Abstract:

In order to study the important role of myogenic regulator (MRF) in the embryonic development of Trachinotus ovatus, the whole genome identification and bioinformatics analysis of MRF gene family in T. ovatus were carried out, and the gene expression in 13 embryonic stages was quantitatively analyzed. Five MRF gene family members, MyoD1, MyoD2, Myf5, Myf6 and MyoG, encoding 297, 263, 240, 231 and 250 amino acids, respectively, were identified in T. ovatus genome data. The MRF family genes had a typical BASIC and HLH domains, where MyoD1, MyoD2 and MyoG were located on chromosome 9, 1 and 2 respectively, while Myf5 and Myf6 were located on chromosome 22 and at the same locus. Quantitative expression studies in embryos showed that the expression level of MyoG was very low during the period from zygote to embryo formed stage, while increased rapidly during the optic vesicle stage, otocyst vesicle stage and heart pulsation stage, but decreased at the formation of eye lens stage. It was speculated that MyoG may play a major role in the regulation of myogenesis during optic vesicle stage, otocyst vesicle stage and heart pulsation stage, but still play an important role in maintaining muscle morphology or muscle development in the later period. The expression levels of MyoD1, MyoD2, Myf5 and Myf6 genes were lower from the zygote to the mid-gastrulation stage, but increased rapidly from the late gastrulation to the formation of eye lens stage (P<0.05), indicating that they began to play an important role in the regulation of myogenesis from late gastrulation stage. The results showed that MRF family members played an important role in the process of embryonic development of T. ovatus, but different MRF family members may play different roles in different time and functions.

Key words: Trachinotus ovatus, myogenic regulatory factors (MRF), MRF gene family, gene expression, embryo