Genetic variations and shell color patterns of spotted babylon Babylonia areolata in the Gulf of Thailand

Abstract

This study aimed to determine genetic variations of spotted babylon, Babylonia aerolata, Link 1807 in the Gulf of Thailand which have five shell color patterns ;1) brown patches on white basal shell 2) orange patches on white basal shell 3) white basal shell without patches 4) rust basal shell without patches 5) continuous dark brown patches on white basal shell. Spotted babylon was collected from Chanthaburi, Rayong, Trad, Phetchaburi, Prachuap Khiri khun, Nakhorn Si Thammarat, Songkhla and Pattani. Two molecular techniques, ISSR and DNA sequencing, were employed to examine the genetic variation of spotted babylon samples. Forty eight ISSR primers were screened and four reliable and polymorphic primers (UBC 841, UBC845, 814 and T8707) were obtained. By screening forty-eight samples of spotted babylon (Five shell color patterns), twenty-one DNA bands were obtained, which 14 bands were polymorphic. The percentage of polymorphic loci is 66.67. These data sets were used to produce the dendrogram which showed no separation on each shell color patterns. For DNA sequencing technique, 20 specimens of B. aerolata were used and B. spirata was used as control. The analysis of partial sequences of mtDNA (16S rRNA 435 bp and COI 460 bp). The result of COI gene showed low genetic variation among the five color patterns variations (0.00-0.64 %) compared with the variation of those with B. spirata (12.72-13.56%). Beside from preliminary cross breeding of three color patterns broodstocks in 9 experiments to support the result of the molecular technique, there was no spawning of eggs occurred throughout 11 months. Therefore, it is possible to conclude that the snail different in shell color patterns are the same species, but the cause of shell color variation is still unclear whether it is the effect of environment or genetics.