变得弯曲．分化晚期，细胞质中出现许多膜片层结构，分泌一些碎细丝状物质，沿核的边缘向核凸起的一端推进，不断聚集、突起，最终形成具横纹精子的棘突．成熟的精子呈漏斗状，包括一个杯形的核和由其发出的一个横纹状棘突．     

基于CUDA并行平台实现核膜系统求解可满足性问题的研究

膜系统能以空间换时间的方式在多项式时间内求解NP难问题,作为膜系统中的一个新类型,核膜系统不仅包含了不同类型膜系统的特征,而且能提供一种统一性的描述．因此基于核膜系统构建系统模型,并以此求解一个典型的NP难问题：可满足性问题．为了加速对核膜系统的仿真过程,程序将在CUDA并行方式下仿真实现,通过与传统的串行方式比较,使用CUDA能减少95％的仿真时间,这也表明使用CUDA并行方式非常适合仿真核膜系统．     

海金沙（Lygodium japonicum）游动精子的形态发生及？…

海金沙（Ｌｙｇｏｄｉｕｍ ｊａｐｏｎｉｃｕｍ）精子发生过程中多层结构由生毛体发育而成,其结构与其他薄囊蕨亚纲植物相似。刚形成的多层结构由微管带和片层组成,微管带由平行排列的微管组成,片尾由电子致密盘组成,无显赫分层。多层结构形成后不久即转向近核侧,片层下部与一椭圆形线粒体相连而微管带沿核膜伸长并增加微管数目,微管带逐渐包围核,核发生变形。成熟精子成３周半螺旋,核位于后部２周半而片层及所连大线粒体     

The microtubule aster formation and its role in nuclear envelope assembly around the sperm chromatin in<Emphasis Type="Italic">Xenopus</Emphasis> egg extracts

Nuclear envelope separates cell genome from cyto-plasm in eucaryotic cells and plays a pivotal role in the cell life. The nuclear envelope is composed of two jointed membranes, the inner membrane and the out membrane, embedded the nuclear pore complexes. The out membrane is continuous with the endoplasmic reticulum (ER). The ARTICLES inner membrane faces to and connects with the chromatin through the nuclear lamina, an intermediate filamentous network thought to play a structural role for…     

Male mammals respond to a risk of sperm competition conveyed by odours of conspecific males

Sperm competition occurs when a female copulates with two or more males and the sperm of those males compete within the female's reproductive tract to fertilize her eggs. The frequent occurrence of sperm competition has forced males of many species to develop different strategies to overcome the sperm of competing males. A prevalent strategy is for males to increase their sperm investment (total number of sperm allocated by a male to a particular female) after detecting a risk of sperm competition. It has been shown that the proportion of sperm that one male contributes to the sperm pool of a female is correlated with the proportion of offspring sired by that male. Therefore, by increasing his sperm investment a male may bias a potential sperm competition in his favour. Here we show that male meadow voles, Microtus pennsylvanicus, increase their sperm investment when they mate in the presence of another male's odours. Such an increase in sperm investment does not occur by augmenting the frequency of ejaculations, but by increasing the amount of sperm in a similar number of ejaculations.     

A role for the nuclear envelope in controlling DNA replication within the cell cycle

In eukaryotes the entire genome is replicated precisely once in each cell cycle. No DNA is re-replicated until passage through mitosis into the next S-phase. We have used a cell-free DNA replication system from Xenopus eggs to determine which mitotic changes permit DNA to re-replicate. The system efficiently replicates sperm chromatin, but no DNA is re-replicated in a single incubation. This letter shows that nuclei replicated in vitro are unable to re-replicate in fresh replication extract until they have passed through mitosis. However, the only mitotic change which is required to permit re-replication is nuclear envelope permeabilization. This suggests a simple model for the control of DNA replication in the cell cycle, whereby an essential replication factor is unable to cross the nuclear envelope but can only gain access to DNA when the nuclear envelope breaks down at mitosis.     

同型孢子蕨类植物卵发生和受精作用的细胞学研究新进展

阐述了同型孢子蕨类植物有性生殖研究中卵发生和受精作用研究的一些新进展,包括颈卵器的形成、卵发育和受精作用3个方面．研究表明颈卵器来自于配子体生长点下方的原始细胞,其细胞质浓,核较大,位于细胞中央,原始细胞经2次分裂产生3层细胞,中间的为初生细胞,初生细胞经2次不等分裂形成1个卵细胞、1个腹沟细胞和1个双核颈沟细胞．卵成熟时,先后在卵细胞外产生分离腔和卵膜,进化的种类卵膜上形成了受精孔,首次证明腹沟细胞参与了受精孔的发生．受精作用研究表明精子是经受精孔钻入卵细胞的,受精时卵细胞剧烈地收缩和产生大的囊泡封阻受精孔可能是阻止多精受精的主要原因,接下来,受精卵经历核融合、雄细胞器的消化,合子细胞器的重排,质膜和细胞壁重建等过程,最终形成功能性合子．     

Sperm death and dumping in Drosophila

Mating with more than one male is the norm for females of many species. In addition to generating competition between the ejaculates of different males, multiple mating may allow females to bias sperm use. In Drosophila melanogaster, the last male to inseminate a female sires approximately 80% of subsequent progeny. Both sperm displacement, where resident sperm are removed from storage by the incoming ejaculate of the copulating male, and sperm incapacitation, where incoming seminal fluids supposedly interfere with resident sperm, have been implicated in this pattern of sperm use. But the idea of incapacitation is problematic because there are no known mechanisms by which an individual could damage rival sperm and not their own. Females also influence the process of sperm use, but exactly how is unclear. Here we show that seminal fluids do not kill rival sperm and that any 'incapacitation' is probably due to sperm ageing during sperm storage. We also show that females release stored sperm from the reproductive tract (sperm dumping) after copulation with a second male and that this requires neither incoming sperm nor seminal fluids. Instead, males may cause stored sperm to be dumped or females may differentially eject sperm from the previous mating.     

Fully effective contraception in male and female guinea pigs immunized with the sperm protein PH-20

Immunization of male and female animals with extracts of whole sperm cells is known to cause infertility. Also, men and women who spontaneously produce antisperm antibodies are infertile but otherwise healthy. Although the critical sperm antigens are unknown, these observations have led to the proposal that sperm proteins might be useful in the development of a contraceptive vaccine. The guinea pig sperm surface protein PH-20 is essential in sperm adhesion to the extracellular coat (zona pellucida) of the egg, a necessary initial step in fertilization. Here, we report that 100% effective contraception was obtained in male and female guinea pigs immunized with PH-20. Antisera from immunized females had high titres, specifically recognized PH-20 in sperm extracts, and blocked sperm adhesion to the egg zona pellucida in vitro. The contraceptive effect was long-lasting and reversible: immunized females, mated at intervals of six to fifteen months after immunization, progressively regained fertility.     

Sophisticated sperm allocation in male fowl

When a female is sexually promiscuous, the ejaculates of different males compete for the fertilization of her eggs; the more sperm a male inseminates into a female, the more likely he is to fertilize her eggs. Because sperm production is limited and costly, theory predicts that males will strategically allocate sperm (1) according to female promiscuity, (2) saving some for copulations with new females, and (3) to females producing more and/or better offspring. Whether males allocate sperm in all of these ways is not known, particularly in birds where the collection of natural ejaculates only recently became possible. Here we demonstrate male sperm allocation of unprecedented sophistication in the fowl Gallus gallus. Males show status-dependent sperm investment in females according to the level of female promiscuity; they progressively reduce sperm investment in a particular female but, on encountering a new female, instantaneously increase their sperm investment; and they preferentially allocate sperm to females with large sexual ornaments signalling superior maternal investment. Our results indicate that female promiscuity leads to the evolution of sophisticated male sexual behaviour.     

Exceptional sperm cooperation in the wood mouse

Spermatozoa from a single male will compete for fertilization of ova with spermatozoa from another male when present in the female reproductive tract at the same time. Close genetic relatedness predisposes individuals towards altruism, and as haploid germ cells of an ejaculate will have genotypic similarity of 50%, it is predicted that spermatozoa may display cooperation and altruism to gain an advantage when inter-male sperm competition is intense. We report here the probable altruistic behaviour of spermatozoa in an eutherian mammal. Spermatozoa of the common wood mouse, Apodemus sylvaticus, displayed a unique morphological transformation resulting in cooperation in distinctive aggregations or 'trains' of hundreds or thousands of cells, which significantly increased sperm progressive motility. Eventual dispersal of sperm trains was associated with most of the spermatozoa undergoing a premature acrosome reaction. Cells undergoing an acrosome reaction in aggregations remote from the egg are altruistic in that they help sperm transport to the egg but compromise their own fertilizing ability.     

MSG is involved in sperm gelatinolytic activity in the prawn, Macrobrachium rosenbergii

Proteases in male reproductive tract are considered to play key roles in fertilization processes.In contrast to mammals,there are limited data concerning crustacean sperm proteases.We previously identified a novel sperm gelatinase(MSG) from Macrobrachium rosenbergii that was inhibited by a male reproduction-related Kazal-type protease inhibitor(MRPINK) specifically.In the present study,MSG was found to be distributed on the vas deferens and terminal ampullae by Western blot.Immunohistochemical analyses revealed that MSG was expressed in secretory epithelial cells and sperm distributed mainly at the base zone.RNA interference(RNAi) mediated knock-down of MSG resulted in a marked loss of sperm gelatinolytic activity.Taken together,the results show that MSG is closely linked to and probably involved in the fertilization process.     

似刺鳊鮈精子的超显微结构及主要生物学特性

 选取健壮无伤的似刺鳊鮈亲鱼进行人工采精,应用扫描电镜和透射电镜观察了其精子超微结构,同时研究了不同温度、盐度对精子活力的影响。结果显示：① 似刺鳊鮈精子由头部、中片和鞭毛组成。头部近圆形,主要结构是细胞核,核前端无顶体,核中染色质致密均匀,后端有植入窝;中片的袖套与细胞核相连,含有丰富的线粒体和囊泡;尾部细长,主要结构是轴丝,为典型的“9+2”微管结构。② 似刺鳊鮈精子活力较适宜温度为20～28 ℃,温度为24 ℃时精子寿命最长,为1 900 s;较适盐度为5‰～8‰,盐度7‰时精子寿命最长,为1 350 s。