Populations In Peninsular Malaysia Research Articles

New evidence on the origin of mangosteen (Garcinia mangostana L.) based on morphology and ITS sequence

Mangosteen (Garcinia mangostana L.), known as one of the most desirable tropical fruits of Southeast Asia, has been considered as an obligate agamospermous hybrid, thought to have arisen from two wild species, G. celebica L. (syn. G. hombroniana Pierre) and G. malaccensis Hook. f. However, this putative origin was based on a misidentification of G. malaccensis, which was confused for G. penangiana Pierre. Intensive field studies and molecular investigations based on internal transcribed spacer (ITS) sequence data of 22 samples were conducted, which included six samples of true G. malaccensis. Morphological observation shows that mangosteen highly resembles G. malaccensis, particularly in its vegetative and fruit characters, even sharing similar taste of ripe fruits. ITS data revealed that mangosteen shared more than 99 % of its sequence with G. malaccensis with a few accessions identical with wild populations in Peninsular Malaysia. Phylogenetic analysis revealed that clades of mangosteen are paraphyletic per se, but monophyletic if both mangosteen and G. malaccensis are grouped together. This show that mangosteen and G. malaccensis are so closely related that they should be combined together as one species. I propose two theories on the origin of mangosteen, first, that it is a hybrid of different varieties of G. malaccensis, and second, that it may be a product of multiple, superior selections from different populations of female trees of G. malaccensis originating in Peninsular Malaysia.

Population Status of Long-Tailed Macaque (Macaca fascicularis) in Peninsular Malaysia

A census on the density and composition of long-tailed macaques was conducted from February to May 2011 in Peninsular Malaysia. Eighty locations were selected in this census program. These locations were categorized in serious zone for Human Macaque conflict. The objective was to get latest estimated macaque population in Peninsular Malaysia which will be very useful in human-macaque conflict management by the Department. Census was done by direct observation. The census outcome showed the total number of macaque population was 127,050 individuals in Peninsular Malaysia but taking into account the population growth rate of 5% per annum, the estimated macaque population was 133,403 individuals. Location based on agriculture which covers the village had recorded the highest macaque population with 44,215 individuals, followed by oil palm plantation area with 26.035 individuals and urban areas with 18.160 individuals.

Autochthonous Human Schistosomiasis, Malaysia

Autochthonous Human Schistosomiasis, Malaysia

PCR-RFLP analysis of mitochondrial DNA cytochrome b gene among Haruan (Channa striatus) in Malaysia

Haruan (Channa striatus) is in great demand in the Malaysian domestic fish market. In the present study, mtDNA cyt b was used to investigate genetic variation of C. striatus among populations in Peninsular Malaysia. The overall population of C. striatus demonstrated a high level of haplotype diversity (h) and a low-to-moderate level of nucleotide diversity (π). Analysis of molecular variance (AMOVA) results showed a significantly different genetic differentiation among 6 populations (FST=0.37566, P=0.01). Gene flow (Nm) was high and ranged from 0.32469 to infinity (∞). No significant relationship between genetic distance and geographic distance was detected. A UPGMA tree based on the distance matrix of net interpopulation nucleotide divergence (dA) and haplotype network of mtDNA cyt b revealed that C. striatus is divided into 2 major clades. The neutrality and mismatch distribution tests for all populations suggested that C. striatus in the study areas had undergone population expansion. The estimated time of population expansion in the mtDNA cyt b of C. striatus populations occurred 0.72–6.19million years ago. Genetic diversity of mtDNA cyt b and population structure among Haruan populations in Peninsular Malaysia will be useful in fisheries management for standardization for Good Agriculture Practices (GAP) in fish-farming technology, as well as providing the basis for Good Manufacturing Practices (GMP).

Population Genetic Structure of Peninsular Malaysia Malay Sub-Ethnic Groups

Patterns of modern human population structure are helpful in understanding the history of human migration and admixture. We conducted a study on genetic structure of the Malay population in Malaysia, using 54,794 genome-wide single nucleotide polymorphism genotype data generated in four Malay sub-ethnic groups in peninsular Malaysia (Melayu Kelantan, Melayu Minang, Melayu Jawa and Melayu Bugis). To the best of our knowledge this is the first study conducted on these four Malay sub-ethnic groups and the analysis of genotype data of these four groups were compiled together with 11 other populations' genotype data from Indonesia, China, India, Africa and indigenous populations in Peninsular Malaysia obtained from the Pan-Asian SNP database. The phylogeny of populations showed that all of the four Malay sub-ethnic groups are separated into at least three different clusters. The Melayu Jawa, Melayu Bugis and Melayu Minang have a very close genetic relationship with Indonesian populations indicating a common ancestral history, while the Melayu Kelantan formed a distinct group on the tree indicating that they are genetically different from the other Malay sub-ethnic groups. We have detected genetic structuring among the Malay populations and this could possibly be accounted for by their different historical origins. Our results provide information of the genetic differentiation between these populations and a valuable insight into the origins of the Malay sub-ethnic groups in Peninsular Malaysia.

60 Prevalence of premature ejaculation and its associated factors

60 Prevalence of premature ejaculation and its associated factors

Genetic Analysis of Population Structure of <I>Coptotermes gestroi</I> (Isoptera: Rhinotermitidae) in Native and Introduced Populations

ABSTRACT We used microsatellite markers to characterize the population structure of Coptotermes gestroi (Wasmann), an economically important termite species in the tropics. Eighty-five colonies were sampled from seven countries (Malaysia, Thailand, Singapore, Indonesia, the Philippines, Taiwan, and the United States [Hawaii]). Ten to 20 workers per colony were genotyped using eight variable microsatellite loci. STRUCTURE analysis partitioned the 13 spatially separated populations into four clusters. Individuals in the Peninsular Malaysia and Singapore population groups displayed admixture clusters. There was low genetic differentiation (FST = 0.073) among the Peninsular Malaysia populations, suggesting moderate gene flow among them. Comparatively, there was moderate genetic differentiation (FST = 0.192) and positive correlation between genetic distance and geographic distance among all of the 13 putative populations studied, which suggests limited gene flow among them. There was no significant isolation b...

Remarkably low genetic variation but high population differentiation in the climbing perch, Anabas testudineus (Anabantidae), based on the mtDNA control region

Anabas testudineus (Anabantidae) is an important food fish in Southeast Asia. We analyzed the mitochondrial DNA control region sequence data to evaluate the genetic variability and population structure of this species. Sixty specimens were collected from four populations in Sumatra and two populations in Peninsular Malaysia. We found a very low level of genetic variability, with five of the six populations exhibiting total absence of genetic variation. Based on analysis of molecular variance, 84.72% of the total variation was among populations and 15.28% within populations. A geographical division based on FST values indicated highly significant genetic differentiation among populations from the four drainage systems: Aceh, Sumatra Utara, Pulau Pinang, and Terengganu (FST ranging from 0.633 to 1.000). No phylogeographic relationships among populations were detected, despite the generation of four distinct clades in a neighbor-joining phylogenetic tree.

Habitat use by green turtles (Chelonia mydas) nesting in Peninsular Malaysia: local and regional conservation implications

Context. Many green sea turtle (Chelonia mydas) populations are declining worldwide owing to their susceptibility to human impacts in the marine environment. Identifying the habitats used throughout different lifecycle stages is therefore important for managing the interactions between turtles and humans. Aims. To identify the habitat utilisation of a C. mydas nesting population in Peninsular Malaysia during breeding, inter-nesting, migration and foraging lifecycle stages. Methods. Satellite telemetry was used to track the movement of three C. mydas nesting females and one adult male from the Ma’Daerah rookery (Peninsular Malaysia). Key results.The male and female turtles remained within 30 km of the nesting beach during the breeding and inter-nesting periods, which includes habitat beyond the ‘no trawl zone’ designed to protect turtles in this area. Following the breeding season, the tracked turtles migrated up to 1955 km to four different foraging grounds in Vietnam, Indonesia, Peninsular Malaysia and Borneo Malaysia. During foraging, turtles occupied areas threatened by human activities such as fishing and pollution. Conclusions. The habitats used by the Ma’Daerah C. mydas population during breeding are outside current local protection zones and extend into unprotected international waters during migration and foraging. Implications. Identification of habitats used by C. mydas populations is a critical element of management and conservation of this endangered, migratory species. Our study highlights the need to increase offshore protection around Ma’Daerah during the nesting season. Furthermore, this study has identified the countries within South-east Asia that Malaysia must cooperate with to ensure effective management of this C. mydas population. This information is particularly relevant to sea turtle conservation and management in regions like South-east Asia, where many coastal countries occupy a small geographical area.

Effects of flowering tree density on the mating system and gene flow in Shorea leprosula (Dipterocarpaceae) in Peninsular Malaysia

Pristine tropical rainforests in Southeast Asia have rich species diversity and are important habitats for many plant species. However, the extent of these forests has declined in recent decades and they have become fragmented due to human activities. These developments may reduce the genetic diversity of species within them and, consequently, the species' ability to adapt to environmental changes. Our objective in the study presented here was to clarify the effect of tree density on the genetic diversity and gene flow patterns of Shorea leprosula Miq. populations in Peninsular Malaysia. For this purpose, we related genetic diversity and pollen flow parameters of seedling populations in study plots to the density of mature trees in their vicinity. The results show that gene diversity and allelic richness were not significantly correlated to the mature tree density. However, the number of rare alleles among the seedlings and the selfing rates of the mother trees were negatively correlated with the density of the adult trees. Furthermore, in a population with high mature tree density pollination distances were frequently <200 m, but in populations with low adult tree density the distances were longer. These findings suggest that the density of flowering trees affects selfing rates, gene flow and, thus, the genetic diversity of S. leprosula populations. We also found an individual S. leprosula tree with a unique reproductive system, probably apomictic, mating system.

Autosomal STR Polymorphism in Sikh Population of Peninsular Malaysia

Abstract Buccal swabs were collected from random ethnic Sikh individuals. Sikh population is a distinct group in the Malaysian Indian population of Peninsular Malaysia. DNA was extracted by simple salting out procedure (1). Using STR multiplex primer kits, Promega Geneprint™ (CTT, FFv and STR III) and following the manufacturer's guidelines 10 ng of DNA was PCR amplified. Allele frequencies were calculated from the numbers of each genotype by gene count method. The randomness of the population was ascertained by subjecting the data to Chi-square test. No deviations from Hardy-Weinberg equilibrium were observed. Heterozygosity and discrimination power were calculated as per the methods already reported (2–4). The allelic distribution in the Sikh population of Malaysia is compared with the Tamil population, which is an another sub-population group of Malaysian Indian population in peninsular Malaysia (5).

Mitochondrial DNA profiling of modern Malay and Orang Asli populations in peninsular Malaysia

A study was undertaken to assess the utility of mtDNA as a forensic tool in the Malay Peninsular. Two populations, modern Malay and Orang Asli, were sampled and their mitochondrial DNA (mtDNA) analysed. Comparing the different haplogroups that were found, there are clear differences between the two populations. As a forensic tool, the use of mtDNA in the Orang Asli is limited as many individuals share the same haplotype, reducing the power of discrimination. In the Malay population, the power of discrimination is sufficiently high to make it a valuable tool.

Nipah virus infection in bats (order Chiroptera) in peninsular Malaysia.

Nipah virus, family Paramyxoviridae, caused disease in pigs and humans in peninsular Malaysia in 1998-99. Because Nipah virus appears closely related to Hendra virus, wildlife surveillance focused primarily on pteropid bats (suborder Megachiroptera), a natural host of Hendra virus in Australia. We collected 324 bats from 14 species on peninsular Malaysia. Neutralizing antibodies to Nipah virus were demonstrated in five species, suggesting widespread infection in bat populations in peninsular Malaysia.

Ethnic differences in parents' coresidence with adult children in Peninsular Malaysia

In this paper we use data from the Second Malaysian Family Life Survey (MFLS-2) to examine the extent to which ethnic differences in the living arrangements of the older population in Peninsular Malaysia can be explained by ethnic differences in demographic and socioeconomic characteristics. We also investigate whether the three main ethnic groups of Malaysia differ in the extent to which their living arrangements are influenced by these factors. For the married, the higher incidence of remarriage and lower housing costs for Malays each contribute importantly to their lower coresidence rates. The relatively poorer health of Indians and better health of Malays also contribute to the ethnic differences in coresidence rates for the married, as does the higher incidence of daughter-only families among Malays. The explanatory variables considered here explain less of the ethnic differences in coresidence rates for the unmarried.

The Population of Peninsular Malaysia.

The Population of Peninsular Malaysia.

BOOK REVIEW: The Population of Peninsular Malaysia, by Saw Swee Hock

BOOK REVIEW: The Population of Peninsular Malaysia, by Saw Swee Hock