scholarly journals A European whitefish linkage map and its implications for understanding genome-wide synteny between salmonids following whole genome duplication

2018 ◽  
Author(s):  
Rishi De-Kayne ◽  
Philine G.D. Feulner
Keyword(s):  
Atlantic Salmon ◽  
Linkage Map ◽  
Genome Structure ◽  
Model Organisms ◽  
Rate Variation ◽  
Linkage Maps ◽  
Linkage Groups ◽  
Sequencing Data ◽  
Starting Point ◽  
Selection Of Species

AbstractGenomic datasets continue to increase in size and ease of production for a wider selection of species including non-model organisms. For many of these species highly contiguous and well-annotated genomes are unavailable due to their prohibitive complexity and cost. As a result, a common starting point for genomic work in non-model species is the production of a linkage map, which involves the grouping and relative ordering of genetic markers along the genome. Dense linkage maps facilitate the analysis of genomic data in a variety of ways, from broad scale observations regarding genome structure e.g. chromosome number and type or sex-related structural differences, to fine scale patterns e.g. recombination rate variation and co-localisation of differentiated regions. Here we present both a sex-averaged and sex-specific linkage maps for Coregonus sp. “Albock” containing 5395 single nucleotide polymorphism (SNP) loci across 40 linkage groups to facilitate future investigation into the genomic basis of whitefish adaptation and speciation. The map was produced using restriction-site associated digestion (RAD) sequencing data from two wild-caught parents and 156 F1 offspring in Lep-MAP3. We discuss the differences between our sex-avagerated and sex-specific maps and identify synteny between C. sp. “Albock” linkage groups and the Atlantic salmon (Salmo salar) genome. Our synteny analysis confirms that many patterns of homology observed between Atlantic salmon and Oncorhynchus and Salvelinus species are also shared by members of the Coregoninae subfamily.

RAPD-based genetic linkage maps of yellow passion fruit (Passiflora edulis Sims. f. flavicarpa Deg.)

Genome ◽  
2002 ◽  
Vol 45 (4) ◽  
pp. 670-678 ◽  
Author(s):  
Monalisa Sampaio Carneiro ◽  
Luis Eduardo Aranha Camargo ◽  
Alexandre Siqueira Guedes Coelho ◽  
Roland Vencovsky ◽  
Rui Pereira Leite Júnior ◽  
...  
Keyword(s):  
Genetic Mapping ◽  
Linkage Map ◽  
Average Distance ◽  
Passion Fruit ◽  
Bacterial Disease ◽  
Linkage Maps ◽  
Linkage Groups ◽  
Passiflora Edulis ◽  
Starting Point ◽  
Passiflora Edulis Sims

A single cross between two clones of passion fruit (Passiflora edulis Sims. f. flavicarpa Deg., 2n = 18) was selected for genetic mapping. The mapping population was composed of 90 F1 plants derived from a cross between 'IAPAR 123' (female parent) and 'IAPAR 06' (male parent). A total of 380 RAPD primers were analyzed according to two-way pseudo-testcross mapping design. The linkage analysis was performed using Mapmaker version 3.0 with LOD 4.0 and a maximum recombination fraction (θ) of 0.30. Map distances were estimated using the Kosambi mapping function. Linkage maps were constructed with 269 loci (2.38 markers/primer), of which 255 segregated 1:1, corresponding to a heterozygous state in one parent and null in the other. The linkage map for 'IAPAR123' consisted of 135 markers. A total of nine linkage groups were assembled covering 727.7 cM, with an average distance of 11.20 cM between framework loci. The sizes of the linkage groups ranged from 56 to 144.6 cM. The linkage map for 'IAPAR 06' consisted of 96 markers, covering 783.5 cM. The average distance between framework loci was 12.2 cM. The length of the nine linkage groups ranged from 20.6 to 144.2 cM. On average, both maps provided 61% genome coverage. Twenty-four loci (8.9%) remained unlinked. Among their many applications, these maps are a starting point for the identification of quantitative trait loci for resistance to the main bacterial disease affecting passion fruit orchards in Brazil, caused by Xanthomonas campestris pv. passiflorae, because parental genotypes exhibit diverse responses to bacterial inoculation.Key words: Passiflora, genetic mapping, molecular markers, pseudo-testcross mapping strategy.

Two genetic linkage maps of mungbean using RFLP and RAPD markers

2000 ◽  
Vol 51 (4) ◽  
pp. 415 ◽  
Author(s):  
C. J. Lambrides ◽  
R. J. Lawn ◽  
I. D. Godwin ◽  
J. Manners ◽  
B. C. Imrie
Keyword(s):  
Linkage Map ◽  
Segregation Distortion ◽  
Recombinant Inbred ◽  
Genetic Linkage ◽  
Rapd Markers ◽  
Rflp Markers ◽  
Linkage Maps ◽  
Linkage Groups ◽  
Genetic Linkage Maps ◽  
Map Distance

Two genetic linkage maps of mungbean derived from the cross Berken ACC 41 are reported. The F2 map constructed from 67 individuals consisted of 110 markers (52 RFLP and 56 RAPD) that grouped into 12 linkage groups. The linked markers spanned a total map distance of 758.3 cM. A recombinant inbred (RI) population derived from the 67 F2 individuals was used for the generation of an additional linkage map. The RI map, composed entirely of RAPD markers, consisted of 115 markers in 12 linkage groups. The linked markers spanned a total map distance of 691.7 cM. Using a framework set of RFLP markers, the F2 map was compared with another F2 mungbean map constructed in Minnesota. In general, the order of these markers was consistent between maps. Segregation distortion was observed for some markers. 14.5% (16/110) of mapped F2 markers and 24% (28/115) of mapped RI markers segregated with distorted ratios. Segregation distortion occurred in each successive generation after the F2 . The regions of distortion identified in the Australian maps did not coincide with regions of the Minnesota map.

scholarly journals Low recombination rates in sexual species and sex–asex transitions

2017 ◽  
Vol 372 (1736) ◽  
pp. 20160461 ◽  
Author(s):  
Christoph R. Haag ◽  
Loukas Theodosiou ◽  
Roula Zahab ◽  
Thomas Lenormand
Keyword(s):  
Model Systems ◽  
Rate Variation ◽  
Linkage Maps ◽  
Undescribed Species ◽  
Linkage Groups ◽  
Recombination Rates ◽  
Homologous Chromosomes ◽  
Genetic Linkage Maps ◽  
Chromosome Maps ◽  
Recombination Rate Variation

In most sexual, diploid eukaryotes, at least one crossover occurs between each pair of homologous chromosomes during meiosis, presumably in order to ensure proper segregation. Well-known exceptions to this rule are species in which one sex does not recombine and specific chromosomes lacking crossover. We review other possible exceptions, including species with chromosome maps of less than 50 cM in one or both sexes. We discuss the idea that low recombination rates may favour sex–asex transitions, or, alternatively may be a consequence of it. We then show that a yet undescribed species of brine shrimp Artemia from Kazakhstan ( A . sp. Kazakhstan), the closest known relative of the asexual Artemia parthenogenetica , has one of the shortest genetic linkage maps known. Based on a family of 42 individuals and 589 RAD markers, we find that many linkage groups are considerably shorter than 50 cM, suggesting either no obligate crossover or crossovers concentrated at terminal positions with little effect on recombination. We contrast these findings with the published map of the more distantly related sexual congener, A. franciscana , and conclude that the study of recombination in non-model systems is important to understand the evolutionary causes and consequences of recombination. This article is part of the themed issue ‘Evolutionary causes and consequences of recombination rate variation in sexual organisms’.

scholarly journals 558 Evaluation of Sequence-based PCR Markers in an F1 Pseudo-testcross and a BC1 Hybrid Citrus Population

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 542D-542
Author(s):  
Courtney A. Weber ◽  
Gloria A. Moore ◽  
Z. Deng ◽  
F. Gmitter ◽  
Courtney A. Weber
Keyword(s):  
Linkage Map ◽  
Poncirus Trifoliata ◽  
Linkage Maps ◽  
Linkage Groups ◽  
Pcr Markers ◽  
Specific Primers ◽  
Sts Markers ◽  
Research And Education

Specific primers were designed for 61 cloned RAPD fragments and from 10 Citrus EST sequences for the production of SCAR, CAPS, and STS markers for a Citrus grandis `DPI 6-4' × Poncirus trifoliata `Rubideaux' F1 pseudo-testcross population. Fifteen SCAR, three CAPS, and one EST/STS markers were developed. An additional 17 SCAR and CAPS primer pairs developed at the Citrus Research and Education Center for a Citrus grandis `Thong Dee' × (Citrus grandis `Thong Dee' × Poncirus trifoliata `Pomeroy') BC1 population were screened in the pseudo-testcross population. A total of 27 markers were identified and scored in the pseudo-testcross population in which 24 were mapped; 13 in the Citrus parental linkage map on seven linkage groups and 11 in the Poncirus parental map on five linkage groups. In the BC1 population, 20 of 27 markers tested were found to be polymorphic and 13 mapped to seven of nine linkage groups. Of these, 11 were mapped in both populations and could be used for aligning presumed homologous regions on the three linkage maps.

Integration of the Cytogenetic and Genetic Linkage Maps of Brassica oleracea

Genetics ◽  
2002 ◽  
Vol 161 (3) ◽  
pp. 1225-1234 ◽  
Author(s):  
Elaine C Howell ◽  
Guy C Barker ◽  
Gareth H Jones ◽  
Michael J Kearsey ◽  
Graham J King ◽  
...  
Keyword(s):  
Linkage Map ◽  
Brassica Oleracea ◽  
Genetic Map ◽  
Genetic Linkage ◽  
Linkage Maps ◽  
Linkage Groups ◽  
Opposite Orientation ◽  
Cytogenetic Map ◽  
Specific Pcr ◽  
Genetic Linkage Maps

Abstract We have assigned all nine linkage groups of a Brassica oleracea genetic map to each of the nine chromosomes of the karyotype derived from mitotic metaphase spreads of the B. oleracea var. alboglabra line A12DHd using FISH. The majority of probes were BACs, with A12DHd DNA inserts, which give clear, reliable FISH signals. We have added nine markers to the existing integrated linkage map, distributed over six linkage groups. BACs were definitively assigned to linkage map positions through development of locus-specific PCR assays. Integration of the cytogenetic and genetic linkage maps was achieved with 22 probes representing 19 loci. Four chromosomes (2, 4, 7, and 9) are in the same orientation as their respective linkage groups (O4, O7, O8, and O6) whereas four chromosomes (1, 3, 5, and 8) and linkage groups (O3, O9, O2, and O1) are in the opposite orientation. The remaining chromosome (6) is probably in the opposite orientation. The cytogenetic map is an important resource for locating probes with unknown genetic map positions and is also being used to analyze the relationships between genetic and cytogenetic maps.

Integration of molecular and classical linkage groups of the silkworm, Bombyx mori (n = 28)

Genome ◽  
2005 ◽  
Vol 48 (4) ◽  
pp. 626-629 ◽  
Author(s):  
Yuji Yasukochi ◽  
Yutaka Banno ◽  
Kohji Yamamoto ◽  
Marian R Goldsmith ◽  
Hiroshi Fujii
Keyword(s):  
Molecular Markers ◽  
Linkage Group ◽  
Linkage Analysis ◽  
Linkage Map ◽  
Bombyx Mori ◽  
Linkage Maps ◽  
Wild Type ◽  
Linkage Groups ◽  
Sequence Tagged Sites ◽  
Silkworm Bombyx Mori

Previously published linkage groups (LGs) composed of molecular markers were assigned to classical LGs in the silkworm, Bombyx mori (n = 28). Four markers from the classical linkage map, og, w-1, Lp, and Pfl, were assigned to the molecular linkage maps using sequence tagged sites. In addition, linkage analysis was carried out using BF1 progeny between wild-type and mutant stocks carrying morphological phenotypic markers. As a result, the counterparts for 26 of 28 molecular LGs were identified with their counterparts of the classical LGs. Two visible markers, Sel and Xan, representing different classical LGs, were found to be linked.Key words: Bombyx mori, classical linkage group (LG), PCR-based genotyping, mutant, STS.

scholarly journals A dense brown trout (Salmo trutta) linkage map reveals recent chromosomal rearrangements in the Salmo genus and the impact of selection on linked neutral diversity

2016 ◽  
Author(s):  
Maeva Leitwein ◽  
Bruno Guinand ◽  
Juliette Pouzadoux ◽  
Erick Desmarais ◽  
Patrick Berrebi ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Linkage Map ◽  
Brown Trout ◽  
Recombination Rate ◽  
Salmo Trutta ◽  
Chromosomal Rearrangements ◽  
High Density ◽  
Linkage Maps ◽  
Map Comparison ◽  
The Impact

ABSTRACTHigh-density linkage maps are valuable tools for conservation and eco-evolutionary issues. In salmonids, a complex rediploidization process consecutive to an ancient whole genome duplication event makes linkage maps of prime importance for investigating the evolutionary history of chromosome rearrangements. Here, we developed a high-density consensus linkage map for the brown trout (Salmo trutta), a socio-economically important species heavily impacted by human activities. A total of 3,977 ddRAD markers were mapped and ordered in 40 linkage groups using sex- and lineage-averaged recombination distances obtained from two family crosses. Performing map comparison between S. trutta and its sister species Salmo salar revealed extensive chromosomal rearrangements. Strikingly, all of the fusion and fission events that occurred after the S. salar/S. trutta speciation happened in the Atlantic salmon branch, whereas the brown trout remained closer to the ancestral chromosome structure. Using the strongly conserved synteny within chromosome arms, we aligned the brown trout linkage map to the Atlantic salmon genome sequence to estimate the local recombination rate in S. trutta at 3,721 loci. A significant positive correlation between recombination rate and within-population nucleotide diversity (π) was found, indicating that selection constrains variation at linked neutral sites in brown trout. This new high density linkage map provides a useful genomic resource for future aquaculture, conservation and eco-evolutionary studies in brown trout.

scholarly journals Genetic linkage maps of 'Pêra' sweet orange and 'Cravo' mandarin with RAPD markers

2004 ◽  
Vol 39 (2) ◽  
pp. 159-165 ◽  
Author(s):  
Roberto Pedroso de Oliveira ◽  
Mariângela Cristofani ◽  
Marcos Antônio Machado
Keyword(s):  
Linkage Map ◽  
Segregation Distortion ◽  
Rapd Markers ◽  
Sweet Orange ◽  
Citrus Canker ◽  
F1 Hybrids ◽  
Citrus Reticulata ◽  
Linkage Maps ◽  
Linkage Groups ◽  
Genetic Linkage Maps

The objective of this work was to construct linkage maps of 'Pêra' sweet orange [Citrus sinensis (L.) Osbeck] and 'Cravo' mandarin (Citrus reticulata Blanco) using RAPD markers and the pseudo-testcross strategy. The parents were chosen according to the resistance/susceptibility to citrus variegate chlorosis (CVC). The segregation of 176 markers was analyzed in 94 progeny of F1 hybrids, which were obtained from controlled crossings. The linkage map of 'Pêra' sweet orange had 117 markers defined by 12 linkage groups, which spanned 612.1 cM. Only six markers could not be linked to the linkage group and 48.7% of the markers showed segregation distortion. The linkage map of 'Cravo' mandarin had 51 markers defined by 12 linkage groups, which spanned 353.3 cM. Only two markers did not link to the groups and 15.7% showed segregation distortion. The construction of linkage maps is relevant to future mapping studies of the inheritance of CVC, citrus canker and leprosis.

scholarly journals Using probabilistic genotypes in linkage analysis of polyploids

2021 ◽  
Author(s):  
Yanlin Liao ◽  
Roeland E. Voorrips ◽  
Peter M. Bourke ◽  
Giorgio Tumino ◽  
Paul Arens ◽  
...  
Keyword(s):  
Linkage Map ◽  
Linkage Mapping ◽  
Mapping Population ◽  
Snp Array ◽  
Linkage Maps ◽  
Sequencing Data ◽  
Genotype Calling ◽  
Map Construction ◽  
Allele Dosage ◽  
Discrete Values

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.

scholarly journals Construction of a microsatellite-based genetic linkage map for half-smooth tongue sole Cynoglossus semilaevis

2013 ◽  
Vol 59 (1) ◽  
pp. 99-108 ◽  
Author(s):  
Wentao Song ◽  
Guidong Miao ◽  
Yongwei Zhao ◽  
Yuze Niu ◽  
Renyi Pang ◽  
...  
Keyword(s):  
Linkage Map ◽  
Genetic Linkage ◽  
Genetic Linkage Map ◽  
Cynoglossus Semilaevis ◽  
Scar Markers ◽  
Linkage Maps ◽  
Linkage Groups ◽  
Tongue Sole ◽  
Genetic Linkage Maps ◽  
Half Smooth Tongue Sole

Abstract The half-smooth tongue sole Cynoglossus semilaevis is an important cultured marine fish and a promising model fish for the study of sex determination. Sex-specific genetic linkage maps of half-smooth tongue sole were developed with 567 markers (565 microsatellite markers and two SCAR markers). The parents and F1 progeny (92 individuals) were used as segregating populations. The female map was composed of 480 markers in 21 linkage groups, covering a total of 1388.1 cM, with an average interval 3.06 cM between markers. The male map consisted of 417 markers in 21 linkage groups, spanning 1480.9 cM, with an average interval of 3.75 cM. The female and male maps had 474 and 416 unique positions, respectively. The genome length of half-smooth tongue sole was estimated to be 1522.9 cM for females and 1649.1cM for males. Based on estimations of map length, the female and male maps covered 91.1% and 89.8% of the genome, respectively. Furthermore, two female-specific SCAR markers, f-382 and f-783, were mapped on LG15f (linkage group 15 in female maps). The present study presents a mid-density genetic linkage map for half-smooth tongue sole. These improved genetic linkage maps may facilitate systematic genome searches to identify quantitative trait loci (QTL), such as disease resistance, growth and sex-related traits, and are very useful for marker-assisted selection breeding programs for economically important traits in half-smooth tongue sole.

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