Despite the large number of genomic and transcriptomic resources in maize, there is still much to learn about the function of genes in developmental and biochemical processes. Some maize mutants that were generated by gamma-irradiation showed clear segregation for the kernel phenotypes in B73 × Mo17 F2 ears. To better understand the functional genomics of kernel development, we developed a mapping and gene identification pipeline, bulked segregant exome sequencing (BSEx-seq), to map mutants with kernel phenotypes including opaque endosperm and reduced kernel size. BSEx-seq generates and compares the sequence of the exon fraction from mutant and normal plant F2 DNA pools. The comparison can derive mapping peaks, identify deletions within the mapping peak, and suggest candidate genes within the deleted regions. We then used the public kernel-specific expression data to narrow down the list of candidate genes/mutations and identified deletions ranging from several kb to more than 1 Mb. A full deletion allele of the Opaque-2 gene was identified in mutant 531, which occurs within a ∼200-kb deletion. Opaque mutant 1486 has a 6248-bp deletion in the mapping interval containing two candidate genes encoding RNA-directed DNA methylation 4 (RdDM4) and AMP-binding protein, respectively. This study demonstrates the efficiency and cost-effectiveness of BSEx-seq for causal mutation mapping and candidate gene selection, providing a new option in mapping-by-sequencing for maize functional genomics studies.
Chromosome Mapping ; methods ; DNA, Plant ; genetics ; DNA-Binding Proteins ; genetics ; Endosperm ; Exome ; genetics ; Exons ; genetics ; Gene Deletion ; Genomics ; Phenotype ; Plant Proteins ; genetics ; Sequence Analysis, DNA ; methods ; Transcription Factors ; genetics ; Zea mays ; genetics

OBJECTIVE: To establish a 15-plex rapid STR multiplex amplification system. METHODS: Fourteen auto-chromosome loci and one sex-chromosome were selected to compare the situations of allelic losses and nonspecific amplication under different conditions. FastStart Taq DNA polymerase and DNA standard sample 9947A were used during amplification and optimization process.15-plex rapid STR amplification system was achieved by performing various experiments including selection of amplification conditions and the volume of DNA polymerase, adjustment of inter-locus balance, optimization of rapid amplification, screening of reaction buffers, selection of reaction volume, and a variety of additives. RESULTS: Using 10 μL rapid PCR system, including 1 ng DNA templates, 0.4 μL polymerase and 10xFastStart high fidelity reaction buffer, a complete and well-balance DNA profile of 15 STR loci for standard genomic DNA was obtained in 32 minutes, without the allele drop-out and non-specific amplicons. Meanwhile, 5% glycerinum, 0.01% gelatin, 0.05% gelatin and 5 mmol/L ammonium sulfate could be used as the reactive additive during the amplification procedure. CONCLUSION The 15-plex rapid STR multiplex amplification system can be used to decrease reaction time and enhance sample throughput.
Alleles ; Chromosome Mapping ; DNA/genetics* ; DNA Fingerprinting/methods* ; Forensic Genetics/methods* ; Humans ; Microsatellite Repeats/genetics* ; Polymerase Chain Reaction/methods* ; Racial Groups/genetics* ; Sensitivity and Specificity ; Tandem Repeat Sequences

Non-coding expansion spinocerebellar ataxias (SCAs) are a group of autosomal dominant neurodegenerative diseases characterized by "CTA/CTG", "ATTCT", "TGGAA" expansion in non-coding region of the causative gene. Until now, 5 subtypes including SCA8, SCA10, SCA12, SCA31 and SCA36 have been mapped. Recently, the causative mutation for SCA36, namely intronic hexanucleotide GGCCTG expansion in NOP56 gene, has been identified in Japanese and Spanish pedigrees in succession. Compared with other subtypes of SCAs, there are certain distinctive characteristics for SCA36. The clinical and genetic features of SCA36 are reviewed in this paper.
Base Sequence ; Biomedical Research ; methods ; trends ; Chromosome Mapping ; Chromosomes, Human, Pair 20 ; genetics ; DNA Repeat Expansion ; genetics ; Genetic Predisposition to Disease ; genetics ; Humans ; Nuclear Proteins ; genetics ; Oligonucleotides ; genetics ; Spinocerebellar Ataxias ; genetics ; pathology

OBJECTIVETuberculosis remains one of the most serious infectious diseases in the world. In this study, a scheme of Mycobacterium tuberculosis (M. tuberculosis) multilocus sequence analysis (MLSA) was established for the phylogenetic and epidemiology analysis.

METHODSTo establish the scheme of M. tuberculosis MLSA, the genome of H37Rv, CCDC5079 and CCDC5180 were compared, and some variable genes were chosen to be the MLSA typing scheme. 44 M. tuberculosis clinical isolates were typed by MLSA, IS6110-RFLP, and soligotyping, to evaluate the MLSA methods.

RESULTSAfter comparison of the genome, seven high discrimination gene loci (recX, rpsL, rmlC, rpmG1, mprA, gcvH, ideR) were chosen to be the MLSA typing scheme finally. 11 variable SNP sites of those seven genes were found among the 44 M. tuberculosis isolate strains and 11 sequence types (STs) were identified. Based on the Hunter-Gaston Index (HGI), MLSA typing was not as good for discrimination at the strain level as IS6110-RFLP, but the HGI was much better than that of spoligotyping. In addition, the MEGA analysis result of MLSA data was similar to spoligotyping/PGG lineage, showing a strong phylogenetic signal in the modern strains of M. tuberculosis. The MLSA data analysis by eBURST revealed that 4 sequence types (ST) came into a main cluster, showing the major clonal complexes in those 44 strains.

CONCLUSIONMLSA genotyping not only can be used for molecular typing, but also is an ideal method for the phylogenetic analysis for M. tuberculosis.

Chromosome Mapping ; Chromosomes, Bacterial ; Gene Expression Regulation, Bacterial ; Genome, Bacterial ; Genotype ; Multilocus Sequence Typing ; methods ; Mycobacterium tuberculosis ; genetics ; metabolism

OBJECTIVETo improve the experimental method of DXS52 (St14) and apply it to genetic testing for hemophilia A (HA).

METHODSPCR of DXS52 and agarose gel electrophoresis were performed for genetic testing in 61 non-inversion HA families. Linkage analysis of 7 loci within the FVIII gene including Bcl I, Hind III, Xba I, STR1, STR13, STR22 and STR24 were also carried out for the 61 families.

RESULTSDXS52 can provide information in 43 out of 61 families and the diagnostic rate was 70.5%. Eight families can be diagnosed only by DXS52 locus, accounting for 13.1%. Two families were found to have recombination between DXS52 and FVIII.

CONCLUSIONThe new experimental conditions can reach accurate and clear results in DXS52 genetic testing. This gene maker has high diagnostic rate, so it is an indispensable linkage analysis method in HA gene diagnosis. More caution should be paid when using the extragenic locus DXS52 to perform gene diagnosis because of its high recombinant rate with FVIII.

Chromosome Mapping ; methods ; Chromosomes, Human, X ; Factor VIII ; genetics ; Female ; Genetic Linkage ; Genetic Markers ; Hemophilia A ; diagnosis ; genetics ; Humans ; Male

OBJECTIVETo elucidate the development of mapping and localization of susceptible genes on chromosomes to asthma related phenotypes.

DATA SOURCESPublished articles about susceptibility genes for asthma related phenotypes were selected using PubMed.

STUDY SELECTIONUsing methods of candidate gene positional clone and genome-wide scan with linkage and association analysis to determine the location in the genome of susceptibility genes to asthma and asthma related phenotypes.

RESULTSThere are multiple regions in the genome harboring susceptibility genes to asthma and asthma related phenotypes, including chromosomes 5, 11, 12, 6, 2, 3, 13, 7, 14, 9, 19 and 17. Many of these regions contain candidate genes involved in asthma development and progression. Some susceptible genes may affect the phenotype expression or response to therapy. In addition, the interaction of multiple genes with the environment may contribute to the susceptibility to asthma.

CONCLUSIONSAs an essential step toward cloning the susceptible genes to asthma, fine mapping and localization on chromosomes are definitely needed. Novel powerful tools for gene discovery and the integration of genetics, biology and bioinformatics should be pursued.

Asthma ; genetics ; Chromosome Mapping ; methods ; Genetic Predisposition to Disease ; genetics ; Humans

Molecular genetic map is a fundamental organizational tool for genomic research. However, a genetic linkage map for Bupleurum chinense DC. has not been developed. In this study, with the theory of pseudo-testcross, 96 F1 plants from an intraspecific cross of B. chinense were used as mapping populations. Twenty eight ISSR (inter-simple sequence repeat) primers and 44 SSR (simple sequence repeat) primers were used to detect the polymorphisms between the parental plants, and of them, 28 ISSRs and 14 SSRs were selected to analyze the F1 populations. The map consisted of 13 linkage groups which included 80 (72 ISSRs and 8 SSRs) loci, and covered 2 633.9 cM with an average density of 33.4 cM. All 13 linkage groups consisted of 2-31 loci ranging in length from 15.4-1295.7 cM. This map will provide a basis for studies on gene mapping, map-based cloning and maker-assisted selection of important traits in B. chinense.
Bupleurum ; genetics ; Chromosome Mapping ; methods ; DNA, Plant ; genetics ; Genetic Linkage ; Microsatellite Repeats ; Plants, Medicinal ; genetics ; Polymorphism, Genetic

OBJECTIVETo map the susceptibility gene of developmental dysplasia of the hip(DDH) in chromosome 17q21 region.

METHODSAccording to the number of alleles (≥ 5), heterozygosity (≥ 0.70) and polymorphic information content (PIC≥ 0.5), 11 STR markers in the 17q21 region were chosen for transmission disequilibrium test (TDT). STR markers were amplified by PCR and genotypes were analyzed by capillary electrophoresis in 103 trio families. TDT was used to locate the susceptibility gene in 17q21 region.

RESULTSBecause of a low genetic polymorphism, D17S810 and D17S931 loci were removed from the TDT. Transmission disequilibrium was detected at D17S855, D17S858, D17S806, D17S1877, D17S941, D17S752 and D17S790, which overlapped 11.7 cM in 17q21. However, no transmission disequilibrium was found at D17S1787 and D17S787. Thus, the susceptibility gene for DDH was located in the chromosome region between D17S855 and D17S790.

CONCLUSIONThe susceptibility gene for DDH is narrowed to an 11.7 cM region of 17q21.31-17q22, between STR loci D17S855 and D17S790.

Child ; Child, Preschool ; Chromosome Mapping ; methods ; Chromosomes, Human, Pair 17 ; genetics ; Cloning, Molecular ; Female ; Genetic Predisposition to Disease ; genetics ; Hip Dislocation, Congenital ; genetics ; Humans ; Infant ; Linkage Disequilibrium ; genetics ; Male ; Microsatellite Repeats ; genetics ; Polymorphism, Genetic ; genetics

OBJECTIVETo define the origin and the precise location of the aberrant fragments on the short arm of the chromosome 8 in a mentally retarded boy, and to understand the mechanism, the characteristic clinical features and the recurrent risk associated with this abnormality.

METHODSHigh-resolution chromosomal banding was performed to analyze the karyotype of the patient and his parents, array comparative genomic hybridization (array-CGH) was employed to investigate the precise location of the aberrant fragments, and quantitative real-time PCR was used to confirm the results.

RESULTSThe rearranged chromosome 8 in the patient was inverted and duplicated for region 8p11.2-p23.1, and deleted for region 8p23.1-pter. In between, a 5.70 Mb single copy region was present, which was delimited by the two olfactory receptor (OR) gene clusters.

CONCLUSIONThis is a case of classic inv dup del(8p) syndrome, which is characterized by severe mental retardation, brain malformation and specific facial dysmorphism, and is induced by non-allelic homologous recombination (NAHR) between the OR genes on 8p23.1. Prenatal diagnosis should be performed to monitor the recurrent risk of inv dup del(8p), as well as the other three harmful consequences resulted from the same NAHR mechanism. To the best of our knowledge, this is the first case of inverted duplicated 8p syndrome identified in Mainland China.

Abnormalities, Multiple ; genetics ; China ; Chromosome Aberrations ; classification ; Chromosome Banding ; methods ; Chromosome Deletion ; Chromosome Inversion ; Chromosome Mapping ; Chromosomes, Human, Pair 8 ; Cytogenetic Analysis ; methods ; Cytogenetics ; methods ; Gene Duplication ; Humans ; In Situ Hybridization, Fluorescence ; Infant ; Karyotyping ; methods ; Male ; Multigene Family ; Syndrome

INTRODUCTIONIgA nephritis (IgAN) is the most common glomerulonephritis worldwide. We aim to genotype SNPs (single nucleotide polymorphisms) genomewide in patients with IgAN to search for genetic clues to its aetiology.

MATERIALS AND METHODSGenotyping for 10,204 SNPs genomewide was done with the Gene Chip Human Mapping 10K Microarray (Affymetrix). Twenty-eight patients with IgAN and 30 normal subjects were screened and analysed for differences in genotype frequency, allele frequency and heterozygosity reduction.

RESULTSAmong the most significantly associated SNPs, 48 SNPs were found mapping directly to the intron of 42 genes that localised in 13 somatic chromosomes and chromosome X. Genotype distribution of these SNPs did not deviate from the Hardy-Weinberg equilibrium in normal subjects. The most significantly associated gene, glial cells missing homolog 1 (GCM, 2 =13.05, P = 0.000) is a transcription factor mapped to 6p12.2. GCM1 reported decreased in placenta of patients with pre-eclampsia. The second gene, Tenascin-R (TNR, 2 = 9.85, P = 0.002) is a glycoprotein and extra-cellular matrix component mapped to 1q25.1. Tenascin-R was associated with motor coordination impairment and enhanced anxiety profile in deficient mice. Interestingly, Triadin (TRDN, 2 = 9.16, P = 0.01) is an integral membrane protein mapped to 6q22.31 within the IgAN1 locus. Triadin was shown to participate in cardiac myocyte arrhythemia. However, there is no published study of these genes in IgAN.

CONCLUSIONForty-two associated genes (particularly GCM1, TNR and TRDN) are identified as possible susceptibility or marker genes for IgAN. Knowledge of their mesangial expression and binding capacity for IgA-containing complexes may help elucidate the pathogenesis of IgAN.

Animals ; Carrier Proteins ; genetics ; Case-Control Studies ; Chromosome Mapping ; methods ; Disease Susceptibility ; Genetic Markers ; Genetic Testing ; Genotype ; Glomerulonephritis, IGA ; diagnosis ; epidemiology ; genetics ; Humans ; Mice ; Microarray Analysis ; Muscle Proteins ; genetics ; Nuclear Proteins ; genetics ; Odds Ratio ; Pilot Projects ; Polymorphism, Single Nucleotide ; genetics ; Singapore ; epidemiology ; Statistics as Topic ; Tenascin ; genetics ; Transcription Factors ; genetics