Molecular cloning, characterisation and expression analysis of the vitellogenin genes

Abstract

Vitellogenesis is essential for oocyte maturation. Vitellogenin (Vtg), a yolk precursor protein, plays an important role in oogenesis and vitellogenesis. Chinese hook snout carp Opsariichthys bidens is an economically important freshwater fish in China whose reproductive and developmental biology are not well understood. In this study, we undertook histological analysis to examine ovary development and oogenesis in O. bidens. The ovaries were divided into Stages II–V and oocytes were divided into perinuclear oocytes, cortical alveoli oocytes, vitellogenic oocytes and mature oocytes. Full-length cDNA sequences were cloned of two vtg genes from the liver of O. bidens, namely Ob-vtgAo1 and Ob-vtgC. Ob-vtgAo1 and Ob-vtgC cDNA are made up of 4136 and 4392 bases respectively and encode proteins containing 1335 and 1250 amino acids respectively. Ob-vtgAo1 contains three yolk protein domains: lipovitellin heavy chain (LvH), phosvitin (Pv) and lipovitellin light chain (LvL), whereas Ob-VtgC contains LvH and LvL, which are incomplete Vtgs. Ob-vtgAo1 and Ob-vtgC mRNA expression was significantly higher in the liver of O. bidens than in all other tissues. In oocytes of Stage II–III ovaries, yolk granules are almost absent and ovarian and hepatic Ob-vtgAo1 and Ob-vtgC expression is low. At Stage IV, the oocyte is filled with yolk granules and ovarian and hepatic Ob-vtgAo1 and Ob-vtgC expression is significantly increased. Collectively, these findings help us better understand vitellogenesis in O. bidens.

Parentage Determination of Chinese Hooksnout Carp (Opsariichthys bidens) Based on Microsatellite DNA Markers

“…For the superior taste, fast growth, and high economic value, O. bidens has become an emerging commercial fish species. Previous studies on O. bidens were mainly focused on artificial propagation [3], reproductive biology [4][5][6], and flesh nutrition content [7]. The natural resources of O. bidens have dramatically decreased in the past decades due to river damming, water environment pollution, and overfishing.…”

Identification and expression analysis of sex biased miRNAs in chinese hook snout carp Opsariichthys bidens

“…What's more, our lab has established a long-term-cultured O. bidens spermatogonial stem cell line that can produce sperm in vitro (Chen et al, 2022). However, there are few reports on the genes related to reproductive development in O. bidens (Jiang et al, 2021;Lin et al, 2021). Most recently, sex-associated genes were obtained by transcriptome analysis in O. bidens by our lab (Tang et al, 2022).…”