Triploid Atlantic salmon Salmo salar is commercially available and ideal means of achieving sterility in fish. The expression patterns of triploid parr and smolt were described before. However, little is known about the gene expression and fatty acid composition of triploid alevins at endogenous nutritional stage, which is an important period for their survival and development. In this study, the development of the diploid and triploid Atlantic salmon embryos and hatched alevins before feeding was compared, and the results showed that there was no obvious morphological difference between them. And then, the transcription profiles of the triploid and diploid alevins on 3, 23 and 33 days post hatching (dph) were investigated by using RNA-seq after the yolk sacs were removed. There were more differentially expressed genes (DEGs) on 3 dph (2925) than those on 23 (589) and 33 dph (606). Compared with the diploid groups, the up-regulated genes in the triploid groups at the three sampling times were 1189, 339 and 340, respectively, while 1736, 250 and 266 genes were down-regulated. There were 2088 and 5215 DEGs on 23 and 33 dph compared with on 3 dph in the diploid groups, while 6533 and 9340 DEGS on 23 and 33 dph compared with 3 dph in the triploid groups. The functional enrichment analysis showed that the DEGs were mainly enriched to digestion and metabolism function, especially on 33 dph when the larvae were about to feeding. Meanwhile, 15 out of 22 kinds of fatty acids of alevins on 33 dph showed significant differences (P < 0.05), in which all the fatty acids contents in the triploid were lower. The results indicated the specific nutritional requirement in the triploid was represented as early as yolk sac stage. The present study gave an important vision in triploid Atlantic salmon breeding.

中文翻译：

---

大西洋鲑鲑鱼人工诱导三倍体 alevin 的转录谱和脂肪酸组成

三倍体大西洋鲑鱼 Salmo salar 是商业上可获得的，是实现鱼类不育的理想方法。三倍体 parr 和 smolt 的表达模式之前已经描述过。然而，内源营养阶段是三倍体alevins生存和发育的重要时期，其基因表达和脂肪酸组成知之甚少。本研究比较了饲养前二倍体和三倍体大西洋鲑鱼胚胎和孵化的鲑鱼的发育情况，结果表明它们之间没有明显的形态差异。然后，在去除卵黄囊后，使用 RNA-seq 研究了孵化后第 3、23 和 33 天的三倍体和二倍体 alevins 的转录谱。3 dph (2925) 比 23 (589) 和 33 dph (606) 有更多的差异表达基因 (DEG)。与二倍体组相比，三倍体组在三个采样时间上调的基因分别为1189、339和340个，而下调的基因为1736、250和266个。与3 dph相比，二倍体组在23和33 dph上有2088和5215°，而在23和33 dph上有6533和9340°，而三倍体组在3 dph上有6533和9340°。功能富集分析表明，DEGs主要富集消化和代谢功能，尤其是在33 dph幼虫即将取食时。同时，33 dph的alevins 22种脂肪酸中有15种差异显着（P < 0.05），其中三倍体中的脂肪酸含量均较低。结果表明，三倍体的特定营养需求早在卵黄囊阶段就已表现出来。本研究为三倍体大西洋鲑鱼育种提供了重要愿景。