Evolutionary changes of embryogenetic plans in major groups of euinsects

本课题从胚胎学的角度对原始六足类的主要类群进行了比较胚胎学研究，以期在更高的层次上更深入地理解六足类的基本原理和系统发育。复数1-1。弹尾目的内鼻构型与Dicellurata的相似，但与弹尾目的明显不同。这有力地支持了Diplura的单系化，但需要仔细重新审视Entognatha.1-2的单系学地位。第二胚膜或羊膜被认为是Etognatha的同源同型，与初生背器官的形成有关，也在Diplura中产生。这可能暗示了Diplura和Ectognatha的单系，但加强了对Entognatha的单系地位的怀疑。Ephem…更多的是2-1的角翅目。胚胎发育过程，我们的知识仍然是支离破碎的，详细描述，重点是同色异谱异构体。尾丝被无条件地认为是第11节腹突的伸长，但这种结构代表着与第11节无关的尾丝。这是昆虫学中首次提到和鉴定端粒子。借助于半薄树脂连续切片和延时录像系统，详细描述了从成熟到解理的发展过程。在受精过程中，男性原核的大量迂回迁移被发现。在昆虫受精生物学领域，表翅目的原始性可能为这一发现增添了额外的重要性。六足类和无角类3-1中胚胎本身和胚膜之间的功能专门化。本文综述了无角类胚胎固有膜和胚膜的进化变化以及它们之间功能特化的进化转变。这表明，在胚胎本身和胚胎膜之间的功能特化转换的背景下，可以对外颌动物的羊角膜褶有更深的了解。较少

In this project, major groups of primitive hexapods of which embryological knowledge is requisite to the phylogenetical accounts but fragmental and insufficient, i. e., the Diplura, Ephemeroptera and Archaeognatha, are comparative embryologically examined, aiming at the deeper comprehension of hexapod ground plan and phylogeny in higher levels.Achievements produced in this project are as follows.1. Diplura1-1. The entognathy formation of Rhabdura closely resembles that of Dicellurata but significantly differs from that of Collembola. This strongly supports the monophyly of Diplura but requires a careful reexamination of monophyletic status of Entognatha.1-2.A second embryonic membrane or the amnion, which has been regarded as an autapomorphy of Ectognatha, is found to be produced in association with the formation of primary dorsal organ, also in Diplura. This may suggest the monophyly of the Diplura and Ectognatha, but reinforces doubts on the monophyletic status of Entognatha.2. Ephem … More eroptera2-1. The embryonic developmental process, of which our knowledge still remains fragmented, is described in detail, focusing on the metamerism. The caudal filament has been unconditionally recognized to be an elongation of eleventh abdominal tergum, but it is revealed that this structure represents the telson independent of the eleventh segment. This is the first reference to and identification of the telson in the entomology.2-2. The developmental process from the maturation to cleavage is described in detail, by aid of the semi-thin resin serial sections and time-lapse video system. An extensive and circuitous migration of male pronucleus is found to be involved in the fertilization. The primitiveness of Ephemeroptera may lend additional importance to this finding in the field of biology of the insect fertilization.3. Functional specialization between the embryo proper and embryonic membranes in the Hexapoda and Atelocerata3-1. Reviewed are the evolutionary changes of the embryo proper and embryonic membranes and the evolutionary transition of functional specialization between them in Atelocerata. It is shown that a deeper insight to the amnioserosal fold in Ectognatha can be given in context of the transition of functional specialization between the embryo proper and embryonic membranes. Less