CO1 유전자와 ITS 염기서열을 이용한 보통해면강 종의 유전적 동정.

Abstract

The phylum Porifera contains approximately 8,000 living species and Demospongiae is the largest class in Porifera. Porifera systematics has traditionally used morphological characters such as the skeleton composition and the spicule shape. However, these characters do not enough to distinguish diverse species apart. Moreover, morphological traits of sponges are known to show homoplasies in many species. Recently, several molecular marker is examined as additional and alternative characters for species identification.In this study, we analyzed partial sequences of the mitochondrial CO1 gene and the nuclear ITS of the Demospongiae species in order to identify. We collected CO1 and ITS sequences of 65 species in 16 genera, 12 families, and 4 orders and examine relationship within and between species using by MEGA 4.0 and PAUP program. As a result, each of variation of CO1 and ITS sequence within species showed 0.2 ~ 4.8% and 0.7 ~ 10.2% and the mean interspecific variations 4.35% and 10.42%, respectively. The result shows that the most of sequence analysis between each species, both CO1 and ITS, accorded with morphological classification. The CO1 sequences could not distinguish Psammocinia spp. belonging to the family Irciniidae, Dictyoceratida from Hymeniacidon spp. of the family Hymeniacidae, Halichondrida which were classified based on the morphological characters. But, ITS sequences, separated them each other. The result of this study provide information about molecular marker as additional and alternative character on controversial Demospongiae classification system.