Institute of Enzymology, Research Centre for Natural Sciences, H-1117 Budapest, Hungary.
Genes (Basel). 2021 Mar 8;12(3):382. doi: 10.3390/genes12030382.
Division of labor and establishment of the spatial pattern of different cell types of multicellular organisms require cell type-specific transcription factor modules that control cellular phenotypes and proteins that mediate the interactions of cells with other cells. Recent studies indicate that, although constituent protein domains of numerous components of the genetic toolkit of the multicellular body plan of Metazoa were present in the unicellular ancestor of animals, the repertoire of multidomain proteins that are indispensable for the arrangement of distinct body parts in a reproducible manner evolved only in Metazoa. We have shown that the majority of the multidomain proteins involved in cell-cell and cell-matrix interactions of Metazoa have been assembled by exon shuffling, but there is no evidence for a similar role of exon shuffling in the evolution of proteins of metazoan transcription factor modules. A possible explanation for this difference in the intracellular and intercellular toolkits is that evolution of the transcription factor modules preceded the burst of exon shuffling that led to the creation of the proteins controlling spatial patterning in Metazoa. This explanation is in harmony with the temporal-to-spatial transition hypothesis of multicellularity that proposes that cell differentiation may have predated spatial segregation of cell types in animal ancestors.
分工和多细胞生物不同细胞类型的空间模式的建立需要细胞类型特异性转录因子模块，这些模块控制细胞表型和介导细胞与其他细胞相互作用的蛋白质。最近的研究表明，尽管后生动物多细胞体计划遗传工具包的许多组成部分的蛋白质结构域存在于动物的单细胞祖先中，但以可重复的方式排列不同身体部位所必需的多结构域蛋白质的 repertoire 仅在后生动物中进化。我们已经表明，后生动物细胞-细胞和细胞-基质相互作用中涉及的大多数多结构域蛋白质是通过外显子改组组装的，但在外显子改组在后生动物转录因子模块蛋白质的进化中没有类似的作用的证据。这种细胞内和细胞间工具包之间差异的一个可能解释是，转录因子模块的进化先于导致控制后生动物空间模式的蛋白质产生的外显子改组的爆发。这个解释与提出细胞分化可能先于动物祖先中细胞类型的空间分离的多细胞性的时间到空间过渡假说一致。
