FORMATION AND DIFFERENTIATION OF POST-NAUPLIAR GERM BAND IN DIASTYLIS-RATHKEI (CRUSTACEA, CUMACEA) .2. DIFFERENTIATION AND PATTERN FORMATION OF ECTODERM
FORMATION AND DIFFERENTIATION OF POST-NAUPLIAR GERM BAND IN DIASTYLIS-RATHKEI (CRUSTACEA, CUMACEA) .2. DIFFERENTIATION AND PATTERN FORMATION OF ECTODERM
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DOI：
10.1007/bf01578696
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发表时间：
1976-01-01
期刊：
影响因子：
--
通讯作者：
DOHLE, W
中科院分区：
文献类型：
--
作者：
DOHLE, W
The differentiation of ectodermal cell rows arranged on the germ band of Diastylis behind the presumptive mandibular segment is described. Of the cell rows, 4 are not budded off from ectoteloblasts, but are formed directly by blastoderm cells. Behind these rows, 12 cell rows are budded off from ectoteloblasts. Eventually, the ectoteloblasts divide to form rows XIII and XIV. All of these cell rows have a fixed sequence of mitoses by which a detailed analysis of the cell-lineage up to the formation of ganglion anlagen and appendage buds is possible. The rows 0 and 1 form the anterior and middle parts of the maxillular segment. The posterior part of this segment is formed by derivatives of the subsequent cell row 2. Thus, the maxillulae are complex structures, composed by cells from different cell clones. The maxillae and the thoracic limbs are complex structures as well. Rows 2 and 3 have a similar differentiation pattern. The differences are mainly found in the appendage-forming parts. The differentiation of row 3 is nearly identical to row I, i.e., the 1st row budded off from ectoteloblasts, and to the subsequent rows II-VI. Ganglion cells are formed by the division of ganglion mother cells budded off from neuroblasts. The neuroblasts have a complicated pattern of divisions. There may be an alternation of unequal and equal mitoses. The intersegmental furrows run in a transverse and slightly oblique plant through the derivatives of one cell row. They do not indicate genealogical boundaries. The results are compared with similar developmental processes in other Mandibulata, especially Insecta. The similarities and differences in the existence of a morphological differentiation center and in the formation of appendage buds, ganglion anlagen and intersegmental furrows are discussed.
