Gevers P, Dulos J, Schipper H, Timmermans L P
Department of Experimental Animal Morphology and Cell Biology, Agricultural University, Wageningen, The Netherlands.
Eur J Morphol. 1992;30(3):195-204.
The presence, location and morphology of cells containing nuage, an ultrastructural characteristic of primordial germ cells (PGCs), is described from the moment of first morphological recognition of PGC (around 100% epiboly) in embryos of the teleost fish Barbus conchonius. Thus characterized cells were studied in relation to their cellular contacts with somatic germ layer cells, possibly involved in the determination of PGCs. The results show that from the very moment that cells, likely to be PGCs, can be light microscopically identified with morphological and positional criteria (from 10 h post fertilization (p.f.) onwards), they contain nuage near the nuclear envelope, which is a strong indication of their PGC-identity. During the studied period (9-12 h and 24 h p.f.) nuage-containing cells seem to translocate from the mesoderm towards the yolk syncytial layer (YSL). These PGCs usually appear not to be directly connected with the YSL but to remain separated from the YSL by one or more endodermal extensions, at least up to 12 h p.f. Also at 24 h p.f. somatic cells separate the PGCs from the YSL.
在鲤科鱼类圆腹雅罗鱼胚胎中，从原生殖细胞（PGCs）首次形态学识别之时（约100%外包期）起，就对含有生殖质（一种原生殖细胞的超微结构特征）的细胞的存在、位置和形态进行了描述。对具有上述特征的细胞与体胚层细胞的细胞接触进行了研究，这些体细胞可能参与了原生殖细胞的确定。结果表明，从通过形态和位置标准在光学显微镜下能够识别出可能是原生殖细胞的细胞之时起（受精后10小时起），它们在核膜附近就含有生殖质，这有力地表明了它们作为原生殖细胞的身份。在研究期间（受精后9 - 12小时和24小时），含有生殖质的细胞似乎从中胚层向卵黄合胞体层（YSL）迁移。这些原生殖细胞通常似乎不与卵黄合胞体层直接相连，而是至少在受精后12小时之前通过一个或多个内胚层延伸与卵黄合胞体层保持分离。在受精后24小时时，体细胞也将原生殖细胞与卵黄合胞体层分隔开。
