Characterization of 18 polymorphic microsatellite loci in the red-crowned crane (Grus japonensis), an endangered bird

Red-crowned cranes (Grus japonensis) were classified as an endangered species by the International Union for Conservation of Nature, but recently, their population has decreased dramatically. For the purpose of conserving this endangered species, 18 microsatellite markers were developed, including 12 newly isolated ones from a genomic library and 6 modified from another crane species. The markers were characterized in 26 red-crowned cranes. As a result, these markers displayed 3-13 alleles, and the observed and expected heterozygosities ranged from 0.462 to 1.000 and from 0.483 to 0.884, respectively. The marker suite averaged 6.390 alleles per locus with an average polymorphic information content of 0.631. The combined exclusion probability (PE-1) was 0.9985, and the combined exclusion probability (PE-2) was 0.9999. Three of the 18 microsatellite loci presented significant deviations from Hardy-Weinberg Equilibrium (P < 0.05), likely due to sampling bias and unknown founder relatedness in a semi-free population. Our results show that microsatellite loci can provide a standard protocol for genetic information in red-crowned crane populations upon which strategies for effective conservation and management may be based.