Search results for "repeats"
showing 10 items of 209 documents
A comparative analysis of genetic variation in rootstocks and scions of old olive trees – a window into the history of olive cultivation practices an…
2014
Background Past clonal propagation of olive trees is intimately linked to grafting. However, evidence on grafting in ancient trees is scarce, and not much is known about the source of plant material used for rootstocks. Here, the Simple Sequence Repeat (SSR) marker technique was used to study genetic diversity of rootstocks and scions in ancient olive trees from the Levant and its implications for past cultivation of olives. Leaf samples were collected from tree canopies (scions) and shoots growing from the trunk base (suckers). A total of 310 trees were sampled in 32 groves and analyzed with 14 SSR markers. Results In 82.7% of the trees in which both scion and suckers could be genotyped, t…
Yeast ecology of vineyards within Marsala wine area (western Sicily) in two consecutive vintages and selection of autochthonous Saccharomyces cerevis…
2012
In this work, the yeast ecology associated with the spontaneous fermentation of Grillo cultivar grapes from 10 vineyards was analyzed from grape harvest till complete consumption of must sugars. The microbiological investigation started with the plate count onto two culture media to distinguish total yeasts (TY) and presumptive Saccharomyces (PS). Yeasts were randomly isolated and identified by a combined genotypic approach consisting of restriction fragment length polymorphism (RFLP) of 5.8S rRNA gene and 26S rRNA and sequencing of D1/D2 domain of the 26S rRNA gene, which resulted in the recognition of 14 species belonging to 10 genera. The distribution of the yeasts within the vineyards s…
TNFA promoter polymorphisms and narcolepsy
2003
Narcolepsy is a debilitating sleep disorder that affects up to 0.05% of individuals in Caucasian populations. It is highly associated with the HLA-DR2 group antigen or the HLA-DRB1*1501-DQB1*0602 haplotype, respectively. However, the HLA association by itself cannot sufficiently explain the increased risk to family members, as HLA-DR2 is quite common in the general population and most people harboring the respective genotype do not develop any symptoms of narcolepsy. Situated in the HLA class II region, the TNFA gene is translated into the pro-inflammatory cytokine TNF-alpha. TNFA promoter polymorphisms have been linked to several inflammatory and autoimmune diseases. We analyzed three SNP …
Inverted and mirror repeats in model nucleotide sequences.
2007
We analytically and numerically study the probabilistic properties of inverted and mirror repeats in model sequences of nucleic acids. We consider both perfect and non-perfect repeats, i.e. repeats with mismatches and gaps. The considered sequence models are independent identically distributed (i.i.d.) sequences, Markov processes and long range sequences. We show that the number of repeats in correlated sequences is significantly larger than in i.i.d. sequences and that this discrepancy increases exponentially with the repeat length for long range sequences.
A region on human chromosome 4 (q35.1→qter) induces senescence in cell hybrids and is involved in cervical carcinogenesis
2005
Human papillomavirus (HPV) types 16 and 18 are known to play a major role in cervical carcinogenesis. Additional genetic alterations are required for the development and progression of cervical cancer. Previously, we showed that the introduction of an entire human chromosome 4 into HPV-immortalized cells by microcell-mediated chromosome transfer (MMCT) can induce senescence in cell hybrids. In the present study, we established eight new murine donor cell lines harboring different fragments of the human chromosome 4. These were tested for their ability to induce senescence by MMCT into HPV16-immortalized keratinocytes (HPK II) and cervical carcinoma cells (HeLa). By exclusion, we could ident…
Association of ADHD with genetic variants in the 5'-region of the dopamine transporter gene: evidence for allelic heterogeneity.
2008
Contains fulltext : 69953.pdf (Publisher’s version ) (Closed access) Multiple studies have reported an association between attention deficit hyperactivity disorder (ADHD) and the 10-repeat allele of a variable number tandem repeat (VNTR) polymorphism in the 3'-untranslated region (3'UTR) of the dopamine transporter gene (DAT1). Yet, recent meta-analyses of available data find little or no evidence for this association; although there is strong evidence for heterogeneity between datasets. This pattern of findings could arise for several reasons including the presence of relatively rare risk alleles on common haplotype backgrounds or the functional interaction of two or more loci within the g…
Using a Multi-Locus Microsatellite Typing method improved phylogenetic distribution of Candida albicans isolates but failed to demonstrate associatio…
2012
EA MERS CT3 Enjeu 3; International audience; The dimorphic yeast Candida albicans is a component of the normal microflora at the mucosal surfaces of healthy individuals. It possesses an array of phenotypic properties considered as virulence traits that contribute to pathogenicity of the yeast in immuno-compromised patients. We addressed the question of the pathogenicity of lineages of C. albicans with regard to their genotype in three series of C. albicans isolates (a series of commensal isolates collected in healthy individuals, a group of bloodstream isolates and a group of non-bloodstream clinical isolates) using a Multi-Locus Microsatellite Typing (MLMT) approach based on the analysis o…
No evidence for prezygotic postcopulatory avoidance of kin despite high inbreeding depression.
2018
11 pages; International audience; Offspring resulting from mating among close relatives can suffer from impaired fitness through the expression of recessive alleles with deleterious effects. Postcopulatory sperm selection (a prezygotic mechanism of cryptic female choice) has been suggested to be an effective way to avoid inbreeding. To investigate whether postcopulatory female choice allows the avoidance of fertilization by close kin, we performed artificial inseminations in a promiscuous bird, the houbara bustard (Chlamydotis undulata undulata). Females were inseminated with a mix of sperm from triads of males, each constituted of a male genetically unrelated to the female, a first cousin …
Strong reproductive barriers in a narrow hybrid zone of West-Mediterranean green toads (Bufo viridis subgroup) with Plio-Pleistocene divergence
2010
Abstract Background One key question in evolutionary biology deals with the mode and rate at which reproductive isolation accumulates during allopatric speciation. Little is known about secondary contacts of recently diverged anuran species. Here we conduct a multi-locus field study to investigate a contact zone between two lineages of green toads with an estimated divergence time of 2.7 My, and report results from preliminary experimental crosses. Results The Sicilian endemic Bufo siculus and the Italian mainland-origin B. balearicus form a narrow hybrid zone east of Mt. Etna. Despite bidirectional mtDNA introgression over a ca. 40 km North-South cline, no F1 hybrids could be found, and nu…
Females tend to prefer genetically similar mates in an island population of house sparrows.
2014
11 pages; International audience; BACKGROUND: It is often proposed that females should select genetically dissimilar mates to maximize offspring genetic diversity and avoid inbreeding. Several recent studies have provided mixed evidence, however, and in some instances females seem to prefer genetically similar males. A preference for genetically similar mates can be adaptive if outbreeding depression is more harmful than inbreeding depression or if females gain inclusive fitness benefits by mating with close kin. Here, we investigated genetic compatibility and mating patterns in an insular population of house sparrow (Passer domesticus), over a three-year period, using 12 microsatellite mar…