Morphology and Development of Left‐Handed Singlets Derived from Mirror‐Image Doublets ofStylonychia mytilus
作者:
XINBAI SHI,
ZIJIAN QIU,
LI LU,
JOSEPH FRANKEL,
期刊:
The Journal of Protozoology
(WILEY Available online 1990)
卷期:
Volume 37,
issue 1
页码: 14-19
ISSN:0022-3921
年代: 1990
DOI:10.1111/j.1550-7408.1990.tb01107.x
出版商: Blackwell Publishing Ltd
关键词: Ciliate morphogenesis;pattern formation;unicelluar
数据来源: WILEY
摘要:
ABSTRACTMirror‐image doublets of Stylonychia mytilus include 2 sets of cortical structures, one with the normal “right‐handed” (RH) arrangement, the other with a reversed “left‐handed” (LH) arrangement. These sets, however, are incomplete, with certain structures, most notably cirri of the right marginal type, missing near the line of symmetry. When a mirror‐image doublet is bisected longitudinally to separate the RH and LH components physically, each fragment undergoes a regeneration process that restores a complete set of cortical structures, including the previously missing cirri of the right marginal type. In the resulting LH cell, all ciliary structures are present in an arrangement that is globally reversed in relation to that found in RH cells; in particular, marginal cirri of the left‐marginal type are formed at the cell's right margin, and marginal cirri of the right‐marginal type are produced at the cell's left margin. Whereas the regenerated RH fragment always divides and initiates a clone of normal singlets, the LH fragment, though structurally nearly complete, in all cases eventually dies without dividing. The cause of death is starvation due to the formation of an abnormal oral apparatus. In the Discussion, we consider the nature and consequences of a reversal of global pos
点击下载:
PDF
(1931KB)
返 回