AUTHOR=Wu Xin-Jun , Williams Marcus Jermaul , Kew Kimberly Ann , Converse Aubrey , Thomas Peter , Zhu Yong 

TITLE=Reduced Vitellogenesis and Female Fertility in Gper Knockout Zebrafish

JOURNAL=Frontiers in Endocrinology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2021.637691

DOI=10.3389/fendo.2021.637691

ISSN=1664-2392

ABSTRACT=<p>The role G-protein coupled estrogen receptor (GPER) plays in vertebrate reproduction remains controversial. To investigate GPER’s reproductive role, we generated a gper zebrafish mutant line (<italic>gper<sup>−/−</sup></italic>) using TALENs. Gper mutant females exhibited reduced fertility with a 40.85% decrease in embryo production which was associated with a significant decrease in the number of Stage V (730–750 μm) ovulated oocytes. Correspondingly, the number of early vitellogenic follicles (Stage III, 400–450 µm) in <italic>gper<sup>−/−</sup></italic> ovaries was greater than that in wildtypes (<italic>wt</italic>), suggesting that subsequent follicle development was retarded in the <italic>gper<sup>−/−</sup></italic> fish. Moreover, plasma vitellogenin levels were decreased in <italic>gper<sup>−/−</sup></italic> females, and epidermal growth factor receptor (Egfr) expression was lower in Stage III vitellogenic oocytes than in <italic>wt</italic> counterparts. However, hepatic nuclear estrogen receptor levels were not altered, and estrogen levels were elevated in ovarian follicles. These results suggest that Gper is involved in the control of ovarian follicle development <italic>via</italic> regulation of vitellogenesis and Egfr expression in zebrafish.</p>