Effects of Temperature on the Expression of Two Ovarian Differentiation-Related Genes foxl2 and cyp19a1a

Abstract

Exposure to stress induces a series of responses and influences a wide range of biological processes including sex differentiation in fish. The present work investigated the molecular and physiological response to thermal stress throughout the early development stage covering the whole period of sex differentiation of bluegill, Lepomis macrochirus. Larvae were treated using three temperatures, 17, 24, and 32°C from 6 to 90 days posthatching (dph) in 30-L round tanks. There is no significant difference of the sex ratio and survival among the three temperature groups in the geographic population used in this study. Two ovarian differentiation-related genes foxl2 and cyp19a1a were detected at 7 dph suggesting that these genes have already played a role prior to sex differentiation. The expression of foxl2 reached the peak and was thermosensitive just prior to the onset of ovarian differentiation at 27 dph. Histological examination displayed that the proliferation of germ cells and ovarian differentiation were delayed at the low-temperature treatment (17°C) at 97 dph compared with higher temperatures. In conclusion, the water temperature regulates the sex differentiation of bluegill through modulation of the expression of foxl2 and cyp19a1a. A comparative study of the expression profile of sex differentiation-related genes in species will shed light on the evolution of sex-determination mechanisms and the impact of stress on sex differentiation.

Spatiotemporal Expression of Foxl2 and Dmrt1 before, during, and after Sex Determination in the Sea Turtle Lepidochelys olivacea

“…This expression pattern implies that Foxl2 plays an important role in sea turtle ovarian development, consistent with the evident feminizing role at embryonic stages among fish, chicken, and mammals [Huang et al, 2017;Shen et al, 2018;Fan et al, 2019;Major et al, 2019].…”

Out-of-season spawning of largemouth bass in a controllable recirculating system

“…The methodology of OSS is realized by compressing the annual reproductive cycle (especially the changes of thermo-photoperiod) into several months to simulate and promote gonadal development and spawning during the non-reproductive season, referring to the LMB annual reproductive cycle under natural conditions. Regimes for thermo-photoperiod manipulation refer to our previous work in Centrarchidae species ( Shen et al, 2016 ; 2018 ; Hussein et al, 2020 ; Cui et al, 2021 ) with adjustment. LMB broodstock of 1+ years old, which had spawned during the reproductive season in April and May, was harvested from a pond and transferred to the indoor recirculating system.…”

“…Gonad tissues were dehydrated (80%, 90%, 95%, and double 100% ethanol), cleared (triplicate xylene), immersed and embedded in paraffin, cut at 6–8 μm, stained with hematoxylin and eosin (HE stain), and mounted using neutral resins following routine histological procedures ( Shen et al, 2016 ; 2018 ; Hussein et al, 2020 ), with extended processing time (including dehydration, clearing, and paraffin immersion) for ovary samples. Tissue slices were checked and photographed under a light microscope equipped with an imaging system (MShot Image Analysis System, Guangzhou Ming-Mei Technology Co., Ltd.).…”

“…The largemouth bass (LMB), Micropterus salmoides , has been the most popular and widely distributed game fish since 1975 in the United States of America ( Wallus and Simon, 2008 ; Cooke and Philipp, 2009 ). It has become one of the most important aquaculture species in China because of the aquaculture (e.g., rapid growth, short culture cycle, and strong adaptability) and dietary advantages (excellent flesh quality and no intermuscular bone) ( Bai and Li, 2018 ; 2019 ; Shen et al, 2018 ; Hussein et al, 2020 ). As the Chinese saying goes, no fish, no feast.…”

A Potential Role of the Translation Elongation Factor eef1a1 in Gonadal High-Temperature Perception in Chinese Tongue Sole (Cynoglossus semilaevis)

“…Many sex-related genes have been found to alter the expression level under high temperature, thus affecting the sexual phenotype, such as dmrt1 (doublesex and mab-3 related transcription factor 1), gsdf (gonadal soma-derived factor), cyp19a1a (gonadal aromatase), foxl2 (forkhead box l2), etc. [6][7][8][9]. Nevertheless, researchers of the early response factors in the hierarchy and their mechanisms are still limited.…”