Genetic differentiation between two host ?races? and two species of cleptoparasitic bees and between their two hosts

Abstract We investigate the usefulness of analyses of population differentiation between different ecological types, such as host races of parasites or sources and sink habitats. To that aim, we formulate a model of population structure involving two classes of subpopulations found in sympatry. Extensions of previous results for Wright's F-statistics in island and isolation-by-distance models of dispersal are given. It is then shown that source and sinks cannot in general be distinguished by F-statistics nor by their gene diversities. The excess differentiation between two partially isolated classes with respect to differentiation within classes is shown to decrease with distance, and for a wide range of parameter values it should be difficult to detect. In the same circumstances little differentiation will be observed in “hierarchical analyses between pools of samples from each habitat, and differences between levels of differentiation within each habitat will only reflect differences between levels of gene diversity within each habitat. Exceptions will indicate strong isolation between the different classes or habitat-related divergent selection.

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Genetic differentiation in Zeiraphera diniana (Lepidoptera: Tortricidae, the larch budmoth): polymorphism, host races or sibling species?

Heredity ◽

10.1038/hdy.1995.154 ◽

1995 ◽

Vol 75 (4) ◽

pp. 416-424 ◽

Cited By ~ 71

Author(s):

Igor Emelianov ◽

James Mallet ◽

Werner Baltensweiler

Keyword(s):

Genetic Differentiation ◽

Sibling Species ◽

Host Races ◽

Zeiraphera Diniana

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Genetic differentiation among sympatric cuckoo host races: males matter

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2010.2090 ◽

2010 ◽

Vol 278 (1712) ◽

pp. 1639-1645 ◽

Cited By ~ 47

Author(s):

Frode Fossøy ◽

Anton Antonov ◽

Arne Moksnes ◽

Eivin Røskaft ◽

Johan R. Vikan ◽

...

Keyword(s):

Gene Flow ◽

Genetic Differentiation ◽

Dna Markers ◽

Host Species ◽

Structured Populations ◽

W Chromosome ◽

Significant Genetic Differentiation ◽

Host Races ◽

Local Adaptations ◽

Female Specific

Generalist parasites regularly evolve host-specific races that each specialize on one particular host species. Many host-specific races originate from geographically structured populations where local adaptations to different host species drive the differentiation of distinct races. However, in sympatric populations where several host races coexist, gene flow could potentially disrupt such host-specific adaptations. Here, we analyse genetic differentiation among three sympatrically breeding host races of the brood-parasitic common cuckoo, Cuculus canorus . In this species, host-specific adaptations are assumed to be controlled by females only, possibly via the female-specific W-chromosome, thereby avoiding that gene flow via males disrupts local adaptations. Although males were more likely to have offspring in two different host species (43% versus 7%), they did not have significantly more descendants being raised outside their putative foster species than females (9% versus 2%). We found significant genetic differentiation for both biparentally inherited microsatellite DNA markers and maternally inherited mitochondrial DNA markers. To our knowledge, this is the first study that finds significant genetic differentiation in biparentally inherited markers among cuckoo host-specific races. Our results imply that males also may contribute to the evolution and maintenance of the different races, and hence that the genes responsible for egg phenotype may be found on autosomal chromosomes rather than the female-specific W-chromosome as previously assumed.

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