Utility of microsatellite markers in species boundary and population genetics of Acropora
Date Issued
2006
Date
2006
Author(s)
Chen, Chien-Wei
DOI
en-US
Abstract
Acropora is by far one of the largest extent reef-building corals genus comprising 113 species. It is also one of the most widespread genera of corals, spanning the Indian and Pacific Oceans and Caribbean Sea. Due to great intraspecific variations and interspecific hybridization, species boundaries among Acropora were not clear. Hence, morphological, breeding, and molecular criteria were utilized to examine species boundaries among Acropora. But, many lower resoluble genetic markers were used for species boundaries among Acropora spp. Therefore, due to high polymorphism within populations, microsatellites, 1-6 bp tandemly repeats stretches, might possibly be utilized for species boundary and population genetics of Acropora.
There were five GT repeats, isolated from A. muricata, and eight AAT repeats, isolated from A. palmata, tested on four Indo-Pacific Acropora species and Caribbean A. palmata. After PCR amplification and sequencing, there were three GT repeats amplified in Indo-Pacific species and five homologous AAT-repeat microsatellite loci applied for Indo-Pacific Acropora species. As a result, there were eight microsatellite markers, including three GT and five AAT repeats, utilized for species boundary between sympatric A. digitifera and A. muricata in Togian Islands, Indonesia. From the results at each locus, allelic frequency distributions of these two Acropora species were significantly different at four microsatellite loci (Acr53, Acr1-60, 180, 181), but the others were not. In multi-locus analyses, FCA (Factorial correspondence analysis) showed that two species were significantly divided into two groups. According to this result, it revealed multi-locus microsatellite markers would be possibly highly resoluble genetic markers for species boundary among Acropora spp.
Due to unsuccessful PCR amplifications at the 181 locus, there were also seven microsatellite markers applied for population subdivisions of A. muricata in Shertoushan, Tiaoshi in Taiwan and Togian Islands, Indonesia. Based on pairwise FST and Nei’s genetic distance (1983), it revealed that the smaller genetic distance between Tiaoshi and Togian Islands compared with Shertoushan. However, the NJ tree, based on Nei’s genetic distance (1983) and the proportion of shared alleles, also revealed the similar patterns. Maybe the sea surface currents of the West Pacific Ocean possibly have significant impacts on the population subdivisions of A. muricata in these sites.
In conclusion, multi-locus microsatellite loci could be applied for the species boundary Acropora spp, and the population subdivision of A. muricata in Indo-Pacific oceans. In the future studies, these highly polymorphic microsatellite loci will be available for further species boundary studies and population genetics of the genera Acropora.
Subjects
微隨體
軸孔珊瑚
種間界線
族群遺傳
microsatellite
Acropora
species boundary
population genetics
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-95-R93241216-1.pdf
Size
23.53 KB
Format
Adobe PDF
Checksum
(MD5):a92bc91b37257366e55563284cbd4fff