Construction and analysis of an AFLP molecular linkage map of the silkworm (Bombyx mori)

2006 ◽  
Vol 3 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Sima Yang-Hu ◽  
Li Bin ◽  
Chen Da-Xia ◽  
Sun De-Bin ◽  
Zhao Ai-Chun ◽  
...  
Keyword(s):  
Linkage Group ◽  
Linkage Map ◽  
Bombyx Mori ◽  
Average Length ◽  
Average Distance ◽  
Linkage Groups ◽  
Molecular Linkage Map ◽  
Average Variation ◽  
The Mean ◽  
Marker Distance

AbstractAn amplification fragment length polymorphism (AFLP) molecular linkage map with a relatively high density for location of quantitative trait loci (QTLs) controlling the quantitative traits of silkworm (Bombyx mori) cocoons, was constructed using 91 individuals of the F2 generation. Among the 692 effective loci, 550 were allocated to subgroups a and b, of which 21 linkage groups in subgroup a had 233 molecular markers and 28 linkage groups in subgroup b had 317 markers. The number of markers on each linkage group in subgroups a and b ranged from 4 to 43 and 3 to 35, respectively. The total length of linkage groups for subgroup a was 1868.10 cM, and 2677.50 cM for subgroup b. The length of linkage group varied from 22.3 to 424.3 cM in subgroup a and from 2.4 to 366.5 cM in subgroup b. The average variation in the distance between markers was 3.39–17.43 cM in subgroup a and 0.8–26.96 cM in subgroup b. The average distance between the markers was 8.81 cM in subgroup a and 9.26 cM in subgroup b. There were 14 linkage groups, with an average distance below 10 cM, in subgroup a and 18 linkage groups in subgroup b. There were seven linkage groups with an average distance between 10 and 20 cM in subgroup a and ten linkage groups in subgroup b. Each linkage group in subgroup a had 11.1 loci on average, while there were 11.31 loci on each linkage group on average in subgroup b. The mean length for linkage groups in subgroups a and b was 89 and 95.6 cM, respectively. The total average length for both a and b subgroups was 2272.8, and 9.06 cM for the average marker distance, fulfilling the basic known requirements for locating QTLs.

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.

A molecular linkage map of olive (Olea europaea L.) based on RAPD, microsatellite, and SCAR markers

Genome ◽  
2004 ◽  
Vol 47 (1) ◽  
pp. 26-35 ◽  
Author(s):  
Shu-Biao Wu ◽  
Graham Collins ◽  
Margaret Sedgley
Keyword(s):  
Disease Resistance ◽  
Linkage Map ◽  
Olea Europaea ◽  
Mapping Population ◽  
Average Distance ◽  
Linkage Groups ◽  
Integrated Map ◽  
Sequence Characterized Amplified Region ◽  
Olea Europaea L ◽  
Molecular Linkage Map

An integrated molecular linkage map of olive (Olea europaea L.) was constructed based on randomly amplified polymorphic DNA (RAPD), sequence characterized amplified region (SCAR), and microsatellite markers using the pseudo-testcross strategy. A mapping population of 104 individuals was generated from an F1 full-sib family of a cross between 'Frantoio' and 'Kalamata'. The hybridity of the mapping population was confirmed by genetic similarity and nonmetric multidimensional scaling. Twenty-three linkage groups were mapped for 'Kalamata', covering 759 cM of the genome with 89 loci and an average distance between loci of 11.5 cM. Twenty-seven linkage groups were mapped for 'Frantoio', covering 798 cM of the genome with 92 loci and an average distance between loci of 12.3 cM. For the integrated map, 15 linkage groups covered 879 cM of the genome with 101 loci and an average distance between loci of 10.2 cM. The size of the genomic DNA was estimated to be around 3000 cM. A sequence characterized amplified region marker linked to olive peacock disease resistance was mapped to linkage group 2 of the integrated map. These maps will be the starting point for studies on the structure, evolution, and function of the olive genome. When the mapping progeny pass through their juvenile phase and assume their adult characters, mapping morphological markers and identification of quantitative trait loci for adaptive traits will be the primary targets.Key words: genome mapping, RAPD, SSR, SCAR, Olea europea, peacock disease resistance.

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 genetic linkage map for Stevia rebaudiana

Genome ◽  
1999 ◽  
Vol 42 (4) ◽  
pp. 657-661 ◽  
Author(s):  
Y Yao ◽  
M Ban ◽  
J Brandle
Keyword(s):  
Linkage Map ◽  
Genetic Linkage ◽  
Rapd Markers ◽  
Genetic Linkage Map ◽  
Average Distance ◽  
Stevia Rebaudiana ◽  
Linkage Groups ◽  
Genome Map ◽  
High Level ◽  
Map Distance

To lay a foundation for molecular breeding efforts, the first genetic linkage map for Stevia rebaudiana has been constructed using segregation data from a pseudo test-cross F1 population. A total of 183 randomly amplified polymorphic DNA (RAPD) markers were analysed and assembled into 21 linkage groups covering a total distance of 1389 cM, with an average distance between markers of of 7.6 cM. The 11 largest linkage groups consisted of 4-19 loci, ranged in length from 56 to 174 cM, and accounted for 75% of the total map distance. Fifteen RAPD loci were found to be unlinked. From the 521 primers showing amplification products, 185 (35.5%) produced a total of 293 polymorphic fragments, indicating a high level of genetic diversity in stevia. Most of the RAPD markers in stevia segregated in normal Mendelian fashion.Key words: stevia, open-pollinated, genome map, RAPD.

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.

Surgical Anatomy of Nasolacrimal Duct and Sac in Human Cadavers

2014 ◽  
Vol 7 (3) ◽  
pp. 91-95 ◽  
Author(s):  
Tulika Gupta ◽  
Suhalika S Sahni ◽  
Ruchi Goyal
Keyword(s):  
Average Length ◽  
Average Distance ◽  
Vertical Plane ◽  
Inferior Turbinate ◽  
Average Diameter ◽  
Nasolacrimal Duct ◽  
Surgical Anatomy ◽  
Lacrimal Sac ◽  
Human Cadavers ◽  
The Mean

ABSTRACT Background Surgical importance of the nasolacrimal duct (NLD) for both otolaryngologists and ophthalmologists cannot be overemphasized. Injury to this structure can lead to iatrogenic epiphora, synechiae formation and need for secondary lacrimal diversion procedures. Materials and methods The present study was conducted on 27 mid-sagittal sections of head and neck of formalin fixed adult cadavers. The inferior opening of the NLD was identified and exposed. The duct and the lacrimal sac were dissected. Pertinent distances of the inferior opening of the NLD from the easily identifiable surgical landmarks were recorded, so as to accurately locate the inferior opening of the duct using a digital vernier calliper (accuracy 0.02 mm, Mitutoya, Japan). Various dimensions and angulation of the duct and lacrimal sac were measured. Results The average length of NLD was 11.42 ± 2.45 mm and it was making an angle of 20° with the vertical plane. The duct was narrowest in caliber in its upper 1/3rd in majority (82%) of the cases. The average diameter of the inferior opening of the NLD was 3.14 mm. In two cases (7.4%), the opening was only 1.8 mm wide. The mean distance of the inferior opening of the duct was 20.7 mm from the columella, 25.5 mm below the skull base and 16.5 mm above the hard palate. The average distance between the inferior opening of the NLD and anterior end of the inferior turbinate was 14.8 mm. The mean A-P diameter of superior opening of NLD was about 3 mm. The average length and width of nasolacrimal sac at its center was 6.95 and 3.24 mm respectively. Conclusion Detailed anatomical knowledge of the NLD is of great importance for safe and successful endonasal surgery. The present study attempts to provide useful surgical guidelines by using anatomic and positional relationships between the NLD and the major surrounding landmarks. How to cite this article Sahni SS, Goyal R, Gupta T, Gupta AK. Surgical Anatomy of Nasolacrimal Duct and Sac in Human Cadavers. Clin Rhinol An Int J 2014;7(3):91-95.

Linkage of random amplified polymorphic DNA, isozyme and morphological markers in grasspea (Lathyrus sativus)

1999 ◽  
Vol 133 (4) ◽  
pp. 389-395 ◽  
Author(s):  
M. A. CHOWDHURY ◽  
A. E. SLINKARD
Keyword(s):  
Linkage Map ◽  
Genetic Linkage ◽  
Rapd Markers ◽  
Genetic Linkage Map ◽  
Average Distance ◽  
Random Amplified Polymorphic Dna ◽  
Lathyrus Sativus ◽  
Morphological Markers ◽  
Linkage Studies ◽  
Linkage Groups

We constructed a genetic linkage map of grasspea (Lathyrus sativus L.; 2n = 14) from 100 F2 individuals derived from a cross between PI 426891.1.3 and PI 283564c.3.2. A total of 71 RAPD, three isozyme and one morphological markers segregated in the F2 progeny. A small fraction of markers (12%) deviated significantly from the expected Mendelian ratio (1[ratio ]2[ratio ]1 or 3[ratio ]1). Out of 75 markers, 69 (one morphological, three isozyme and 65 RAPD markers) were assigned to 14 linkage groups comprising 898 cM. The average distance between two adjacent markers was 17·2 cM. The present linkage map will serve as a reference point for further linkage studies in grasspea.

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.

A core linkage map of the bumblebee Bombus terrestris

Genome ◽  
2006 ◽  
Vol 49 (10) ◽  
pp. 1215-1226 ◽  
Author(s):  
Lena Wilfert ◽  
Jürgen Gadau ◽  
Paul Schmid-Hempel
Keyword(s):  
Linkage Map ◽  
Fragment Length Polymorphism ◽  
Bombus Terrestris ◽  
Linkage Groups ◽  
Haploid Chromosome Number ◽  
Genetic Linkage Maps ◽  
Marker Distance ◽  
Core Linkage Map ◽  
Mapping Populations ◽  
Reference Tool

The bumblebee Bombus terrestris is an economically important pollinator and an emerging model species in quantitative and population genetics. We generated genetic linkage maps for 3 independent mapping populations of B. terrestris. The linkage map with the highest resolution had 21 linkage groups, which adequately represents the haploid chromosome number of B. terrestris (n = 18). This map can be considered saturated, with an average marker distance of 10.3 cM and an estimated genome coverage of 81%. Using flow cytometry, we have estimated the genome size of this species to be 625 Mb. With an estimated total recombination genome length of 2760 cM, this results in a ratio of 226 kb/cM between the physical and genetic genome sizes. A recurring set of microsatellites and amplified fragment length polymorphism (AFLP) markers allowed the alignment of 14 linkage groups between the 3 maps. We propose to adopt this core map as a reference tool for future genetic and molecular work in B. terrestris.

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