ULTRASTRUCTURAL STUDIES ON FETAL AND EARLY POSTNATAL MOUSE OVARIES .1. HISTOGENESIS AND ORGANOGENESIS
ULTRASTRUCTURAL STUDIES ON FETAL AND EARLY POSTNATAL MOUSE OVARIES .1. HISTOGENESIS AND ORGANOGENESIS
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DOI：
10.1002/aja.1001240204
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发表时间：
1969-01-01
影响因子：
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通讯作者：
BLANDAU, RJ
中科院分区：
文献类型：
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作者：
ODOR, DL;BLANDAU, RJ
本文对妊娠第12 ~ 18天和出生后第1 ~ 3天的小鼠胚胎卵巢进行了电镜观察。卵泡细胞与卵原细胞和结缔组织细胞的相互关系受到了特别的关注。在第12天，当雌性性腺可以第一次区分，相对较少的大卵原细胞可见。这些细胞松散地聚集在一起，只有少数滤泡细胞。在第13和14天，松散的卵原细胞群变得更明显，现在总是被滤泡细胞包围。从第14天开始，滤泡细胞的非常薄的胞质突起插入相邻的寡精原细胞之间。随后，通过这个过程，卵泡细胞被吸引到卵原细胞或卵母细胞群中。越来越多的结缔组织细胞和毛细血管从髓质和肺门区生长到皮质。到第18天和出生后第1天，这种向内生长进一步分离了卵母细胞和卵泡细胞。到出生后第2和3天，大多数卵细胞已被扁平、立方或柱状细胞的滤泡上皮所包围。可以识别出透明珊瑚形成的许多阶段。据推测，胎儿和出生后早期卵巢分化的方式解释了许多偏离正常的卵泡构型。从未观察到细胞索起源于生殖上皮。与此相反，下面的图尼卡白蛋白层是由髓质细胞向内生长而形成的。光镜下对哺乳动物卵巢胚胎和出生后早期发育的研究强调了生殖细胞的成分，而不是非生殖细胞的起源、分化和相互关系。最常见的观点是卵泡细胞起源于生殖上皮（艾伦，'04; Hargitt，' 25; Hartman，'26; Brambell，' 27; Gillman，'48）。在这些研究者的时代，人们还认为原始生殖细胞本身来自生殖上皮。然而，一些早期的研究表明，而且最近的证据也已确凿地表明，原始生殖细胞起源于性腺外，并通过自身的变形虫运动迁移到生殖嵴（埃弗雷特，'43;威契，' 48;祖克曼，'51;奇奎因，' 54;明茨，'57;布兰道，白色和鲁默里，' 63）。由于我们相信这一证据是确凿的，本文将不涉及生殖细胞的起源问题。
Ovaries of fetal mice obtained during the twelfth to eighteenth day of gestation and from the first to third postnatal day have been studied by electron microscopy. The interrelationships of follicle cells to oogonia and to connective tissue cells have received special attention. On day 12, when the female gonad can first be distinguished, relatively few large oogonia are visible. These are loosely aggregated and are accompanied by only a few follicle cells. On days 13 and 14 loose groups of oogonia become better demonstrated, and now are always surrounded peripherally by follicle cells. Beginning on day 14 very thin cytoplasmic processes of the follicle cells are interposed between adjacent oiigonia. Subsequently, by following this process the follicle cells are drawn into the groups of oogonia or oocytes. Increasing numbers of connective tissue cells and capillaries are growing into the cortex from the medulla and hilar regions. By day 18 and postnatal day 1 this ingrowth has separated the groups of oocytes and follicle cells further. By postnatal days 2 and 3 most oijcytes have become enclosed by a follicular epithelium of either flattened, cuboidal or columnar cells. Many stages of zona pellucida formation can be recognized. It is postulated that the manner of fetal and early postnatal differentiation of the ovary explains a number of follicular configurations which deviate from the normal. At no time have cords of cells been observed to originate from germinal epithelium. By contrast the underlying tunica albuginea is derived by ingrowth of cells from the medulla.Light microscopic studies concerned with fetal and early postnatal development of mammalian ovaries have emphasized germinal elements rather than the origin, differentiation and interrelationships of non-germinal cells. The most common view has been that the follicle cells originate from the germinal epithelium (Allen,'04; Hargitt,'25; Hartman,'26; Brambell,'27; Gillman,'48). During the era of these investigators it was believed also that the primordial germ cells themselves were derived from the germinal epithelium. How-ever, some earlier work suggested, and more recent evidence has indicated conclusively, that the primordial germ cells have an extra-gonadal origin and migrate by their own ameboid motion to the genital ridge (Everett,'43; Witschi,'48; Zuckerman,'51; Chiquoine,'54; Mintz,'57; Blandau, White and Rumery,'63). Since we believe this evidence to be firm, the present paper will not deal with the problem of the origin of germ cells.