Nakamura Yoji
Bioinformatics and Biosciences Division, Fisheries Stock Assessment Center, Fisheries Resources Institute, Japan Fisheries Research and Education Agency, 2-12-4 Fuku-ura, Kanazawa, Yokohama, 236-8648, Kanagawa, Japan.
BMC Res Notes. 2025 Jul 17;18(1):308. doi: 10.1186/s13104-025-07372-3.
Estrogen sulfotransferase is an enzyme involved in the inactivation of estrogen, and the encoding gene, sult1st6, is widely conserved among animal species. Recently, it was reported that a paralog of the estrogen sulfotransferase gene is paternally inherited in Pacific bluefin tuna (Thunnus orientalis), suggesting that this gene, sult1st6y, may be involved in sex determination or differentiation of Thunnus species as a suppressor of feminization. However, current knowledge on fish sult1st6 is still limited. This study aims to update the previous findings by thoroughly examining the distribution of sult1st6 in tuna (the species of tribe Thunnini) and their relatives (the species of family Scombridae).
Based on a survey of the sult1st6 loci in the available chromosome-level genomes of Scombridae species, it was found that tuna species carry two copies of sult1st6. Based on phylogenetic analysis and genome comparison, these paralogs were identified as sult1st6y and its paralog, namely sult1st6a, respectively, suggesting that sult1st6y may have originated from sult1st6a by duplication prior to the divergence of the Thunnini tribe. In addition, the sult1st6y locus may have undergone more structural changes than has the sult1st6a locus. These results provide insight into the evolutionary scenario of the sex determination system of tunas.
雌激素磺基转移酶是一种参与雌激素失活的酶，其编码基因sult1st6在动物物种中广泛保守。最近有报道称，雌激素磺基转移酶基因的一个旁系同源基因在太平洋蓝鳍金枪鱼（Thunnus orientalis）中是父系遗传的，这表明该基因sult1st6y可能作为一种雌性化抑制因子参与金枪鱼物种的性别决定或分化。然而，目前关于鱼类sult1st6的知识仍然有限。本研究旨在通过全面研究sult1st6在金枪鱼（金枪鱼族物种）及其亲属（鲭科物种）中的分布来更新先前的研究结果。
基于对鲭科物种现有染色体水平基因组中sult1st6基因座的调查，发现金枪鱼物种携带两个sult1st6拷贝。基于系统发育分析和基因组比较，这些旁系同源基因分别被鉴定为sult1st6y及其旁系同源基因sult1st6a，这表明sult1st6y可能在金枪鱼族分化之前通过复制从sult1st6a起源。此外，sult1st6y基因座可能比sult1st6a基因座经历了更多的结构变化。这些结果为金枪鱼性别决定系统的进化情况提供了见解。
