褐飞虱翅型分化分子机理研究

发布时间：2018-04-20 19:27

本文选题：褐飞虱 + 翅型分化　；参考：《浙江大学》2015年博士论文

【摘要】：在不同环境条件下,基因型相同生物的外部形态和内部组织结构可能表现出显著的差异,这种发育可塑性是生物在长期进化过程中为适应不断变化的生态环境而形成的一种极其重要的生存策略,褐飞虱的长短翅分化就是一个很好的例子。长翅型褐飞虱具飞行能力,利于种群扩散,而短翅型褐飞虱丧失飞行能力,但具有较高的生殖力,更利于种群增长。半个世纪以来,虽然众多学者以蚜虫、飞虱、蟋蟀为模式,对昆虫翅多型进行了广泛的研究,也积累了大量的资料,但尚未揭示翅型分化的分子机制。本论文针对这一科学问题,以褐飞虱为模型,从基因组和转录组数据分析入手,经过系统研究,揭示了其翅型分化的分子机理。所取得的主要研究结果如下： 1.分析了褐飞虱的全基因组序列和翅型分化相关的基因。用全基因组鸟枪法和fosmid文库结合的方法做测序拼接,最终得到了1.14Gbp的褐飞虱基因组草图,contig N50大小为24.2kbp, scaffold N50大小为356.6kbp,共注释了27,571个CDS序列。基因组序列为进一步研究褐飞虱的生物学机理提供了必要的序列信息基础。进一步分析了基因组中与翅型分化相关的基因,包括营养通路基因、保幼激素合成相关基因、翅发育网络基因、迁飞及生物钟相关的基因,表明TOR信号通路参与了褐飞虱的生殖和激素合成调控；胰岛素信号转导通路中有2个受体基因存在；翅发育网络基因在褐飞虱中是保守的,这些基因在长短翅褐飞虱若虫中的表达量差异显著,干扰这些基因能引起翅发育不正常；迁飞及生物钟相关基因在褐飞虱中同样存在,它对褐飞虱迁飞过程中时间补偿以及定向机制有重要意义；基因组DNA甲基化与不同翅型褐飞虱间的差异也有一定联系。 2.分析了褐飞虱转录组并比较了长短翅表达谱的差异。通过转录组分析,共得到了85,526条褐飞虱的转录组序列。对短翅型雌成虫和长翅型雌成虫做表达谱比较,发现了和翅型差异相关的基因。其中,与肌肉组成、能量代谢和生殖相关的基因表达差异显著。同时,基因组分析中与翅型分化相关的基因同样能在转录组中找到表达信息,其中有8个基因在长短翅型比较中有显著性差异表达。转录组的分析为褐飞虱翅型分化提供了大量有价值的信息。 3.揭示了褐飞虱翅型分化的分子机制。发现褐飞虱两个胰岛素受体基因(NllnRl和NlInR2)通过调控NIFOXO的活性分别控制了长翅型和短翅型的发育。NlInRl通过激活NlPI3K-NlAkt信号级联诱导长翅型飞虱产生,如果这条通路被抑制,则诱导短翅型飞虱产生。与NlnR1相反,NlnR2是这条通路的负调控因子,抑制这条通路诱导长翅型飞虱产生。我们还发现一个分泌于脑的类胰岛素多肽NlLP3激活了胰岛素信号通路,从而诱导长翅型褐飞虱产生。同时,在白背飞虱和灰飞虱中证明了胰岛素信号通路在飞虱科中是控制翅型分化的普遍机理,这也是昆虫中首次证明翅型分化分子基础的研究。 4.比较了长短翅型飞行肌,分析了飞行肌的关键基因。通过转录组和蛋白质谱的比较,筛选了与间接飞行肌相关的关键基因,如flightin和TpnC4基因等。其中,flightin对间接飞行肌的结构和功能起到了决定性作用。鉴于flightin在非昆虫的六足总纲和甲壳纲的物种中都是保守的,这为研究昆虫翅的进化提供了一丝线索,并为翅二型物种飞行肌分化提供重要的参考。
[Abstract]:Under different environmental conditions, there may be significant differences in the external morphology and internal structure of the same genotypic organisms. This developmental plasticity is an extremely important survival strategy for the organisms to adapt to the changing ecological environment in the long-term evolution process. The long and short wing differentiation of the brown planthopper is a good one. For example, the long winged brown planthopper has the ability to fly, which is conducive to the spread of the population, while the short winged brown planthopper loses its ability to fly, but has higher fertility and is more beneficial to the population growth. The molecular mechanism of wing type differentiation was not revealed. In this paper, the molecular mechanism of wing type differentiation was revealed by systematic study of the brown planthopper as a model and the analysis of genome and transcriptome data. The main results obtained are as follows:
1. the whole genome sequence of the brown planthopper and the genes related to the wing type differentiation were analyzed. The whole genome shotgun method and fosmid library were combined to do sequencing and splicing. Finally, the genome sketch of 1.14Gbp was obtained. The size of contig N50 was 24.2kbp, scaffold N50 was 356.6kbp, and 27571 CDS sequences were annotated. Further studies on the biological mechanism of the brown planthopper provide the necessary sequence information basis. Further analysis of genes related to the wing differentiation in the genome, including nutrient pathway genes, juvenile hormone synthesis related genes, wing development network genes, migratory and biological clock related genes, indicates that the TOR signaling pathway participates in the growth of the brown planthopper. There are 2 receptor genes in the insulin signal transduction pathway; the wing development network gene is conservative in the brown planthopper, and these genes differ significantly in the nymph of long winged brown planthopper, and the interference of these genes can cause abnormal wing development; the migratory and biological clock related genes are the same in the brown planthopper. It is of great significance to the time compensation and orientation mechanism during the migration of the brown planthopper, and the genomic DNA methylation is also related to the difference between the different winged brown planthopper.
2. the transcriptional groups of the brown planthopper were analyzed and the differences in the expression profiles of long and short wings were compared. Through the analysis of the transcriptional group, a total of 85526 transcriptional sequences of the brown planthopper were obtained. The genes related to the difference of the wing type were found for the short winged female adult and the long winged female adult. At the same time, genes associated with wing differentiation in genomic analysis can also find expression information in the transcriptional group, of which 8 genes are significantly different in the long and short wing comparison. The analysis of the transcriptional group provides a large number of valuable information for the wing type differentiation of the brown planthopper.
3. the molecular mechanism of wing type differentiation of brown planthopper was revealed. Two insulin receptor genes (NllnRl and NlInR2) of the brown planthopper (NllnRl and NlInR2) controlled the development of long winged and short wing type.NlInRl by regulating the activity of the long wing type and the short wing type, inducing the production of long winged planthopper by activating the NlPI3K-NlAkt signal cascade. If this pathway was suppressed, it induced the short wing type flying. In contrast to NlnR1, NlnR2 is a negative regulator of this pathway, which inhibits the pathway to induce long winged planthoppers. We also found that an insulin like polypeptide, NlLP3 secreted in the brain, activates the insulin signaling pathway to induce long winged brown planthopper, and the insulin signal is demonstrated in white back and grey planthopper. The pathway is a universal mechanism for controlling wing type differentiation in the family hopper. This is also the first study of the molecular basis of wing differentiation in insects.
4. compared with the long and short wing type flying muscles, the key genes of the flying muscles were analyzed. Through the comparison of the transcriptional and protein mass spectra, the key genes related to the indirect flying muscles, such as flightin and TpnC4 genes, were screened. Among them, flightin played a decisive role in the structure and function of the indirect flying muscles. In view of the six FA in the non insect. All species of the class and crustacea are conservative, which provides a clue to the evolution of insect wings and provides an important reference for the differentiation of wing two species.

【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：S433

【参考文献】