Abstract：
As the global aquaculture industry grows, attention is increasingly turning towards assisted reproductive technologies. In this study, we examined the impact of D-Ala6, Pro9-Net-mGnRH (LHRHa: 0.4 mL/kg) and two doses (1 and 10 μg/kg fish) of thyroxin (T4) administered through a single injection on oocyte maturation, spawning performance, sex steroid hormone levels, as well as the expression of genes related to steroidogenesis and follicle development (ZP2, Cyp19a1a and SF-1) in Rohu (Labeo rohita). The study found that untreated female Rohu did not spawn, while those treated with LHRHa and thyroxin ovulated and spawned across a hormonal gradient. The highest spawning success was observed with a thyroxin dosage of 10 µg/kg (no significant change with a dose of 1 μg/kg), and female latency period decreased with increasing dosage. Additionally, females treated with thyroxin exhibited significantly higher fecundity than other experimental groups. Treatment with LHRHa and two doses of thyroxin significantly increased the gonadal somatic index compared to the control and sham groups. Hormonal treatment also led to increased fertilization success, hatching rate, and larval survival. At 12 h post-injection, females treated with thyroxin exhibited a significant decline in estradiol levels and expression of Zp2, Cyp19a1a, and SF-1 compared to other experimental groups. Levels of DHP significantly increased across the hormonal gradient. Histological analyses supported a steroidogenic shift, where oocyte maturation was accelerated by hormone administration, particularly with both doses of thyroxin. In conclusion, the findings suggest that thyroxin is a recommended treatment for assisted reproduction of Rohu due to its ability to induce spawning, increase fecundity and improve larval survival.
摘要：
随着全球水产养殖业的发展，人们越来越关注辅助生殖技术。在这项研究中,我们检查了D-Ala6，Pro9-Net-mGnRH（LHRHa：0.4mL/kg）和两个剂量（1和10μg/kg鱼）的甲状腺素（T4）通过单次注射对卵母细胞成熟的影响，产卵性能，性类固醇激素水平,以及Rohu（Labeorohita）中与类固醇生成和卵泡发育相关的基因（ZP2，Cyp19a1a和SF-1）的表达。研究发现，未经处理的雌性Rohu不会产卵，而那些用LHRHa和甲状腺素治疗的人排卵并通过激素梯度产生。最高的产卵成功率观察到甲状腺激素剂量为10µg/kg（剂量为1μg/kg时没有显着变化），女性潜伏期随着剂量的增加而减少。此外,接受甲状腺素治疗的女性的繁殖力明显高于其他实验组。与对照组和假手术组相比，用LHRHa和两种剂量的甲状腺素治疗可显着增加性腺体细胞指数。激素治疗也导致受精成功率增加，孵化率,和幼虫生存。注射后12小时，用甲状腺素治疗的女性表现出雌二醇水平和Zp2，Cyp19a1a表达的显着下降，和SF-1与其他实验组相比。DHP水平在整个激素梯度中显著增加。组织学分析支持类固醇生成转移，通过激素管理加速卵母细胞成熟，特别是两种剂量的甲状腺素.总之,研究结果表明，由于其诱导产卵的能力，甲状腺素是Rohu辅助繁殖的推荐治疗方法，增加繁殖力，提高幼虫的存活率。
