scholarly journals A Dense Genetic Map of the Silkworm, Bombyx mori, Covering All Chromosomes Based on 1018 Molecular Markers

Genetics ◽  
1998 ◽  
Vol 150 (4) ◽  
pp. 1513-1525 ◽  
Author(s):  
Yuji Yasukochi
Keyword(s):  
Drosophila Melanogaster ◽  
Molecular Markers ◽  
Linkage Map ◽  
Bombyx Mori ◽  
Genetic Markers ◽  
Genetic Map ◽  
Z Chromosome ◽  
Linkage Groups ◽  
Average Interval ◽  
Silkworm Bombyx Mori

Abstract A dense linkage map was constructed for the silkworm, Bombyx mori, containing 1018 genetic markers on all 27 autosomes and the Z chromosome. Most of the markers, covering ∼2000 cM, were randomly amplified polymorphic DNAs amplified with primer-pairs in combinations of 140 commercially available decanucleotides. In addition, eight known genes and five visible mutations were mapped. Bombyx homologues of engrailed and invected genes were found to be closely linked, as in Drosophila melanogaster. The average interval between markers was ∼2 cM, equal to ∼500 kb. The correspondence of seven linkage groups to counterparts of the conventional linkage map was determined. This map is the first linkage map in insects having a large number of chromosomes (n = 28) that covers all chromosomes without any gaps.

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.

Construction of a reference linkage map for melon

Genome ◽  
2001 ◽  
Vol 44 (5) ◽  
pp. 836-845 ◽  
Author(s):  
M Oliver ◽  
J Garcia-Mas ◽  
M Cardús ◽  
N Pueyo ◽  
A I López-Sesé ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Genetic Distance ◽  
Linkage Map ◽  
Genetic Map ◽  
Cucumis Melo ◽  
Morphological Trait ◽  
Linkage Groups ◽  
Resistant Gene ◽  
Anchor Points ◽  
Cucumis Melo L

A map of melon (Cucumis melo L.) with 411 markers (234 RFLPs, 94 AFLPs, 47 RAPDs, 29 SSRs, five inter-SSRs, and two isozymes) and one morphological trait (carpel number) was constructed using the F2 progeny of a cross between the Korean accession PI161375 and the Spanish melon type 'Pinyonet Piel de Sapo'. RFLPs were obtained using 212 probes from different genomic and cDNA melon libraries, including 16 Arabidopsis ESTs, 13 Cucumis known genes, and three resistant gene homologues. Most loci (391) mapped to 12 major linkage groups, spanning a total genetic distance of 1197 cM, with an average map interval of 3 cM/marker. The remaining 21 loci (six RAPDs and 15 AFLPs) were not linked. A majority (66%) of the markers were codominant (RFLPs, SSRs, and isozymes), making them easily transferable to other melon crosses. Such markers can be used as a reference, to merge other melon and cucumber maps already constructed. Indeed, some of them (23 SSRs, 14 RFLPs, one isozyme, and one morphological trait) could act as anchor points with other published cucurbit maps.Key words: Cucumis melo, genetic map, molecular markers, RFLPs, SSRs.

scholarly journals Linkage map of random amplified polymorphic DNAs (RAPDs) in the silkworm, Bombyx mori

1995 ◽  
Vol 66 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Amornrat Promboon ◽  
Toru Shimada ◽  
Haruhiko Fujiwara ◽  
Masahiko Kobayashi
Keyword(s):  
Linkage Map ◽  
Bombyx Mori ◽  
Mapping Function ◽  
Mendelian Inheritance ◽  
Linkage Groups ◽  
Lod Score ◽  
Chi Square ◽  
Segregation Ratios ◽  
Chi Square Test ◽  
Silkworm Bombyx Mori

SummaryWe have constructed a linkage map of random amplified polymorphic DNAs (RAPDs) in Bombyx mori. We screened 320 10-mer primers, and found 243 clear polymorphic bands between C108 and p50 strains. In the F2 generation, segregation ratios of 168 bands were nearly 3:1 in a chi square test, showing Mendelian inheritance. The MAPMAKER program sorted 168 bands into 29 linkage groups and 10 unlinked loci at minimum LOD score 3·0, and determined orders of loci in each group, which contained 2–11 markers. It also detected typing errors in our data. We calculated map distances between pairs of neighbouring loci using recombination values in males and the Kosambi mapping function. Our RAPD map consists of 169 loci including the p locus, and the sum of map distances is approximately 900 cM. Linkage groups 1 and 2 of our map correspond to chromosomes 1 and 2 on the conventional linkage map because of linkage to sex and p, respectively.

scholarly journals A genetic linkage map for cattle.

Genetics ◽  
1994 ◽  
Vol 136 (2) ◽  
pp. 619-639 ◽  
Author(s):  
M D Bishop ◽  
S M Kappes ◽  
J W Keele ◽  
R T Stone ◽  
S L Sunden ◽  
...  
Keyword(s):  
Linkage Map ◽  
Genetic Markers ◽  
Genetic Map ◽  
Genetic Linkage ◽  
Genetic Linkage Map ◽  
Bovine Genome ◽  
Type I ◽  
Linkage Groups ◽  
Y Chromosomes ◽  
Economic Trait

Abstract We report the most extensive physically anchored linkage map for cattle produced to date. Three-hundred thirteen genetic markers ordered in 30 linkage groups, anchored to 24 autosomal chromosomes (n = 29), the X and Y chromosomes, four unanchored syntenic groups and two unassigned linkage groups spanning 2464 cM of the bovine genome are summarized. The map also assigns 19 type I loci to specific chromosomes and/or syntenic groups and four cosmid clones containing informative microsatellites to chromosomes 13, 25 and 29 anchoring syntenic groups U11, U7 and U8, respectively. This map provides the skeletal framework prerequisite to development of a comprehensive genetic map for cattle and analysis of economic trait loci (ETL).

scholarly journals Inheritance and linkage analysis of co-dominant SSR markers on the Z chromosome of the silkworm (Bombyx mori L.)

2008 ◽  
Vol 90 (2) ◽  
pp. 151-156 ◽  
Author(s):  
XUE-XIA MIAO ◽  
WEI-HUA LI ◽  
MU-WANG LI ◽  
YUN-PO ZHAO ◽  
XIAN-RU GUO ◽  
...  
Keyword(s):  
Linkage Map ◽  
Bombyx Mori ◽  
Ssr Markers ◽  
Positional Cloning ◽  
Z Chromosome ◽  
Pcr Marker ◽  
Backcross Population ◽  
In The Beginning ◽  
Simple Sequence ◽  
Visible Mutation

SummaryMicrosatellites or simple sequence repeats (SSRs) are co-dominant molecular markers. When we used fluorescent SSR markers to construct a linkage map for the female heterogametic silkworm (Bombyx mori, ZW), we found that some loci did not segregate in a Mendelian ratio of 1:1 in a backcross population. These loci segregated in a 3:1 ratio of single bands compared with double bands. Further examination of band patterns indicated that three types of SSR bands were present: two homozygotes and one heterozygote. In the beginning, we considered to discard these markers. By scoring male and female F1 individuals, we confirmed that these loci were located on the Z chromosome. Using the sex-linked visible mutation sch (K05) and its wild-type (C108), we constructed an F1 male backcross (BC1M) mapping population. The combination of sch backcross and SSR data enabled us to map the SSR markers to the Z chromosome. By adjusting input parameters based on these data, we were able to use Mapmaker software to construct a linkage map. This strategy takes advantage of co-dominant markers for positional cloning of genes on the Z chromosome. We localized sch to the Z chromosome relative to six SSR markers and one PCR marker, covering a total of 76·1 cM. The sch mutation is an important sex-linked visible mutation widely used in breeding of commercial silkworms (e.g. male silkworm selection rearing). Localization of the sch gene may prove helpful in cloning the gene and developing strains for marker-assisted selection in silkworm breeding.

scholarly journals An enhanced molecular marker based genetic map of perennial ryegrass (Lolium perenne) reveals comparative relationships with other Poaceae genomes

Genome ◽  
2002 ◽  
Vol 45 (2) ◽  
pp. 282-295 ◽  
Author(s):  
Elizabeth S Jones ◽  
Natalia L Mahoney ◽  
Michael D Hayward ◽  
Ian P Armstead ◽  
J Gilbert Jones ◽  
...  
Keyword(s):  
Molecular Marker ◽  
Linkage Map ◽  
Genetic Map ◽  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Genetic Linkage Map ◽  
Population Based ◽  
Genetic Maps ◽  
Linkage Groups ◽  
Integrated Genetic Map

A molecular-marker linkage map has been constructed for perennial ryegrass (Lolium perenne L.) using a one-way pseudo-testcross population based on the mating of a multiple heterozygous individual with a doubled haploid genotype. RFLP, AFLP, isoenzyme, and EST data from four collaborating laboratories within the International Lolium Genome Initiative were combined to produce an integrated genetic map containing 240 loci covering 811 cM on seven linkage groups. The map contained 124 codominant markers, of which 109 were heterologous anchor RFLP probes from wheat, barley, oat, and rice, allowing comparative relationships between perennial ryegrass and other Poaceae species to be inferred. The genetic maps of perennial ryegrass and the Triticeae cereals are highly conserved in terms of synteny and colinearity. This observation was supported by the general agreement of the syntenic relationships between perennial ryegrass, oat, and rice and those between the Triticeae and these species. A lower level of synteny and colinearity was observed between perennial ryegrass and oat compared with the Triticeae, despite the closer taxonomic affinity between these species. It is proposed that the linkage groups of perennial ryegrass be numbered in accordance with these syntenic relationships, to correspond to the homoeologous groups of the Triticeae cereals.Key words: Lolium perenne, genetic linkage map, RFLP, AFLP, conserved synteny.

scholarly journals A genetic linkage map for the domesticated silkworm, Bombyx mori, based on restriction fragment length polymorphisms

1995 ◽  
Vol 66 (2) ◽  
pp. 109-126 ◽  
Author(s):  
Jinrui Shi ◽  
David G. Heckel ◽  
Marian R. Goldsmith
Keyword(s):  
Linkage Map ◽  
Bombyx Mori ◽  
Restriction Fragment ◽  
Fragment Length ◽  
Restriction Fragment Length Polymorphisms ◽  
Genetic Maps ◽  
Crossing Over ◽  
Linkage Groups ◽  
Length Polymorphisms ◽  
Restriction Fragment Length

SummaryWe present data for the initial construction of a molecular linkage map for the domesticated silkworm, Bombyx mori, based on 52 progeny from an F2 cross from a pair mating of inbred strains p50 and C108, using restriction fragment length polymorphisms (RFLPs). The map contains 15 characterized single copy sequences, 36 anonymous sequences derived from a follicular cDNA library, and 10 loci corresponding to a low copy number retrotransposon, mag. The 15 linkage groups and 8 ungrouped loci account for 23 of the 28 chromosomes and span a total recombination length of 413 cM; 10 linkage groups were correlated with established classic genetic maps. Scoring data from Southern blots were analysed using two Pascal programs written specifically to analyse linkage data in Lepidoptera, where females are the heterogametic sex and have achiasmatic meiosis (no crossing-over). These first examine evidence for linkage by calculating the maximum lod score under the hypothesis that the two loci are linked over the likelihood under the hypothesis that the two loci assort independently, and then determine multilocus linkage maps for groups of putatively syntenic loci by calculating the maximum likelihood estimate of the recombination fractions and the log likelihood using the EM algorithm for a specified order of loci along the chromosome. In addition, the possibility of spurious linkage was exhaustively tested by searching for genotypes forbidden by the absence of crossing-over in one sex.

scholarly journals Centromere-Linkage Analysis and Consolidation of the Zebrafish Genetic Map

Genetics ◽  
1996 ◽  
Vol 142 (4) ◽  
pp. 1277-1288
Author(s):  
Stephen L Johnson ◽  
Michael A Gates ◽  
Michele Johnson ◽  
William S Talbot ◽  
Sally Horne ◽  
...  
Keyword(s):  
Linkage Group ◽  
Linkage Analysis ◽  
Genetic Analysis ◽  
Linkage Map ◽  
Rapid Method ◽  
Genetic Map ◽  
Dna Polymorphisms ◽  
Linkage Groups

Abstract The ease of isolating mutations in zebrafish will contribute to an understanding of a variety of processes common to all vertebrates. To facilitate genetic analysis of such mutations, we have identified DNA polymorphisms closely linked to each of the 25 centromeres of zebrafish, placed centromeres on the linkage map, increased the number of mapped PCR-based markers to 652, and consolidated the number of linkage groups to the number of chromosomes. This work makes possible centromere-linkage analysis, a novel, rapid method to assign mutations to a specific linkage group using half-tetrads.

A peach linkage map integrating RFLPs, SSRs, RAPDs, and morphological markers

Genome ◽  
2001 ◽  
Vol 44 (5) ◽  
pp. 783-790 ◽  
Author(s):  
Maria Teresa Dettori ◽  
Roberta Quarta ◽  
Ignazio Verde
Keyword(s):  
Molecular Markers ◽  
Comparative Analysis ◽  
Linkage Map ◽  
Morphological Traits ◽  
Prunus Persica ◽  
Average Distance ◽  
Morphological Markers ◽  
Linkage Groups ◽  
Peach Genome ◽  
The Common

A linkage map was obtained using a BC1 progeny (Prunus persica × (P. persica × P. ferganensis)). The map is composed of 109 loci (74 RFLPs, 17 SSRs, 16 RAPDs, and two morphological traits) distributed in 10 linkage groups. Loci, segregating in five different ratios, were integrated in the map with JoinMap 2.0 software. The map covers 521 cM of the peach genome. The average distance between adjacent loci is 4.8 cM. Two monogenic traits, flesh adhesion (F/f) and leaf glands (E/e), were placed on the map. Thirty-two loci in common with a saturated linkage map of Prunus allowed a comparative analysis to be made between the two maps. Homologies were found among the respective linkage groups. No relevant differences were observed in the linear order of the common loci.Key words: peach, linkage map, Prunus persica, Prunus ferganensis, molecular markers.

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.

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