Integrated Analysis of miR-430 on Steroidogenesis-Related Gene Expression of Larval Rice Field Eel Monopterus albus

The present study aims to reveal the mechanism by which miR-430s regulate steroidogenesis in larval rice field eel Monopterus albus. To this end, M. albus embryos were respectively microinjected with miRNA-overexpressing mimics (agomir430a, agomir430b, and agomir430c) or miRNA-knockdown inhibitors (antagomir430a, antagomir430b, and antagomir430c). Transcriptome profiling of the larvae indicated that a total of more than 149 differentially expressed genes (DEGs) were identified among the eight treatments. Specifically, DEGs related to steroidogenesis, the GnRH signaling pathway, the erbB signaling pathway, the Wnt signaling pathway, and other pathways were characterized in the transcriptome. We found that steroidogenesis-related genes (hydroxysteroid 17-beta dehydrogenase 3 (17β-hsdb3), hydroxysteroid 17-beta dehydrogenase 7 (17β-hsdb7), hydroxysteroid 17-beta dehydrogenase 12 (17β-hsdb12), and cytochrome P450 family 19 subfamily a (cyp19a1b)) were significantly downregulated in miR-430 knockdown groups. The differential expressions of miR-430 in three gonads indicated different roles of three miR-430 (a, b, and c) isoforms in regulating steroidogenesis and sex differentiation. Mutation of the miR-430 sites reversed the downregulation of cytochrome P450 family 17 (cyp17), cyp19a1b, and forkhead box L2 (foxl2) reporter activities by miR-430, indicating that miR-430 directly interacted with cyp17, cyp19a1b, and foxl2 genes to inhibit their expressions. Combining these findings, we concluded that miR-430 regulated the steroidogenesis and the biosynthesis of steroid hormones by targeting cyp19a1b in larval M. albus. Our results provide a novel insight into steroidogenesis at the early stage of fish at the molecular level.

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Construction and analysis of gonad suppression subtractive hybridization library of rice field eel (Monopterus albus)

Journal of Fishery Sciences of China ◽

10.3724/sp.j.1118.2011.00023 ◽

2013 ◽

Vol 18 (1) ◽

pp. 23-28

Author(s):

Xiancheng QU ◽

Xiaoli SHANG ◽

Cui CHENG ◽

Xuewei QU ◽

Yong ZHANG ◽

...

Keyword(s):

Suppression Subtractive Hybridization ◽

Rice Field ◽

Subtractive Hybridization ◽

Suppression Subtractive Hybridization Library ◽

Monopterus Albus ◽

Rice Field Eel

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Effects of Different Stocking Densities on Growth, Serum Steroid Hormone Concentrations, Gonadosomatic Index and Sex Reversal in the Rice Field Eel, Monopterus albus (Zuiew)

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.142.233 ◽

2011 ◽

Vol 142 ◽

pp. 233-237

Author(s):

Han Wen Yuan ◽

Fang Chen ◽

Qiao Qing Xu ◽

Shi Yuan Gong ◽

Zhang Jie Chu ◽

...

Keyword(s):

Rice Field ◽

Steroid Hormone ◽

Gonadosomatic Index ◽

Stocking Density ◽

Sex Reversal ◽

The Other ◽

Daily Weight Gain ◽

Monopterus Albus ◽

Rice Field Eel ◽

Significant Difference

The effects of stocking density on various growth parameters and sex reversal in the rice field eel (Monopterus albus) were investigated by evaluating steroid hormone, the gonadosomatic index (GSI) and sex ratio. Fish (mean initial weight of 9.88 ± 0.70 g) were stocked to densities of 4, 20, 36, 52, 68, 84 or 100 fish/m2 in cages (2 m × 1 m × 1.5 m) in a pond, with five replicate cages for each density. Fish were fed for 420 days on a formulated isocaloric diet containing 40.22% crude protein and 12.86 MJ/kg. Serum E2 and T concentrations were determined by radioimmunoassays. There were no significant differences in final bodyweight (FBW) and daily weight gain (DWG) for fish in the groups containing less than 52 fish/m2, while FBW and DWG were significant lower in groups at 68 fish/m2 or more. Specific growth rate (SGR) differed significantly between the 84 and 100 fish/m2 groups compared with the 4, 20 and 36 fish/m2 groups. There was no significant difference in SGR in groups containing less than 84 fish/m2. There were no significant difference between the 4 and 20 fish/m2 groups in net yield (NY), but these groups did differ significantly from the other groups. The final condition factors of fish stocked at 84 or 100 fish/m2 were significantly lower than fish stocked at the other densities. E2 and T hormone concentrations declined as stocking density increased, while GSI values increased initially but then reduced with increasing stocking density. Female ratio and survival decreased with increasing stocking density. The proportion of male fish was significantly greater in the three highest stocking density groups. Therefore, high stocking density may promote sex change from female to male in M. albus.

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