A QUANTITATIVE-ANALYSIS OF CELL ALLOCATION TO TROPHECTODERM AND INNER CELL MASS IN THE MOUSE BLASTOCYST
A QUANTITATIVE-ANALYSIS OF CELL ALLOCATION TO TROPHECTODERM AND INNER CELL MASS IN THE MOUSE BLASTOCYST
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DOI：
10.1016/0012-1606(87)90055-8
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发表时间：
1987-02-01
影响因子：
2.7
通讯作者：
FLEMING, TP
中科院分区：
文献类型：
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作者：
FLEMING, TP
通过用短期细胞谱系标记物黄绿色荧光乳胶（FL）微粒标记早期桑椹胚（16细胞期），研究了小鼠囊胚中滋养外胚层和内细胞团（ICM）的细胞分配。FL只被内吞到外极细胞群中，并对这些卵裂球的后代保持自主性。罗丹明-伴刀豆球蛋白A被用作FL标记的对照（16细胞期）和培养（约32- 64细胞期）胚胎中外部细胞的当代标记物，即将进行细胞标记模式的解聚和分析。通过这种技术，16-细胞胚胎中外部与内部细胞数的比率在胚胎之间变化很大（平均值为10.8：5.2;范围为9：7至14：2）。在培养的胚胎中，滋养外胚层几乎完全（超过99%的细胞）来自外极16-细胞卵裂球。ICM的起源在胚胎之间变化;平均而言，大多数细胞（75%）来自内部非极性卵裂球，其余来自外部极性谱系，可能是通过分化卵裂。在连续切片检查的囊胚中，极性来源的ICM细胞主要与滋养外胚层相关，并且不在ICM核心中。在新生的囊胚正好有32个细胞之间的比例的ICM下降的极性血统和推断的大小的内部16个细胞的人口呈反比关系。从这些结果可以得出结论，16细胞桑葚胚中外部与内部细胞数量比的胚间变化通过下一次分裂时极性16细胞分配到ICM的程度来补偿，从而调节滋养外胚层与ICM的细胞数量比早期囊胚。
The allocation of cells to the trophectoderm and inner cell mass (ICM) in the mouse blastocyst has been examined by labelling early morulae (16-cell stage) with the short-term cell lineage marker yellow-green fluorescent latex (FL) microparticles. FL is endocytosed exclusively into the outside polar cell population and remains autonomous to the progeny of these blastomeres. Rhodamine-concanavalin A was used as a contemporary marker for outside cells in FL-labelled control (16-cell stage) and cultured (approximately 32- to 64-cell stage) embryos, immediately prior to the disaggregation and analysis of cell labelling patterns. By this technique, the ratio of outside to inside cell numbers in 16-cell embryos was shown to vary considerably between embryos (mean 10.8:5.2; range 9:7 to 14:2). In cultured embryos, the trophectoderm was derived almost exclusively (over 99% cells) from outside polar 16-cell blastomeres. The origin of the ICM varied between embryos; on average, most cells (75%) were descended from inside nonpolar blastomeres with the remainder derived from the outside polar lineage, presumably by differentiative cleavage. In blastocysts examined by serial sectioning, polar-derived ICM cells were localized mainly in association with trophectoderm and were absent from the ICM core. In nascent blastocyts with exactly 32 cells an inverse relationship was found between the proportion of the ICM descended from the polar lineage and the deduced size of the inside 16-cell population. From these results, it is concluded that interembryonic variation in the outside to inside cell number ratio in 16-cell morulae is compensated by the extent of polar 16-cell allocation to the ICM at the next division, thereby regulating the trophoectoderm to ICM cell number ratio in early blastocysts.