Deheer Christopher J, Vargo Edward L
Department of Entomology, Box 7613 Gardner Hall, North Carolina State University, Raleigh NC 27695-7613, USA.
Mol Ecol. 2004 Feb;13(2):431-41. doi: 10.1046/j.1365-294x.2003.2065.x.
Temporal and spatial analyses are seldom utilized in the study of colony genetic structure, but they are potentially powerful methods which can yield novel insights into the mechanisms underlying variation in breeding systems. Here we present the results of a study which incorporated both of these dimensions in an examination of genetic structure of subterranean termites in the genus Reticulitermes (primarily R. flavipes). Most colonies of this species (70%) were simple families apparently headed by outbred primary reproductives, while most of the remaining (27% of the total) colonies contained low effective numbers of moderately inbred reproductives. Mapping the spatial distribution of colony foraging sites over time revealed that despite the high colony density, the absolute foraging boundaries of most R. flavipes colonies were persistent and exclusive of other conspecific colonies, which suggests that this species is more territorial than has been implied by laboratory studies of intraspecific aggression. Nevertheless, we found a single colony (3% of all colonies) which contained the offspring of more than two unrelated reproductives. Although other studies have also described subterranean termite colonies with a similarly complex genetic composition, we demonstrate here that such colonies can form under natural conditions via the fusion of whole colonies. This study underscores how repeated sampling from individual colonies over time and space can yield information about colony spatial and genetic structure that cannot be obtained from conventional analyses or sampling methods.
时间和空间分析在群体遗传结构研究中很少被使用，但它们是潜在的有力方法，能够为繁殖系统变异背后的机制提供新的见解。在此，我们展示了一项研究的结果，该研究在对白蚁属（主要是黄胸散白蚁）地下白蚁的遗传结构进行考察时纳入了这两个维度。该物种的大多数群体（70%）是简单的家族群体，显然由远交的初级繁殖蚁领导，而其余大多数群体（占总数的27%）包含有效数量较少的中度近交繁殖蚁。绘制群体觅食地点随时间的空间分布图谱显示，尽管群体密度很高，但大多数黄胸散白蚁群体的绝对觅食边界是持久的，并且排除了其他同种群体，这表明该物种比种内攻击行为的实验室研究所暗示的更具领地性。然而，我们发现了一个群体（占所有群体的3%），其中包含两个以上不相关繁殖蚁的后代。尽管其他研究也描述过具有类似复杂遗传组成的地下白蚁群体，但我们在此证明，这样的群体可以在自然条件下通过整个群体的融合形成。这项研究强调了随着时间和空间对个体群体进行重复采样如何能够产生关于群体空间和遗传结构的信息，而这些信息是无法从传统分析或采样方法中获得的。
