Adenine methylation may contribute to endosymbiont selection in a clonal aphid population.
Adenine methylation may contribute to endosymbiont selection in a clonal aphid population.
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DOI：
10.1186/1471-2164-15-999
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发表时间：
2014-11-19
期刊：
影响因子：
4.4
通讯作者：
Dombrovsky A
中科院分区：
文献类型：
--
作者：
Reingold V;Luria N;Robichon A;Dombrovsky A
豌豆蚜有两种繁殖方式：春夏孤雌生殖和秋季有性生殖。这种在繁殖模式之间切换的能力以及在有利条件下克隆种群的出现，使这种生物成为遗传学和表观遗传学研究的有趣模型。豌豆蚜在细菌细胞内寄生着不同类型的内共生细菌，这些细菌帮助豌豆蚜虫生存并适应新的环境条件和栖息地。专性内共生菌Buchnera aphidicola的基因组急剧减少和稳定，而兼性内共生菌如Regiella insecticola由于噬菌体、可移动元件和高水平的基因重组而具有大而动态的基因组。在前人的工作中，对冷适应的选择导致了以较重的体重和显著的绿色色素为特征的孤雌生殖豌豆个体的出现。利用脱氧腺苷甲基酶(DAM)，分别识别GATC的甲基化和去甲基化的GATC位点，用DPNI和DpnII限制性内切酶从冷诱导绿变异体豌豆基因组DNA(GDNA)中分离到6个腺嘌呤甲基化的DNA片段。得到的6个片段与豌豆根结线虫或Buchnera基因组中的任何序列都不匹配，这意味着它们来自兼性内共生体。选择编码转座酶的A1片段和编码解旋酶的A6片段，在Dam分析和PCR扩增的基础上对豌豆根结线虫的两个变异体(绿色和橙色)进行进一步的比较。与橙色变异体相比，绿色变异体的两个基因上的腺嘌呤甲基化水平都较高，从而证明了腺嘌呤甲基化与两个豌豆根结线虫变异体之间的关联。温度选择可能会影响次生内生共生菌和参与蚜虫生存和适应低温的敏感DAM。在8℃时，内共生体基因的GATC位点上有高度的腺嘌呤甲基化，这种效应在22℃时消失。我们建议在不利的气候条件下对内共生体进行修饰或选择，以增加寄主的适合性，并且新适应的蚜虫的表型可以遗传。本文的在线版本(DOI：10.1186/1471-2164-15-999)包含补充材料，授权用户可以使用。
The pea aphid Acyrthosiphon pisum has two modes of reproduction: parthenogenetic during the spring and summer and sexual in autumn. This ability to alternate between reproductive modes and the emergence of clonal populations under favorable conditions make this organism an interesting model for genetic and epigenetic studies. The pea aphid hosts different types of endosymbiotic bacteria within bacteriocytes which help the aphids survive and adapt to new environmental conditions and habitats. The obligate endosymbiont Buchnera aphidicola has a drastically reduced and stable genome, whereas facultative endosymbionts such as Regiella insecticola have large and dynamic genomes due to phages, mobile elements and high levels of genetic recombination. In previous work, selection toward cold adaptation resulted in the appearance of parthenogenetic A. pisum individuals characterized by heavier weights and remarkable green pigmentation. Six adenine-methylated DNA fragments were isolated from genomic DNA (gDNA) extracted from the cold-induced green variant of A. pisum using deoxyadenosine methylase (Dam) by digesting the gDNA with the restriction enzymes DpnI and DpnII, which recognize the methylated and unmethylated GATC sites, respectively. The six resultant fragments did not match any sequence in the A. pisum or Buchnera genomes, implying that they came from facultative endosymbionts. The A1 fragment encoding a putative transposase and the A6 fragment encoding a putative helicase were selected for further comparison between the two A. pisum variants (green and orange) based on Dam analysis followed by PCR amplification. An association between adenine methylation and the two A. pisum variants was demonstrated by higher adenine methylation levels on both genes in the green variant as compared to the orange one. Temperature selection may affect the secondary endosymbiont and the sensitive Dam involved in the survival and adaptation of aphids to cold temperatures. There is a high degree of adenine methylation at the GATC sites of the endosymbiont genes at 8°C, an effect that disappears at 22°C. We suggest that endosymbionts can be modified or selected to increase host fitness under unfavorable climatic conditions, and that the phenotype of the newly adapted aphids can be inherited. The online version of this article (doi:10.1186/1471-2164-15-999) contains supplementary material, which is available to authorized users.
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影响因子：
4
作者：
Brisson, Jennifer A.;Stern, David L.
通讯作者：
Stern, David L.
影响因子：
2.2
作者：
Montllor, CB;Maxmen, A;Purcell, AH
通讯作者：
Purcell, AH
影响因子：
9.2
作者：
Boxem, M;van den Heuvel, S
通讯作者：
van den Heuvel, S
影响因子：
4.1
作者：
Field, LM
通讯作者：
Field, LM
DOI：
10.1007/bf02428040
发表时间：
1986-01-01
期刊：
MOLECULAR & GENERAL GENETICS
影响因子：
--
作者：
KUCHERER, C;LOTHER, H;MESSER, W
通讯作者：
MESSER, W