Genetic Analyses And Sex-biased Dispersal Of The Elliot's Pheasant (Syrmaticus Ellioti)

Elliot's Pheasant(Symaticus ellioti),is a vulnerable species endemic to China and is the national level protected animal.Its population size is believed to be declining because of the impact of human and the loss,fragmentation,degradation of habitats during recent years.In this study,we reported the genetic diversity and genetic structure analyses in the Elliot's Pheasant,using seven polymorphism microsatellite loci based on 105 individuals from 4 geographical populations (Guizhou,Human,Fujian and Gutianshan geographical populations),compared with the result form mtDNA.Here we reported the indication of sex-biased dispersal in Elliot's Pheasant using polymorphic DNA microsatellite loci(105 individuals and seven loci) and mitochondrial DNA control-region sequences(63 individuals).The results were as follows:1.Departures from Hardy-Weinberg equilibrium were found in four geographic populations.The average number of alleles was 8.86,with a total of 62 alleles across 7 loci.The observed heterozygosity(H_O) was generally low,ranging from 0.261 (SE02) to 0.782(SE06),and the average number was 0.504.For the seven microsatellite loci,the polymorphism information content ranged from 0.549 to 0.860, with an average number 0.712.2.The sex-biased dispersal analyses.(1) Five different tests from microsatellite:the gene diversity(H_S),differentiation among populations(F_st),relatedness(r),mean assignment index(mAIc) and variance of the assignment index(vAIc) were quantified separately for both sexes over all populations.The difference in the F_st,r and H_S were significant(P＜0.05).(2) AMOVA based on mtDNA had recovered stronger genetic structure for females(Fst=0.350) than males(Fst=0.290).(3)Microsatellite and mtDNA are two genetic markers with different modes of inheritance.We found that the overall differentiation based on mtDNA was almost six times higher(mtDNA: overall Fst=0.32;microsatellite overall Fst=0.058) using simple comparison between the measure of differentiation based on haplotype and that based on allele frequencies. All the genetic information extracted from the two markers suggested that it is male-biased dispersal in Elliot's Pheasant which was in concordance with the mating system hypothesis.We argued that polygynous species in Galliforrnes without lekking behavior were more likely to exhibit male-biased dispersal pattern.3.The gene flows of all loci were larger,so did that between 4 geographical populations(Hunan,Guizhou,Gutianshan and Fujian).Population bottlenecks of the four geographical populations of Elliot's Pheasant were tested by infinite allele mutation model,step-wise mutation model and two-phase mutation model,which found that all geographic populations had experienced bottleneck effects during the recent period.Fst analyses across all geographical populations indicated that the genetic differentiaton between the Guizhou geographical population and the Hunan geographical population was highly significant(P＜0.001),a finding supported by the far genetic relationship showed by the neighbor-joining tree and UPGMA dendrogram of four geographic populations based on Nei's unbiased genetic distances.Using hierarchical analysis of molecular variance(Guizhou geographic population relative to all others pooled) based on microsatellite and mtDNA respectively,the results showed that the genetic variation among individuals within geographical populations were both higher(mtDNA:64.89%,microsatellite:92.84%),and significant (P＜0.001).However,the genetic variation among geographical populations within groups were inconsistent(mtDNA:9.41%,P＜0.001;microsatellite:5.6%,P＞0.001), which may be related to the different characteristics of these two genetic markers.