MRTF specifies a muscle-like contractile module in Porifera.

ABSTRACT: Muscle-based movement is a hallmark of animal biology, but the evolutionary origins of myocytes are unknown. Although believed to lack muscles, sponges (Porifera) are capable of coordinated whole-body contractions that purge debris from internal water canals. This behavior has been observed for decades, but their contractile tissues remain uncharacterized with respect to their ultrastructure, regulation, and development. We examine the sponge Ephydatia muelleri and find tissue-wide organization of a contractile module composed of actin, striated-muscle myosin II, and transgelin, and that contractions are regulated by the release of internal Ca²⁺ stores upstream of the myosin-light-chain-kinase (MLCK) pathway. The development of this contractile module appears to involve myocardi

SUBMITTER: Colgren J 

PROVIDER: S-EPMC9287330 | biostudies-literature | 2022 Jul

REPOSITORIES: biostudies-literature