A chromosome-level genome of black rockfish, Sebastes schlegelii, provides insights into the evolution of live birth.

Authors: He, Yan and Chang, Yue and Bao, Lisui and Yu, Mengjun and Li, Rui and Niu, Jingjing and Fan, Guangyi and Song, Weihao and Seim, Inge and Qin, Yating and Li, Xuemei and Liu, Jinxiang and Kong, Xiangfu and Peng, Meiting and Sun, Minmin and Wang, Mengya and Qu, Jiangbo and Wang, Xuangang and Liu, Xiaobing and Wu, Xiaolong and Zhao, Xi and Wang, Xuliang and Zhang, Yaolei and Guo, Jiao and Liu, Yang and Liu, Kaiqiang and Wang, Yilin and Zhang, He and Liu, Longqi and Yu, Haiyang and Wang, Xubo and Cheng, Jie and Wang, Zhigang and Xu, Xun and Wang, Jian and Yang, Huanming and Lee, Simon Ming-Yuen and Liu, Xin and Zhang, Quanqi and Qi, Jie

Black rockfish (Sebastes schlegelii) is a teleost species where eggs are fertilized internally and retained in the maternal reproductive system, where they undergo development until live birth (termed viviparity). In the present study, we report a chromosome-level black rockfish genome assembly. High-throughput transcriptome analysis (RNA-seq and ATAC-seq), coupled with in situ hybridization (ISH) and immunofluorescence, identify several candidate genes for maternal preparation, sperm storage and release, and hatching. We propose that zona pellucida (ZP) proteins retain sperm at the oocyte envelope, while genes in two distinct astacin metalloproteinase subfamilies serve to release sperm from the ZP and free the embryo from chorion at pre-hatching stage. Finally, we present a model of black rockfish reproduction, and propose that the rockfish ovarian wall has a similar function to the uterus of mammals. Taken together, these genomic data reveal unprecedented insights into the evolution of an unusual teleost life history strategy, and provide a sound foundation for studying viviparity in non-mammalian vertebrates and an invaluable resource for rockfish ecological and evolutionary research. This article is protected by copyright. All rights reserved.This article is protected by copyright. All rights reserved.

Journal: Molecular ecology resources
DOI: 10.1111/1755-0998.13034
Year: 2019

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