Terracol R, Lengyel J A
Centre de Génétique Moléculaire CNRS, Gif sur Yvette, France.
Genetics. 1994 Sep;138(1):165-78. doi: 10.1093/genetics/138.1.165.
We have discovered a new member of the class of genes controlling embryonic dorsoventral patterning. Mutants of the thick veins (tkv) gene have been described previously (as slater alleles) as embryonic lethal, lacking dorsal epidermis, but not as showing a recognizable dorsoventral phenotype. We show here that maternal alteration of function coupled with zygotic reduction of function of tkv is strongly ventralizing. In addition, in double heterozygous combinations in the mother, tkv mutations increase the ventralizing effect of dominant, weakly ventralizing alleles of the maternal effect, dorsoventral genes easter and cactus. An interaction is also seen with zygotic dorsoventral genes: tkv interacts maternally and zygotically in double heterozygotes with decapentaplegic and zygotically with screw in double homozygotes. We conclude that both maternally and zygotically supplied wild-type tkv product can play a role in dorsoventral patterning of the early embryo. On the basis of the phenotype of trans-heterozygous adult escapers, we propose that tkv might act by potentiating the activity of the zygotically acting decapentaplegic gene.
我们发现了一类控制胚胎背腹模式形成的基因中的一个新成员。厚脉（tkv）基因的突变体先前已被描述（作为斯莱特等位基因）为胚胎致死，缺乏背部表皮，但未表现出可识别的背腹表型。我们在此表明，母体功能改变与合子中tkv功能降低相结合会强烈地使胚胎腹化。此外，在母体中的双杂合组合中，tkv突变会增强母体效应背腹基因easter和cactus的显性、弱腹化等位基因的腹化作用。在合子背腹基因中也观察到相互作用：在双杂合子中，tkv在母体和合子中与decapentaplegic相互作用，在双纯合子中与screw在合子中相互作用。我们得出结论，母体和合子提供的野生型tkv产物都可以在早期胚胎的背腹模式形成中发挥作用。基于反式杂合成年存活个体的表型，我们提出tkv可能通过增强合子作用的decapentaplegic基因的活性来发挥作用。
