title: Asymmetrical introgression patterns between rusty-necklaced partridge (Alectoris magna) and chukar partridge (Alectoris chukar) in China.
abstract: The rusty-necklaced partridge (Alectoris magna) and the chukar partridge (Alectoris chukar) are the most common gamebirds in northern China. Previous comparisons of mitochondrial DNA (mtDNA) have revealed an introgression phenomenon between 2 species of partridge in the Liupan Mountain region of China. mtDNA is maternally inherited, making it difficult to determine the origin of parental genes. We assessed the genetic variation and gene flow between these 2 species of partridges using 8 microsatellite loci as neutral diagnostic markers in 171 samples from the hybrid zone. Our data revealed an extensive divergence of genetic structure between populations of rusty-necklaced partridges and chukar partridges. In this study, we found that 19 samples had been previously morphologically identified as rusty-necklaced partridge were genetically identified as hybrids through Bayesian analysis using STRUCTURE analysis. These hybrids exhibited a mosaic of alleles that were derived from both parental lineages. However, chukar partridges did not present the genotype of the rusty-necklaced partridge. Thus, our findings demonstrate that the hybridization between the 2 species was the result of asymmetrical introgression, with gene flow occurring only from the chukar partridge to the rusty-necklaced partridge. In addition, we also note the high linkage disequilibrium in populations of the rusty-necklaced partridge. These results indicate that although unidirectional introgression did not reduce genetic diversity of the Alectoris partridges, it affected the balance of gene flow between populations. The data from microsatellite DNA prompted our concern about the genetic integrity of the rusty-necklaced partridge.
authors.affiliation: Experiment Center of Biomedical Research School of Medicine, Xi'an Jiaotong University, Xi'an, China.
authors.forename: Yanke
authors.initials: Y
authors.lastname: Chen
authors.affiliation: School of Life Sciences, Lanzhou University, Lanzhou, China.
authors.forename: Bei
authors.initials: B
authors.lastname: An
authors.affiliation: School of Life Sciences, Lanzhou University, Lanzhou, China. naifaliu@sohu.com.
authors.forename: Naifa
authors.initials: N
authors.lastname: Liu
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D002681:China; D005260:Female; D046094:Galliformes / Q000145:classification / Q000235:genetics*; D051456:Gene Flow; D006824:Hybridization, Genetic / Q000235:genetics*; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics*
keywords: chukar partridge (Alectoris chukar); hybridization; introgression; microsatellite DNA; rusty-necklaced partridge (Alectoris magna)