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Impairment of mixed melanin-based pigmentation in parrots

Parrots and allies (Order Psittaciformes) have evolved an exclusive capacity to synthesize polyene pigments called psittacofulvins at feather follicles, which allows them to produce a striking diversity of pigmentation phenotypes. Melanins are polymers constituting the most abundant pigments in animals, and the sulphurated form (pheomelanin) produces colors that are similar to those produced by psittacofulvins. However, the differential contribution of these pigments to psittaciform phenotypic diversity has not been investigated. Given the color redundancy, and physiological limitations associated to pheomelanin synthesis, this study assumed that the latter would be avoided by psittaciform birds. This hypothesis was tested by using Raman spectroscopy to identify pigments in feathers exhibiting colors suspicious of being produced by pheomelanin (i.e., dull red, yellow and grey- and green-brownish) in 26 species from the three main lineages of Psittaciformes. The non-sulphurated melanin form (eumelanin) were detected in black, grey and brown plumage patches, and psittacofulvins in red, yellow and green patches, but no evidence of pheomelanin was found. As natural melanins are assumed to be composed of eumelanin and pheomelanin in varying ratios, these results represent the first report of impairment of mixed melanin-based pigmentation in animals. Given that psittaciforms also avoid the uptake of circulating carotenoid pigments, these birds seem to have evolved a capacity to avoid functional redundancy between pigments, likely by regulating follicular gene expression. The study provides the first vibrational characterization of different psittacofulvin-based colors and thus helps to determine the relative polyene chain length in these pigments, which is related to their antireductant protection activity. informacion[at]ebd.csic.es: Neves et al (2020) Impairment of mixed melanin-based pigmentation in parrots. J Experim Biol. DOI 10.1242/jeb.225912


https://jeb.biologists.org/content/early/2020/05/08/jeb.225912
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Genetic evaluation of the Iberian lynx ex situ conservation programme

Genetic evaluation of the Iberian lynx ex situ conservation programme

Ex situ programmes have become critical for improving the conservation of many threatened species, as they establish backup populations and provide individuals for reintroduction and reinforcement of wild populations. The Iberian lynx was considered the most threatened felid species in the world in the wake of a dramatic decline during the second half of the 20th century that reduced its numbers to around only 100 individuals. An ex situ conservation programme was established in 2003 with individuals from the two well-differentiated, remnant populations, with great success from a demographic point of view. This study evaluates the genetic status of the Iberian lynx captive population based on molecular data from 36 microsatellites, including patterns of relatedness and representativeness of the two remnant genetic backgrounds among founders, the evolution of diversity and inbreeding over the years, and genetic differentiation among breeding facilities. In general terms, the ex situ population harbours most of the genetic variability found in the two wild populations and has been able to maintain reasonably low levels of inbreeding and high diversity, thus validating the applied management measures and potentially representing a model for other species in need of conservation. The Iberian lynx ex situ breeding programme has been a key piece in the multifaceted conservation of the Iberian lynx. After 12 years, it has accomplished the two main goals that were set at the start. Firstly, it has succeeded in establishing a demographically and genetically healthy ex situ population that may act as a safeguard for the species in case of extinction in the wild. Secondly, after a few years of internal growth, the population has been serving as the almost exclusive source of individuals for reintroduction in the wild. Besides, the programme has assembled a set of experts in many different fields as well as fostered and coordinated research on issues of high relevance for the conservation of the species, while becoming a major driver of awareness and dissemination. The Iberian lynx ex situ programme has been quite effective in representing, boosting and maintaining the low genetic diversity that survived the latest severe bottleneck of the species while minimising the accumulation of inbreeding, which should ultimately result in increased adaptive potential and average fitness. In this regard, the Iberian lynx ex situ programme could serve as an example of marker-assisted pedigree-based management for other species at similar conservation stages. informacion[at]ebd.csic.es: Kleinman-Ruiz et al (2019) Genetic evaluation of the Iberian lynx ex situ conservation programme. Heredity Doi 10.1038/s41437-019-0217-z


https://www.nature.com/articles/s41437-019-0217-z