Complete sequence determination and phylogenetic analysis of FKN among seven higher primates including homonids and Old World Monkeys

To obtain full-length FKN nucleotide sequences of homonids including human, chimpanzee, gorilla, orangutan and gibbon, and Old World Monkeys including macaque and leaf monkey and make phylogenetic analysis, three exons of FKN were amplified by degenerated PCR using obtained peripheral blood cells DNA as template which was extracted from homonids and Old World Monkeys. After extracting and purifying from agarose gels, PCR products were sequenced and then spliced by using BioEdit. All the FKN sequences were aligned and compared the percent identity by using DNAStar. The phylogenetic tree was constructed using maximum evolution approach in Mega. The negative selection sites were analyzed by using Datamonkey. There is an apparent 30 bp nucleotides deletion mutation in homonids FKN comparing to that of Old World Monkeys besides other point mutations. Homology of nucleotide sequence between human and chimpanzee, gorilla, orangutan, gibbon, macaque and leaf monkey is 99.2%, 98.4%, 98.1%, 96.5%, 95.9% and 93.8%, respectively. Homology of amino acid sequence of them is 98.5%, 98.0%, 97.7%, 94.7%, 93.7% and 90.5%, respectively. In the same time, the genealogical relationship of human is a lot closer to chimpanzee than it is to gorilla and other apes. It is generally agreed that the evolution rule of FKN gene is in accord with that of the higher primates. In addition, Datamonkey shows that there are 3 negative selection sites 53Q, 84D and 239N in FKN. The full-length FKN gene of human, chimpanzee, gorilla, orangutan, gibbon, macaque and leaf monkey were sequenced successfully, and the FKN sequences analysis lays the foundation for further studying its evolution in immunological function in higher primates and the relation between its structure and function.