Search results for "Length"

Environmental effects on molecular and phenotypic variation in populations of Eruca sativa across a steep climatic gradient

2013

Abstract In Israel Eruca sativa has a geographically narrow distribution across a steep climatic gradient that ranges from mesic Mediterranean to hot desert environments. These conditions offer an opportunity to study the influence of the environment on intraspecific genetic variation. For this, we combined an analysis of neutral genetic markers with a phenotypic evaluation in common-garden experiments, and environmental characterization of populations that included climatic and edaphic parameters, as well as geographic distribution. A Bayesian clustering of individuals from nine representative populations based on amplified fragment length polymorphism (AFLP) divided the populations into a…

Disorder-induced single-mode transmission.

2017

Localized states trap waves propagating in a disordered potential and play a crucial role in Anderson localization, which is the absence of diffusion due to disorder. Some localized states are barely coupled with neighbours because of differences in wavelength or small spatial overlap, thus preventing energy leakage to the surroundings. This is the same degree of isolation found in the homogeneous core of a single-mode optical fibre. Here we show that localized states of a disordered optical fibre are single mode: the transmission channels possess a high degree of resilience to perturbation and invariance with respect to the launch conditions. Our experimental approach allows identification…

Mitochondrial Dna Variation in Rhopalosiphum padi (Homoptera: Aphididae) Populations from four Spanish Localities

1992

In total, 35 clones of the bird cherry-oat aphid, Rhopalosiphum padi (L.) established from samples collected in four distant localities of Spain during fall 1989 and spring 1990 were examined for mitochondrial DNA variation using 20 restriction endonucleases. Individual parthenogenetic adults were used to establish clonal lines on wheat (‘Talento’) seedlings. Restriction site polymorphism was detected only with endonuclease Rsa I, but no statistical treatment of data could be done until more polymorphic endonucleases are found. Length variation of the mitochondrial DNA molecule, however, was extensive among R. padi clones. Distribution among populations of this size polymorphism was used to…

Screening and identification ofvipgenes inBacillus thuringiensisstrains

2009

Aims:  To identify known vip genes and to detect potentially novel vip genes in a collection of 507 strains of Bacillus thuringiensis. Methods and Results:  Following a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) strategy, four restriction patterns were found within the vip1 family: vip1Aa1, vip1Ba1/vip1Ba2 and vip1Ca. In the screening of vip2 genes, patterns similar to those of vip2Aa1, vip2Ba1/vip2Ba2 and vip2Ac1 genes were observed. Patterns for vip3Aa1, vip3Ae2 and vip3Af1 were found among vip3 genes. Two new patterns revealed novel vip1 and vip3A genes. The observed frequency of genes belonging to vip1 and vip2 families was around 10%, whereas 48·9% of…

2004

Background As an alternative to direct DNA sequencing of PCR products, random PCR-RFLP is an efficient technique to discriminate between species. The PCR-RFLP-method is an inexpensive tool in forensic science, even if the template is degraded or contains only traces of DNA from various species.

Amplified fragment length polymorphism (AFLP) and biochemical typing of Photobacterium damselae subsp. damselae.

2002

Aims: The aim of the present study was to characterize subspecifically Photobacterium damselae subsp. damselae strains isolated from cultured Sparus aurata and Dicentrarchus labrax by means of phenotypic and molecular typing techniques (amplified fragment length polymorphism, AFLP). Methods and Results: Seventy-one strains of P. damselae subsp. damselae were isolated from 38 cultured fishes at different fish farms located on the Mediterranean coast near Valencia, Spain. Most fish studied were asymptomatic and some were recovered during infectious outbreaks. Phenotypic characterization revealed a considerable degree of variability within the subspecies, including some characters, such as pro…

DNA polymorphism of the human complement C8 beta gene: formal genetics and intragenic localization.

1989

The eighth component of human complement consists of three subunits of different molecular mass, which are coded for by three separate genetic loci. Polymorphisms have been described at the protein level for the alpha and beta subunits by means of sodium dodecyl sulfate gel electrophoresis and isoelectric focusing. Using a full-length human C8 beta cDNA probe, we have studied more than 100 individuals by Southern blot analysis to detect DNA polymorphisms. We have found two restriction fragment length polymorphisms (RFLPs) with the enzymes Taq I and Bam HI. The Taq I polymorphism is defined by two alleles, i.e., a single 4.9 kb fragment or two 2.8/2.1 kb fragments. The allele frequencies are…

Cytokine Gene Polymorphisms and Breast Cancer Susceptibility

2006

Human breast cancer (BC) is characterized by a considerable clinical heterogeneity. Steroid hormone receptor expression and growth factor receptor expression have been considered suitable diagnostic and prognostic markers, whereas mutations of oncosuppressor and gatekeeper genes have been found associated with an increased risk for this malignancy. To evaluate the role that polymorphisms of genes involved in the regulation of inflammatory response might play in BC susceptibility, we investigated associations between cytokine functionally relevant polymorphisms in 84 BC patients compared to 110 age- and sex-matched controls. TNF-alpha (-308G/A), TGF-beta1 (+869C/T), IL-10 (-1117G/A; -854C/T;…

Amplified fragment length polymorphisms and sequence data in the phylogenetic analysis of polyploids: multiple origins of Veronica cymbalaria (Planta…

2007

Summary • The origin of polyploid Veronica cymbalaria (Plantaginaceae) was investigated using DNA sequence data and amplified fragment length polymorphism (AFLP) fingerprints to reveal the parentage of this taxon. The use of AFLP fingerprints in phylogenetic analysis is problematic and various methods have therefore been compared. • DNA sequence data (for the internal transcribed spacer (ITS) region and the plastid trnL-F region (trnL intron, 3’exon, and trnL-F spacer)) and polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) analysis of the ITS region suggested a reliable hypothesis for the evolution of the V. cymbalaria complex. This hypothesis allowed evaluation …

A simple sequence repeat-based linkage map of barley.

2000

Abstract A total of 568 new simple sequence repeat (SSR)-based markers for barley have been developed from a combination of database sequences and small insert genomic libraries enriched for a range of short simple sequence repeats. Analysis of the SSRs on 16 barley cultivars revealed variable levels of informativeness but no obvious correlation was found with SSR repeat length, motif type, or map position. Of the 568 SSRs developed, 242 were genetically mapped, 216 with 37 previously published SSRs in a single doubled-haploid population derived from the F1 of an interspecific cross between the cultivar Lina and Hordeum spontaneum Canada Park and 26 SSRs in two other mapping populations. A …