Genetic Diversity in Sri Lanka: Some implications in Paternity and Forensic testing

1994 ◽  
pp. 632-634
Author(s):  
S. S. Mastana ◽  
R. Jayasekara ◽  
S. S. Papiha
Keyword(s):  
Genetic Diversity ◽  
Sri Lanka ◽  
Forensic Testing

scholarly journals Validation of molecular markers for the analysis of genetic diversity of amylase content and gel consistency among representative rice varieties in Sri Lanka

2015 ◽  
Vol 26 (2) ◽  
pp. 317 ◽  
Author(s):  
H.K.D.H. Fernando ◽  
T.J.C. Kajenthini ◽  
S.P. Rebeira ◽  
T.C. Bamunuarachchige ◽  
H.A.M. Wickramasinghe
Keyword(s):  
Genetic Diversity ◽  
Molecular Markers ◽  
Sri Lanka ◽  
Rice Varieties ◽  
Gel Consistency

scholarly journals High Genetic Diversity but Absence of Population Structure in Local Chickens of Sri Lanka Inferred by Microsatellite Markers

2021 ◽  
Vol 12 ◽  
Author(s):  
Amali Malshani Samaraweera ◽  
Ranga Liyanage ◽  
Mohamed Nawaz Ibrahim ◽  
Ally Mwai Okeyo ◽  
Jianlin Han ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Sri Lanka ◽  
Microsatellite Markers ◽  
Allelic Diversity ◽  
Genetic Distances ◽  
Population Substructure ◽  
High Genetic Diversity ◽  
Naked Neck ◽  
Local Chicken ◽  
Local Chickens

Local chicken populations belonging to five villages in two geographically separated provinces of Sri Lanka were analyzed using 20 microsatellite markers to determine the genetic diversity of local chickens. Population genetic parameters were estimated separately for five populations based on geographic locations and for eight populations based on phenotypes, such as naked neck, long legged, crested or crown, frizzle feathered, Giriraj, commercial layer, crossbreds, and non-descript chicken. The analysis revealed that there was a high genetic diversity among local chickens with high number of unique alleles, mean number of alleles per locus (MNA), and total number of alleles per locus per population. A total of 185 microsatellite alleles were detected in 192 samples, indicating a high allelic diversity. The MNA ranged from 8.10 (non-descript village chicken) to 3.50 (Giriraj) among phenotypes and from 7.30 (Tabbowa) to 6.50 (Labunoruwa) among village populations. In phenotypic groups, positive inbreeding coefficient (FIS) values indicated the existence of population substructure with evidence of inbreeding. In commercial layers, a high expected heterozygosity He = 0.640 ± 0.042) and a negative FIS were observed. The positive FIS and high He estimates observed in village populations were due to the heterogeneity of samples, owing to free mating facilitated by communal feeding patterns. Highly admixed nature of phenotypes was explained as a result of rearing many phenotypes by households (58%) and interactions of chickens among neighboring households (53%). A weak substructure was evident due to the mating system, which disregarded the phenotypes. Based on genetic distances, crown chickens had the highest distance to other phenotypes, while the highest similarity was observed between non-descript village chickens and naked neck birds. The finding confirms the genetic wealth conserved within the populations as a result of the breeding system commonly practiced by chicken owners. Thus, the existing local chicken populations should be considered as a harbor of gene pool, which can be readily utilized in developing locally adapted and improved chicken breeds in the future.

scholarly journals Insight into genetic diversity of Mycobacterium tuberculosis in Kandy, Sri Lanka reveals predominance of the Euro-American lineage

2019 ◽  
Vol 87 ◽  
pp. 84-91 ◽  
Author(s):  
Charitha Mendis ◽  
Vasanthi Thevanesam ◽  
Athula Kumara ◽  
Susiji Wickramasinghe ◽  
Dushantha Madegedara ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Mycobacterium Tuberculosis ◽  
Sri Lanka ◽  
Insight Into

Population biology and genetic diversity of two adjacent shrimp (Parapenaeopsis coromandelica) populations exploited under different fishing pressures in the coastal waters of Sri Lanka

2011 ◽  
Vol 92 (4) ◽  
pp. 819-829 ◽  
Author(s):  
M.D.S.T de Croos ◽  
Snæbjörn Pálsson
Keyword(s):  
Genetic Diversity ◽  
Sri Lanka ◽  
Population Biology ◽  
Gonadosomatic Index ◽  
Western Coast ◽  
Cytochrome Oxidase Subunit ◽  
Mitochondrial Cytochrome Oxidase Subunit ◽  
Routine Monitoring ◽  
Significant Divergence ◽  
Mitochondrial Cytochrome Oxidase

Parapenaeopsis coromandelica shrimp populations along the western coast of Sri Lanka have supported coastal trawling for the last hundreds of years. Two non-overlapping adjacent fishing grounds (Hendala and Negombo) sustain different fishing intensities. In order to obtain information on the population structure and genetic diversity of P. coromandelica in these two regions, differences in length–weight relationships, growth, spawning seasons, sex-ratios, gonadosomatic index, length at 50% maturity (L50) and sequence variation of the mitochondrial cytochrome oxidase subunit I were examined. Significant differences in population biology and genetic diversity were revealed from the two fishing grounds. Samples of Hendala showed lower L50 and genetic diversity which are considered as potential effects and symptoms of extensive selective harvesting. Further, the shrimps' behaviour seems to be triggering the separation through low mixing of individuals at the two fishing grounds resulting in significant divergence based on haplotype frequencies. Management of P. coromandelica should consider the revealed biological and genetic evidences on existence of two sub-populations/stocks together with a routine monitoring of genetic effects due to harvesting.

scholarly journals Genetic diversity of Mycobacterium tuberculosis isolates obtained from three distinct population groups in the Central Province, Sri Lanka

2015 ◽  
Vol 5 (5) ◽  
pp. 385-392 ◽  
Author(s):  
Dulanthi Weerasekera ◽  
Dhammika Magana-Arachchi ◽  
Dushantha Madegedara ◽  
Neranjan Dissanayake ◽  
Vasanthi Thevanesam
Keyword(s):  
Genetic Diversity ◽  
Mycobacterium Tuberculosis ◽  
Sri Lanka ◽  
Central Province ◽  
Distinct Population ◽  
Population Groups

scholarly journals The Sri Lankan paradox: high genetic diversity in Plasmodium vivax populations despite decreasing levels of malaria transmission

Parasitology ◽  
2014 ◽  
Vol 141 (7) ◽  
pp. 880-890 ◽  
Author(s):  
SHARMINI GUNAWARDENA ◽  
MARCELO U. FERREIRA ◽  
G. M. G. KAPILANANDA ◽  
DYANN F. WIRTH ◽  
NADIRA D. KARUNAWEERA
Keyword(s):  
Genetic Diversity ◽  
Sri Lanka ◽  
Plasmodium Vivax ◽  
Malaria Transmission ◽  
Population Size ◽  
Effective Population Size ◽  
Allele Frequency Distribution ◽  
Effective Population ◽  
High Genetic Diversity ◽  
Mode Shift

SUMMARYHere we examined whether the recent dramatic decline in malaria transmission in Sri Lanka led to a major bottleneck in the local Plasmodium vivax population, with a substantial decrease in the effective population size. To this end, we typed 14 highly polymorphic microsatellite markers in 185 P. vivax patient isolates collected from 13 districts in Sri Lanka over a period of 5 years (2003–2007). Overall, we found a high degree of polymorphism, with 184 unique haplotypes (12–46 alleles per locus) and average genetic diversity (expected heterozygosity) of 0·8744. Almost 69% (n = 127) isolates had multiple-clone infections (MCI). Significant spatial and temporal differentiation (FST = 0·04–0·25; P⩽0·0009) between populations was observed. The effective population size was relatively high but showed a decline from 2003–4 to 2006–7 periods (estimated as 45 661 to 22 896 or 10 513 to 7057, depending on the underlying model used). We used three approaches – namely, mode-shift in allele frequency distribution, detection of heterozygote excess and the M-ratio statistics – to test for evidence of a recent population bottleneck but only the low values of M-ratio statistics (ranging between 0·15–0·33, mean 0·26) were suggestive of such a bottleneck. The persistence of high genetic diversity and high proportion of MCI, with little change in effective population size, despite the collapse in demographic population size of P. vivax in Sri Lanka indicates the importance of maintaining stringent control and surveillance measures to prevent resurgence.

Evaluation of the genetic diversity of domain II of Plasmodium vivax Apical Membrane Antigen 1 (PvAMA-1) and the ensuing strain-specific immune responses in patients from Sri Lanka

Vaccine ◽  
2011 ◽  
Vol 29 (43) ◽  
pp. 7491-7504 ◽  
Author(s):  
Sajani Dias ◽  
Maheshika Somarathna ◽  
Aresha Manamperi ◽  
Ananias A. Escalante ◽  
Anusha M. Gunasekera ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Sri Lanka ◽  
Immune Responses ◽  
Plasmodium Vivax ◽  
Apical Membrane ◽  
Apical Membrane Antigen 1 ◽  
Apical Membrane Antigen

scholarly journals Biogeography and genetic diversity of clinical isolates of Burkholderia pseudomallei in Sri Lanka

2021 ◽  
Vol 15 (12) ◽  
pp. e0009917
Author(s):  
Himali S. Jayasinghearachchi ◽  
Enoka M. Corea ◽  
Kumari I. Jayaratne ◽  
Regina A. Fonseka ◽  
Thilini A. Muthugama ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Sri Lanka ◽  
Southeast Asia ◽  
Burkholderia Pseudomallei ◽  
Evolutionary Relationship ◽  
Type A ◽  
Clinical Isolates ◽  
Sri Lankan ◽  
Evolutionary Analysis ◽  
Relationship Of

Background Melioidosis is a potentially fatal infectious disease caused by Burkholderia pseudomallei and the disease is endemic in SoutheastAsia and Northern Australia. It has been confirmed as endemic in Sri Lanka. Genomic epidemiology of B. pseudomallei in Sri Lanka is largely unexplored. This study aims to determine the biogeography and genetic diversity of clinical isolates of B. pseudomallei and the phylogenetic and evolutionary relationship of Sri Lankan sequence types (STs) to those found in other endemic regions of Southeast Asia and Oceania. Methods The distribution of variably present genetic markers [Burkholderia intracellular motility A (bimA) gene variants bimABP/bimABM, filamentous hemagglutinin 3 (fhaB3), Yersinia-like fimbrial (YLF) and B. thailandensis-like flagellum and chemotaxis (BTFC) gene clusters and lipopolysaccharide O-antigen type A (LPS type A)] was examined among 310 strains. Multilocus sequence typing (MLST) was done for 84 clinical isolates. The phylogenetic and evolutionary relationship of Sri Lankan STs within Sri Lanka and in relation to those found in other endemic regions of Southeast t Asia and Oceania were studied using e BURST, PHYLOViZ and minimum evolutionary analysis. Results The Sri Lankan B. pseudomallei population contained a large proportion of the rare BTFC Clade (14.5%) and bimABM allele variant (18.5%) with differential geographic distribution. Genotypes fhaB3 and LPSA were found in 80% and 86% respectively. This study reported 43 STs (including 22 novel). e-BURST analysis which include all Sri Lankan STs (71) resulted in four groups, with a large clonal group (group 1) having 46 STs, and 17 singletons. ST1137 was the commonest ST. Several STs were shared with India, Bangladesh and Cambodia. Conclusion This study demonstrates the usefulness of high-resolution molecular typing to locate isolates within the broad geographical boundaries of B. pseudomallei at a global level and reveals that Sri Lankan isolates are intermediate between Southeast Asia and Oceania.

scholarly journals RFLP clusters of rifampicin resistant and susceptible Mycobacterium tuberculosis strains in Western province of Sri Lanka

2017 ◽  
Vol 11 (08) ◽  
pp. 619-625
Author(s):  
Chamila Priyangani Adikaram ◽  
Sandya Sulochana Wijesundera ◽  
Jennifer Perera
Keyword(s):  
Genetic Diversity ◽  
Mycobacterium Tuberculosis ◽  
Sri Lanka ◽  
Novel Mutation ◽  
Point Mutations ◽  
Clonal Expansion ◽  
Rpob Gene ◽  
The Novel ◽  
Western Province ◽  
Control And Prevention

Introduction: Continuous studies on genetic diversity of Mycobacterium tuberculosis could enhance the awareness on transmission, control and prevention of tuberculosis (TB). In this study, we investigated current genetic diversity of TB and rifampicin resistant TB by, Restriction Fragment Length Polymorphism (RFLP) based on fingerprinting of the IS6110 insertion sequence, in the Western province of Sri Lanka, the famous touristic destination with the highest TB burden in the country. Methodology: Genomic DNA extracted from susceptible and rifampicin resistant TB strains (confirmed for rpoB gene point mutations) were digested with PvuII restriction enzyme, electrophoresed and subjected to Southern transfer. The blots were hybridised with IS6110 probe and visualized using a chemiluminescence detection. Results: The number of copies of IS6110 per isolate varied from 1 to 14. The dendrogram revealed a total of 68 distinct strains among 77 TB isolates and they belonged to nine clusters. Both rifampicin resistant and susceptible strains were distributed in all clusters. This evaluation revealed the absence of genetically identical or strong relatedness between susceptible and resistant isolates. However, clonal expansion was detected in transmission of both TB and rifampicin resistant TB. In addition, the resistant isolates having the novel mutation had no clonal relatedness. Conclusion: This is the first observational study regarding clonal expansion of TB in Sri Lanka. Thus, further investigation on genotypes, clonal expansion and transmission of drug resistance using additional markers would be useful for controlling TB.

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