Female house sparrows "count on" male genes: experimental evidence for MHC-dependent mate preference in birds

<p>Abstract</p> <p>Background</p> <p>Females can potentially assess the quality of potential mates using their secondary sexual traits, and obtain "good genes" that increase offspring fitness. Another potential indirect benefit from mating preferences is genetic compatibility, which does not require extravagant or viability indicator traits. Several studies with mammals and fish indicate that the genes of the major histocompatibility complex (MHC) influence olfactory cues and mating preferences, and such preferences confer genetic benefits to offspring. We investigated whether individual MHC diversity (class I) influences mating preferences in house sparrows (<it>Passer domesticus</it>).</p> <p>Results</p> <p>Overall, we found no evidence that females preferred males with high individual MHC diversity. Yet, when we considered individual MHC allelic diversity of the females, we found that females with a low number of alleles were most attracted to males carrying a high number of MHC alleles, which might reflect a mating-up preference by allele counting.</p> <p>Conclusions</p> <p>This is the first experimental evidence for MHC-dependent mating preferences in an avian species to our knowledge. Our findings raise questions about the underlying mechanisms through which birds discriminate individual MHC diversity among conspecifics, and they suggest a novel mechanism through which mating preferences might promote the evolution of MHC polymorphisms and generate positive selection for duplicated MHC loci.</p

Strategies for Successful Aging: A Research Update

Population aging is an enormous public health issue and there is clear need for strategies to maximize opportunities for successful aging. Many psychiatric illnesses are increasingly thought to be associated with accelerated aging, therefore emerging data on individual and policy level interventions that alter typical aging trajectories are relevant to mental health practitioners. Although the determinants and definition of successful aging remain controversial, increasing data indicate that psychiatric illnesses directly impact biological aging trajectories and diminish lifestyle, psychological and socio-environmental factors that seem reduce risk of morbidity and mortality. Many interventions designed to enhance the normal course of aging may be adjunctive approaches to management of psychiatric illnesses. We highlight recent data on interventions seeking to promote healthy aging, such as cognitive remediation, physical activity, nutrition, and complementary and alternative treatments for older people with and without psychiatric illnesses