Metallothionein 유전자를 기초로 한 멸종위기 육상 달팽이 Satsuma myomphala (거제외줄달팽이) 의 분자계통학적 연구

Abstract

Metallothionein (MT) family of metal-binding proteins are involved in maintaining homeostasis and heavy metal poisoning. Recently, MT has been considered as a biomarker that can identify a particular species, very similar to the use of cytochrome oxidase I (COI) gene. Satsuma myomphala species of land snails have been reported from North-East Asia, including South Korea and Japan. In particular, the land snail species have been known from only a limited area of Geoje Island, Gyeongsangnam-do province of South Korea. Genetic studies of S. myomphala has been limited with only 6 nucleotide, 2 protein registered on the NCBI server. For elucidating the genetic information of S. myomphala, we conducted RNA sequencing analysis using Illumina HiSeq 2500 next-generation platform. We screened the MT gene from the RNA-Seq database to confirm the molecular phylogenetic relationship. After sequencing, the de novo analysis and clustering generated 103,774 unigenes. After annotation against PANM database using BLAST program, we obtained MT sequence of 74 amino acid residues containing the coding region of 222 bp. Based on this sequence, we found about 53 sequences using the BLAST program in NCBI nr database. Using ClustalX alignment, Maximum-Likehood Tree of MEGA program, we confirmed the molecular phylogenetic relationships that showed similarity with mollusks such as Helix pomatia and H. aspersa, Megathura crenulata.