Analysis of genetic diversity and population structure within the Icelandic cattle breed using molecular markers

2010 ◽  
Vol 60 (4) ◽  
pp. 203-210 ◽  
Author(s):  
M. G. Ásbjarnardóttir ◽  
T. Kristjánsson ◽  
M. B. Jónsson ◽  
J. H. Hallsson
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.


2012 ◽  
Vol 298 (9) ◽  
pp. 1701-1710 ◽  
Author(s):  
Maria Luisa Savo Sardaro ◽  
Maroun Atallah ◽  
Maurizio Enea Picarella ◽  
Benedetto Aracri ◽  
Mario A. Pagnotta

F1000Research ◽  
2014 ◽  
Vol 3 ◽  
pp. 66 ◽  
Author(s):  
Javier Monzón

Previous genetic studies of eastern coyotes (Canis latrans) are based on one of two strategies: sampling many individuals using one or very few molecular markers, or sampling very few individuals using many genomic markers. Thus, a regional analysis of genetic diversity and population structure in eastern coyotes using many samples and several molecular markers is lacking. I evaluated genetic diversity and population structure in 385 northeastern coyotes using 16 common single nucleotide polymorphisms (SNPs). A region-wide analysis of population structure revealed three primary genetic populations, but these do not correspond to the same three subdivisions inferred in a previous analysis of mitochondrial DNA sequences. More focused geographic analyses of population structure indicated that ample genetic structure occurs in coyotes from an intermediate contact zone where two range expansion fronts meet. These results demonstrate that genotyping several highly heterozygous SNPs in a large, geographically dense sample is an effective way to detect cryptic population genetic structure. The importance of SNPs in studies of population and wildlife genomics is rapidly increasing; this study adds to the growing body of recent literature that demonstrates the utility of SNPs ascertained from a model organism for evolutionary inference in closely related species.


2021 ◽  
Author(s):  
Simon Frederick Lashmar ◽  
Carina Visser ◽  
Moses Okpeku ◽  
Farai Catherine Muchadeyi ◽  
Ntanganedzeni Olivia Mapholi ◽  
...  

Abstract In southern Africa, the Nguni cattle breed is classified as an indigenous and transboundary animal genetic resource that manifests unique adaptation abilities across distinct agroecological zones. The genetic integrity of various ecotypes is under potential threat due to both indiscriminate crossbreeding and uncontrolled inbreeding. The aim of this study was to assess the genetic diversity and autozygosity that exists both across countries (ES: eSwatini; SA: South Africa) and within-country (SA), between purebred stud animals (SA-S) and research herds (SA-R). Subsets of 96 ES, 96 SA-S and 96 SA-R genotyped for 40 930 common SNPs were used to study inbreeding, runs of homozygosity (ROH) and heterozygosity (ROHet) profiles as well as population structure. The highest proportion (0.513) of the 3 595 ROH was <4Mb in length, while the majority (0.560) of the 4 409 ROHet segments fell within the 0.5-1Mb length category. Inbreeding coefficients indicated low inbreeding (FROH range: 0.025 for SA-S to 0.029 for SA-R). Principal component (PCA) and population structure (K=5) analyses illustrated genomic distinctiveness between SA and ES populations, greater admixture for SA-R (mean±standard deviation proportion shared=0.631±0.353) compared to SA-S (mean±standard deviation proportion shared=0.741±0.123), and three subpopulations for ES. Overall, results illustrated that genetic distinctiveness in the Nguni resulted from both geographic isolation and exposure to different production strategies. Although no impending threat to genetic diversity was observed, further loss should be monitored to prevent endangerment of unique and beneficial indigenous resources.


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