【正文】 re we show that sperm of deer mice (genus Peromyscus) form motile aggregations, then we use this system to test predictions of sperm cooperation. We find that sperm aggregate more often with conspecific than heterospecific sperm, suggesting that individual sperm can discriminate on the basis of genetic relatedness. Next, we provide evidence that the cooperative behaviour of closely related sperm is driven by sperm competition. In a monogamous species lacking sperm competition, Peromyscus polionotus, sperm indiscriminately group with unrelated conspecific sperm. In contrast, in the highly promiscuous deer mouse, Peromyscus maniculatus, sperm are significantly more likely to aggregate with those obtained from the same male than with sperm from an unrelated conspecific donor. Even when we test sperm from sibling males, we continue to see preferential aggregations of related sperm in P. maniculatus. These results suggest that sperm from promiscuous deer mice discriminate among relatives and thereby cooperate with the most closely related sperm, an adaptation likely to have been driven by sperm competition.,第十六頁(yè)，共一百零九頁(yè)。 進(jìn)化生物學(xué)家?jiàn)W倫,2010525 9:39:40 Science：首次(shǒu c236。利用綠色熒光蛋白質(zhì)給這些細(xì)胞做上標(biāo)記以后，研究人員發(fā)現(xiàn)許多新形成的卵也會(huì)發(fā)出綠色熒光，這說(shuō)明這些細(xì)胞的確發(fā)育成了卵，因此(yīncǐ)這些細(xì)胞就是干細(xì)胞。)（migration)生殖嵴（genital ridge)germ cells 2.1.1 生殖質(zhì)與生殖細(xì)胞分化 Zygote—cleavage—AB cells and P1 cells P1P2P3P4germ cells Genes: Pie1,maternaleffect gene,oskar gene,etc.,第二十頁(yè)，共一百零九頁(yè)。,精子發(fā)生 （spermatogenesis）,第二十二頁(yè)，共一百零九頁(yè)。nɡ),功能(gōngn233。n)（testis）,睪丸的一般(yībān)結(jié)構(gòu)：,白膜,睪丸縱隔,睪丸小葉,生精小管,直精小管,睪丸網(wǎng),第二十四頁(yè)，共一百零九頁(yè)。bāo),第二十六頁(yè)，共一百零九頁(yè)。 j237。)精母細(xì)胞 (Primary spermatocyte),A型(Ad, Ap ),B型,第三十頁(yè)，共一百零九頁(yè)。,生 精 細(xì) 胞：,(1)精原細(xì)胞 (spermatogonium),(2)初級(jí)(chūj237。,生 精 細(xì) 胞：,(1)精原細(xì)胞 (spermatogonium),(2)初級(jí)(chūj237。,精 子 形 成 （ spermiogenesis ）,(4)精子細(xì)胞 ( spermatid ),第三十四頁(yè)，共一百零九頁(yè)。,精 子 發(fā) 生,Ad型精原細(xì)胞,初級(jí)(chūj237。,精子發(fā)生 Spermatogenesis,Growth,Mitosis I, Cytoplasmic division,Meiosis II, Cytoplasmic division,spermatids (haploid),secondary spermatocytes (haploid),primary spermatocyte (diploid),spermato gonium (diploid male reproductive cell),第三十八頁(yè)，共一百零九頁(yè)。,第四十一頁(yè)，共一百零九頁(yè)。,第四十五頁(yè)，共一百零九頁(yè)。,第四十九頁(yè)，共一百零九頁(yè)。,第五十三頁(yè)，共一百零九頁(yè)。,第五十七頁(yè)，共一百零九頁(yè)。,第六十一頁(yè)，共一百零九頁(yè)。,第六十五頁(yè)，共一百零九頁(yè)。,第六十九頁(yè)，共一百零九頁(yè)。,3.Germline specification in elegans（線(xiàn)蟲(chóng)(xi224。)…的of stem cell divisions, each producing the founder of a somatic cell lineage and another stem cell（aP cell). The fourth division produces a somatic founder cell and the P4 cell, which is the source of the germ line. The unfertilized egg contains germ cell determinants called Pgranules. These are initially distributed uniformly in the egg, but become restricted to the Pcells during cleavage and are eventually restricted to the P4 cell. Mutations that disrupt the embryonic cleavage pattern also affect germ line specification, while other mutations block germ cells specification without influencing embryonic polarity.,第七十三頁(yè)，共一百零九頁(yè)。ng)的） lining of the blastocoel（囊胚腔) , from which the germ cells are derived. Inactivation of the germ plasm by UVirradiation produces tadpoles(蝌蚪） that lack germ cells but are otherwise normal. In birds and mammals, there are no cytoplasmic determinants（決定子） in the eggs, and germ cells arise during gastrulation by largely uncharacterized cellcell interactions.,第七十五頁(yè)，共一百零九頁(yè)。n)） has been established. The gonads arise later in development, often at some distance from the origin of the primordial germ cells (PGCs). The PGCs must be transported to the developing gonads before forming gametes（配子）, and this involves a combination of passive （被動(dòng)的）movements rounds of division, so that the population of cells colonizing the gonads is larger than the population that started the journey.,第七十七頁(yè)，共一百零九頁(yè)。)嵴）. Migration may involve a polarized network of fibronectin（纖連蛋白） molecules in the extracellular matrix, and factors secreted by cells along the migratory route stimulate the PGCs to proliferate. In reptiles（爬行類(lèi)） and birds, germ cells are transported to the gonadal ridges by a completely different route involving the vascular system, but migration from the capillarites（毛細(xì)血管） into the gonadal ridge may also involve chemoattraction（化學(xué)吸引）.,第七十九頁(yè)，共一百零九頁(yè)。,Comparison of oogenesis and spermatogenesis,Sperm and eggs are haploid gametes that unite at fertilization to generate a diploid zygote. Their development form diploid primordial germ cells has certain features in common indicating homology (e.g. the requirement for meiosis and the derivation of specialized secretory organelles（細(xì)胞器） from the Golgi apparatus).There are also major differences, including the asymmetry and interrupted nature of oogenic meiosis, and differences in the timing of maturation.,第八十二頁(yè)，共一百零九頁(yè)。,第八十四頁(yè)，共一百零九頁(yè)。,第八十八頁(yè)，共一百零九頁(yè)。,第九十二頁(yè)，共一百零九頁(yè)。,第九十五頁(yè)，共一百零九頁(yè)。,第九十九頁(yè)，共一百零九頁(yè)。,disentangle松開(kāi)(sōnɡ kāi),第一百零三頁(yè)，共一百零九頁(yè)。),忠誠(chéng)(zhōngch233。,Sperm,Highly conserved and differentiated cell. Consists of: Head: Contains the nucleus and the acrosome – organelle filled with enzymes. Midpiece: Chock full of mitochondria Tail: Contains the flagellum,第一百零七頁(yè)，共一百零九頁(yè)。ng)總結(jié),Chapter 2。