Obtaining citrus hybrids by in vitro culture of embryos from mature seeds and early identification of hybrid seedlings by allele-specific PCR

ABSTRACT The occurrence of mutations in the genes coding for gyrase (gyrA and gyrB) and topoisomerase IV (parE and parC) of Salmonella typhimurium experimental mutants selected in vitro and in vivo and of 138 nalidixic acid-resistant Salmonella field isolates was investigated. The sequencing of the quinolone resistance-determining region of these genes in highly fluoroquinolone-resistant mutants (MICs of 4 to 16 μg/ml) revealed the presence of gyrA mutations at codons corresponding to Gly-81 or Ser-83, some of which were associated with a mutation at Asp-87. No mutations were found in the gyrB,parC, and parE genes. An assay combining allele-specific PCR and restriction fragment length polymorphism was developed to rapidly screen mutations at codons 81, 83, and 87 ofgyrA. The MICs of ciprofloxacin for the field isolates reached only 2 μg/ml, versus 16 μg/ml for some in vitro-selected mutants. The field isolates, like the mutants selected in vivo, had only a single gyrA mutation at codon 83 or 87. SinglegyrA mutations were also found in highly resistant in vitro-selected mutants (MIC of ciprofloxacin, 8 μg/ml), which indicates that mechanisms other than the unique modification of the intracellular targets could participate in fluoroquinolone resistance in Salmonella spp. A comparison of experimental mutants selected in vitro, field strains, and mutants selected in vivo suggests that highly fluoroquinolone-resistant strains are counterselected in field conditions in the absence of selective pressure.

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Plasmodium falciparum: in vitro chloroquine susceptibility and allele-specific PCR detection of Pfmdr1 Asn86Tyr polymorphism in Lambarene, Gabon

Parasitology ◽

10.1017/s0031182097002266 ◽

1998 ◽

Vol 116 (3) ◽

pp. 211-217 ◽

Cited By ~ 31

Author(s):

M. P. GROBUSCH ◽

I. S. ADAGU ◽

P. G. KREMSNER ◽

D. C. WARHURST

Keyword(s):

Plasmodium Falciparum ◽

Pcr Detection ◽

Specific Pcr ◽

Allele Specific ◽

Allele Specific Pcr

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Simple and Rapid Detection of Factor V Leiden by Allele-specific PCR Amplification

Thrombosis and Haemostasis ◽

10.1055/s-0038-1650362 ◽

1996 ◽

Vol 75 (05) ◽

pp. 757-759 ◽

Cited By ~ 11

Author(s):

Rainer Blasczyk ◽

Markus Ritter ◽

Christian Thiede ◽

Jenny Wehling ◽

Günter Hintz ◽

...

Keyword(s):

Direct Sequencing ◽

Activated Protein C ◽

Factor V Leiden ◽

Pcr Amplification ◽

Factor V ◽

Specific Pcr ◽

Pcr Rflp ◽

Allele Specific ◽

Specific Amplification ◽

Allele Specific Pcr

SummaryResistance to activated protein C is the most common hereditary cause for thrombosis and significantly linked to factor V Leiden. In this study, primers were designed to identify the factor V mutation by allele-specific PCR amplification. 126 patients with thromboembolic events were analysed using this technique, PCR-RFLP and direct sequencing. The concordance between these techniques was 100%. In 27 patients a heterozygous factor VGln506 mutation was detected, whereas one patient with recurrent thromboembolism was homozygous for the point mutation. Due to its time- and cost-saving features allele-specific amplification should be considered for screening of factor VGln506.

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MUPrimer : a tool for finding allele specific PCR-primers for homologous gene sequences

10.32469/10355/6660 ◽

2009 ◽

Author(s):

M. Mursaleen Ahmad

Keyword(s):

Pcr Primers ◽

Homologous Gene ◽

Gene Sequences ◽

Specific Pcr ◽

Allele Specific ◽

Allele Specific Pcr

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Development of genic KASP SNP markers from RNA-Seq data for map-based cloning and marker-assisted selection in maize

BMC Plant Biology ◽

10.1186/s12870-021-02932-8 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Zhengjie Chen ◽

Dengguo Tang ◽

Jixing Ni ◽

Peng Li ◽

Le Wang ◽

...

Keyword(s):

Marker Assisted Selection ◽

Inbred Lines ◽

Average Density ◽

Snp Markers ◽

Data Sets ◽

Rna Seq ◽

Specific Pcr ◽

Maize Inbred Lines ◽

Allele Specific ◽

Allele Specific Pcr

Abstract Background Maize is one of the most important field crops in the world. Most of the key agronomic traits, including yield traits and plant architecture traits, are quantitative. Fine mapping of genes/ quantitative trait loci (QTL) influencing a key trait is essential for marker-assisted selection (MAS) in maize breeding. However, the SNP markers with high density and high polymorphism are lacking, especially kompetitive allele specific PCR (KASP) SNP markers that can be used for automatic genotyping. To date, a large volume of sequencing data has been produced by the next generation sequencing technology, which provides a good pool of SNP loci for development of SNP markers. In this study, we carried out a multi-step screening method to identify kompetitive allele specific PCR (KASP) SNP markers based on the RNA-Seq data sets of 368 maize inbred lines. Results A total of 2,948,985 SNPs were identified in the high-throughput RNA-Seq data sets with the average density of 1.4 SNP/kb. Of these, 71,311 KASP SNP markers (the average density of 34 KASP SNP/Mb) were developed based on the strict criteria: unique genomic region, bi-allelic, polymorphism information content (PIC) value ≥0.4, and conserved primer sequences, and were mapped on 16,161 genes. These 16,161 genes were annotated to 52 gene ontology (GO) terms, including most of primary and secondary metabolic pathways. Subsequently, the 50 KASP SNP markers with the PIC values ranging from 0.14 to 0.5 in 368 RNA-Seq data sets and with polymorphism between the maize inbred lines 1212 and B73 in in silico analysis were selected to experimentally validate the accuracy and polymorphism of SNPs, resulted in 46 SNPs (92.00%) showed polymorphism between the maize inbred lines 1212 and B73. Moreover, these 46 polymorphic SNPs were utilized to genotype the other 20 maize inbred lines, with all 46 SNPs showing polymorphism in the 20 maize inbred lines, and the PIC value of each SNP was 0.11 to 0.50 with an average of 0.35. The results suggested that the KASP SNP markers developed in this study were accurate and polymorphic. Conclusions These high-density polymorphic KASP SNP markers will be a valuable resource for map-based cloning of QTL/genes and marker-assisted selection in maize. Furthermore, the method used to develop SNP markers in maize can also be applied in other species.

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Two User-Friendly Molecular Markers Developed for the Identification of Hybrid Lethality Genes in Brassica oleracea

Agronomy ◽

10.3390/agronomy11050982 ◽

2021 ◽

Vol 11 (5) ◽

pp. 982

Author(s):

Zhiliang Xiao ◽

Congcong Kong ◽

Fengqing Han ◽

Limei Yang ◽

Mu Zhuang ◽

...

Keyword(s):

Molecular Markers ◽

Brassica Oleracea ◽

Rapid Identification ◽

Inbred Lines ◽

Hybrid Lethality ◽

Specific Pcr ◽

Allele Specific ◽

User Friendly ◽

Allele Specific Pcr ◽

Kasp Marker

Cabbage (Brassica oleracea) is an important vegetable crop that is cultivated worldwide. Previously, we reported the identification of two dominant complementary hybrid lethality (HL) genes in cabbage that could result in the death of hybrids. To avoid such losses in the breeding process, we attempted to develop molecular markers to identify HL lines. Among 54 previous mapping markers closely linked to BoHL1 or BoHL2, only six markers for BoHL2 were available in eight cabbage lines (two BoHL1 lines; three BoHL2 lines; three lines without BoHL); however, they were neither universal nor user-friendly in more inbred lines. To develop more accurate markers, these cabbage lines were resequenced at an ~20× depth to obtain more nucleotide variations in the mapping regions. Then, an InDel in BoHL1 and a single-nucleotide polymorphism (SNP) in BoHL2 were identified, and the corresponding InDel marker MBoHL1 and the competitive allele-specific PCR (KASP) marker KBoHL2 were developed and showed 100% accuracy in eight inbred lines. Moreover, we identified 138 cabbage lines using the two markers, among which one inbred line carried BoHL1 and 11 inbred lines carried BoHL2. All of the lethal line genotypes obtained with the two markers matched the phenotype. Two markers were highly reliable for the rapid identification of HL genes in cabbage.

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