Developmental Biology 第七章性别决定及生殖发育 Sex determination and reproduction
Developmental Biology 第七章 性别决定及生殖发育 Sex determination and reproduction
Developmental Biology 、性别表现型的决定 公元前335年, Aristotle指出性别决定于热heat),当母亲子宫的 冷超过父亲的精热时子代发育为 Ifemale, female是发育不健全 的 men。 1600s/1700s,已认识到feme可以产生能够传递亲本性状的卵子。 19世纪末之前,人们认为温度、营养、年龄等环境因素决定了性 别。有利于能量和营养储存的因子将使一个人生产女婴,而 有利于能量和营养利用的因子则使人有男婴 20世纪初, Mendel定律重新发现(900、 Mcclung发现性染色体 (1902)、 Stevens和 Wilson在昆虫上发现了性染色体组成与性 别的关系(male= XYor Xo while female=XX(1905),从而认 识到遗传物质在性别决定中起重要作用
Developmental Biology 公元前335年，Aristotle指出性别决定于热(heat)，当母亲子宫的 冷超过父亲的精热时子代发育为female，female是发育不健全 的men。 1600s/1700s，已认识到female可以产生能够传递亲本性状的卵子。 19世纪末之前，人们认为温度、营养、年龄等环境因素决定了性 别。有利于能量和营养储存的因子将使一个人生产女婴，而 有利于能量和营养利用的因子则使人有男婴。 20世纪初，Mendel定律重新发现(1900)、McClung发现性染色体 (1902)、Stevens和Wilson在昆虫上发现了性染色体组成与性 别的关系(male=XY or XO while female=XX)(1905)，从而认 识到遗传物质在性别决定中起重要作用。 一、性别表现型的决定
Developmental Biology (一)、嘴乳动物的性别决定 1. Primary sex determination 指生殖腺发育为睾丸或卵巢的选择。胚胎生殖 腺( gonad)的发育命运决定于其染色体组成,Y染 色体的存在使生殖腺的体细胞发育为 testis而非 ovary。 eg,基因型为XXY的 Klinefelter综合症惠者的 表型为mae,但不具生殖力;基因型为XO的 Turner综合症患者为不能产卵的 female
Developmental Biology (一)、哺乳动物的性别决定 1. Primary sex determination: 指生殖腺发育为睾丸或卵巢的选择。胚胎生殖 腺(gonad)的发育命运决定于其染色体组成，Y染 色体的存在使生殖腺的体细胞发育为testis而非 ovary。 e.g., 基因型为XXY的Klinefelter综合症患者的 表型为male，但不具生殖力；基因型为XO的 Turner综合症患者为不能产卵的female
Developmental Biology INDIFFERENT CONADS (U o WEEKS 生殖嵴原基有两种发育方向: Testis-Ovary mesonephric wY cord ISTIS DEVELOTMENT OVARY DEVELOIMENT Wolffian danc Degenerating Cameral Differentiation of human gonads shown in transverse section. (A)Genital ridge df a tweek embryo. (B) Genital ndge ot a 6-week indifferent gonad showing primitive conls (O S wELKS sex cords (@) Testis development in the eighth week. The sex cords kee contact Tunica / Ath the Wolffian duct(E) Ovary drvelopment in an &week human四小 the Wolffian duct, and new cortical sex cmnd surround the germ cells that have Efferent uuds Granulosa cells differentiated from Cortical sex cords and thecal cells derived from wason durt mesenchymal cells form follicles (vas deferens Wa fan duct that envelop the germ cells (H 20 WCEKS
Developmental Biology 生殖嵴原基有两种发育方向： Testis－Ovary Granulosa cells differentiated from Cortical sex cords and thecal cells derived from mesenchymal cells form follicles that envelop the germ cells
(A) SEXUALLY INDIFFERENT Gonads Figure 20. 4 Summary of the development of gonads and their ducts in mammals. Note that both the Wolffian and Mullerian ducts Metanephric are present at the indiffcrent-gonad Me tage. The regional development of the Wolffian ducts depends on the mes- Ureter Wolffian enchyme that they encounter. Lower portions of the Wolffian duct that would MUllerian normally form the epididymis will form seminal vesicle tissue if cultured with mesenchyme associated with the upp (seminal vesicle) portions of the duct. (Higgins et al., 1989) Epididymis Metanephric Oviduct kidneys Ovaries Ureters Degenerated D Mullerian duct Urinary Urinary bladder Mullerian duct Wolffian duct (vas deferens) Uterus (B) MALE (C) FEMALE GONADS Gonadal type Testis Sex cords Medullary (internal Cortical (external) DUCTS Remaining duct Wolffian for germ Duct differentiation Vas deferens, epididymis, Oviduct, uterus, cervix, seminal vesicle upper portion of vagina
Developmental Biology