Biological Sciences Department, Dezhou University, Dezhou, 253023, Shandong, China.
Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi, China.
Genes Genomics. 2019 May;41(5):583-597. doi: 10.1007/s13258-019-00799-6. Epub 2019 Mar 4.
Strongylocentrotus nudus is an important cultured sea urchin species in north China, because its gonad is rich in unsaturated fatty acids, particularly long polyunsaturated fatty acids (LC-PUFAs). These PUFAs play pleiotropic and crucial roles in a wide range of biological process.
However, the genes contributing to biosynthesis PUFAs have not been elucidated yet, and the molecular mechanism relative to the difference in PUFA composition between male and female gonad as been revealed but the corresponding has not been understood.
In this paper, solexa sequencing based transcriptomic approach was used to identify and characterize the key genes relative to PUFA synthesis and further conducted different expressed genes between male and female gonad.
A total of 130,124 transcripts and 189330 unigenes were de novo assembled from 64.32 Gb data. Next, these unigenes were subjected to functional annotation by mapping to six public databases, and this process revealed a lot of genes involving in lipid metabolism. In addition, three types of fatty acids front-end desaturase and three species of very long fatty acids elongase were identified and the pathway for PUFA biosynthesis was hypothesized. Last, comparative analysis revealed the higher expression level of Δ5 desaturase, Δ6 desaturase, ELOVL-4, -6 and -7 in male gonad compared with female.
This results could plausible explain the differ in composition of PUFAs between male and female gonad of sea urchin.
光棘球海胆是中国北方重要的养殖海胆品种，因其性腺富含不饱和脂肪酸，尤其是长链多不饱和脂肪酸（LC-PUFAs）。这些多不饱和脂肪酸在广泛的生物学过程中发挥着多效性和关键作用。
然而，参与生物合成多不饱和脂肪酸的基因尚未阐明，雄性和雌性性腺中多不饱和脂肪酸组成差异的分子机制已被揭示，但尚未得到理解。
本文采用基于 solexa 测序的转录组学方法，鉴定和描述与 PUFA 合成相关的关键基因，并进一步对雌雄性腺中差异表达的基因进行分析。
从 64.32GB 的数据中总共组装了 130124 个转录本和 189330 个 unigenes。接下来，通过将这些 unigenes映射到六个公共数据库进行功能注释，这一过程揭示了许多涉及脂质代谢的基因。此外，鉴定了三种脂肪酸前端去饱和酶和三种非常长链脂肪酸延长酶，并假设了 PUFA 生物合成途径。最后，比较分析表明，雄性性腺中 Δ5 去饱和酶、Δ6 去饱和酶、ELOVL-4、-6 和 -7 的表达水平高于雌性性腺。
这些结果可以合理地解释海胆雌雄性腺中多不饱和脂肪酸组成的差异。
