Galvan I.,CSIC - Donana Biological Station |
Gangoso L.,University of Lausanne |
Grande J.M.,University of Saskatchewan |
Negro J.J.,CSIC - Donana Biological Station |
And 3 more authors.
PLoS ONE | Year: 2010
Colour polymorphism results from the expression of multiallelic genes generating phenotypes with very distinctive colourations. Most colour polymorphisms are due to differences in the type or amount of melanins present in each morph, which also differ in several behavioural, morphometric and physiological attributes. Melanin-based colour morphs could also differ in the levels of glutathione (GSH), a key intracellular antioxidant, because of the role of this molecule in melanogenesis. As GSH inhibits the synthesis of eumelanin (i.e. the darkest melanin form), individuals of darker morphs are expected to have lower GSH levels than those of lighter morphs. We tested this prediction in nestlings of two polymorphic raptors, the booted eagle Hieraaetus pennatus and the Eleonora's falcon Falco eleonorae, both of which occur in two morphs differing in the extent of eumelanic plumage. As expected, melanic booted eagle nestlings had lower blood GSH levels than light morph eagle nestlings. In the Eleonora's falcon, however, melanic nestlings only had lower GSH levels after controlling for the levels of other antioxidants. We also found that melanic female eagle nestlings had higher levels of antioxidants other than GSH and were in better body condition than light female eagle nestlings. These findings suggest an adaptive response of melanic nestlings to compensate for reduced GSH levels. Nevertheless, these associations were not found in falcons, indicating species-specific particularities in antioxidant machinery. Our results are consistent with previous work revealing the importance of GSH on the expression of melanic characters that show continuous variation, and suggest that this pathway also applies to discrete colour morphs. We suggest that the need to maintain low GSH levels for eumelanogenesis in dark morph individuals may represent a physiological constraint that helps regulate the evolution and maintenance of polymorphisms. © 2010 Galvan et al. Source
Arroyo J.M.,Estacio n Biologica de Donana CSIC |
Rigueiro C.,Estacio n Biologica de Donana CSIC |
Rodriguez R.,Estacio n Biologica de Donana CSIC |
Hampe A.,Estacio n Biologica de Donana CSIC |
And 3 more authors.
American Journal of Botany | Year: 2010
Premise of the study: Microsatellite primers were developed for the evergreen tree Laurus to investigate population genetic structure and patterns of gene flow via animal-dispersed pollen and seeds. Methods and Results: Twenty polymorphic nuclear microsatellite markers were developed using CA, GA, AAC, and ATG n-enriched genomic libraries. Given the tetraploidy of the sampled populations, we analyzed our data both as dominant loci and as codominant genotypic data to calculate allele frequencies and genetic diversity. A total of 196 and 222 alleles were found in 37 Mediterranean (L. nobilis) and 26 Macaronesian islands (L. azorica) individuals, respectively. Conclusions: Levels of polymorphism of the reported markers are adequate for studies of diversity and parentage in natural populations of this Tertiary relict tree. © 2010 Botanical Society of America. Source