Domingue Michael J, Starmer William T, Teale Stephen A
Department of Environmental and Forest Biology, College of Environmental Science and Forestry, State University of New York, Syracuse, NY 13210, USA.
J Chem Ecol. 2006 May;32(5):1005-26. doi: 10.1007/s10886-006-9042-y. Epub 2006 May 20.
The genetic nature of pheromone variation within species has rarely been studied, and never for male-produced long-range pheromones. Males from western North American populations of Ips pini produce predominantly (R)-(-)-ipsdienol, whereas those from eastern North American populations produce higher proportions of (S)-(+)-ipsdienol. From a population in the hybrid zone, we divergently selected lines for the opposing pheromonal types and then created F1, F2, and backcross lines. We formed additional F1, F2, and backcross lines, first by using populations with low (+)-ipsdienol enantiomeric ratios near to and distant from the hybrid zone, and then by using populations with high (+)-ipsdienol enantiomeric ratios near to and distant from the hybrid zone. Three types of analysis were employed: (1) line means analysis; (2) Mendelian analysis of assigned high and low (+)-ipsdienol enantiomeric ratio phenotypes when applicable; and (3) Castle-Wright estimation of the number of effective factors. Dominance at one autosomal locus explains much of the variation in ipsdienol blend between the divergently selected lines. Thus, as in all previously studied female long-range pheromone systems, a major genetic element is implicated. The populations with low (+)-ipsdienol enantiomeric ratios near and distant to the hybrid zone differ negligibly for this trait. We confirmed previous studies showing slightly higher ratios of (+)-ipsdienol at the hybrid zone than in a distant eastern population and reveal a genetic basis for this difference.
物种内信息素变异的遗传本质很少被研究，对于雄性产生的远距离信息素更是从未有过研究。北美西部云杉八齿小蠹种群的雄性主要产生（R）-（-）-异长叶烯醇，而北美东部种群的雄性产生更高比例的（S）-（+）-异长叶烯醇。我们从杂交区域的一个种群中，针对相反的信息素类型进行了分歧选择品系，然后创建了F1、F2和回交品系。我们首先使用了杂交区域附近和远离杂交区域的具有低（+）-异长叶烯醇对映体比例的种群，然后使用了杂交区域附近和远离杂交区域的具有高（+）-异长叶烯醇对映体比例的种群，形成了额外的F1、F2和回交品系。采用了三种分析类型：（1）品系均值分析；（2）在适用时对指定的高和低（+）-异长叶烯醇对映体比例表型进行孟德尔分析；（3）有效因子数量的Castle-Wright估计。一个常染色体位点的显性解释了分歧选择品系之间异长叶烯醇混合物的大部分变异。因此，与所有先前研究的雌性远距离信息素系统一样，涉及一个主要的遗传因素。杂交区域附近和远离杂交区域的具有低（+）-异长叶烯醇对映体比例的种群在这一性状上差异可忽略不计。我们证实了先前的研究，即杂交区域的（+）-异长叶烯醇比例略高于东部一个远距离种群，并揭示了这种差异的遗传基础。
