Dronnet Stéphanie, Lohou Caroline, Christides Jean-Philippe, Bagnères Anne-Geneviève
Institut de Recherche sur la Biologie de l'Insecte, UMR CNRS 6035, Faculté des Sciences et Techniques, Parc Grandmont, Université François Rabelais, 37200 Tours, France.
J Chem Ecol. 2006 May;32(5):1027-42. doi: 10.1007/s10886-006-9043-x. Epub 2006 May 21.
Nestmate recognition plays a key role in kin selection to maintain colony integrity in social insects. Previous studies have demonstrated that nestmate recognition is dependent on detection of cuticular hydrocarbons. However, the absence of intraspecific aggression between some colonies of Isoptera and social Hymenoptera questions whether kin recognition must occur in social insects. The purpose of this study was to determine if cuticular hydrocarbon similarity and high genetic relatedness could explain the lack of intraspecific aggression among and within colonies of the introduced subterranean termite Reticulitermes santonensis. We performed both GC analysis of cuticular hydrocarbons and genotyping by using 10 DNA microsatellite loci on the same 10 workers from each of 14 parisian colonies. Multivariate analyses demonstrated correspondence between cuticular hydrocarbon patterns and genetic variation. By using a redundancy analysis combining chemical and genetic data, we found that a few hydrocarbons (mainly short vs. long chains; saturated vs. unsaturated alkanes) were associated with most genetic variation. We also found a strong positive correlation between chemical and genetic distances between colonies, thus providing evidence of a genetic basis for cuticular hydrocarbon variation. However, genetic distance did not account for all chemical variation, thus suggesting that some hydrocarbon variation was environmentally derived. Investigation at the intracolony level indicated that cuticular hydrocarbons did not depend on colony social structure. Based on our findings, we speculate that the absence of intraspecific aggression in R. santonensis may result from a loss of diversity in genetically derived recognition compounds in this species that presumably descended from R. flavipes populations imported from North America.
巢伴识别在亲属选择中起着关键作用，以维持社会性昆虫群体的完整性。先前的研究表明，巢伴识别依赖于表皮碳氢化合物的检测。然而，等翅目和社会性膜翅目的一些群体之间缺乏种内攻击行为，这让人质疑亲属识别是否必然发生在社会性昆虫中。本研究的目的是确定表皮碳氢化合物的相似性和高度的遗传相关性是否可以解释引入的地下白蚁桑氏散白蚁群体之间和群体内部缺乏种内攻击行为的原因。我们对来自14个巴黎群体的10只工蚁进行了表皮碳氢化合物的气相色谱分析，并使用10个DNA微卫星位点进行基因分型。多变量分析表明表皮碳氢化合物模式与遗传变异之间存在对应关系。通过结合化学和遗传数据的冗余分析，我们发现一些碳氢化合物（主要是短链与长链；饱和与不饱和烷烃）与大多数遗传变异相关。我们还发现群体之间化学距离和遗传距离之间存在很强的正相关，从而为表皮碳氢化合物变异提供了遗传基础的证据。然而，遗传距离并不能解释所有的化学变异，因此表明一些碳氢化合物变异是环境衍生的。群体内水平的研究表明，表皮碳氢化合物不依赖于群体社会结构。基于我们的研究结果，我们推测桑氏散白蚁缺乏种内攻击行为可能是由于该物种中遗传衍生的识别化合物多样性的丧失，该物种可能起源于从北美引入的黄肢散白蚁种群。
