In the course of present investigation in interspecific hybrid of tritical crops , cytomixis mas observed at microspore stage , the present investigation deals with detailed analysis of this phenomenon at different conditions 作者在麦类远缘杂种的减数分裂过程中发现,在减数分裂的前期和小孢子时期均存在核穿壁的现象,并对各种状态下的穿壁现象进行了详细的观察研究。
In order to determine the function and possible relationship between cdc2 and p70s6k in testicle and germ cells in deferent phase , we study the expression and kinase activity of cdc2 and p70s6k in male mouse germ cells 为此我们研究了雄性小鼠在不同发育阶段的睾丸组织及生殖细胞中cdc2与p ~ ( 70 ) s6k蛋白表达及活性变化,揭示了cdcz与p70s6k在生殖细胞减数分裂的调控作用及相关性。
In order to find out the cytoplasmic and nuclear mechanisms regulating meiosis and the relations between meiotic errors and age - associated changes in the oocytes , gvs were exchanged between gv oocytes from different age groups of mice 同时,在年轻小鼠的gv期卵母细胞与不同年龄段小鼠的gv期卵母细胞之间进行gv互换,以探讨细胞核与细胞质调控减数分裂的机制以及减数分裂错误与卵母细胞衰老相关变化的关系。
However , the oocytes will arrest the first meiosis at prophase in their follicles . after a long development and acquiring the meiotic resumption competence , oocytes in preovulatory follicles will resume meiosis to mature under the stimulation of preovulatory gonadotropins surge 卵母细胞减数分裂随之停滞于第一次减数分裂的前期,在卵泡中通过漫长的生长发育过程后,在一定的刺激条件下才恢复减数分裂而成熟。
Cortical granule ( cg ) is an unique type organelle of mammalian oocyte . during the maturation of oocyte , cgs shows a specific change in distribution . the generally accepted indicator of final cytoplasmic maturation is the line underneath oocyte membrane constituted by cgs 卵母细胞在成熟和受精过程中,细胞骨架发生一系列明显的变化,微管是一种重要的细胞骨架成分,对于哺乳动物卵母细胞减数分裂的完成、精子的运动、雌雄原核的结合是必不可少的。
The cyst cells enclosing spermatomeres maybe synthesize a kind of scf - like protein , which can recognize specially the c - kit receptor on the cellular membrane of spermatomeres . then c - kit is activated , dimerizing and autophosphorylating . at the same time , the tyrosine kinase domain of c - kit is activized , which phosphorylates the proteins that have sh2 domain 精母细胞周围的囊细胞可能合成scf样蛋白,特异地识别精母细胞膜上的c - kit受体,并刺激c - kit发生二聚化、自体磷酸化,激活胞内酪氨酸激酶活性,活化具有“ sh _ 2结构域”的靶蛋白,可能通过一系列信号级联,最终激活与减数分裂的相关蛋白或基因。
Linkage analysis plays an important role in gene mapping . the foundation : the two gene locuses which locate on the same chromosomal ( eg . disease gene and marker gene ) happen to cross over and recombine . the farther the distance between two locuses is , the higher the probability happening to cross over is , the lower the probability that the two locuses are inherited to offspring together is , that is , the degree of linkage is not strong . so we can estimate the distance and the degree of linkage by the recombination fraction between the two locuses to locate gene 连锁分析是基因定位主要策略之一,其基本原理是位于同一染色体上两个基因位点(例致病基因与标记基因)在减数分裂的过程中会发生交换与重组,染色体上的两个位点间距离越远,发生重组的概率就越大,两个位点在一起传给后代的机会就越少,即连锁程度弱,这样由标记位点与疾病位点间的重组率可估算出两者间的距离以及连锁程度,达到基因定位的目的。
However , kit protein doesn " t exist in oogenesis after birth . there are also c - myc positive protein granules in the spermatomeres from metaphase i to telophase ii , in the spermatozoa and in the secretory cells of the spermatheca . c - myc protein expresses not in the normal follicles , but in the follicular cells of the apoptotic ones Myc在处于减数分裂的中期至末期的精母细胞的细胞质或细胞核内呈阳性表达,在减数分裂后形成的精细胞和受精囊囊壁的上皮细胞的细胞质内也有阳性表达:但在出生后的卵子正常发生过程中无阳性表达,然而在凋亡卵泡的滤泡细胞的细胞质内有阳性表达。