Establishment of the body plan of multicellular organisms by the primary body axis determination and cell-fate specification is a key issue in biology. We have examined the mRNA localization of three Wnt pathway components gsk3β, β-catenin, and disheveled and investigated the effects of four selective inhibitors of these proteins on the early developmental stages of the spiral cleavage embryo of the fresh water snail Lymnaea (L.) stagnalis. mRNAs for gsk3β and β-catenin were distributed uniformly throughout the embryo during development whereas disheveled mRNA showed specific localization with intra- and inter-blastomere differences in concentration along the A-V axis during spiral cleavages. Remarkably, through inhibitor studies, we identified a short sensitive period from the 2- to 4-cell stage in which GSK3β inhibition by the highly specific 1-azakenpaullone (AZ) and by LiCl induced a subsequent dramatic developmental delay and alteration of the cleavage patterns of blastomeres at the fifth cleavage (16- to 24-cell stage) resulting in exogastrulation and other abnormalities in later stages. Inhibition of β-Catenin or Disheveled had no effect. Our inhibitor experiments establish a novel role for GSK3β in the developmental timing and orientated cell division of the snail embryo. Further work will be needed to identify the downstream targets of the kinase.

中文翻译：

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GSK3β控制着剑兰（Lymnaea stagnalis）在2-4个细胞阶段进行第五次螺旋切割的时间和模式。

通过主要的机体轴确定和细胞命运规范建立多细胞生物的身体计划是生物学中的关键问题。我们已经研究了3种Wnt信号通路成分的mRNA定位GSK3 β，β-catenin的，和蓬乱，调查对淡水蜗牛螺旋卵裂胚胎的早期发育阶段，这些蛋白质四个选择性抑制剂的作用椎实螺（L. ）stagnalis。对于mRNA的GSK 3β和β-catenin的是发展过程中整个胚胎均匀分布，而散着在螺旋切割过程中，mRNA表现出特定的定位，沿卵轴的卵裂球内和卵裂球间浓度不同。值得注意的是，通过抑制剂研究，我们确定了从2到4细胞期的短敏感期，其中高特异性1-氮杂paullone（AZ）和LiCl对GSK3β的抑制作用导致随后的显着发育延迟和切割模式的改变。卵裂的卵裂在第五次分裂（16至24细胞阶段）会导致凝乳和其他异常。抑制β-连环蛋白或Disheveled无效。我们的抑制剂实验确定了GSK3β在蜗牛胚胎的发育时机和定向细胞分裂中的新作用。需要进一步的工作来鉴定激酶的下游靶标。