Molin L, Schnabel H, Kaletta T, Feichtinger R, Hope I A, Schnabel R
Max Planck Institut für Biochemie, 82152 Martinsried, Germany.
Genetics. 1999 Jan;151(1):131-41. doi: 10.1093/genetics/151.1.131.
In the early Caenorhabditis elegans embryo five somatic founder cells are born during the first cleavages. The first of these founder cells, named AB, gives rise to 389 of the 558 nuclei present in the hatching larva. Very few genes directly involved in the specification of the AB lineage have been identified so far. Here we describe a screen of a large collection of maternal-effect embryonic lethal mutations for their effect on the early expression of a pes-1::lacZ fusion gene. This fusion gene is expressed in a characteristic pattern in 14 of the 32 AB descendants present shortly after the initiation of gastrulation. Of the 37 mutations in 36 genes suspected to be required specifically during development, 12 alter the expression of the pes-1::lacZ marker construct. The gene expression pattern alterations are of four types: reduction of expression, variable expression, ectopic expression in addition to the normal pattern, and reduction of the normal pattern together with ectopic expression. We estimate that approximately 100 maternal functions are required to establish the pes-1 expression pattern in the early embryo.
在秀丽隐杆线虫早期胚胎中，五个体细胞奠基细胞在最初几次卵裂期间产生。这些奠基细胞中的第一个，名为AB，产生了孵化幼虫中558个细胞核中的389个。到目前为止，很少有直接参与AB谱系特化的基因被鉴定出来。在这里，我们描述了一个针对大量母源效应胚胎致死突变体的筛选，以研究它们对pes-1::lacZ融合基因早期表达的影响。这个融合基因在原肠胚形成开始后不久出现的32个AB后代中的14个中以一种特征性模式表达。在怀疑在发育过程中特别需要的36个基因中的37个突变中，有12个改变了pes-1::lacZ标记构建体的表达。基因表达模式的改变有四种类型：表达减少、可变表达、除正常模式外的异位表达，以及正常模式减少并伴有异位表达。我们估计，在早期胚胎中建立pes-1表达模式大约需要100种母源功能。
