Maternally expressed and partially redundant β-tubulins in Caenorhabditis elegans are autoregulated

摘要: The mitotic spindle, which partitions replicated chromosomes to daughter cells during cell division, is composed of microtubule assemblies α/β-tubulin heterodimers. Positioning the spindle influences size and location cells, can be important for proper partitioning developmental determinants. We describe two semi-dominant mis-sense mutations in tbb-2, one C. elegans β-tubulin genes that are maternally expressed together required microtubule-dependent processes early embryo. These result a posteriorly displaced misoriented first division. In contrast, probable tbb-2 null allele recessive, when homozygous results less severe positioning defects only partially penetrant embryonic lethality. Two reduced levels TBB-2 protein, increased second β-tubulin, TBB-1. However, TBB-1 not mutant with an does protein. conclude feedback regulation maternal expression elegans, but cannot fully restore normal function absence isoform.