多肠目薄背涡虫生殖细胞发生的组织学研究

将薄背涡虫（Notoplana humilis）制成石蜡切片,通过光学显微镜观察其生殖细胞的发生过程．结果表明：薄背涡虫的精巢可划分为6个时相,每个时相的生精细胞组合图像不同,精子发生先后经历精原细胞、初级精母细胞、次级精母细胞、精细胞和精子;卵子发生先后经历卵黄发生前期的卵母细胞、卵黄发生期的卵母细胞、成熟的卵母细胞以及受精卵．对精子发生过程中各级生精细胞的特征以及卵子发生过程中各级卵细胞的特征进行了描述．     

尖唇散白蚁蚁后的性腺发育及卵子发生

采用组织学染色观察以及生物学测量与统计方法对尖唇散白蚁Reticulitermes aculabialis成熟蚁后的性腺发育以及卵子发生各阶段生殖细胞发育程度进行了研究,并与分飞繁殖蚁的性腺发育进行了比较。蚁后和分飞繁殖蚁性腺发育大小呈极显著性差异(P<0.01),两者卵巢纵切面长度之比为3.5∶1,宽度之比为3∶1,蚁后卵巢体积约是分飞繁殖蚁的19倍。蚁后在一个卵巢组织切面内卵巢管卵原区分布有数量较多的分化期卵原细胞,有130±9个;生长期卵母细胞有99±6个以及卵黄期卵母细胞有27±4个;而分飞繁殖蚁具卵黄的卵母细胞仅有3±1个。蚁后与分飞繁殖蚁相比,卵子发生的各个阶段的生殖细胞数目呈现极显著性差异(P<0.01)。研究表明,在新建巢群至成熟巢群的过程中,即由分飞繁殖蚁向蚁后发育的过程中,卵巢呈现逐渐增大以及生殖细胞增多的趋势,其生殖能力也逐步增强;成熟蚁后强大的产卵能力与其发达的卵巢以及庞大的生殖细胞数量有着直接关系。     

5种细胞周期调控基因在小鼠生殖细胞发育过程中的表达研究

 以成熟(10周龄以上)的昆明种正常小鼠的精巢和卵巢为材料,利用地高辛标记的基因探针进行组织切片上的DNA-mRNA分子原位杂交,研究了PCNA,cdc2,cyclin D1,p2 1和 p16 5种细胞周期调控基因在生殖细胞发育过程中的表达.结果表明:PCNA基因在睾丸组织的精原细胞和精母细胞中有强杂交信号,而在雌性生殖细胞及滤泡细胞的发育过程都没有杂交信号;cyclin D1,cdc2,p2 1,p16基因在生殖细胞的发育过程中都没有,表明这些基因并没有参与小鼠生殖细胞的生长和分化调控.这些事实表明在生殖细胞发育过程中,控制细胞增殖和增殖抑制的基因与培养细胞有不同的机制,它们可能采用了不同的调控系统.     

原生殖细胞的迁移、增殖及其与细胞因子的关系

原生殖细胞(PGCs)是配子的始祖细胞,它发育演变生成卵细胞或精子细胞．PGCs在其发育过程中不断地增殖并迁移,最终到达生殖嵴．本文综述了原生殖细胞的发生,迁移及其机制,原生殖细胞与细胞因子,如干细胞因子(SCF)、白血病抑制因子(LIF)、碱性成纤维细胞生长因子(bFGF)和骨形态发生蛋白(BMPs)等的关系．     

短额负蝗卵子发生及卵母细胞凋亡的组织学观察

用组织学方法对短额负蝗卵子发生和卵母细胞凋亡进行了显微观察.根据卵母细胞的大小、形态、胞核的变化、卵黄物质的形成以及滤泡细胞的形态变化等特征,将短额负蝗卵子发生分为3个时期8个阶段,并描述了各个阶段卵母细胞和滤泡细胞的形态特征.卵子发生过程中卵母细胞凋亡现象主要发生在卵母细胞生长期,特征主要表现为滤泡细胞向卵母细胞质内分裂增殖,卵母细胞的胞质不均匀,出现许多空泡状物质.     

敏感和抗性的白血病HL60细胞对staurosporine诱导凋亡的不同反应(英)

用对蛋白激酶具有强烈抑制、作用广泛的抑制剂staurosporine（Sta）,研究敏感和抗三尖杉酯碱的人白血病HL60细胞中凋亡和多药抗药性的关系．Sta均能诱导2种细胞发生典型的凋亡,但抗性细胞发生凋亡需更长的时间,凋亡的细胞数减少．Sta增加柔红霉素在抗性细胞内的积聚,说明其能逆转多药抗药性．在抗性细胞凋亡过程中,mdrl基因表达没有变化,c-myc基因表达稍有增加．结果显示：Sta能诱导敏感和抗三尖杉酯碱的HL60细胞发生凋亡,mdrl基因表达与凋亡过程无关．     

细胞凋亡与动物再生

凋亡是有机体自主程序性死亡方式之一,是生物体正常的生理机能.再生主要指生物体组织或器官在遭受到损伤之后,重建恢复的过程.越来越多的研究表明,细胞凋亡能促进再生程序启动,两者之间存在紧密关系.本文根据动物在演化进程中的地位,阐述了细胞凋亡在低等无脊椎动物、鱼类、有尾两栖类及高等哺乳动物再生过程中的主要成果和最新进展,并总结了细胞凋亡对动物再生可能的作用机制.     

波纹巴非蛤雌性生殖腺的组织学研究

波纹巴非蛤雌性生殖腺中的卵巢由生殖管和输卵管构成．生殖管反复分枝形成生卵小管和其末端膨大的生殖泡囊状结构．卵巢壁薄,由外膜和内生殖上皮组成．外膜主要由结缔组织、单层上皮和薄层肌肉组成,它有许多延伸物伸入卵巢中把卵巢分成一个个不规则小区（即分枝的管状结构,或卵巢小管）．内生殖上皮不断增殖产生生殖带,其中含有卵原细胞等各阶段雌性生殖细胞．卵子的发生可根据卵细胞、细胞核及核仁的大小形态和卵黄积累情况分为：１．卵原细胞期;２．初级卵母细胞期;３．次级卵母细胞期;４．卵黄合成初期卵母细胞;５．卵黄合成中期的卵母细胞;６．卵黄合成后期卵母细胞;７．卵母细胞成熟期．发育早期卵母细胞的核仁出现核仁排出物,较晚期的卵母细胞和成熟卵子的核仁变成双质核仁．本文还报道了波纹巴非蛤卵巢中独特的卵子退化现象．卵巢的发育有季节性的变化．     

栉江珧生殖细胞的发生

通过观察栉江珧（Ａｔｒｉｎａ ｐｅｃｔｉｎａｔａ ｌｉｎｎａｅｕｓ）的未分化生殖细胞,精原细胞和卵原细胞,精母细胞和卵母细胞,精子和卵子的形态结构与分布状况及核仁在卵成熟过程中的变化,对栉江珧生殖细胞发生及成熟过程的关问题进行了探讨。     

中华蚱蜢卵子发生的观察

对中华蚱(Acrida chinensis)卵子发生过程进行了形态观察及描述．根据卵母细胞体积及核的变化、卵黄形成、滤泡细胞的形态变化等特征指标显示，可将卵子发生划分为八个阶段．第一阶段：卵母细胞位于原卵区，处于第一次减数分裂的前期．第二阶段：卵母细胞进入生长阶段，滤泡细胞零星地在其周围．第三阶段：卵母细胞体积变大，滤泡细胞呈单层均匀包围卵母细胞．第四阶段：进入卵黄形成准备期．第五阶段：卵黄形成开始．第六阶段：卵母细胞内充满卵黄，卵母细胞核膜消失．第七阶段：卵壳出现，滤泡细胞呈扁平状．第八阶段：卵子发育成熟．     

Gene silencing: maturation of mouse fetal germ cells in vitro

Nuclear reprogramming is essential during gametogenesis for the production of totipotent zygotes. Here we show that premeiotic female germ cells derived from mouse fetuses as early as 12.5 days post coitum are able to complete meiosis and genomic imprinting in vitro and that these matured oocytes are highly competent in supporting development to full term after nuclear transfer and in vitro fertilization. To our knowledge, this is the first time that complete oogenesis has been successfully accomplished in vitro.     

Genetically haploid spermatids are phenotypically diploid

Because chromosomal homologues segregate from one another during meiosis, spermatids are genetically different. Post-meiotic gene expression could lead to gametic differences, some of which might lead to preferential transmission of certain alleles over others. In both insects and mammals, however, all the cells derived from a single spermatogonial cell develop within a common syncytium formed as a result of incomplete cytokinesis at each of the mitotic and meiotic cell divisions. It has been proposed that the intercellular bridges connecting the cells, which are about 1 micron in diameter, permit the sharing of cytoplasmic constituents, thus ensuring the synchronous development of a clone of cells and gametic equivalence between haploid spermatids. By analysing the product of a transgene which is expressed exclusively in post-meiotic germ cells in hemizygous transgenic mice, we have shown that genetically distinct spermatids share the product of the transgene and hence can be phenotypically equivalent.     

细胞凋亡与肿瘤治疗

细胞凋亡与许多疾病特别是肿瘤的发生发展有关，许多癌基因与抑癌基因参与细胞凋亡过程。对细胞凋亡以及在肿瘤治疗中的有关系进行了综述。     

拟黑多刺蚁(Polyrhachis vicina)性腺雌激素相关受体基因的表达

采用原位杂交方法对拟黑多刺蚁(Polyrhachis vicina)蚁后卵巢中和雄蚁精巢中pvERR mRNA的表达进行了检测.结果表明,pvERR mRNA在卵子发生过程中滤泡细胞的胞质和生长期、卵黄发生期的卵母细胞有表达.在变形期的精细胞胞质和成熟精子头部有很强的表达.     

Release of mature starfish oocytes from interphase arrest by microinjection of human centrosomes

Mature oocytes (unfertilized eggs) are arrested at definite cell-cycle stages which vary from species to species. In frogs and mammals, the oocytes are arrested at the second metaphase of meiosis whereas in echinoderms they are blocked later, at the pronucleus stage. What causes the maturing oocytes to stop at some point in the cell cycle is not entirely clear. In frogs, the metaphase arrest seems to be maintained by a cytostatic factor. In echinoderms, which stop at interphase, no such a factor has so far been found. The fertilization process, beyond the introduction of paternal chromosomes, releases the oocyte from cell-cycle arrest and provides a functional centrosome to replace the endogenous centrosome which is apparently lost during oogenesis in most species. Several lines of evidence suggest that release from cell-cycle arrest is mediated by a Ca2+ burst which is associated with fertilization, and it is known that the functional centrosome provided by the sperm is necessary for mitotic spindle formation and cleavages. We report here that microinjection of purified human centrosomes into mature starfish oocytes is sufficient to release them from arrest at interphase and to support many cleavages leading to the occasional formation of normal embryos. In this species centrosome induced re-entry into the cell cycle does not require a transient calcium burst nor does it require intact microtubules.     

中华绒螯蟹(Eriocheir sinensis)雌性生殖系统的组织学研究

以组织切片方法研究中华绒螯蟹雌性生殖系统结构以及卵子发生和卵巢发育的周年变化表明:卵巢壁由外膜及内生殖上皮组成;输卵管壁由外膜及管壁上皮组成;受精囊分为伸展腔和皱缩腔,二者囊壁上皮结构不同,并有周期性变化。卵子发生根据卵细胞、细胞核及核仁的大小形态、核质比(NP)和卵黄积累情况可分为:1.卵原细胞期:2.小生长期;3.大生长期;4.成熟前期和5.成熟期。卵巢发育则根据第一批卵细胞的发育情况、卵巢长度及颜色分为五期,大致可归纳为三个阶段:5～7月为延缓期;8～11月为对数增长期:12～4月为稳定期。     

中华绒螯蟹(Eriocheir sinensis)雌性生殖系统的组织学研究

以组织切片方法研究中华绒螯蟹雌性生殖系统结构以及卵子发生和卵巢发育的周年变化表明:卵巢壁由外膜及内生殖上皮组成;输卵管壁由外膜及管壁上皮组成;受精囊分为伸展腔和皱缩腔,二者囊壁上皮结构不同,并有周期性变化。卵子发生根据卵细胞、细胞核及核仁的大小形态、核质比(NP)和卵黄积累情况可分为:1.卵原细胞期;2.小生长期;3.大生长期;4.成熟前期和5.成熟期。卵巢发育则根据第一批卵细胞的发育情况、卵巢长度及颜色分为五期,大致可归纳为三个阶段:5～7月为延缓期;8～11月为对数增长期;12～4月为稳定期。     

Eomesodermin is required for mouse trophoblast development and mesoderm formation

The earliest cell fate decision in the mammalian embryo separates the extra-embryonic trophoblast lineage, which forms the fetal portion of the placenta, from the embryonic cell lineages. The body plan of the embryo proper is established only later at gastrulation, when the pluripotent epiblast gives rise to the germ layers ectoderm, mesoderm and endoderm. Here we show that the T-box gene Eomesodermin performs essential functions in both trophoblast development and gastrulation. Mouse embryos lacking Eomesodermin arrest at the blastocyst stage. Mutant trophoectoderm does not differentiate into trophoblast, indicating that Eomesodermin may be required for the development of trophoblast stem cells. In the embryo proper, Eomesodermin is essential for mesoderm formation. Although the specification of the anterior-posterior axis and the initial response to mesoderm-inducing signals is intact in mutant epiblasts, the prospective mesodermal cells are not recruited into the primitive streak. Our results indicate that Eomesodermin defines a conserved molecular pathway controlling the morphogenetic movements of germ layer formation and has acquired a new function in mammals in the differentiation of trophoblast.     

Expression and regulation of orphan receptor TR2 mRNA in germ cells of cryptorchid testis in rat and rhesus monkey

Expression and cellular localization of orphan receptor TR2 mRNA in relation to germ cell apoptosis in cryptorchid testes of rat and rhesus monkey have been studied by usingin situ hybridization andin situ 3′-end labeling of DNA fragments (TUNEL). The results show that: (i) TR2 mRNA is specifically expressed in the germ cells, mainly in the spermatocytes, round and elongated spermatids. The expression level of TR2 mRNA varies with the seminiferous cycle, (ii) In the rat cryptorchid testes on days 3 and 5 after the surgery, the germ cells began to undergo apoptosis with no evident decrease in TR2 mRNA level. On day 7.5, however, most germ cells underwent apoptosis, while the expression level of TR2 mRNA declined markedly, and TR2 mRNA was rarely expressed on day 10 thereafter, (iii) On days 15 and 20 of the cryptorchid testes of rhesus monkey, TR2 mRNA was only expressed in a few of primary spermatocytes and the mRNA was almost undetectable on days 30, 45, 60. These results suggest that TR2 mRNA probably plays an important role in spermatogenesis and germ cell apoptosis.