Population Genetics of Tor douronensis in Sarawak
Tor douronensis, known locally as Semah, is one of the valuable and potential resources in Sarawak due to its high food value and demand as game fish. Several molecular studies related to T. douronensis had been carried out but limited in populations. No study had involved T. douronensis from Baku...
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| Format: | Final Year Project Report / IMRAD |
| Language: | English |
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Universiti Malaysia Sarawak, (UNIMAS)
2014
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| Online Access: | http://ir.unimas.my/id/eprint/8271/ http://ir.unimas.my/id/eprint/8271/11/M%20Khairulazman.pdf |
| Summary: | Tor douronensis, known locally as Semah, is one of the valuable and potential resources in Sarawak due
to its high food value and demand as game fish. Several molecular studies related to T. douronensis had been
carried out but limited in populations. No study had involved T. douronensis from Bakun. Therefore, this study
was designed to infer population subdivision, the genetic structure, evolutionary neutrality, and population
expansion of T. douronensis among 4 populations from Sarawak including Bakun using partial DNA sequencing
of the Cytochrome c oxidase I (COI) mtDNA gene. A total 465 bp of CO1 gene of T. douronensis had been
successfully amplified, and based on phylogenetic tree, there are 3 distinct geographical population subdivision
observed (Central, Southern, and Northern population); 1st clade (haplogroup I) from Bakun, 2nd clade
(haplogroup II) from Layar and 3rd clade (haplogroup III) from Ba Kelalan and Ulu Limbang. Overall, there were
13 haplotypes and none is shared by any population. Low level gene flow has been observed. Small number of
migrants per generation (Nm<1.0) among the population indicated the small population or separated populations
with large geographical and topological barrier. Population expansion was undergone for the species for the
whole populations except for northern population as shown by small and non-significant values of the sum of the
standard deviation of the observed (SSD<0.5) and expected mismatch distributions (unimodal) and Harpending
raggedness index (r <1.2). Furthermore a large negative value and significant test of Fu’ Fs in Bakun population
suggested recent expansion. The result also suggested that all the populations do not deviate with evolutionary
neutrality supported with no significant in Tajima’s neutrality test (p<0.05). |
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