scholarly journals Using nuclear microsatellite data to trace the gene flow and population structure in Czech horses

2019 ◽  
Vol 64 (No. 2) ◽  
pp. 67-77
Author(s):  
L. Putnová ◽  
R. Štohl ◽  
I. Vrtková

Based on a data set comprising 2879 animals and 17 nuclear microsatellite DNA markers, we propose the most comprehensive in-depth study mapping the genetic structure and specifying the assignment success rates in horse breeds at the Czech population scale. The STRUCTURE program was used to perform systematic Bayesian clustering via the Markov chain Monte Carlo estimation, enabling us to explain the population stratification and to identify genetic structure patterns within breeds worldwide. In total, 182 different alleles were found over all the populations and markers, with the mean number of 10.7 alleles per locus. The expected heterozygosity ranged from 0.459 (Friesian) to 0.775 (Welsh Part Bred), and the average level reached 0.721. The average observed heterozygosity corresponded to 0.709, with the highest value detected in the Czech Sport Pony (0.775). The largest number of private alleles was found in Equus przewalskii. The population inbreeding coefficient F<sub>IS</sub> ranged from –0.08 in the Merens to 0.14 in the Belgian Warmblood. The total within-population inbreeding coefficient was estimated to be moderate. As expected, very large genetic differentiation and small gene flow were established between the Friesian and Equus przewalskii (F<sub>ST </sub>= 0.37, Nm = 0.43). Zero F<sub>ST</sub> values indicated no differences between the Czech Warmblood–Slovak Warmblood and the Czech Warmblood–Bavarian Warmblood. A high level of breeding and connectivity was revealed between the Slovak Warmblood–Bavarian Warmblood, Dutch Warmblood–Oldenburg Horse, Bavarian Warmblood–Dutch Warmblood, and Bavarian Warmblood–Oldenburg Horse. The breeds’ contribution equalled about 6% of the total genetic variability. The overall proportion of individuals correctly assigned to a population corresponded to 82.4%. The posterior Bayesian approach revealed a hierarchical dynamic genetic structure in four clusters (hot-blooded, warm-blooded, cold-blooded, and pony). While most of the populations were genetically distinct from each other and well-arranged with solid breed structures, some of the entire sets showed signs of admixture and/or fragmentation.

Genetics ◽  
1981 ◽  
Vol 98 (1) ◽  
pp. 157-178
Author(s):  
J S Jones ◽  
S H Bryant ◽  
R C Lewontin ◽  
J A Moore ◽  
T Prout

ABSTRACT This paper discusses the relation between the geographical distribution of an enzyme polymorphism and population structure in Drosophila pseudoobscura. California populations of this species living in very different montane and lowland habitats separated by several kilometers are similar to each other in the frequency of an esterase allele. Previous estimates suggest that gene flow is too limited to account for this homogeneity of genetic structure, so that it must reflect some balancing force of natural selection. We show, however, that dispersal over unfavorable habitats is much greater than earlier supposed. Isolated populations of D. pseudoobscura separated by 15 km from other populations are subject to large amounts of immigration. This is shown by changes in the seasonal abundance of this species and in the annual pattern of lethal alleles in such populations. The genetic structure of an experimentally perturbed isolated population in an oasis returned to normal within a single year, suggesting that such populations are ephemeral and that the oasis is subject to annual recolonization by distant migrants. Direct assessment of marked flies shows that they can move at least 10 km in 24 hours over a desert. Such extensive gene flow may help explain the distribution of the esterase allele, and is relevant to the high level of molecular polymorphism and its general lack of geographic differentiation throughout the range of D. pseudoobscura.


Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1893
Author(s):  
Ana Maria Figueira Gomes ◽  
David Draper ◽  
Pedro Talhinhas ◽  
Paula Batista Santos ◽  
Fernanda Simões ◽  
...  

Cowpea is a multiple-purpose drought-tolerant leguminous pulse crop grown in several dry tropical areas. Its domestication center is thought to be East or West Africa, where a high level of genetic diversity is apparently still found. However, detailed genetic information is lacking in many African countries, limiting the success of breeding programs. In this work, we assessed the genetic variation and gene flow in 59 Vigna unguiculata (cowpea) accessions from 10 landraces spanning across six agro-ecological zones of Mozambique, based on nuclear microsatellite markers. The results revealed the existence of high genetic diversity between the landraces, even in comparison to other world regions. Four genetic groups were found, with no specific geographic pattern, suggesting the presence of gene flow between landraces. In comparison, the two commercial varieties had lower values of genetic diversity, although still close to the ones found in local landraces. The high genetic diversity found in Mozambique sustains the importance of local genetic resources and farm protection to enhance genetic diversity in modern varieties of cowpea worldwide.


2017 ◽  
Vol 37 (02) ◽  
pp. 71-78 ◽  
Author(s):  
P. Hondelmann ◽  
J.O. Nyasani ◽  
S. Subramanian ◽  
R. Meyhöfer

Abstract Western flower thrips (WFT) (Frankliniella occidentalis) is an introduced pest that harms French bean production in Kenya and other countries. Since new WFT management approaches are being developed, a closer look at the genetic makeup of WFT populations can give new insights into source habitats, crop colonization patterns or host plant preferences, which are prerequisites for integrated pest management (IPM) strategies. For this purpose, we used six microsatellite loci to analyse the genetic structure, diversity and gene flow of WFT sampled on French beans, intercrops and weeds in Kenyan French bean production areas. The results of this preliminary study indicate that the available microsatellites are sufficiently polymorphic for more detailed analyses on local dispersal patterns of WFT in Kenya. Even with the limited data set, the results reveal that F. occidentalis populations show considerable genetic differentiation between host plant species but not between regions, which suggests reduced gene flow and a possible development of biotypes. Possible consequences of the results on IPM are discussed.


2007 ◽  
Vol 17 (2) ◽  
pp. 177-185 ◽  
Author(s):  
Ping Ping Jiang ◽  
Yun Fa Ge ◽  
Qiu Lei Lang ◽  
Ping Ding

AbstractGenetic structure among five populations of Elliot's Pheasant sampled from five different provinces – Anhui (AH), Zhejiang (ZJ), Fujian (FJ), Hunan (HN) and Guizhou (GZ) – was assayed using mitochondrial control region sequences from 33 individuals. Using AMOVA, we found a high level of haplotype variation within populations, and a degree of genetic structure among groups (GZ population relative to all others pooled). However, this difference was not statistically significant and little geographical structure was indicated among the remaining populations. Furthermore, using a rooted maximum parsimony tree, we found the sequences of the GZ population were largely grouped in their own branch, while sequences of the other four populations were interspersed among branches. We identified a lower level of gene flow between the GZ population and all others, a finding supported by significant FST values. Conversely, we identified a larger amount of gene flow between the remaining four populations, particularly among the three easternmost populations (AH, ZJ and FJ). Given our results, further study should be focused on the GZ population and on management units for the purpose of maintaining the genetic structure of the species in the west of China.


2017 ◽  
Vol 54 ◽  
pp. 134-140
Author(s):  
H. S. Rudoman ◽  
V. M. Balatsky ◽  
V. Y. Nor ◽  
V. O. Vovk

One of the top priorities at the present stage of development of pig breeding remains the development of a set of measures aimed at increasing the resistance animals to various diseases, especially – to colibacteriosis .One of the recent and effective approaches to prevent colibacillosis is using markers of selection; it involves pig genotyping by genome locuses. Chosen locuses are associated with animal sensitivity to the disease and selection of the results of genotyping of animals with increased resistance. Due to researches, one of such locuses is alpha-fukozyltrasferаza 1 gene (FUT1). Gene FUT1 is located in chromosome 6. As a result of its sequencing in the swine breeds of Large White and Swedish Landrace, single-nucleotide polymorphism (g.307 G > A SNP) has been detected. AA genotype determines the resistance of animals to colibacteriosis, while AG and GG genotypes are susceptible to this disease. According to the results of previous studies, the positive effect of allele A was determined not only on the resistance of pigs to colibacteriosis, but also on indicators of fattening and meat productivity and on reproductive performance. In Ukraine, the studies of polymorphism FUT1 g.307 G > A SNP were held fragmentedly and only on certain populations of Ukrainian Meat and Large White breed but without establishing its association with the indicators of productivity of pigs. The aim of our work was to study the genetic structure of Ukrainian Large White breeds, type 1 and the establishment of association. g. 307 G > A SNP FUT1 gene with pigs indicators of productivity. For research the 96 samples of hair were used. DNA isolation from samples with biomaterial were carried out using ion exchange resin Chelex-100. Genotyping was performed by PCR-RFLP by method of Jorgensen et al. (2006). Using DNA analysis of this breeds locus FUT1 was determined by genetic structure. Allele frequency of allele G (0,573) and allele A (0,427) was established The distribution of genotype frequencies was not statistically significantly different from the theoretically expected, calculated by the Hardy-Weinberg criterion. Thus, according to the locus of FUT1 g.307 G > A, the breeds investigated are in a state close to the genetic equilibrium. The negative value of the fixation index by the locus FUT1 g.307 G > A indicates an excess of heterozygotes in the population, and hence the lack of targeted selection for this marker. The valuation was performed by calculating the PIC (polymorphic information content) – information content of polymorphism marker. In the analyzed pig herd for this marker, the PIC has an average value (0,367), which indicates the high level of polymorphism of the given locus and is favorable for the possibility of conducting a search for links between individual genotypes and indicators of productivity. To establish the association g.307 G > A SNP FUT1 gene with indicators of animal productivity, a one-way analysis of variance of the experimental data was used. Based on the results of a one-way analysis of variance, a significant effect of the genotypes of the FUT1gene (g.1849 G > C) on the indicator of the average daily weight gain (р ≤ 0,001), the thickness of the bacon at the level of the VI-VII vertebrae (p ≤ 0.01), reaching live weight of 100 kg (р ≤ 0,001) and breeding index of fattening qualities (р ≤ 0,01) was found. The parameter of the influence of the genetic factor on the test feature was 28,54%, 10,4%, 33,4% and 8,8% respectively. According to the investigated indicators of productivity, animals with genotype AA, which determines resistance to colibacteriosis, dominated the animals with genotypes GG and AG. Based on the results of our research and pre-published data, the multiple effect of the g.307 G > A SNP FUT1 gene is observed, which is associated with the indicators of productivity, which again confirms the polygenicity of the quantitative trait loci of farm animals. Taking into account a high level of polymorphism of the investigated gene and reliable associations of genotypes with indicators of productivity found, it can be recommended to carry out breeding of pigs using genetic information of the g.307 G > A SNP gene FUT1.


2020 ◽  

BACKGROUND: This paper deals with territorial distribution of the alcohol and drug addictions mortality at a level of the districts of the Slovak Republic. AIM: The aim of the paper is to explore the relations within the administrative territorial division of the Slovak Republic, that is, between the individual districts and hence, to reveal possibly hidden relation in alcohol and drug mortality. METHODS: The analysis is divided and executed into the two fragments – one belongs to the female sex, the other one belongs to the male sex. The standardised mortality rate is computed according to a sequence of the mathematical relations. The Euclidean distance is employed to compute the similarity within each pair of a whole data set. The cluster analysis examines is performed. The clusters are created by means of the mutual distances of the districts. The data is collected from the database of the Statistical Office of the Slovak Republic for all the districts of the Slovak Republic. The covered time span begins in the year 1996 and ends in the year 2015. RESULTS: The most substantial point is that the Slovak Republic possesses the regional disparities in a field of mortality expressed by the standardised mortality rate computed particularly for the diagnoses assigned to the alcohol and drug addictions at a considerably high level. However, the female sex and the male sex have the different outcome. The Bratislava III District keeps absolutely the most extreme position. It forms an own cluster for the both sexes too. The Topoľčany District bears a similar extreme position from a point of view of the male sex. All the Bratislava districts keep their mutual notable dissimilarity. Contrariwise, evaluation of a development of the regional disparities among the districts looks like notably heterogeneously. CONCLUSIONS: There are considerable regional discrepancies throughout the districts of the Slovak Republic. Hence, it is necessary to create a common platform how to proceed with the solution of this issue.


Author(s):  
Richard Frankham ◽  
Jonathan D. Ballou ◽  
Katherine Ralls ◽  
Mark D. B. Eldridge ◽  
Michele R. Dudash ◽  
...  

Inbreeding is reduced and genetic diversity enhanced when a small isolated inbred population is crossed to another unrelated population. Crossing can have beneficial or harmful effects on fitness, but beneficial effects predominate, and the risks of harmful ones (outbreeding depression) can be predicted and avoided. For crosses with a low risk of outbreeding depression, there are large and consistent benefits on fitness that persist across generations in outbreeding species. Benefits are greater in species that naturally outbreed than those that inbreed, and increase with the difference in inbreeding coefficient between crossed and inbred populations in mothers and zygotes. However, benefits are similar across invertebrates, vertebrates and plants. There are also important benefits for evolutionary potential of crossing between populations.


2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii464-iii464
Author(s):  
Dharmendra Ganesan ◽  
Nor Faizal Ahmad Bahuri ◽  
Revathi Rajagopal ◽  
Jasmine Loh PY ◽  
Kein Seong Mun ◽  
...  

Abstract The University of Malaya Medical Centre, Kuala Lumpur had acquired a intraoperative MRI (iMRI) brain suite via a public private initiative in September 2015. The MRI brain suite has a SIEMENS 1.5T system with NORAS coil system and NORAS head clamps in a two room solution. We would like to retrospectively review the cranial paediatric neuro-oncology cases that had surgery in this facility from September 2015 till December 2019. We would like to discuss our experience with regard to the clear benefits and the challenges in using such technology to aid in the surgery. The challenges include the physical setting up the paediatric case preoperatively, the preparation and performing the intraoperative scan, the interpretation of intraoperative images and making a decision and the utilisation of the new MRI data set to assist in the navigation to locate the residue safely. Also discuss the utility of the intraoperative images in the decision of subsequent adjuvant management. The use of iMRI also has other technical challenges such as ensuring the perimeter around the patient is free of ferromagnetic material, the process of transfer of the patient to the scanner and as a consequence increased duration of the surgery. CONCLUSION: Many elements in the use of iMRI has a learning curve and it improves with exposure and experience. In some areas only a high level of vigilance and SOP (Standard operating procedure) is required to minimize mishaps. Currently, the iMRI gives the best means of determining extent of resection before concluding the surgery.


Genetics ◽  
1997 ◽  
Vol 147 (2) ◽  
pp. 643-655 ◽  
Author(s):  
Kenneth G Ross ◽  
Michael J B Krieger ◽  
D DeWayne Shoemaker ◽  
Edward L Vargo ◽  
Laurent Keller

We describe genetic structure at various scales in native populations of the fire ant Solenopsis invicta using two classes of nuclear markers, allozymes and microsatellites, and markers of the mitochondrial genome. Strong structure was found at the nest level in both the monogyne (single queen) and polygyne (multiple queen) social forms using allozymes. Weak but significant microgeographic structure was detected above the nest level in polygyne populations but not in monogyne populations using both classes of nuclear markers. Pronounced mitochondrial DNA (mtDNA) differentiation was evident also at this level in the polygyne form only. These microgeographic patterns are expected because polygyny in ants is associated with restricted local gene flow due mainly to limited vagility of queens. Weak but significant nuclear differentiation was detected between sympatric social forms, and strong mtDNA differentiation also was found at this level. Thus, queens of each form seem unable to establish themselves in nests of the alternate type, and some degree of assortative mating by form may exist as well. Strong differentiation was found between the two study regions usinga all three sets of markers. Phylogeographic analyses of the mtDNA suggest that recent limitations on gene flow rather than longstanding barriers to dispersal are responsible for this large-scale structure.


Genetics ◽  
1997 ◽  
Vol 147 (4) ◽  
pp. 1843-1854 ◽  
Author(s):  
Nancy N FitzSimmons ◽  
Craig Moritz ◽  
Colin J Limpus ◽  
Lisa Pope ◽  
Robert Prince

Abstract The genetic structure of green turtle (Chelonia mydas) rookeries located around the Australian coast was assessed by (1) comparing the structure found within and among geographic regions, (2) comparing microsatellite loci vs. restriction fragment length polymorphism analyses of anonymous single copy nuclear DNA (ascnDNA) loci, and (3) comparing the structure found at nuclear DNA markers to that of previously analyzed mitochondrial (mtDNA) control region sequences. Significant genetic structure was observed over all regions at both sets of nuclear markers, though the microsatellite data provided greater resolution in identifying significant genetic differences in pairwise tests between regions. Inferences about population structure and migration rates from the microsatellite data varied depending on whether statistics were based on the stepwise mutation or infinite allele model, with the latter being more congruent with geography. Estimated rates of gene flow were generally higher than expected for nuclear DNA (nDNA) in comparison to mtDNA, and this difference was most pronounced in comparisons between the northern and southern Great Barrier Reef (GBR). The genetic data combined with results from physical tagging studies indicate that the lack of nuclear gene divergence through the GBR is likely due to the migration of sGBR turtles through the courtship area of the nGBR population, rather than male-biased dispersal. This example highlights the value of combining comparative studies of molecular variation with ecological data to infer population processes.


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