The highly polymorphic genes within the major histocompatibility complex (MHC) not only play a major role in immunity resistance, but also seem to provide hints for mate choice in some animal populations. In the present study we investigated MHC‐related mate choice in a small natural population (group size 40–55 individuals) of a polygynous primate, the Sichuan snub‐nosed monkey (Rhinopithecus roxellana). We found that there was no evidence either for MHC‐disassortative mating, or for females to mate with males based on MHC heterozygosity or specific alleles. Nevertheless, of the 11 alleles identified, we found that the frequencies of 2 alleles, Rhro‐DRB2 (P < 0.01) and Rhro‐DRB5 (P < 0.05) were higher in offspring than in their parents. These findings suggest that MHC‐DRB in this population of R. roxellana is unlikely to be associated with mating preferences. Limited female opportunities for mate choice are likely due, in part, to the harem breeding structure present in R. roxellana, and the relatively small number of resident adult males in our study band (N = 4–6). In addition, we suggest that differences in the frequency of particular alleles across generations may be linked to parasite resistance in a fluctuating environment; however, confirmation of this finding requires further study. 相似文献
The authors studied a population of 582 gilthead sea breams (Sparus aurata), aged 25–600 days, in order to describe the abnormalities of the opercular complex.
Particular attention was paid to: (1) the different degrees of abnormality of the opercular complex as a whole and of the individual dermal bones (preopercle, interopercle, subopercle and opercle) that compose it; (2) the ways in which the operculum folds into the gill cavity and the relevant histological characteristics. This study discusses the origin and nature of the abnormalities.
Though these abnormalities have a major impact on market value and product image, and are often linked to other disorders in fish, they are still difficult to eliminate. Gaining a basic understanding of these abnormalities will be a first step towards reducing their occurrence. 相似文献