Duplicated alkaline phosphatase genes in the wild silkworm Bombyx mandarina inhabiting Japan: phylogenetic relationship to the orthologs in Bombyx mori

摘要

The silkworm, Bombyx mori, is closely related to the wild silkworm, B. mandarina, although process of their divergence is not fully elucidated. To evaluate the evolutionary relationship of the domesticated silkworm strains, alkaline phosphatase gene (Alp) cluster in B. mandarina was identified and characterized. Two Alp genes, Alp-m (man) and Alp-s (man), were shown to be duplicated in tandem in the genome of B. mandarina inhabiting Japan. Gene arrangement and exon-intron structure of each gene were highly identical to those in B. mori. Localization of the two ALP proteins in the epithelial cells of the B. mandarina's midgut were similar to those of B. mori. These results consistently suggest that Alp-m (man) and Alp-s (man) are B. mandarina orthologs of Alp-m and Alp-s of B. mori, respectively, and that the duplication of Alp genes was prior to the speciation. By comparing the structure of the intervening sequences of two Alp genes, a possible phylogenetic relationship among the polymorphism in B. mori was discussed. The nucleotide sequence reported in this paper has been submitted to DDBJ/ GeneBank (accession number: AB270698).