Mhc dating

Conversely, if alleles are more similar at putatively selected sites compared to neutral sites between species then convergent evolution is more likely (Klein et al., 1998).When a population adapts to its new environment, MHC allele diversity is comprised of alleles maintained through TSP and new genetic variants.

The eastern breeding populations occur southeast of Heilongjiang Province, east of Jilin Province, to the extreme south of Russian Far East and the boundary region between Russia, China, and North Korea (Yamashina, 1957; Fu & Chen, 1966; Panov, 1973; Stresemann & Portenko, 1981; Zhao, Nickel & Groh, 1994). Therefore, these two passerine birds represent good relative models to investigate the genetic diversity of MHC genes and associated genetic maintenance mechanisms in E. Two sympatrically distributed and one non-sympatrically distributed E.

The western populations occur in west Jilin Province and the adjacent areas of Inner Mongolia (Fu & Chen, 1966; Zhao, Nickel & Groh, 1994; Gao, 2002). cioides populations were chosen for comparison with E. In general, common species are more genetically diverse than endangered species (Akst, Boersma & Fleischer, 2002; Bollmer, Vargas & Parker, 2007). The aims of this study were to: (i) reveal the genetic diversity of the MHCIIB gene in E. cioides; (ii) screen for associated selection and recombination signatures; (iii) determine the extent of TSP in E.

Pathogen-mediated selection is the driving force behind the genetic diversity associated with MHC gene loci (Bernatchez & Landry, 2003), and some studies have suggested that gene conversion, recombination, or sexual selection may play an important role in maintaining MHC genetic diversity (Promerová et al., 2013; Sardell, Kempenaers & Duval, 2014).

In a wide range of taxa, trans-species polymorphisms (TSPs) may contribute to MHC genetic diversity (Ballingall et al., 2010; Luo & Pan, 2013; Jaratlerdsiri et al., 2014; Eimes et al., 2015; Balasubramaniam et al., 2016).

However, no information pertaining to either of these two breeding distributions has been reported in recent years (Wang, Jiang & Gao, 2010). cioides have a close genetic relationship and always cluster into the same highly supported clade with two other congeneric species, based on analyses of mitochondrial (Cytb, Cox gene) and nuclear (ODC gene, AFLP) loci (Alström et al., 2008; Liang et al., 2008; Li et al., 2013). In this study, we investigated polymorphisms in the exon 2 of the MHCIIB gene of both E. jankowskii; and (iv) aid in the proposal of measures to protect E. All field studies were approved by the National Animal Research Authority in Northeast Normal University, China (approval number: NENU-20080416). jankowskii individuals were collected from three populations: ALH, GHT and LB. cioides individuals were also collected from three locations: ALH, GHT and Bayantala (BYTL) (Fig. The blood samples (up to 10 µl) were collected by wing vein puncture.

The recently discovered breeding populations (Aolunhua (ALH), Gahaitu (GHT) and Lubei557 (LB)) are distributed in Inner Mongolia and belong to the western breeding population of E. We only observed these three populations between May and August 2012. The blood samples (up to 10 µl) were extracted from birds by wing vein puncture. They were subsequently mixed with 1 ml of absolute ethyl alcohol and stored at room temperature.

MHC genes are known to be highly polymorphic and play a major role in immune function.

MHC class I molecules present peptides from intracellular pathogens, whereas MHC class II molecules display peptides from extracellular pathogens (Piertney & Oliver, 2006).

Efforts focused on facilitating the conservation of the Rufous-backed Bunting (Emberiza jankowskii) are becoming increasingly important. A total of 1.59 alleles/individual were detected in E. jankowskii, 10.17 segregating sites per allele were detected, and the nucleotide diversity was 0.1865. cioides, eight segregating sites per allele were detected, and the nucleotide diversity was 0.1667. Positive selection was detected by PAML/SLAC/FEL analyses in the region encoding the peptide-binding region in both species, and no recombination was detected.

jankowskii and 1.73 alleles/individual were identified in E. The maximum number of alleles per individual from the three E. Overall, compared to other passerine birds, a relatively low level of MHC polymorphism was revealed in E. Phylogenetic analysis showed that the alleles from E. cioides belong to the same clade and the two species shared similar alleles, suggesting the occurrence of a trans-species polymorphism between the two Emberiza species.

TSP occurs when alleles are shared between species as a result of orthologous MHC allelic lineages being maintained by balancing selection and persisting through speciation events (Klein et al., 1998; Lenz et al., 2013).

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