scholarly journals Efficient construction of a linkage map and haplotypes for Mentha suaveolens using sequence capture

Author(s):  
Helen Tsai ◽  
Nestor Kippes ◽  
Alana Firl ◽  
Meric Lieberman ◽  
Luca Comai ◽  
...  

Abstract The sustainability of many crops is hindered by the lack of genomic resources and a poor understanding of natural genetic diversity. Particularly, application of modern breeding requires high-density linkage maps that are integrated into a highly contiguous reference genome. Here, we present a rapid method for deriving haplotypes and developing linkage maps, and its application to Mentha suaveolens, one of the diploid progenitors of cultivated mints. Using sequence-capture via DNA hybridization to target single nucleotide polymorphisms (SNPs), we successfully genotyped ∼5,000 SNPs within the genome of > 400 individuals derived from a self cross. After stringent quality control, and identification of non-redundant SNPs, 1,919 informative SNPs were retained for linkage map construction. The resulting linkage map defined a total genetic space of 942.17 cM divided among 12 linkage groups, ranging from 56.32 to 122.61 cM in length. The linkage map is in good agreement with pseudomolecules from our preliminary genome assembly, proving this resource effective for the correction and validation of the reference genome. We discuss the advantages of this method for the rapid creation of linkage maps.

2020 ◽  
Vol 61 (7) ◽  
pp. 1262-1272
Author(s):  
Hiromi Kajiya-Kanegae ◽  
Hideki Takanashi ◽  
Masaru Fujimoto ◽  
Motoyuki Ishimori ◽  
Norikazu Ohnishi ◽  
...  

Abstract Sorghum [Sorghum bicolor (L.) Moench] grown locally by Japanese farmers is generically termed Takakibi, although its genetic diversity compared with geographically distant varieties or even within Takakibi lines remains unclear. To explore the genomic diversity and genetic traits controlling biomass and other physiological traits in Takakibi, we focused on a landrace, NOG, in this study. Admixture analysis of 460 sorghum accessions revealed that NOG belonged to the subgroup that represented Asian sorghums, and it was only distantly related to American/African accessions including BTx623. In an attempt to dissect major traits related to biomass, we generated a recombinant inbred line (RIL) from a cross between BTx623 and NOG, and we constructed a high-density linkage map based on 3,710 single-nucleotide polymorphisms obtained by restriction-site-associated DNA sequencing of 213 RIL individuals. Consequently, 13 fine quantitative trait loci (QTLs) were detected on chromosomes 2, 3, 6, 7, 8 and 9, which included five QTLs for days to heading, three for plant height (PH) and total shoot fresh weight and two for Brix. Furthermore, we identified two dominant loci for PH as being identical to the previously reported dw1 and dw3. Together, these results corroborate the diversified genome of Japanese Takakibi, while the RIL population and high-density linkage map generated in this study will be useful for dissecting other important traits in sorghum.


2017 ◽  
Author(s):  
Kelly J Vining ◽  
Natalia Salinas ◽  
Jacob A Tennessen ◽  
Jason D Zurn ◽  
Daniel James Sargent ◽  
...  

With the goal of evaluating genotyping-by-sequencing (GBS) in a species with a complex octoploid genome, GBS was used to survey genome-wide single-nucleotide polymorphisms (SNPs) in three biparental strawberry (Fragaria ×ananassa) populations. GBS sequence data were aligned to the F. vesca ‘Fvb’ reference genome in order to call SNPs. Numbers of polymorphic SNPs per population ranged from 1,163 to 3,190. Linkage maps consisting of 30-65 linkage groups were produced from the SNP sets derived from each parent. The linkage groups covered 99% of the Fvb reference genome, with three to seven linkage groups from a given parent aligned to any particular chromosome. A phylogenetic analysis performed using the POLiMAPS pipeline revealed linkage groups that were most similar to ancestral species F. vesca for each chromosome. Linkage groups that were most similar to a second ancestral species, F. iinumae, were only resolved for Fvb 4. The quantity of missing data and heterogeneity in genome coverage inherent in GBS complicated the analysis, but POLiMAPS resolved F. ×ananassa chromosomal regions derived from diploid ancestor F. vesca.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3731 ◽  
Author(s):  
Kelly J. Vining ◽  
Natalia Salinas ◽  
Jacob A. Tennessen ◽  
Jason D. Zurn ◽  
Daniel James Sargent ◽  
...  

Genotyping-by-sequencing (GBS) was used to survey genome-wide single-nucleotide polymorphisms (SNPs) in three biparental strawberry (Fragaria× ananassa) populations with the goal of evaluating this technique in a species with a complex octoploid genome. GBS sequence data were aligned to theF. vesca‘Fvb’ reference genome in order to call SNPs. Numbers of polymorphic SNPs per population ranged from 1,163 to 3,190. Linkage maps consisting of 30–65 linkage groups were produced from the SNP sets derived from each parent. The linkage groups covered 99% of theFvbreference genome, with three to seven linkage groups from a given parent aligned to any particular chromosome. A phylogenetic analysis performed using the POLiMAPS pipeline revealed linkage groups that were most similar to ancestral speciesF. vescafor each chromosome. Linkage groups that were most similar to a second ancestral species,F. iinumae, were only resolved forFvb4. The quantity of missing data and heterogeneity in genome coverage inherent in GBS complicated the analysis, but POLiMAPS resolvedF.× ananassachromosomal regions derived from diploid ancestorF. vesca.


2019 ◽  
Vol 35 (17) ◽  
pp. 3160-3162
Author(s):  
Davoud Torkamaneh ◽  
Jérôme Laroche ◽  
Istvan Rajcan ◽  
François Belzile

Abstract Motivation Reduced-representation sequencing is a genome-wide scanning method for simultaneous discovery and genotyping of thousands to millions of single nucleotide polymorphisms that is used across a wide range of species. However, in this method a reproducible but very small fraction of the genome is captured for sequencing, while the resulting reads are typically aligned against the entire reference genome. Results Here we present a skinny reference genome approach in which a simplified reference genome is used to decrease computing time for data processing and to increase single nucleotide polymorphism counts and accuracy. A skinny reference genome can be integrated into any reduced-representation sequencing analytical pipeline. Availability and implementation https://bitbucket.org/jerlar73/SRG-Extractor. Supplementary information Supplementary data are available at Bioinformatics online.


Genetics ◽  
2001 ◽  
Vol 158 (2) ◽  
pp. 715-726 ◽  
Author(s):  
Ruth E Fulton ◽  
Michael L Salasek ◽  
Nancy M DuTeau ◽  
William C Black

AbstractAn intensive linkage map of the yellow fever mosquito, Aedes aegypti, was constructed using single-strand conformation polymorphism (SSCP) analysis of cDNA markers to identify single nucleotide polymorphisms (SNPs). A total of 94 A. aegypti cDNAs were downloaded from GenBank and primers were designed to amplify fragments <500 bp in size. These primer pairs amplified 94 loci, 57 (61%) of which segregated in a single F1 intercross family among 83 F2 progeny. This allowed us to produce a dense linkage map of one marker every 2 cM distributed over a total length of 134 cM. Many A. aegypti cDNAs were highly similar to genes in the Drosophila melanogaster genome project. Comparative linkage analysis revealed areas of synteny between the two species. SNP polymorphisms are abundant in A. aegypti genes and should prove useful in both population genetics and mapping studies.


2017 ◽  
Author(s):  
Kelly J Vining ◽  
Natalia Salinas ◽  
Jacob A Tennessen ◽  
Jason D Zurn ◽  
Daniel James Sargent ◽  
...  

With the goal of evaluating genotyping-by-sequencing (GBS) in a species with a complex octoploid genome, GBS was used to survey genome-wide single-nucleotide polymorphisms (SNPs) in three biparental strawberry (Fragaria ×ananassa) populations. GBS sequence data were aligned to the F. vesca ‘Fvb’ reference genome in order to call SNPs. Numbers of polymorphic SNPs per population ranged from 1,163 to 3,190. Linkage maps consisting of 30-65 linkage groups were produced from the SNP sets derived from each parent. The linkage groups covered 99% of the Fvb reference genome, with three to seven linkage groups from a given parent aligned to any particular chromosome. A phylogenetic analysis performed using the POLiMAPS pipeline revealed linkage groups that were most similar to ancestral species F. vesca for each chromosome. Linkage groups that were most similar to a second ancestral species, F. iinumae, were only resolved for Fvb 4. The quantity of missing data and heterogeneity in genome coverage inherent in GBS complicated the analysis, but POLiMAPS resolved F. ×ananassa chromosomal regions derived from diploid ancestor F. vesca.


GigaScience ◽  
2020 ◽  
Vol 9 (2) ◽  
Author(s):  
Stephen J Bush ◽  
Dona Foster ◽  
David W Eyre ◽  
Emily L Clark ◽  
Nicola De Maio ◽  
...  

Abstract Background Accurately identifying single-nucleotide polymorphisms (SNPs) from bacterial sequencing data is an essential requirement for using genomics to track transmission and predict important phenotypes such as antimicrobial resistance. However, most previous performance evaluations of SNP calling have been restricted to eukaryotic (human) data. Additionally, bacterial SNP calling requires choosing an appropriate reference genome to align reads to, which, together with the bioinformatic pipeline, affects the accuracy and completeness of a set of SNP calls obtained. This study evaluates the performance of 209 SNP-calling pipelines using a combination of simulated data from 254 strains of 10 clinically common bacteria and real data from environmentally sourced and genomically diverse isolates within the genera Citrobacter, Enterobacter, Escherichia, and Klebsiella. Results We evaluated the performance of 209 SNP-calling pipelines, aligning reads to genomes of the same or a divergent strain. Irrespective of pipeline, a principal determinant of reliable SNP calling was reference genome selection. Across multiple taxa, there was a strong inverse relationship between pipeline sensitivity and precision, and the Mash distance (a proxy for average nucleotide divergence) between reads and reference genome. The effect was especially pronounced for diverse, recombinogenic bacteria such as Escherichia coli but less dominant for clonal species such as Mycobacterium tuberculosis. Conclusions The accuracy of SNP calling for a given species is compromised by increasing intra-species diversity. When reads were aligned to the same genome from which they were sequenced, among the highest-performing pipelines was Novoalign/GATK. By contrast, when reads were aligned to particularly divergent genomes, the highest-performing pipelines often used the aligners NextGenMap or SMALT, and/or the variant callers LoFreq, mpileup, or Strelka.


Author(s):  
Yanlin Liao ◽  
Roeland E. Voorrips ◽  
Peter M. Bourke ◽  
Giorgio Tumino ◽  
Paul Arens ◽  
...  

Abstract Key message In polyploids, linkage mapping is carried out using genotyping with discrete dosage scores. Here, we use probabilistic genotypes and we validate it for the construction of polyploid linkage maps. Abstract Marker genotypes are generally called as discrete values: homozygous versus heterozygous in the case of diploids, or an integer allele dosage in the case of polyploids. Software for linkage map construction and/or QTL analysis usually relies on such discrete genotypes. However, it may not always be possible, or desirable, to assign definite values to genotype observations in the presence of uncertainty in the genotype calling. Here, we present an approach that uses probabilistic marker dosages for linkage map construction in polyploids. We compare our method to an approach based on discrete dosages, using simulated SNP array and sequence reads data with varying levels of data quality. We validate our approach using experimental data from a potato (Solanum tuberosum L.) SNP array applied to an F1 mapping population. In comparison to the approach based on discrete dosages, we mapped an additional 562 markers. All but three of these were mapped to the expected chromosome and marker position. For the remaining three markers, no physical position was known. The use of dosage probabilities is of particular relevance for map construction in polyploids using sequencing data, as these often result in a higher level of uncertainty regarding allele dosage.


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