Parental age has profound consequences for offspring’s phenotype. However, whether patrilineal age affects offspring sperm production remains unknown, despite the importance of sperm production for male reproductive success in species facing post‐copulatory sexual selection. Using a longitudinal dataset on ejaculate attributes of the houbara bustard, we showed that offspring sired by old fathers had different age‐dependent tra...

The classical class I and class II molecules of the major histocompatibility complex (MHC) play crucial roles in immune responses to infectious pathogens and vaccines as well as being important for autoimmunity, allergy, cancer and reproduction. These classical MHC genes are the most polymorphic known, with roughly 10,000 alleles in humans. In chickens, the MHC (also known as the BF-BL region) determines decisive resistance an...

Offspring resulting from mating among close relatives can suffer from impaired fitness through the expression of recessive alleles with deleterious effects. Postcopulatory sperm selection (a prezygotic mechanism of cryptic female choice) has been suggested to be an effective way to avoid inbreeding. To investigate whether postcopulatory female choice allows the avoidance of fertilization by close kin, we performed artificial i...

Genes of the major histocompatibility complex (MHC) are the most polymorphic loci known in vertebrates. Two main hypotheses have been put forward to explain the maintenance of MHC diversity: pathogen‐mediated selection and MHC‐based mate choice. Host–parasite interactions can maintain MHC diversity via frequency‐dependent selection, heterozygote advantage, and diversifying selection (spatially and/or temporally heterogeneous s...

Genes of the Major Histocompatibility Complex ( Mhc ) play a fundamental role during the immune response because MHC molecules expressed on cell surface allow the recognition and presentation of antigenic peptides to T‐lymphocytes. Although Mhc alleles have been found to correlate with pathogen resistance in several host‐parasite systems, several studies have also reported associations between Mhc alleles and an accrued infect...

In iteroparous species high investment in current reproduction is usually paid in terms of reduced future reproduction and increased mortality. However, the proximal mechanisms of these costs remain poorly understood. Free radicals arising as by‐products of normal metabolic activities have deleterious effects on cellular proteins, lipids and DNA, and this phenomenon is known as oxidative stress. Since reproduction is an energe...

Maternal effects can have an adaptive value if they improve the performance of offspring. As such, the transfer of maternal testosterone (T) to the eggs has been suggested as a mechanism for adaptive maternal control of offspring phenotype in birds, although recent studies have shown negative effects of testosterone on hatching rate and chick survival. Here, we experimentally investigated whether socially stressful conditions...