scholarly journals Whole Genome Re-sequencing of Soybean Accession EC241780 Providing Genomic Landscape of Candidate Genes Involved in Rust Resistance

2020 ◽  
Vol 21 (7) ◽  
pp. 504-511
Author(s):  
Milind Balkrishna Ratnaparkhe ◽  
Niharika Marmat ◽  
Giriraj Kumawat ◽  
Maranna Shivakumar ◽  
Viraj Gangadhar Kamble ◽  
...  

Background: In this study, whole genome re-sequencing of rust resistant soybean genotype EC241780 was performed to understand the genomic landscape involved in the resistance mechanism. Methods: A total of 374 million raw reads were obtained with paired-end sequencing performed with Illumina HiSeq 2500 instrument, out of which 287.3 million high quality reads were mapped to Williams 82 reference genome. Comparative sequence analysis of EC241780 with rust susceptible cultivars Williams 82 and JS 335 was performed to identify sequence variation and to prioritise the candidate genes. Results: Comparative analysis indicates that genotype EC241780 has high sequence similarity with rust resistant genotype PI 200492 and the resistance in EC241780 is conferred. by the Rpp1 locus. Based on the sequence variations and functional annotations, three genes Glyma18G51715, Glyma18G51741 and Glyma18G51765 encoding for NBS-LRR family protein were identified as the most prominent candidate for Rpp1 locus. Conclusion: The study provides insights of genome-wide sequence variation more particularly at Rpp1 loci which will help to develop rust resistant soybean cultivars through efficient exploration of the genomic resource.

2008 ◽  
Vol 35 (5) ◽  
pp. 427 ◽  
Author(s):  
Timothy J. March ◽  
Jason A. Able ◽  
Kerrie Willsmore ◽  
Carolyn J. Schultz ◽  
Amanda J. Able

The dark discoloration of the embryo end of barley grain (known as black point) is a physiological disorder and the discovery of a quantitative trait locus (QTL) on 2H confirms this trait is controlled genetically. The mechanisms underlying black point tolerance can now be dissected through identification of candidate genes. Comparisons between the QTL identified on chromosomes 2H of barley and 2B of wheat suggest that they are in similar positions near the centromere. In silico analysis, using rice, identified genes residing on two comparative chromosomes (4 and 7) of the rice genome. Analysis of the 12.6 Mb region revealed 1928 unique annotations classified into 11 functional categories. Expressed sequence tags (ESTs) with high sequence similarity to enzymes proposed to be involved in black point formation were used to develop restriction fragment length polymorphisms (RFLPs). To ensure an even coverage of markers across the QTL, RFLP markers were also developed from other ESTs. Mapping of these markers has reduced the QTL region from 28 to 18 cM. This study has identified candidate genes for the control of black point formation and paves the way for future research to develop black point resistant barley cultivars.


Genetics ◽  
1998 ◽  
Vol 148 (1) ◽  
pp. 305-315
Author(s):  
Lynn Mertens King

Abstract Nucleotide sequences of eight Est-5A and Est-5C genes corresponding to previously sequenced Est-5B genes in Drosophila pseudoobscura were determined to compare patterns of polymorphism and divergence among members of this small gene family. The three esterase genes were also sequenced from D. persimilis and D. miranda for interspecific comparisons. The data provide evidence that gene conversion between loci contributes to polymorphism and to the homogenization of the Est-5 genes. For Est-5B, which encodes one of the most highly polymorphic proteins in Drosophila, 12% of the segregating amino acid variants appear to have been introduced via gene conversion from other members of the gene family. Interlocus gene conversion can also explain high sequence similarity, especially at synonymous sites, between Est-5B and Est-5A. Tests of neutrality using interspecific comparisons show that levels of polymorphism conform to neutral expectations at each Est-5 locus. However, McDonald-Kreitman tests based on intraspecific gene comparisons indicate that positive selection on amino acids has accompanied Est-5 gene duplication and divergence in D. pseudoobscura.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3226 ◽  
Author(s):  
Georgia Kapatai ◽  
Juliana Coelho ◽  
Steven Platt ◽  
Victoria J. Chalker

Streptococcus pyogenesgroup AStreptococcus(GAS) is the most common cause of bacterial throat infections, and can cause mild to severe skin and soft tissue infections, including impetigo, erysipelas, necrotizing fasciitis, as well as systemic and fatal infections including septicaemia and meningitis. Estimated annual incidence for invasive group A streptococcal infection (iGAS) in industrialised countries is approximately three per 100,000 per year. Typing is currently used in England and Wales to monitor bacterial strains ofS. pyogenescausing invasive infections and those isolated from patients and healthcare/care workers in cluster and outbreak situations. Sequence analysis of theemmgene is the currently accepted gold standard methodology for GAS typing. A comprehensive database ofemmtypes observed from superficial and invasive GAS strains from England and Wales informs outbreak control teams during investigations. Each year the Bacterial Reference Department, Public Health England (PHE) receives approximately 3,000 GAS isolates from England and Wales. In April 2014 the Bacterial Reference Department, PHE began genomic sequencing of referredS. pyogenesisolates and those pertaining to selected elderly/nursing care or maternity clusters from 2010 to inform future reference services and outbreak analysis (n = 3, 047). In line with the modernizing strategy of PHE, we developed a novel bioinformatics pipeline that can predictemmtypes using whole genome sequence (WGS) data. The efficiency of this method was measured by comparing theemmtype assigned by this method against the result from the current gold standard methodology; concordance toemmsubtype level was observed in 93.8% (2,852/3,040) of our cases, whereas in 2.4% (n = 72) of our cases concordance was observed toemmtype level. The remaining 3.8% (n = 117) of our cases corresponded to novel types/subtypes, contamination, laboratory sample transcription errors or problems arising from high sequence similarity of the allele sequence or low mapping coverage. De novo assembly analysis was performed in the two latter groups (n = 72 + 117) and was able to diagnose the problem and where possible resolve the discordance (60/72 and 20/117, respectively). Overall, we have demonstrated that our WGS emm-typing pipeline is a reliable and robust system that can be implemented to determine emm type for the routine service.


2019 ◽  
Vol 8 (25) ◽  
Author(s):  
Andrey V. Karlyshev

Whole-genome sequencing of Acanthamoeba polyphaga Linc Ap-1 resulted in a draft assembly of the chromosomal DNA and a complete sequence of the mitochondrial DNA (mtDNA). Despite very high sequence similarity with the mtDNA of Acanthamoeba castellanii Neff, in contrast to Acanthamoeba polyphaga Linc Ap-1, the determined DNA sequence revealed a complete absence of introns.


Plant Methods ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Mohamed Ramadan ◽  
Muna Alariqi ◽  
Yizan Ma ◽  
Yanlong Li ◽  
Zhenping Liu ◽  
...  

Abstract Background Upland cotton (Gossypium hirsutum), harboring a complex allotetraploid genome, consists of A and D sub-genomes. Every gene has multiple copies with high sequence similarity that makes genetic, genomic and functional analyses extremely challenging. The recent accessibility of CRISPR/Cas9 tool provides the ability to modify targeted locus efficiently in various complicated plant genomes. However, current cotton transformation method targeting one gene requires a complicated, long and laborious regeneration process. Hence, optimizing strategy that targeting multiple genes is of great value in cotton functional genomics and genetic engineering. Results To target multiple genes in a single experiment, 112 plant development-related genes were knocked out via optimized CRISPR/Cas9 system. We optimized the key steps of pooled sgRNAs assembly method by which 116 sgRNAs pooled together into 4 groups (each group consisted of 29 sgRNAs). Each group of sgRNAs was compiled in one PCR reaction which subsequently went through one round of vector construction, transformation, sgRNAs identification and also one round of genetic transformation. Through the genetic transformation mediated Agrobacterium, we successfully generated more than 800 plants. For mutants identification, Next Generation Sequencing technology has been used and results showed that all generated plants were positive and all targeted genes were covered. Interestingly, among all the transgenic plants, 85% harbored a single sgRNA insertion, 9% two insertions, 3% three different sgRNAs insertions, 2.5% mutated sgRNAs. These plants with different targeted sgRNAs exhibited numerous combinations of phenotypes in plant flowering tissues. Conclusion All targeted genes were successfully edited with high specificity. Our pooled sgRNAs assembly offers a simple, fast and efficient method/strategy to target multiple genes in one time and surely accelerated the study of genes function in cotton.


Author(s):  
Angélique Buton ◽  
Louis-Marie Bobay

Abstract Homologous recombination is a key pathway found in nearly all bacterial taxa. The recombination complex allows bacteria to repair DNA double strand breaks but also promotes adaption through the exchange of DNA between cells. In Proteobacteria, this process is mediated by the RecBCD complex, which relies on the recognition of a DNA motif named Chi to initiate recombination. The Chi motif has been characterized in Escherichia coli and analogous sequences have been found in several other species from diverse families, suggesting that this mode of action is widespread across bacteria. However, the sequences of Chi-like motifs are known for only five bacterial species: E. coli, Haemophilus influenzae, Bacillus subtilis, Lactococcus lactis and Staphylococcus aureus. In this study we detected putative Chi motifs in a large dataset of Proteobacteria and we identified four additional motifs sharing high sequence similarity and similar properties to the Chi motif of E. coli in 85 species of Proteobacteria. Most Chi motifs were detected in Enterobacteriaceae and this motif appears well conserved in this family. However, we did not detect Chi motifs for the majority of Proteobacteria, suggesting that different motifs are used in these species. Altogether these results substantially expand our knowledge on the evolution of Chi motifs and on the recombination process in bacteria.


Genetics ◽  
2004 ◽  
Vol 166 (2) ◽  
pp. 947-957 ◽  
Author(s):  
John G Jelesko ◽  
Kristy Carter ◽  
Whitney Thompson ◽  
Yuki Kinoshita ◽  
Wilhelm Gruissem

Abstract Paralogous genes organized as a gene cluster can rapidly evolve by recombination between misaligned paralogs during meiosis, leading to duplications, deletions, and novel chimeric genes. To model unequal recombination within a specific gene cluster, we utilized a synthetic RBCSB gene cluster to isolate recombinant chimeric genes resulting from meiotic recombination between paralogous genes on sister chromatids. Several F1 populations hemizygous for the synthRBCSB1 gene cluster gave rise to Luc+ F2 plants at frequencies ranging from 1 to 3 × 10-6. A nonuniform distribution of recombination resolution sites resulted in the biased formation of recombinant RBCS3B/1B::LUC genes with nonchimeric exons. The positioning of approximately half of the mapped resolution sites was effectively modeled by the fractional length of identical DNA sequences. In contrast, the other mapped resolution sites fit an alternative model in which recombination resolution was stimulated by an abrupt transition from a region of relatively high sequence similarity to a region of low sequence similarity. Thus, unequal recombination between paralogous RBCSB genes on sister chromatids created an allelic series of novel chimeric genes that effectively resulted in the diversification rather than the homogenization of the synthRBCSB1 gene cluster.


Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1692
Author(s):  
Li Gu ◽  
Ting Su ◽  
Ming-Tai An ◽  
Guo-Xiong Hu

Oreocharis esquirolii, a member of Gesneriaceae, is known as Thamnocharis esquirolii, which has been regarded a synonym of the former. The species is endemic to Guizhou, southwestern China, and is evaluated as vulnerable (VU) under the International Union for Conservation of Nature (IUCN) criteria. Until now, the sequence and genome information of O. esquirolii remains unknown. In this study, we assembled and characterized the complete chloroplast (cp) genome of O. esquirolii using Illumina sequencing data for the first time. The total length of the cp genome was 154,069 bp with a typical quadripartite structure consisting of a pair of inverted repeats (IRs) of 25,392 bp separated by a large single copy region (LSC) of 85,156 bp and a small single copy region (SSC) of18,129 bp. The genome comprised 114 unique genes with 80 protein-coding genes, 30 tRNA genes, and four rRNA genes. Thirty-one repeat sequences and 74 simple sequence repeats (SSRs) were identified. Genome alignment across five plastid genomes of Gesneriaceae indicated a high sequence similarity. Four highly variable sites (rps16-trnQ, trnS-trnG, ndhF-rpl32, and ycf 1) were identified. Phylogenetic analysis indicated that O. esquirolii grouped together with O. mileensis, supporting resurrection of the name Oreocharis esquirolii from Thamnocharisesquirolii. The complete cp genome sequence will contribute to further studies in molecular identification, genetic diversity, and phylogeny.


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