MAINTENANCE OF NORMAL STRUCTURE IN HETEROPLOID SALAMANDER LARVAE, THROUGH COMPENSATION OF CHANGES IN CELL SIZE BY ADJUSTMENT OF CELL NUMBER AND CELL SHAPE
MAINTENANCE OF NORMAL STRUCTURE IN HETEROPLOID SALAMANDER LARVAE, THROUGH COMPENSATION OF CHANGES IN CELL SIZE BY ADJUSTMENT OF CELL NUMBER AND CELL SHAPE
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DOI：
10.1002/jez.1401000310
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发表时间：
1945-01-01
影响因子：
--
通讯作者：
FANKHAUSER, G
中科院分区：
文献类型：
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作者：
FANKHAUSER, G
绿三尾鱼及其他种类的多倍体幼虫。火蜥蜴的数量接近。正常大小，因为细胞核和细胞的大小与染色体数目成比例地增加，被细胞数目的相应减少所抵消。在单倍体幼虫中，细胞数量的增加至少会部分补偿较小的细胞大小。在具有单细胞层的器官中，正常的尺寸和结构是通过细胞数量的变化结合单个细胞形状的变化来维持的，单个细胞的形状随着染色体数量的增加而逐渐变平。直径。因此，从单倍体到五倍体水平，前肾小管和前肾管壁的厚度以及透镜上皮的厚度保持大致相同。在五倍体幼鱼的视网膜中，细胞的行数减少到二倍体的一半。视觉细胞的单层核保持相同的直径。因为五倍体的细胞核与其高度成比例地比二倍体宽得多。这些观察结果表明，在两栖动物胚胎中，细胞数量和细胞形状都可能发生变化，以形成正常大小和结构的器官。这表明两者都受到发育中的生物体的某种控制。
Polyploid larvae of Triturus viridescens and other spp. of salamanders are of approx. normal size because the size of the nuclei and cells, which increases in proportion to the chromosome number, is neutralized by a corresponding decrease in the number of cells. In haploid larvae, an increase in cell number brings about at least a partial compensation of the smaller cell size. In organs with single cell layers, normal dimensions and structure are maintained by changes in cell number combined with changes in the shape of the individual cells which show a progressive flattening with increase in chromosome number. The diam. of the wall of the pronephric tubules and pronephric ducts, and the thickness of the epithelium of the lens thus remain about the same from the haploid to the pentaploid levels. In the retina of young pentaploid larvae the number of rows of cells is reduced to about one-half of that in the diploid. The single layer of nuclei of the visual cells retains the same diam. because the pentaploid nuclei are much wider in proportion to their height than the diploid. These observations show that in the amphibian embryo both cell number and cell shape may be modified to allow the formation of organs of normal size and structure. This indicates that both are subject to some control by the developing organism.