A TRANSECT FOR REPRODUCTIVE COMPATIBILITY AND EVIDENCE FOR A "HYBRID SINK" IN A HYBRID ZONE OF HYALOPHORA (INSECTA: LEPIDOPTERA: SATURNIIDAE)
A TRANSECT FOR REPRODUCTIVE COMPATIBILITY AND EVIDENCE FOR A "HYBRID SINK" IN A HYBRID ZONE OF HYALOPHORA (INSECTA: LEPIDOPTERA: SATURNIIDAE)
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DOI：
10.2992/007.082.0204
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发表时间：
2013-12-31
影响因子：
1.1
通讯作者：
Rawlins, John E.
中科院分区：
文献类型：
--
作者：
Collins, Michael M.;Rawlins, John E.
利用实验杂交方法，测定了卵的生育力、胚胎活力和生殖力，以产生跨越Hyalophora eznyalus（Boisduval，1855）和Hyalophora eznyalus（Boisduval，1855）杂交区的生殖相容性概况。哥伦比亚（Columbia gloveri）（Strecker，1872）（鳞翅目：土星科）在加州的Sierra内华达州山脉。本文从三个方面讨论了杂种区的遗传结构：1）杂种区雌性具有正常的生殖力，与实验室饲养的来自广泛异域亲本类群间杂交的典型不育F-1杂种雌性相反; 2）来自样带沿着确定地点的杂种区雌性与来自同一地点的雄性交配时，与异域物种交配相比，其生殖力和生存力没有降低;（3）发现了一个“杂交库”，在不同的地点间杂交中，来自该库的蛾类是最不亲和的。地形影响杂交区的遗传结构，特别是通过减少与雨影和相关生态特征有关的基因流。在杂交区内，自然选择通过有利于调节卵子发生的相容基因型而明显改变了合子后隔离。在复杂的山地景观生态异质性的长期结构和稳定性的混合带进行了讨论。讨论了Hyalophora混合区的“张力区”模型的适用性，该模型描述了选择平衡对扩散的影响之间的平衡。
Egg fertility, embryo viability, and fecundity were measured, using experimental hybridization, to produce a profile of reproductive compatibility across a hybrid zone between Hyalophora eznyalus (Boisduval, 1855) and H. columbia gloveri (Strecker, 1872) (Lepidoptera: Saturniidae) in the Sierra Nevada mountains of California. Three aspects of the genetic structure of the hybrid zone are discussed: 1) hybrid zone females have normal fecundity, in contrast to typically barren laboratory-reared F-1 hybrid females from crosses between widely allopatric parental taxa; 2) hybrid zone females from defined sites along the transect, in comparison to allopatric species matings, showed no reduction in fertility or viability in matings with males from the same site; and 3) a "hybrid sink" was discovered, the moths from which were the least compatible among various inter-site crosses. Topography affects the genetic structure of the hybrid zone, especially by reducing gene flow in relation to rain shadows and associated ecological features. Within the hybrid zone, natural selection has apparently modified postzygotic isolation by favoring compatible genotypes regulating oogenesis. The long-term structure and stability of the hybrid zone is discussed in terms of ecological heterogeneity in complex montane landscapes. The suitability of the "tension zone" model, which depicts an equilibrium between the effects of selection balanced against dispersal, is discussed for the Hyalophora hybrid zone.