1 on 1 random sex cam
1 on 1 random sex cam
For example, in three-spined sticklebacks (Gasterosteus aculeatus), which are characterized by gene replication at the MHC class IIB, individuals with an intermediate number of alleles showed greater resistance when challenged by multiple pathogens (Kurtz et al., 2004).Furthermore, female three-spined sticklebacks appear to select mates such that their offspring have the optimal number of MHC alleles (Reusch et al., 2001).
Because Pacific salmon are semelparous, it is relatively easy to assess lifetime reproductive success (Fleming et al., 2000; Seamons et al., 2007).
Mate choice for compatible genes has largely focused on inbreeding avoidance and disassortative mating at the immune loci of the major histocompatibility complex (MHC; reviewed by Mays and Hill, 2004).
In the present study, we partition variation in reproductive success to body size and coloration (phenotype) and diversity at the MHC (genotype) in Chinook salmon (Oncorhynchus tshawytscha).
Mate choice, on the other hand, can select for genetic benefits including ‘good genes’ that show additive genetic variance and ‘compatible genes’ that show non-additive genetic variance (Neff and Pitcher, 2005).
For example, female gray tree frogs prefer to mate with males that have long courtship calls and the offspring of long-calling males consistently have higher fitness than those of short-calling males, which suggests an additive genetic effect (Klump and Gerhardt, 1987; Welch et al., 1998).
We found that large males, and males with brighter coloration and a more greenblue hue on their lateral integument sired more offspring, albeit only body size and brightness had independent effects.
There was no similar relationship between these variables and female reproductive success.In Savannah sparrows (Passerculus sandwichensis), females paired to social mates that were similar to themselves at the MHC class IIB gene were more likely to seek extra-pair mates (Freeman-Gallant et al., 2003).Yet other studies have suggested that there can be an optimal level of diversity at the MHC.Correspondence: Professor BD Neff, Department of Biology, University of Western Ontario, 1151 Richmond Street, London, Ontario, Canada N6A 5B7.E-mail: [email protected] 7 February 2008; Revised 14 April 2008; Accepted 18 April 2008; Published online .Detailed analysis of variation in reproductive success can provide an understanding of the selective pressures that drive the evolution of adaptations.