Population Genetics And Molecular Taxonomy Of Two Important Cultured Oyster Species In Malaysia, Crassostrea Iredalei (Faustino, 1932) And C. Belcheri (Sowerby, 1871)
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Date
2011-08
Authors
Mustaffa, Suzana
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
A total of 140 Crassostrea iredalei (Faustino 1932) and 83 C. belcheri
(Sowerby 1871) samples were analysed from 16 locations along the coast of
Malaysia. Genetic diversities were assessed using a 581-nucleotide fragment of the
mtDNA cytochrome oxidase subunit 1 (COI) gene. FST and AMOVA analyses
generally structured C. iredalei samples into two major groups, consistent with their
geographic origins in mainland Peninsular Malaysia and Malaysian Borneo (Sabah).
In C. belcheri, FST analysis showed that the Tawau population was differentiated
from the rest including the other Sabah population of Sandakan. Phylogenetic
relationship inferred by neighbour-joining (NJ) and maximum parsimony (MP)
algorithm generally failed to detect any differentiation between these two regions.
Barcoding approach of COI and 16S rRNA based on neighbour-joining (NJ)
algorithm revealed that many individuals had been misidentified and did not cluster
with their morphologically presumed species. BLAST results showed the presence of
a previously unreported C. madrasensis species in the Peninsular Malaysian waters
(98% identity). The ambiguous Sebatu species was believed to be Saccostrea
cucullata (99% identity). However, the true identities of the Muar (Crassostrea sp.),
Sungai Menghulu (Ostrea sp.) and Semporna (Saccostrea sp.) samples were
unresolved by BLAST search (<88% identity). Nine polymorphic microsatellite
markers were isolated from C. iredalei based on the microsatellite-enriched library
construction and evaluated in 43 wild samples from Kuala Penyu, Sabah. The
average allele number was 21 per locus with 0.395 to 1.000 and 0.780 to 0.970
observed and expected heterozygosities respectively.
Description
Keywords
Population genetics and molecular taxonomy , two important cultured oyster species in Malaysia