scholarly journals Advances in BAC-Based Physical Mapping and Map Integration Strategies in Plants

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Ruvini Ariyadasa ◽  
Nils Stein

In the advent of next-generation sequencing (NGS) platforms, map-based sequencing strategy has been recently suppressed being too expensive and laborious. The detailed studies on NGS drafts alone indicated these assemblies remain far from gold standard reference quality, especially when applied on complex genomes. In this context the conventional BAC-based physical mapping has been identified as an important intermediate layer in current hybrid sequencing strategy. BAC-based physical map construction and its integration with high-density genetic maps have benefited from NGS and high-throughput array platforms. This paper addresses the current advancements of BAC-based physical mapping and high-throughput map integration strategies to obtain densely anchored well-ordered physical maps. The resulted maps are of immediate utility while providing a template to harness the maximum benefits of the current NGS platforms.

Genetics ◽  
1988 ◽  
Vol 119 (2) ◽  
pp. 227-236
Author(s):  
C L Smith ◽  
R D Kolodner

Abstract A low resolution Not I physical map of Escherichia coli was recently constructed. In this report we demonstrated that this map can be used to map Tn5 and F insertions physically. The transposon, Tn5, contains Not I recognition sequences in its IS50 sequences. F plasmid contains an unmapped Not I site. Hence, the location of Tn5 and F in the chromosome can be mapped by identifying the location of the introduced Not I sites using pulsed field gel electrophoresis. The physical mapping of genetically mapped Tn5 insertions confirm the previously constructed Not I map and helps align the E. coli physical and genetic maps. The use of Tn5 can assist the construction of both physical and genetic maps for microorganisms lacking such maps. Variations on this approach will facilitate physical mapping with a wide variety of organisms, enzymes, and genetic elements.


1999 ◽  
Vol 181 (17) ◽  
pp. 5160-5166 ◽  
Author(s):  
Brad W. Goodner ◽  
Brian P. Markelz ◽  
M. Casey Flanagan ◽  
Chris B. Crowell ◽  
Jodi L. Racette ◽  
...  

ABSTRACT A combined genetic and physical map of the Agrobacterium tumefaciens A348 (derivative of C58) genome was constructed to address the discrepancy between initial single-chromosome genetic maps and more recent physical mapping data supporting the presence of two nonhomologous chromosomes. The combined map confirms the two-chromosome genomic structure and the correspondence of the initial genetic maps to the circular chromosome. The linear chromosome is almost devoid of auxotrophic markers, which probably explains why it was missed by genetic mapping studies.


Genetics ◽  
1996 ◽  
Vol 142 (2) ◽  
pp. 537-548 ◽  
Author(s):  
Michael W Nachman ◽  
Gary A Churchill

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.


1994 ◽  
Vol 58 (2) ◽  
pp. 81-85 ◽  
Author(s):  
D. HUNT ◽  
V. VAN HEYNINGEN ◽  
C. JONES ◽  
C. McCONVILLE ◽  
F. J. BENHAM

Author(s):  
Romesh Kumar Salgotra ◽  
Rafiq Ahmad Bhat ◽  
Deyue Yu ◽  
Javaid Akhter Bhat

Abstract: Over the past two decades, the advances in the next generation sequencing (NGS) platforms have led to the identification of numerous genes/QTLs at high-resolution for their potential use in crop improvement. The genomic resources generated through these high-throughput sequencing techniques have been efficiently used in screening of particular gene of interest particularly for numerous types of plant stresses and quality traits. Subsequently, the identified-markers linked to a particular trait have been used in marker-assisted backcross breeding (MABB) activities. Besides, these markers are also being used to catalogue the food crops for detection of adulteration to improve the quality of food. With the advancement of technologies, the genomic resources are originating with new markers; however, to use these markers efficiently in crop breeding, high-throughput techniques (HTT) such as multiplex PCR and capillary electrophoresis (CE) can be exploited. Robustness, ease of operation, good reproducibility and low cost are the main advantages of multiplex PCR and CE. The CE is capable of separating and characterizing proteins with simplicity, speed and small sample requirements. Keeping in view the availability of vast data generated through NGS techniques and development of numerous markers, there is a need to use these resources efficiently in crop improvement programmes. In summary, this review describes the use of molecular markers in the screening of resistance genes in breeding programmes and detection of adulterations in food crops using high-throughput techniques.


2018 ◽  
Vol 24 (9_suppl) ◽  
pp. 94S-103S ◽  
Author(s):  
Qi Wang ◽  
Lijuan Cao ◽  
Guangying Sheng ◽  
Hongjie Shen ◽  
Jing Ling ◽  
...  

Inherited thrombocytopenia is a group of hereditary diseases with a reduction in platelet count as the main clinical manifestation. Clinically, there is an urgent need for a convenient and rapid diagnosis method. We introduced a high-throughput, next-generation sequencing (NGS) platform into the routine diagnosis of patients with unexplained thrombocytopenia and analyzed the gene sequencing results to evaluate the value of NGS technology in the screening and diagnosis of inherited thrombocytopenia. From a cohort of 112 patients with thrombocytopenia, we screened 43 patients with hereditary features. For the blood samples of these 43 patients, a gene sequencing platform for hemorrhagic and thrombotic diseases comprising 89 genes was used to perform gene detection using NGS technology. When we combined the screening results with clinical features and other findings, 15 (34.9%) of 43patients were diagnosed with inherited thrombocytopenia. In addition, 19 pathogenic variants, including 8 previously unreported variants, were identified in these patients. Through the use of this detection platform, we expect to establish a more effective diagnostic approach to such disorders.


Genome ◽  
2004 ◽  
Vol 47 (1) ◽  
pp. 179-189 ◽  
Author(s):  
J L Stephens ◽  
S E Brown ◽  
N L.V Lapitan ◽  
D L Knudson

The primary objective of this study was to elucidate gene organization and to integrate the genetic linkage map for barley (Hordeum vulgare L.) with a physical map using ultrasensitive fluorescence in situ hybridization (FISH) techniques for detecting signals from restriction fragment length polymorphism (RFLP) clones. In the process, a single landmark plasmid, p18S5Shor, was constructed that identified and oriented all seven of the chromosome pairs. Plasmid p18S5Shor was used in all hybridizations. Fourteen cDNA probes selected from the linkage map for barley H. vulgare 'Steptoe' × H. vulgare 'Morex' (Kleinhofs et al. 1993) were mapped using an indirect tyramide signal amplification technique and assigned to a physical location on one or more chromosomes. The haploid barley genome is large and a complete physical map of the genome is not yet available; however, it was possible to integrate the linkage map and the physical locations of these cDNAs. An estimate of the ratio of base pairs to centimorgans was an average of 1.5 Mb/cM in the distal portions of the chromosome arms and 89 Mb/cM near the centromere. Furthermore, while it appears that the current linkage maps are well covered with markers along the length of each arm, the physical map showed that there are large areas of the genome that have yet to be mapped.Key words: Hordeum vulgare, barley, physical mapping, FISH, cDNA, genetics, linkage, chromosome, BACs.


Genes ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 374 ◽  
Author(s):  
Anna Dziewulska ◽  
Aneta Dobosz ◽  
Agnieszka Dobrzyn

Type 2 diabetes (T2D) is a complex disorder that is caused by a combination of genetic, epigenetic, and environmental factors. High-throughput approaches have opened a new avenue toward a better understanding of the molecular bases of T2D. A genome-wide association studies (GWASs) identified a group of the most common susceptibility genes for T2D (i.e., TCF7L2, PPARG, KCNJ1, HNF1A, PTPN1, and CDKAL1) and illuminated novel disease-causing pathways. Next-generation sequencing (NGS)-based techniques have shed light on rare-coding genetic variants that account for an appreciable fraction of T2D heritability (KCNQ1 and ADRA2A) and population risk of T2D (SLC16A11, TPCN2, PAM, and CCND2). Moreover, single-cell sequencing of human pancreatic islets identified gene signatures that are exclusive to α-cells (GCG, IRX2, and IGFBP2) and β-cells (INS, ADCYAP1, INS-IGF2, and MAFA). Ongoing epigenome-wide association studies (EWASs) have progressively defined links between epigenetic markers and the transcriptional activity of T2D target genes. Differentially methylated regions were found in TCF7L2, THADA, KCNQ1, TXNIP, SOCS3, SREBF1, and KLF14 loci that are related to T2D. Additionally, chromatin state maps in pancreatic islets were provided and several non-coding RNAs (ncRNA) that are key to T2D pathogenesis were identified (i.e., miR-375). The present review summarizes major progress that has been made in mapping the (epi)genomic landscape of T2D within the last few years.


2019 ◽  
Vol 70 (15) ◽  
pp. 3825-3833 ◽  
Author(s):  
Shengjun Li ◽  
Shangang Jia ◽  
Lili Hou ◽  
Hanh Nguyen ◽  
Shirley Sato ◽  
...  

Abstract Transgenic technology was developed to introduce transgenes into various organisms to validate gene function and add genetic variations >40 years ago. However, the identification of the transgene insertion position is still challenging in organisms with complex genomes. Here, we report a nanopore-based method to map the insertion position of a Ds transposable element originating in maize in the soybean genome. In this method, an oligo probe is used to capture the DNA fragments containing the Ds element from pooled DNA samples of transgenic soybean plants. The Ds element-enriched DNAs are then sequenced using the MinION-based platform of Nanopore. This method allowed us to rapidly map the Ds insertion positions in 51 transgenic soybean lines through a single sequencing run. This strategy is high throughput, convenient, reliable, and cost-efficient. The transgenic allele mapping protocol can be easily translated to other eukaryotes with complex genomes.


1993 ◽  
Vol 23 (2) ◽  
pp. 234-238 ◽  
Author(s):  
B. Karpinska ◽  
S. Karpinski

A physical map of Pinussylvestris L. chloroplast DNA for three restriction endonucleases (PstI, SacI, and KpnI) has been prepared by hybridization of isolated or cloned restriction fragments. Pinussylvestris chloroplast DNA is about 120 kilobases. Ten chloroplast genes have been localized by hybridization with heterologous chloroplast DNA probes. The genome contains single copies of the 23S and 16S rRNA genes and lacks any large repeated sequences. The restriction site arrangement and gene order have been compared with other known chloroplast DNA genetic maps of pine species.


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