Crowding stress during the period of sex determination causes masculinization in pejerrey Odontesthes bonariensis, a fish with temperature-dependent sex determination
Crowding stress during the period of sex determination causes masculinization in pejerrey Odontesthes bonariensis, a fish with temperature-dependent sex determination
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DOI：
10.1016/j.cbpa.2020.110701
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发表时间：
2020-07-01
影响因子：
2.3
通讯作者：
Strussmann, Carlos A.
中科院分区：
文献类型：
--
作者：
Garcia-Cruz, Estefany L.;Yamamoto, Yoji;Strussmann, Carlos A.
Pejerrey 是来自南美洲的一种斑蝽属物种，它呈现出基因型和环境（温度依赖性）性别决定的结合，其中低温和高温分别诱导女性化和男性化。男性化涉及热诱导的应激反应，导致循环皮质醇和雄激素增加。我们测试了拥挤是否会引起与高温类似的反应并影响佩杰瑞的性别比例。具有 XX 和 XY 基因型的幼虫在 0.4、1.6 和 6.4 L 容器中以 15、62 和 250 只幼虫/L 饲养，在 25 摄氏度（促进混合性别的温度）下进行性别决定的关键时期。在 3-7 周时对鱼的全身皮质醇和 11-酮睾酮 (11-KT) 滴度以及羟基类固醇脱氢酶 (hsd11b2) mRNA 转录本丰度进行分析，并在性腺性别分化完成后（10-14 周）分析鱼的表型和基因型性别不匹配。与中等和/或低饲养密度相比，拥挤与生长抑制、皮质醇和 11-KT 滴度升高、hsd11b2 转录增加以及雄性化频率增加有关。感知的拥挤（通过在镜面反射墙的容器中饲养）也导致了男性化。这些结果表明，除了温度之外的其他环境因素也可能影响佩杰瑞犬的性别决定，并且导致皮质醇和雄激素水平升高的应激反应可能被大脑感知，这可能是该物种不同形式的环境性别决定的共同特征。
The pejerrey is an atherinopsid species from South America that presents a combination of genotypic and environmental (temperature-dependent) sex determination whereby low and high temperatures induce feminization and masculinization, respectively. Masculinization involves a heat-induced stress response leading to increased circulating cortisol and androgens. We tested whether crowding would elicit a similar response as high temperature and affect the sex ratios of pejerrey. Larvae with XX and XY genotypes were reared at 15, 62 and 250 larvae/L in 0.4, 1.6, and 6.4 L containers during a period considered critical for sex determination at 25 degrees C, a mixed-sex promoting temperature. Fish were analysed at 3-7 weeks for whole-body cortisol and 11-ketotestosterone (11-KT) titer and hydroxy-steroid dehydrogenase (hsd11b2) mRNA transcript abundance, and after completion of gonadal sex differentiation (10-14 weeks) for determination of phenotypic and genotypic sex mismatches. Crowding was associated with depressed growth, higher cortisol and 11-KT titers, increased hsd11b2 transcription, and increased frequency of masculinization compared to intermediate and/or low rearing densities. Perceived crowding (by rearing in containers with mirror-finish, reflecting walls) also caused masculinization. These results suggest the possibility that other environmental factors besides temperature can also affect sex determination in pejerrey and that a stress response leading to increased cortisol and androgen levels, which is potentially perceived by the brain, may be a common feature among different forms of environmental sex determination in this species.