cDNA cloning of myosin heavy chain genes from medaka Oryzias latipes embryos and larvae and their expression patterns during development

Abstract

Several sarcomeric myosin heavy chains (MYHs) were cloned from embryos and larvae of medaka Oryzias latipes. Three genes encoding medaka MYHs (mMYHs) predominantly expressed in embryos (mMYHemb1) and larvae (mMYH L1 and mMYHL2), all belonged to fast skeletal MYHs, showing spatiotemporally different expression patterns during development. Besides these mMYHs, a few novel mMYHs were cloned from embryos and larvae at hatching. Whereas mMYHemb2, mMYHemb3, and mMYH L3 belonged to fast skeletal MYH, mMYHC1 and mMYH C2 did to slow/cardiac MYH. mMYHemb1 was expressed ahead of mMYHL1 and mMYHL2. In situ hybridization analysis demonstrated that the transcripts of mMYHemb1 and mMYHC1 were located in the horizontal myoseptum, whereas those of mMYHL1 and mMYHL2 in the inner part of myotomes and pharyngeal muscles, and those of mMYHC2 in the heart rudiment. In silico cloning based on the medaka genome database showed another mMYHs of the slow/cardiac types, mMYHC3 and mMYHC4. © 2006 Wiley-Liss, Inc.