Search results for " polymorphism"
showing 10 items of 1028 documents
Identification of yeasts by RFLP analysis of the 5.8S rRNA gene and the two ribosomal internal transcribed spacers
1999
The identification and classification of yeasts have traditionally been based on morphological, physiological and biochemical traits. Various kits have been developed as rapid systems for yeast identification, but mostly for clinical diagnosis. In recent years, different molecular biology techniques have been developed for yeast identification, but there is no available database to identify a large number of species. In the present study, the restriction patterns generated from the region spanning the internal transcribed spacers (ITS1 and ITS2) and the 5.8S rRNA gene were used to identify a total of 132 yeast species belonging to 25 different genera, including teleomorphic and anamorphic a…
Inter- and intraspecific chromosome pattern variation in the yeast genusKluyveromyces
1998
The analysis of the electrophoretic chromosome patterns of the species of the genus Kluyveromyces, reveals a high polymorphism in size, number and intensity of bands. DiVerent sets of electrophoresis running conditions were used to establish species-specific patterns and also to detect intraspecific variation. According to their karyotypes, the species of this genus can be divided into two major groups. The first group includes the species K. africanus, K. bacillisporus, K. delphensis, K. lodderae, K. phaY, K. polysporus and K. yarrowii, composing the so-called ‘Saccharomyces cerevisiae-like’ group, because their karyotypes resemble that of the species S. cerevisiae. The second group compri…
Exploring diversity among Spanish strains of Erwinia amylovora and possible infection sources
2007
Aims: We have examined the intraspecific diversity of a collection of 63 Spanish strains of Erwinia amylovora, isolated from 1995 to 2001, to determine whether or not they could be grouped based on phenotypic or genotypic criteria and to investigate the sources of inoculum for fire blight dissemination in Spain. Methods and Results: Several biochemical and molecular techniques, such as miniaturized API 20E, API 50CH, ATB G-5 and API-ZYM tests, BIOLOG metabolic fingerprinting, PCR ribotyping, pulsed-field gel electrophoresis (PFGE), minisatellite-primed PCR (MSP-PCR), random amplified polymorphic DNA (RAPD) analyses and AFLP were used. We report the first identification in Spain of the PFG…
A genetic linkage map ofPhysocarpus, a member of the Spiraeoideae (Rosaceae), based on RAPD, AFLP, RGA, SSR and gene specific markers
2008
Physocarpus opulifolius is a deciduous shrub native to North America belonging to the Spiraeoideae subfamily of the Rosaceae. The cultivars 'Luteus' and 'Diabolo' are grown in gardens for their ornamental foliage, golden and purple respectively. We developed a linkage map of P. opulifolius with a view to detecting markers for the leaf colour genes, which are under major gene control. A total of 162 molecular markers (128 RAPDs, 27 AFLPs, three RGA, three STS markers and one SSR) and the leaf colour genes Pur and Aur were scored in the Physocarpus progeny and used to create a linkage map covering 586.1 cM over nine linkage groups. There was an average of 18.2 markers per linkage group and a …
Microduplications At 22q11.21 are Associated with Classic Bladder Exstrophy
2010
Purpose Classic exstrophy of the bladder (CBE) is part of the exstrophy-epispadias complex (EEC), a spectrum of urogenital anomalies in which part or all of the distal urinary tract fails to close. Familial occurrence has been observed, and previous studies have suggested an underlying multifactorial mode of inheritance. To date, no causative genetic or non-genetic factor has been unequivocally identified in humans. The present study aimed to identify microaberrations characterized by loss or gain of genomic material that contribute to the EEC at a genome-wide level. Material and Methods Molecular karyotyping, utilizing 549,839 single nucleotide polymorphisms (SNPs) with an average spacing …
Identification and prevention of genotyping errors caused by G-quadruplex- and i-motif-like sequences.
2009
Abstract Background: Reliable PCR amplification of DNA fragments is the prerequisite for most genetic assays. We investigated the impact of G-quadruplex– or i-motif–like sequences on the reliability of PCR-based genetic analyses. Methods: We found the sequence context of a common intronic polymorphism in the MEN1 gene (multiple endocrine neoplasia I) to be the cause of systematic genotyping errors by inducing preferential amplification of one allelic variant [allele dropout (ADO)]. Bioinformatic analyses and pyrosequencing-based allele quantification enabled the identification of the underlying DNA structures. Results: We showed that G-quadruplex– or i-motif–like sequences can reproducibly …
The haplotype distribution of two genes of citrus tristeza virus is altered after host change or aphid transmission.
1999
Genetic variability of citrus tristeza virus (CTV) was studied using the haplotypes detected by single-strand conformation polymorphism (SSCP) analysis of genes p18 and p20 in six virus populations of two origins. The Spanish group included a CTV isolate and subisolates obtained by graft-transmission to different host species. The other included two subisolates aphid-transmitted from a single Japanese isolate. The homozygosity observed for gene p20 was always significantly higher than that expected under neutral evolution, whereas only three populations showed high homozygosity for p18, suggesting stronger host constraints for p20 than for p18. Sequential transmissions of a Spanish isolate …
Successful Replication of GWAS Hits for Multiple Sclerosis in 10,000 Germans Using the Exome Array
2015
Genome-wide association studies (GWAS) successfully identified various chromosomal regions to be associated with multiple sclerosis (MS). The primary aim of this study was to replicate reported associations from GWAS using an exome array in a large German study. German MS cases (n = 4,476) and German controls (n = 5,714) were genotyped using the Illumina HumanExome v1-Chip. Genotype calling was performed with the Illumina Genome Studio(TM) Genotyping Module, followed by zCall. Single-nucleotide polymorphisms (SNPs) in seven regions outside the human leukocyte antigen (HLA) region showed genome-wide significant associations with MS (P values < 5 × 10(-8) ). These associations have been repor…
Genetic differentiation in the striped dolphin Stenella coeruleoalba from European waters according to mitochondrial DNA (mtDNA) restriction analysis
1999
We used mitochondrial DNA (mtDNA) restriction analysis to study genetic variation in 98 striped dolphins (Stenella coeruleoalba) stranded on coasts from different European countries and from animals caught by fisheries. A total of 63 different restriction sites was mapped after digestion of mtDNA with 15 restriction endonucleases that yielded a total of 27 haplotypes. No haplotype was shared between Mediterranean and Atlantic areas. All the analyses indicate the existence of two different populations with a very limited gene flow across the Strait of Gibraltar.
Temporal changes of chromosomal polymorphism in natural populations of Drosophila subobscura
1984
The behaviour of the chromosomal polymorphism of D. subobscura was analyzed in relation to temporal changes, daily, seasonal and annual. Firstly, chromosome analyses were carried out over a year in a natural population. Samples were taken at monthly intervals in Tibidabo, a locality close to Barcelona. In all the months except January, the number of individuals captured was enough to carry out a chromosome analysis of that population. The A, E and O chromosomes showed a great uniformity in the frequencies of gene arrangement over the year. However, significant changes occur in the frequencies of J and U chromosomes. The J1 and U1+2+8 arrangements showed a similar tendency, with two maxima, …