Oh Hyeon Ji, Kim Jung-Hyun, Mun Seong Hee, Kim Jin Hui, Kim Dae-Jung, Kwon Joon Yeong
Dept. of Aquatic Life Medical Sciences, Sunmoon University, Asan 31460, Korea.
Aquaculture Research Team, NFRDI, Busan 46083, Korea.
Dev Reprod. 2018 Sep;22(3):289-295. doi: 10.12717/DR.2018.22.3.289. Epub 2018 Sep 30.
Large quantity of eggs fail to be fertilized and many of fertilized eggs are unable to hatch in the eel, . Larvae of eel absorb egg yolk up to 8 days after hatching but the majority of hatched larvae die before they reach the stage of first feeding in this species. Genes of key enzymes for yolk processing (cathepsin B, D, L and lipoprotein lipase - abbreviated as and , respectively) could be associated with egg quality. In this study, we investigated differences in the expression of these genes between floating eggs and sinking eggs, and also the relationship between the gene expressions of the enzymes and fertilization rates in the fertilized eggs obtained from artificially matured female eels. Expressions of yolk processing enzyme genes did not show significant difference between floating and sinking egg groups. Expression of decreased when fertilization rate was high. Expression of and , however, did not show any significant differences. These results suggest that expression could be an indicator of egg quality, and that some proteins prone to be digested by could be very important in the process of fertilization and normal cleavage in this species. Further study should identify these critical proteins to improve our understanding on the quality of fish eggs.
大量的鳗鱼卵未能受精，且许多受精卵无法孵化。鳗鱼幼体在孵化后8天内吸收卵黄，但大多数孵化出的幼体在达到该物种首次摄食阶段之前就死亡了。卵黄加工关键酶（组织蛋白酶B、D、L和脂蛋白脂肪酶，分别简称为 和 ）的基因可能与卵的质量有关。在本研究中，我们调查了浮性卵和沉性卵之间这些基因表达的差异，以及从人工催熟的雌鳗获得的受精卵中这些酶的基因表达与受精率之间的关系。浮性卵组和沉性卵组之间卵黄加工酶基因的表达没有显著差异。受精率高时， 的表达下降。然而， 和 的表达没有任何显著差异。这些结果表明， 的表达可能是卵质量的一个指标，并且一些容易被 消化的蛋白质在该物种的受精和正常卵裂过程中可能非常重要。进一步的研究应该鉴定这些关键蛋白质，以增进我们对鱼卵质量的理解。
