豹纹鳃棘鲈MyoG克隆及胚后发育表达分析OA

Plectropomus leopardus,a highly favored aquatic product among consumers,exhibits muscle development that directly determines its meat yield and quality.To investigate the expression patterns of the myogenin(MyoG)gene in muscle tissues during different post-embryonic developmental stages of the leopard coral grouper(Plectropomus leopardus),CDS of the MyoG gene was amplified by PCR.Bioinformatics analysis of the sequence and its encoded protein was performed using bioinformatic tools.The gene expression levels were examined at 13 time points(0,5,10,15,20,25,30,35,40,45,50,55,and 60 days post hatching)using qPCR.The results showed that the MyoG gene CDS was 753 bp long.The protein prediction yielded a 250-amino-acid sequence,with a calculated molecular mass of 27 345.56 D and a theoretical isoelectric point(pI)of 6.82.The molecular formula was C1172H1853N342O384S15.The instability index was 72.06,indicating that the protein is unstable.The aliphatic index was 57.76,and the grand average of hydropathicity(GRAVY)was-0.644,classifying it as a hydrophilic protein.No signal peptide or transmembrane region was predicted,suggesting it was a non-secretory protein.Amino acid sequence homology analysis with MyoG proteins from 10 other species revealed a closer phylogenetic relationship to teleost fishes like Sebastes umbrosus and Cottoperca gobio,and a more distant relationship to mammals like Homo sapiens and amphibians like Xenopus laevis.qPCR results indicated that,with 0 d as the control group,the expression level of the MyoG gene was significantly upregulated at all time points during the larval stage(0～20 d)(P＜0.05).Upon entering the juvenile stage(20～35 d),MyoG expression showed another significant rise at 25 d(P＜0.001);the expression level remained high at 30 d(P＜0.05)but started to decline.Subsequently,during the juvenile stage(after 35 d),the relative expression of MyoG decreased continuously,with a subsequent upward trend observed at 45 and 55 d,among which the upregulation at 55 d was significant(P＜0.05).The MyoG gene exhibited a degree of evolutionary conservation and played a certain role in the post-embryonic muscle development of P.leopardus.Its relative expression levels were relatively high and showed significant differences in the larval and early juvenile stages,while the expression gradually decreased after entering the juvenile stage(after 35 d).These results suggested that the MyoG gene exerts a core function mainly in the muscle tissue of P.leopardus during the larval and early juvenile stages of post-embryonic development.This study revealed the expression pattern of the MyoG gene during early post-embryonic development and enriches the fundamental research data related to muscle development of this species.