Transplantation of posterior polar plasm in Drosophila. Induction of germ cells at the anterior pole of the egg.
Transplantation of posterior polar plasm in Drosophila. Induction of germ cells at the anterior pole of the egg.
复制标题
果蝇后极质移植。
DOI：
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发表时间：
1974
影响因子：
11.1
通讯作者：
A. Mahowald
中科院分区：
文献类型：
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作者：
K. Illmensee;A. Mahowald
在果蝇中，原始生殖细胞通常在前胚盘期形成于卵的后尖。为了确定后极细胞质是否能够在胚胎的另一个区域诱导原始生殖细胞的形成，将该细胞质的一部分从早期卵裂阶段的野生型胚胎转移到相同年龄的mwh e胚胎的前端。在注射后的不同时间（15 - 200分钟），将胚胎固定用于组织学分析。交替厚和薄的部分进行了检查实验诱导极细胞的存在。在以这种方式分析的一半以上的胚胎中，发现1至6个细胞含有极颗粒以及圆形核结构，这两者都是正常极细胞的特征，而不存在于胚盘细胞中。为了确定这些"极细胞"是否正常工作，即，进一步发育为生殖细胞，将mwh e胚盘胚前端诱导的细胞导入同龄的y w sn（3）宿主的后部区域。由这些胚胎产生的果蝇与y w sn（3）配偶交配。除了预期的y w sn（3）后代外，在4%的杂交中发现了mwh e杂合的野生型果蝇，因此，它们是实验诱导的极细胞的后代。从未注射的胚盘胚胎中移植正常前细胞后，在对照实验中没有出现这种果蝇。这些结果表明，后极细胞质可以转移到胚胎的前端，并且在这个假定的体细胞区域中，它仍然保留着决定原始生殖细胞形成的能力。
In Drosophila melanogaster the primordial germ cells are normally formed at the posterior tip of the egg during the preblastoderm stage. In order to determine whether the posterior polar plasm is capable of inducing the formation of primordial germ cells in another region of the embryo, portions of this cytoplasm were transferred from wild-type embryos of the early cleavage stage to the anterior tip of mwh e embryos of the same age. At various times after the injection (15-200 min), embryos were fixed for histological analysis. Alternating thick and thin sections were examined for the presence of experimentally induced pole cells. In more than half of the embryos analyzed in this way, one to six cells were found containing the polar granules as well as round nuclear structures, both of which are characteristic of normal pole cells and are not present in blastoderm cells. In order to determine whether these "pole cells" function normally, i.e., develop further into germ cells, the cells induced at the anterior tip of mwh e blastoderm embryos were introduced into the posterior region of y w sn(3) hosts of the same age. The flies resulting from these embryos were mated to y w sn(3) partners. In addition to the expected y w sn(3) progeny, wild-type flies heterozygous for mwh e and, therefore, descended from the experimentally induced pole cells were found in 4% of the crosses. Such flies did not appear in the control experiments after transfer of normal anterior cells from noninjected blastoderm embryos. These results demonstrate that the posterior polar plasm can be transferred to the anterior tip of the embryo and that in this presumptive somatic region it still retains its capacity to determine the formation of the primordial germ cells.