Gene Orthologs of Myogenic Regulatory Factors (MRF) Family and their Possible Functions in Echinoderms

MRF family genes are found in all animals and play an important role in the development of the muscular system. The study of the available transcriptomes and genomes of different members of Echinodermata showed that they have orthologs of the vertebrate MyoD gene. Crinoids and echinoids have three genes: MyoD1, MyoD2, and MyoD3 . Asteroids apparently lost the MyoD3 gene, while holothurians lost MyoD2 . In the holothurian Eupentacta fraudatrix, the expression of MyoD3 was significantly increased during muscle regeneration, while the number of MyoD1 transcripts did not change. This may indicate the involvement of MyoD3 in the regulation of myogenesis in holothurians.