Schistosome genetic diversity: the implications of population structure as detected with microsatellite markers

Parasitology ◽  
2002 ◽  
Vol 125 (7) ◽  
pp. S51-S59 ◽  
Author(s):  
J. CURTIS ◽  
R. E. SORENSEN ◽  
D. J. MINCHELLA

Blood flukes in the genus Schistosoma are important human parasites in tropical regions. A substantial amount of genetic diversity has been described in populations of these parasites using molecular markers. We first consider the extent of genetic variation found in Schistosoma mansoni and some factors that may be contributing to this variation. Recently, though, attempts have been made to analyze not only the genetic diversity but how that diversity is partitioned within natural populations of schistosomes. Studies with non-allelic molecular markers (e.g. RAPDs and mtVNTRs) have indicated that schistosome populations exhibit varying levels of gene flow among component subpopulations. The recent characterization of microsatellite markers for S. mansoni provided an opportunity to study schistosome population structure within a population of schistosomes from a single Brazilian village using allelic markers. Whereas the detection of population structure depends strongly on the type of analysis with a mitochondrial marker, analyses with a set of seven microsatellite loci consistently revealed moderate genetic differentiation when village boroughs were used to define parasite subpopulations and greater subdivision when human hosts defined subpopulations. Finally, we discuss the implications that such strong population structure might have on schistosome epidemiology.

2014 ◽  
Vol 25 (4) ◽  
pp. 234-249 ◽  
Author(s):  
Po-An Tu ◽  
Der-Yuh Lin ◽  
Guang-Fu Li ◽  
Jan-Chi Huang ◽  
De-Chi Wang ◽  
...  

2019 ◽  
Vol 160 (3) ◽  
pp. 825-830 ◽  
Author(s):  
Thainara O. Souza ◽  
Leilton W. Luna ◽  
Juliana Araripe ◽  
Mauro A. D. Melo ◽  
Weber A. G. Silva ◽  
...  

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 543A-543
Author(s):  
F.J. Keiper ◽  
R. McConchie

Umbrella fern [Sticherus flabellatus (R. Br.) St John] is a successful Australian native foliage product. Currently, all umbrella fern sold on the market is bush-harvested. To meet the growing demand for this product on local and international markets, a commercially viable method for its production must be developed, with effective management of the germplasm resource in terms of conservation and exploitation. To manage this resource, breeders require a detailed knowledge of the amount and distribution of genetic variability within the species. Traditionally, plant breeders focus on a combination of agronomic and morphological traits (phenotype) to measure genetic diversity. In umbrella fern there are a limited number of morphological traits, and these are influenced by environmental factors and therefore do not reflect true genetic diversity. To overcome these problems, molecular techniques such as PCR-based DNA markers are used to complement traditional strategies for genotype assessment. DNA markers have the advantages of being independent of environmental effects, as well as being fast, cost-effective, reproducible, and largely accessible to the nonmolecular geneticist. Amplified fragment length polymorphisms (AFLPs) fulfil many of the desirable features of molecular markers, as well as requiring little knowledge of the genome to be investigated. AFLPs have been used widely in the analysis of breeding systems, ecogeographical variation, and genetic variation within and between natural populations. To date there are no published accounts of DNA molecular marker research on umbrella fern. A DNA extraction protocol has been developed for this species, and AFLP markers have been used to analyse genetic diversity within and between natural populations sampled in the Sydney Basin. A large number of polymorphic loci were revealed using 11 primer combinations. The genetic variation detected was partitioned between rather than within populations, suggesting that the mating system in Sticherus is primarily inbreeding. Data will be presented illustrating AFLPs as useful molecular markers for assessing genetic diversity within and between populations of umbrella fern and providing insight on the breeding system used by the species.


2017 ◽  
Vol 51 (1) ◽  
pp. 31-36
Author(s):  
K. E. Ogbuebunu ◽  
M. O. Awodiran

Abstract Thirty Lates niloticus (Linnaeus, 1758) from three Nigerian waterbodies were genotyped on six RAPD primers and five microsatellites loci. RAPD revealed that effective number of alleles (AE) at population level per locus was within the range of 1.641 ± 0.066 to 1.645 ± 0.041 while the mean number of alleles (AN) across populations equals 2.000. Characterization on five microsatellites loci revealed genetic diversity within and among studied populations. Observed heterozygousity (HO) was within the range of 0.317 ± 0.335 to 0.523 ± 0.315 while expected heterozygousity (HE) was within the range of 0.414 ± 0.306 to 0.715 ± 0.097. Proportion of differentiation (FST) within populations was 0.236. Overall gene flow (Nm) among populations equals 0.806. This study established the successful use of RAPD and microsatellite as tools for studying population structure of fish species, especially L. niloticus. Thus, it can be concluded that L. niloticus in the three (3) sampled Nigerian waterbodies is undergoing evolution.


2019 ◽  
Vol 25 (4) ◽  
pp. 965-974 ◽  
Author(s):  
Joseph Mbasani-Mansi ◽  
Mounia Ennami ◽  
Fatima Zahra Briache ◽  
Fatima Gaboun ◽  
Nadia Benbrahim ◽  
...  

2019 ◽  
Vol 37 (2) ◽  
pp. 152-160
Author(s):  
Rafaela de Jesus ◽  
Gabriel do N Santos ◽  
Andressa S Piccin ◽  
Thiago WA Balsalobre ◽  
Fernando C Sala ◽  
...  

ABSTRACT Peppers of the genus Capsicum are of great socioeconomic importance, being pungency trait their main attraction. Pungency characterization, genetic distance estimates and population structure analysis of the accessions belonging to germplasm banks are important for parent selection which allows to obtain superior progenies. Therefore, the aims of this study were: i) evaluate 81 accessions of the Capsicum spp. Germplasm Bank of Universidade Federal de São Carlos (BGC-UFSCar) with molecular markers linked to pungency; ii) estimate the genetic diversity among accessions of the BGC-UFSCar using microsatellite markers (SSR); and iii) evaluate the efficiency of these markers in the distinction among species of Capsicum spp. We noticed that pun11 and SNP molecular markers were efficient in predicting the pungent phenotype of BGC-UFSCar accessions in 84.85% and 95.59%, respectively. From a total of 13 amplified microsatellite markers, seven were polymorphic and efficient to discriminate species of Capsicum genus, both through genetic diversity analysis and population structure analysis, which showed three subpopulations. The molecular markers used in this study are useful tools for breeding programs since they were able to characterize and discriminate Capsicum spp. species at DNA level. Information obtained with molecular markers can assist in the selection of contrasting parents for future breeding programs.


2021 ◽  
pp. 1-4
Author(s):  
Yu-Wei Tseng ◽  
Chi-Chun Huang ◽  
Chih-Chiang Wang ◽  
Chiuan-Yu Li ◽  
Kuo-Hsiang Hung

Abstract Epilobium belongs to the family Onagraceae, which consists of approximately 200 species distributed worldwide, and some species have been used as medicinal plants. Epilobium nankotaizanense is an endemic and endangered herb that grows in the high mountains in Taiwan at an elevation of more than 3300 m. Alpine herbs are severely threatened by climate change, which leads to a reduction in their habitats and population sizes. However, only a few studies have addressed genetic diversity and population genetics. In the present study, we developed a new set of microsatellite markers for E. nankotaizanense using high-throughput genome sequencing data. Twenty polymorphic microsatellite markers were developed and tested on 30 individuals collected from three natural populations. These loci were successfully amplified, and polymorphisms were observed in E. nankotaizanense. The number of alleles per locus (A) ranged from 2.000 to 3.000, and the observed (Ho) and expected (He) heterozygosities ranged from 0.000 to 0.929 and from 0.034 to 0.631, respectively. The developed polymorphic microsatellite markers will be useful in future conservation genetic studies of E. nankotaizanense as well as for developing an effective conservation strategy for this species and facilitating germplasm collections and sustainable utilization of other Epilobium species.


Author(s):  
Workia Ahmed ◽  
Tileye Feyissa ◽  
Kassahun Tesfaye ◽  
Sumaira Farrakh

Abstract Background Date palm tree (Phoenix dactylifera L.) is a perennial monocotyledonous plant belonging to the Arecaceae family, a special plant with extraordinary nature that gives eminent contributions in agricultural sustainability and huge socio-economic value in many countries of the world including Ethiopia. Evaluation of genetic diversity across date palms at DNA level is very important for breeding and conservation. The result of this study could help to design for genetic improvement and develop germplasm introduction programmes of date palms mainly in Ethiopia. Results In this study, 124 date palm genotypes were collected, and 10 polymorphic microsatellite markers were used. Among 10 microsatellites, MPdCIR085 and MPdCIR093 loci showed the highest value of observed and expected heterozygosity, maximum number of alleles, and highest polymorphic information content values. A total of 112 number of alleles were found, and the mean number of major allele frequency was 0.26, with numbers ranging from 0.155 (MPdCIR085) to 0.374 (MPdCIR016); effective number of alleles with a mean value of 6.61, private alleles ranged from 0.0 to 0.65; observed heterozygosity ranged from 0.355 to 0.726; expected heterozygosity varied from 0.669 to 0.906, polymorphic information content with a mean value of 0.809; fixation index individuals relative to subpopulations ranged from 0.028 for locus MPdCIR032 to 0.548 for locus MPdCIR025, while subpopulations relative to total population value ranged from − 0.007 (MPdCIR070) to 0.891 (MPdCIR015). All nine accesstions, neighbour-joining clustering analysis, based on dissimilarity coefficient values were grouped into five major categories; in population STRUCTURE analysis at highest K value, three groups were formed, whereas DAPC separated date palm genotypes into eight clusters using the first two linear discriminants. Principal coordinate analysis was explained, with a 17.33% total of variation in all populations. Generally, the result of this study revealed the presence of allele variations and high heterozygosity (> 0.7) in date palm genotypes. Conclusions Microsatellites (SSR) are one of the most preferable molecular markers for the study of genetic diversity and population structure of plants. In this study, we found the presence of genetic variations of date palm genotypes in Ethiopia; therefore, these genetic variations of date palms is important for crop improvement and conservation programmes; also, it will be used as sources of information to national and international genbanks.


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