Analysis of the Agrotis segetum pheromone gland transcriptome in the light of sex pheromone biosynthesis.
Analysis of the Agrotis segetum pheromone gland transcriptome in the light of sex pheromone biosynthesis.
复制标题
DOI：
10.1186/s12864-015-1909-2
复制
发表时间：
2015-09-18
期刊：
影响因子：
4.4
通讯作者：
Löfstedt C
中科院分区：
文献类型：
--
作者：
Ding BJ;Löfstedt C
蛾类在很大程度上依赖于信息素的交流来寻找配偶。大多数蛾类的信息素成分是由一组组织特异性酶从正常脂肪酸代谢产物中修饰而来的。萝卜蛾（Agrotis segetum）利用一系列同源脂肪醇乙酸酯（（Z）-5-癸烯基、（Z）-7-十二烯基和（Z）-9-十四烯基乙酸酯）作为其性信息素成分。不同种群之间的成分比例不同，使该物种成为研究生物合成途径中涉及的酶及其对性信息素变异影响的有趣主题。信息素腺体和腹部表皮组织的转录组的Illumina测序和比较分析使我们能够鉴定编码参与信息素生物合成途径的推定关键酶的基因，例如脂肪酸合成酶、β-氧化酶、脂肪酰基去饱和酶（FAD）、脂肪酰基还原酶（FAR）和乙酰转移酶。我们通过在酵母中异源表达对先前鉴定的β 11-去饱和酶[GenBank：ES 583599，JX 679209]和FAR [GenBank：JX 679210]以及候选乙酰转移酶（34个基因）进行了功能性测定。功能分析证实，β 11-去饱和酶与棕榈酸相互作用并产生（Z）-11-十六碳烯酸，其是随后通过缩短链、还原和乙酰化产生的三种同源信息素组分乙酸酯的共同不饱和前体。低得多，但仍然可见，14 C和12 C饱和酸的活动可能占次要的信息素化合物先前观察到的信息素腺体。所表征的FAR可以对作为不同A的直接酰基前体的各种不饱和脂肪酸起作用。莎草信息素组分。我们所表达的假定的乙酰转移酶都没有异源乙酰化任何作为底物的脂肪醇。大规模测序技术产生了大量可能参与信息素生物合成的候选基因，但通过异源表达或基因沉默来测试它们的功能是一个瓶颈。我们证实了以前确定的去饱和酶基因和脂肪酰基还原酶基因的异源表达的功能，但乙酰转移酶假定参与信息素的生物合成仍然是虚幻的，尽管34个候选人进行分析。我们还生成了可能用于表征乙酰辅酶A羧化酶、脂肪酸合成酶和β-氧化酶的候选基因列表。
Moths rely heavily on pheromone communication for mate finding. The pheromone components of most moths are modified from the products of normal fatty acid metabolism by a set of tissue-specific enzymes. The turnip moth, Agrotis segetum uses a series of homologous fatty-alcohol acetate esters ((Z)-5-decenyl, (Z)-7-dodecenyl, and (Z)-9 tetradecenyl acetate) as its sex pheromone components. The ratio of the components differs between populations, making this species an interesting subject for studies of the enzymes involved in the biosynthetic pathway and their influence on sex pheromone variation. Illumina sequencing and comparative analysis of the transcriptomes of the pheromone gland and abdominal epidermal tissue, enabled us to identify genes coding for putative key enzymes involved in the pheromone biosynthetic pathway, such as fatty acid synthase, β-oxidation enzymes, fatty-acyl desaturases (FAD), fatty-acyl reductases (FAR), and acetyltransferases. We functionally assayed the previously identified ∆11-desaturase [GenBank: ES583599, JX679209] and FAR [GenBank: JX679210] and candidate acetyltransferases (34 genes) by heterologous expression in yeast. The functional assay confirmed that the ∆11-desaturase interacts with palmitate and produces (Z)-11-hexadecenoate, which is the common unsaturated precursor of three homologous pheromone component acetates produced by subsequent chain-shortening, reduction and acetylation. Much lower, but still visible, activity on 14C and 12C saturated acids may account for minor pheromone compounds previously observed in the pheromone gland. The FAR characterized can operate on various unsaturated fatty acids that are the immediate acyl precursors of the different A. segetum pheromone components. None of the putative acetyltransferases that we expressed heterologously did acetylate any of the fatty alcohols tested as substrates. The massive sequencing technology generates enormous amounts of candidate genes potentially involved in pheromone biosynthesis but testing their function by heterologous expression or gene silencing is a bottleneck. We confirmed the function of a previously identified desaturase gene and a fatty-acyl reductase gene by heterologous expression, but the acetyltransferase postulated to be involved in pheromone biosynthesis remains illusive, in spite of 34 candidates being assayed. We also generated lists of gene candidates that may be useful for characterizing the acetyl-CoA carboxylase, fatty acid synthetase and β-oxidation enzymes.