Germline cell formation and gonad regeneration in solitary and colonial ascidians.
نویسندگان
چکیده
The morphology of ascidian gonad is very similar among species. The testis consists of variable number of testicular follicles; the ovary consists of ovarian tubes that are thickened forming the germinal epithelium with stem cells for female germ cells with the exception of botryllid ascidians. Peculiar accessory cells that would be germline in origin accompany the oocytes. Using vasa homologues as a molecular marker, germline precursor cells can be traced back to the embryonic posterior-most blastomeres and are found in the tail of tailbud embryo in some solitary and colonial ascidians. In Ciona, they are subsequently located in the larval tail, while in colonial botryllid ascidians vasa-expressing cells become obscure in the tail. Recent evidence suggests that ascidian germ cells can regenerate from cells other than embryonic germline. An ensemble of the embryonic stringency of germ cell lineage and the postembryonic flexibility of gonad formation is discussed.
منابع مشابه
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ورودعنوان ژورنال:
- Developmental dynamics : an official publication of the American Association of Anatomists
دوره 240 2 شماره
صفحات -
تاریخ انتشار 2011