scholarly journals First-Generation Linkage Map of the Gray, Short-Tailed Opossum,Monodelphis domestica, Reveals Genome-Wide Reduction in Female Recombination Rates

Genetics ◽  
2004 ◽  
Vol 166 (1) ◽  
pp. 307-329 ◽  
Author(s):  
Paul B. Samollow ◽  
Candace M. Kammerer ◽  
Susan M. Mahaney ◽  
Jennifer L. Schneider ◽  
Scott J. Westenberger ◽  
...  
Keyword(s):  
Linkage Map ◽  
First Generation ◽  
Monodelphis Domestica ◽  
Recombination Rates ◽  
Genome Wide

scholarly journals Heterogeneity in Rates of Recombination Across the Mouse Genome

Genetics ◽  
1996 ◽  
Vol 142 (2) ◽  
pp. 537-548 ◽  
Author(s):  
Michael W Nachman ◽  
Gary A Churchill
Keyword(s):  
Linkage Map ◽  
Genetic Map ◽  
Large Scale ◽  
Physical Map ◽  
Genetic Maps ◽  
Recombination Rates ◽  
Physical Maps ◽  
Genomic Patterns ◽  
Mary Lyon ◽  
Microsatellite Linkage

Abstract If loci are randomly distributed on a physical map, the density of markers on a genetic map will be inversely proportional to recombination rate. First proposed by MARY LYON, we have used this idea to estimate recombination rates from the Drosophila melanogaster linkage map. These results were compared with results of two other studies that estimated regional recombination rates in D. melanogaster using both physical and genetic maps. The three methods were largely concordant in identifying large-scale genomic patterns of recombination. The marker density method was then applied to the Mus musculus microsatellite linkage map. The distribution of microsatellites provided evidence for heterogeneity in recombination rates. Centromeric regions for several mouse chromosomes had significantly greater numbers of markers than expected, suggesting that recombination rates were lower in these regions. In contrast, most telomeric regions contained significantly fewer markers than expected. This indicates that recombination rates are elevated at the telomeres of many mouse chromosomes and is consistent with a comparison of the genetic and cytogenetic maps in these regions. The density of markers on a genetic map may provide a generally useful way to estimate regional recombination rates in species for which genetic, but not physical, maps are available.

scholarly journals Evolution of strong reproductive isolation in plants: broad-scale patterns and lessons from a perennial model group

2020 ◽  
Vol 375 (1806) ◽  
pp. 20190544 ◽  
Author(s):  
Huiying Shang ◽  
Jaqueline Hess ◽  
Melinda Pickup ◽  
David L. Field ◽  
Pär K. Ingvarsson ◽  
...  
Keyword(s):  
Reproductive Isolation ◽  
Association Studies ◽  
Great Promise ◽  
Genome Wide Association Studies ◽  
Model Group ◽  
Recombination Rates ◽  
Genome Wide ◽  
Theoretical Predictions ◽  
Tree Topologies ◽  
Exemplary Model

Many recent studies have addressed the mechanisms operating during the early stages of speciation, but surprisingly few studies have tested theoretical predictions on the evolution of strong reproductive isolation (RI). To help address this gap, we first undertook a quantitative review of the hybrid zone literature for flowering plants in relation to reproductive barriers. Then, using Populus as an exemplary model group, we analysed genome-wide variation for phylogenetic tree topologies in both early- and late-stage speciation taxa to determine how these patterns may be related to the genomic architecture of RI. Our plant literature survey revealed variation in barrier complexity and an association between barrier number and introgressive gene flow. Focusing on Populus, our genome-wide analysis of tree topologies in speciating poplar taxa points to unusually complex genomic architectures of RI, consistent with earlier genome-wide association studies. These architectures appear to facilitate the ‘escape’ of introgressed genome segments from polygenic barriers even with strong RI, thus affecting their relationships with recombination rates. Placed within the context of the broader literature, our data illustrate how phylogenomic approaches hold great promise for addressing the evolution and temporary breakdown of RI during late stages of speciation. This article is part of the theme issue ‘Towards the completion of speciation: the evolution of reproductive isolation beyond the first barriers'.

scholarly journals A high-density SNP-based genetic map and several economic traits-related loci in Pelteobagrus vachelli

BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Guosong Zhang ◽  
Jie Li ◽  
Jiajia Zhang ◽  
Xia Liang ◽  
Tao Wang ◽  
...  
Keyword(s):  
Sex Determination ◽  
Linkage Map ◽  
Candidate Genes ◽  
Genetic Map ◽  
Genetic Linkage ◽  
Genetic Linkage Map ◽  
High Density ◽  
Hypoxia Tolerance ◽  
Genome Wide ◽  
Pelteobagrus Vachelli

Abstract Background A high-density genetic linkage map is essential for QTL fine mapping, comparative genome analysis, identification of candidate genes and marker-assisted selection in aquaculture species. Pelteobagrus vachelli is a very popular commercial species in Asia. However, some specific characters hindered achievement of the traditional selective breeding based on phenotypes, such as lack of large-scale genomic resource and short of markers tightly associated with growth, sex determination and hypoxia tolerance related traits. Results By making use of 5059 ddRAD markers in P. vachelli, a high-resolution genetic linkage map was successfully constructed. The map’ length was 4047.01 cM by using an interval of 0.11 cm, which is an average marker standard. Comparative genome mapping revealed that a high proportion (83.2%) of markers with a one-to-one correspondence were observed between P. vachelli and P. fulvidraco. Based on the genetic map, 8 significant genome-wide QTLs for 4 weight, 1 body proportion, 2 sex determination, and 1 hypoxia tolerance related traits were detected on 4 LGs. Some SNPs from these significant genome-wide QTLs were observably associated with these phenotypic traits in other individuals by Kompetitive Allele Specific PCR. In addition, two candidate genes for weight, Sipa1 and HSD11B2, were differentially expressed between fast-, medium- and slow-growing P. vachelli. Sema7a, associated with hypoxia tolerance, was induced after hypoxia exposure and reoxygenation. Conclusions We mapped a set of suggestive and significant QTLs as well as candidate genes for 12 growth, 1 sex determination and 1 hypoxia tolerance related traits based on a high-density genetic linkage map by making use of SNP markers for P. fulvidraco. Our results have offered a valuable method about the much more efficient production of all-male, fast growth and hypoxia tolerance P. vachelli for the aquaculture industry.

scholarly journals Predicting the Landscape of Recombination Using Deep Learning

2020 ◽  
Vol 37 (6) ◽  
pp. 1790-1808 ◽  
Author(s):  
Jeffrey R Adrion ◽  
Jared G Galloway ◽  
Andrew D Kern
Keyword(s):  
Deep Learning ◽  
Evolutionary History ◽  
Model Misspecification ◽  
Natural Populations ◽  
High Accuracy ◽  
Demographic Model ◽  
Recombination Rates ◽  
Genome Wide ◽  
A Genome ◽  
The Face

Abstract Accurately inferring the genome-wide landscape of recombination rates in natural populations is a central aim in genomics, as patterns of linkage influence everything from genetic mapping to understanding evolutionary history. Here, we describe recombination landscape estimation using recurrent neural networks (ReLERNN), a deep learning method for estimating a genome-wide recombination map that is accurate even with small numbers of pooled or individually sequenced genomes. Rather than use summaries of linkage disequilibrium as its input, ReLERNN takes columns from a genotype alignment, which are then modeled as a sequence across the genome using a recurrent neural network. We demonstrate that ReLERNN improves accuracy and reduces bias relative to existing methods and maintains high accuracy in the face of demographic model misspecification, missing genotype calls, and genome inaccessibility. We apply ReLERNN to natural populations of African Drosophila melanogaster and show that genome-wide recombination landscapes, although largely correlated among populations, exhibit important population-specific differences. Lastly, we connect the inferred patterns of recombination with the frequencies of major inversions segregating in natural Drosophila populations.

scholarly journals Inferring the Genomic Landscape of Recombination Rate Variation in European Aspen (Populus tremula)

2019 ◽  
Vol 10 (1) ◽  
pp. 299-309 ◽  
Author(s):  
Rami-Petteri Apuli ◽  
Carolina Bernhardsson ◽  
Bastian Schiffthaler ◽  
Kathryn M. Robinson ◽  
Stefan Jansson ◽  
...  
Keyword(s):  
Linkage Disequilibrium ◽  
Linkage Map ◽  
Recombination Rate ◽  
Gene Density ◽  
Populus Tremula ◽  
Rate Variation ◽  
Recombination Rates ◽  
Genomic Features ◽  
European Aspen ◽  
Recombination Rate Variation

The rate of meiotic recombination is one of the central factors determining genome-wide levels of linkage disequilibrium which has important consequences for the efficiency of natural selection and for the dissection of quantitative traits. Here we present a new, high-resolution linkage map for Populus tremula that we use to anchor approximately two thirds of the P. tremula draft genome assembly on to the expected 19 chromosomes, providing us with the first chromosome-scale assembly for P. tremula (Table 2). We then use this resource to estimate variation in recombination rates across the P. tremula genome and compare these results to recombination rates based on linkage disequilibrium in a large number of unrelated individuals. We also assess how variation in recombination rates is associated with a number of genomic features, such as gene density, repeat density and methylation levels. We find that recombination rates obtained from the two methods largely agree, although the LD-based method identifies a number of genomic regions with very high recombination rates that the map-based method fails to detect. Linkage map and LD-based estimates of recombination rates are positively correlated and show similar correlations with other genomic features, showing that both methods can accurately infer recombination rate variation across the genome. Recombination rates are positively correlated with gene density and negatively correlated with repeat density and methylation levels, suggesting that recombination is largely directed toward gene regions in P. tremula.

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