Lampreys Have a Single Gene Cluster for the Fast Skeletal Myosin Heavy Chain Gene Family

Abstract

Muscle tissues contain the most classic sarcomeric myosin, called myosin II, which consists of 2 heavy chains (MYHs) and 4 light chains. In the case of humans (tetrapod), a total of 6 fast skeletal-type MYH genes (MYHs) are clustered on a single chromosome. In contrast, torafugu (teleost) contains at least 13 fast skeletal MYHs, which are distributed in 5 genomic regions; the MYHs are clustered in 3 of these regions. In the present study, the evolutionary relationship among fast skeletal MYHs is elucidated by comparing the MYHs of teleosts and tetrapods with those of cyclostome lampreys, one of two groups of extant jawless vertebrates (agnathans). We found that lampreys contain at least 3 fast skeletal MYHs, which are clustered in a head-to-tail manner in a single genomic region. Although there was apparent synteny in the corresponding MYH cluster regions between lampreys and tetrapods, phylogenetic analysis indicated that lamprey and tetrapod MYHs have independently duplicated and diversified. Subsequent transgenic approaches showed that the 5′-flanking sequences of Japanese lamprey fast skeletal MYHs function as a regulatory sequence to drive specific reporter gene expression in the fast skeletal muscle of zebrafish embryos. Although zebrafish MYH promoters showed apparent activity to direct reporter gene expression in myogenic cells derived from mice, promoters from Japanese lamprey MYHs had no activity. These results suggest that the muscle-specific regulatory mechanisms are partially conserved between teleosts and tetrapods but not between cyclostomes and tetrapods, despite the conserved synteny.

Voltage-gated sodium channel gene repertoire of lampreys: gene duplications, tissue-specific expression and discovery of a long-lost gene

“…The pairing of Nav1d and Nav1e is supported by synteny but too few flanking genes were recovered from the other putative pair (Nav1b and Nav1g) to ascertain syntenic relationships. Our analysis of lamprey -gnathostome gene orthology resulted in the lamprey channels being grouped together alongside the gnathostome channels exactly as observed for lamprey myosin, KCNA, Hox, Runx, p53 and somatostatin family genes [15,21,[40][41][42][43]. While this may suggest that Nav channels as well as these other genes duplicated independently in agnathans and ganthostomes, there are other circumstances that might have led to this clustering pattern.…”

Novel Insights into the Differences in Nutrition Value, Gene Regulation and Network Organization between Muscles from Pasture-Fed and Barn-Fed Goats

“…Meanwhile, these factors can also be regulated by lncRNAs and proteins. Myosins are hexamers composed of two myosin heavy chains (MHCs), and four myosin light chains (MLCs) [34]. MHCs, which are encoded by the MYHs gene, are considered as the molecular markers of muscle fiber type [34].…”

“…Myosins are hexamers composed of two myosin heavy chains (MHCs), and four myosin light chains (MLCs) [34]. MHCs, which are encoded by the MYHs gene, are considered as the molecular markers of muscle fiber type [34]. MRFs control the differentiation of skeletal muscle cells during myogenesis, and the expression of Myf5 and Myf6 were remarkably affected by feeding system [35].…”

Unique Features of River Lamprey (Lampetra fluviatilis) Myogenesis

“…In contrast, central muscles show histochemical characteristics similar to fast contracting white muscle fibers. Ikeda et al, (2013) [ 51 ] compared heavy chains of myosin (MYHs) expressed in fast skeletal muscles among vertebrates with their lamprey counterparts.…”