UBIQUITOUS EXPRESSION OF SEVENLESS - POSITION-DEPENDENT SPECIFICATION OF CELL FATE
UBIQUITOUS EXPRESSION OF SEVENLESS - POSITION-DEPENDENT SPECIFICATION OF CELL FATE
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DOI：
10.1126/science.2493159
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发表时间：
1989-02-17
期刊：
影响因子：
56.9
通讯作者：
HAFEN, E
中科院分区：
文献类型：
--
作者：
BASLER, K;HAFEN, E
果蝇复眼中细胞命运的规范似乎完全由细胞相互作用控制。sevenless基因是正确决定每个小眼中八个感光细胞（R7）之一所必需的。它编码一种具有酪氨酸激酶结构域的跨膜蛋白，并在包括R7前体的小眼前体细胞亚群上瞬时表达。这里显示，在整个发育过程中，热休克诱导的sevenless互补DNA的不加选择的表达可以正确地指定R7细胞的身份，而不影响其他细胞的发育。此外，在眼睛发育过程中，sevenless蛋白的不连续供应导致形成含有sevenless+和sevenless-小眼条纹的马赛克眼睛，这表明R7细胞的命运只能在小眼组装过程中相对较短的时间内指定。这些结果支持了这样的假设，即细胞命运的规格的位置依赖于一个本地化的信号与受体上存在于许多未分化的细胞的相互作用，而仅仅存在的受体本身是不够的，以指定细胞的命运。
Specification of cell fate in the compound eye of Drosophila appears to be controlled entirely by cell interactions. The sevenless gene is required for the correct determination of one of the eight photoreceptor cells (R7) in each ommatidium. It encodes a transmembrane protein with a tyrosine kinase domain and in expressed transiently on a subpopulation of ommatidial precursor cells including the R7 precursors. It is shown here that heat shock-induced indiscriminate expression of a sevenless complementary DNA throughout development can correctly specify R7 cell identity without affecting the development of other cells. Furthermore, discontinuous supply of sevenless protein during eye development leads to the formation of mosaic eyes containing stripes of sevenless+ and sevenless- ommatidia, suggesting the R7 cell fate can be specified only within a relatively short period during ommatidial assembly. These results support the hypothesis that the specification of cell fate by position depends on the interaction of a localized signal with a receptor present on many undifferentiated cells, and that the mere presence of the receptor alone is not sufficient to specify cell fate.