Genecology Research Centre, University of the Sunshine Coast, Locked Bag 4, Maroochydore DC 4558, Queensland, Australia.
Genecology Research Centre, University of the Sunshine Coast, Locked Bag 4, Maroochydore DC 4558, Queensland, Australia; Aquaculture Department, Southeast Asian Fisheries Development Center, Tigbauan 5021, Iloilo, Philippines.
Gen Comp Endocrinol. 2020 Sep 15;296:113542. doi: 10.1016/j.ygcen.2020.113542. Epub 2020 Jul 13.
A recombinant giant grouper Luteinizing Hormone (LH) consisting of tethered beta and alpha subunits was produced in a yeast expression system. The giant grouper LH β-subunit was also produced and administered to rabbits for antibody development. The recombinant LH and its antibody were used to develop an Enzyme Linked Immunosorbent Assay (ELISA). This ELISA enabled detection of plasma LH levels in groupers at a sensitivity between 391 pg/ml and 200 ng/ml. Different species of grouper were assayed with this ELISA in conjunction with gonadal histology and body condition data to identify links between circulating LH levels and sexual development. We found that circulating levels of LH decreased when oocytes began to degenerate, and sex-transition gonadal characteristics were apparent when LH levels decreased further. When circulating LH levels were related to body condition (body weight/ body length), transitioning-stage fish had relatively high body condition but low plasma LH levels. This observation was similar across multiple grouper species and indicates that plasma LH levels combined with body condition may be a marker for early male identification in the protogynous hermaphrodite groupers.
一种由连接的β和α亚基组成的重组巨型石斑鱼促黄体生成素（LH）在酵母表达系统中产生。巨型石斑鱼 LHβ-亚基也被生产出来并用于兔子抗体的开发。重组 LH 及其抗体被用于开发酶联免疫吸附测定（ELISA）。该 ELISA 能够检测到敏感性在 391pg/ml 和 200ng/ml 之间的石斑鱼血浆 LH 水平。用这种 ELISA 结合性腺组织学和身体状况数据对不同种类的石斑鱼进行了检测，以确定循环 LH 水平与性发育之间的联系。我们发现，当卵母细胞开始退化时，循环中的 LH 水平下降，当 LH 水平进一步下降时，性转变性腺特征明显。当循环 LH 水平与身体状况（体重/体长）相关时，过渡阶段的鱼类具有相对较高的身体状况，但血浆 LH 水平较低。这种观察结果在多种石斑鱼物种中是相似的，表明结合身体状况的血浆 LH 水平可能是雌雄同体石斑鱼中早期雄性鉴定的标志。
