Key Laboratory of Aquatic Genomics, Ministry of Agriculture and Rural Affairs, Beijing Key Laboratory of Fishery Biotechnology, Chinese Academy of Fishery Sciences, Beijing 100141, China.
Int J Mol Sci. 2022 Nov 24;23(23):14666. doi: 10.3390/ijms232314666.
Most diploid freshwater and marine fish encode one elongase, having substrate specificity and activities towards C18, C20 and C22 polyunsaturated fatty acids (PUFAs). The allo-tetraploid common carp is hypothesized to encode two duplicated genes. How these two genes adapt to coordinate the PUFA biosynthesis through elongase function and expression divergence requires elucidation. In this study, we obtained the full-length cDNA sequences of two genes in common carp, named as and . Functional characterization showed that both enzymes had elongase activity towards C18, C20 and C22 PUFAs. Especially, the activities of these two enzymes towards C22 PUFAs ranged from 3.87% to 8.24%, higher than those in most freshwater and marine fish. The Elovl5a had higher elongase activities than Elovl5b towards seven substrates. The spatial-temporal expression showed that both genes co-transcribed in all tissues and development stages. However, the expression levels of were significantly higher than those of in all examined conditions, suggesting that would be the dominantly expressed gene. These two genes had different potential transcriptional binding sites. These results revealed the complicated roles of on PUFA synthesis in common carp. The data also increased the knowledge of co-ordination between two homoeologs of the polyploid fish through function and expression divergence.
大多数二倍体淡水和海洋鱼类编码一个 elongase，该酶具有底物特异性，并对 C18、C20 和 C22 多不饱和脂肪酸（PUFA）具有活性。异源四倍体鲤鱼被假设编码两个重复的 elongase 基因。这两个 elongase 基因如何通过 elongase 功能和表达分化来适应协调 PUFA 生物合成，这需要阐明。在这项研究中，我们获得了鲤鱼中两个 elongase 基因的全长 cDNA 序列，分别命名为 和 。功能特征表明，这两种酶对 C18、C20 和 C22 PUFAs 都具有 elongase 活性。特别是，这两种酶对 C22 PUFAs 的活性范围为 3.87%至 8.24%，高于大多数淡水和海洋鱼类。Elovl5a 对七种底物的 elongase 活性高于 Elovl5b。时空表达表明，这两个基因在所有组织和发育阶段都共同转录。然而，在所有检查条件下， 基因的表达水平均显著高于 基因，表明 基因将是主要表达的基因。这两个基因具有不同的潜在转录结合位点。这些结果揭示了 基因在鲤鱼中对 PUFA 合成的复杂作用。这些数据还增加了对多倍体鱼类两个同源基因通过功能和表达分化进行协调的认识。
