The genetic diversity and population genetic structure of Formosan sika deer

ABSTRACT
Formosan sika deer (C. n. taiouanus) is endemic to Taiwan, and was widely distributed in the woodlands under 300 m elevation. The wild Formosan sika deer was extinct in 1960, while some individuals were conserved in Taipei Zoo and deer farm. The Recovering Program of Formosan sika deer started in 1986, and Twenty-two individuals were chosen from Taipei zoo and conserved in the wild of Kenting National Park. The population size of wild deer in Kenting National Park has increased to about 1,500 nowadays (2010). However, the genetic structure of the wild Formosan sika deer is not clear. The research aim to select applicable microsatellite markers for Formosan sika deer; to investigate the genetic diversity and genetic structure of Formosan sika deer conserved population for population management; to analyze the introgression from red deer to sika deer populations.
A total 196 sika deer samples form 6 sites were collected (90 from Kenting National Park, 36 from Kinmen Livestock Research Institute, 39 from Ta Chiu islet, 8 from Shou Shan Zoo, 10 form Taitung deer farm and 13 from Tainan deer farm) for population study. The cross-species microsatellite markers were selected form 22 bovine and ovine markers. The markers with short tandem repeat sequences were examined cloning to separate sequences and sequencing. The genetic diversity and genetic structure of Formosan sika deer was examined by 11microsatellite markers. Identification of species is conducted by Zfy gene and cytochrome b for investigating cultivated deer populations.
The selected 11 crossed-species markers showed medium level of polymorphic information content in whole Formosan sika deer population. And the probability of identity (P（ID）) is less than 0.0001. These results reveal The selected 11 crossed-species markers are polymorphic and achieve a very low probability of finding two random individuals with identical genotypes. The average polymorphic information is 0.439 in Kenting National Park population (KNP). The average expected heterozygosity (He) and observed heterozygosity (Ho) were both 0.512. It showed KNP population maintained more alleles and heterozygosity than other conservation populations. The result of Neighbor-Joining tree showed KNP, Kinmen and Ta Chiu islet population can cluster together. It agrees with the process of introduced founder populations. Utilizing Zfy gene and Cytochrome b gene can acquire maternal and paternal genetic information. The genetic structure showed red deer population has different pattern with sika deer population. And only a few individuals in deer farm showed introgression.
In conclusion, this study can provide the applicable method to investigate population genetic structure of Formosan sika deer with microsatellite markers. The information of genectic diversity in Kenting National Park population can be refer as population management. With microsatellite, Zfy and Cytochrome b gene, the futher study of introgression from red deer to sika deer population can be implemented.