van den Biggelaar Jo A M, Haszprunar G
Department of Experimental Zoology, University of Utrecht, Padualaan 8, 3584 CH, Utrecht, The Netherlands.
Zoologische Staatssammlung München, Münchhausenstrasse 21, D-81247, München, Germany.
Evolution. 1996 Aug;50(4):1520-1540. doi: 10.1111/j.1558-5646.1996.tb03925.x.
The larger gastropod taxa are characterized by distinctive cleavage patterns. The cell stage at which the mesentoblast is formed appears to be crucial. In none of the taxa is it formed earlier than the 24- and not later than the 63-cell stage. A heterochronic shift from late to early mesentoblast formation appears to coincide with successive steps in gastropod evolution. Comparison of the early cleavage patterns appears to be a powerful method for investigating the evolutionary relations between major gastropod taxa.
较大的腹足纲分类群具有独特的卵裂模式。中胚层母细胞形成的细胞阶段似乎至关重要。在所有分类群中，中胚层母细胞的形成都不会早于24细胞阶段，也不会晚于63细胞阶段。从中胚层母细胞形成较晚到较早的异时性转变似乎与腹足纲进化的连续步骤相一致。比较早期卵裂模式似乎是研究主要腹足纲分类群之间进化关系的有力方法。
