Search results for " genetica"
showing 10 items of 659 documents
ATXN2 trinucleotide repeat length correlates with risk of ALS
2017
We investigated a CAG trinucleotide repeat expansion in the ATXN2 gene in amyotrophic lateral sclerosis (ALS). Two new case-control studies, a British dataset of 1474 ALS cases and 567 controls, and a Dutch dataset of 1328 ALS cases and 691 controls were analyzed. In addition, to increase power, we systematically searched PubMed for case-control studies published after 1 August 2010 that investigated the association between ATXN2 intermediate repeats and ALS. We conducted a meta-analysis of the new and existing studies for the relative risks of ATXN2 intermediate repeat alleles of between 24 and 34 CAG trinucleotide repeats and ALS. There was an overall increased risk of ALS for those carry…
Transmission pattern of hobo transposable element in transgenic lines of Drosophila melanogaster
1998
This study is an attempt to trace the fate of hobo elements in the genomes of E strains of Drosophila melanogaster that have been transfected with pHFL1, a plasmid containing an autonomous hobo. Such long-term population studies (over 105 generations) could be very useful for better understanding the population and genomic dynamics of transposable elements and their pattern of insertions. Molecular analyses of hobo elements in the transfected lines were performed using Southern blots of XhoI-digested genomic DNAs. The complete element was observed in all six injected lines. In two lines we observed, at generation 100, two deleted elements, which did not correspond to Th1 and Th2. The result…
Revisited Roles of Drosophila Female Pheromones
2005
All tests involved a pair of 5-day-old male and female (intact or decapitated) flies. Females were ‘homotypic’ (same species and strain as the tested male: D. melanogaster, Cs strain; D. mauritiana, 163.1 strain; D. simulans, Seychelles strain), ‘desat1 non-perfumed’ (D. melanogaster desat1 mutant), ‘perfumed’ (desat1 with transfer of Cs females pheromones), or ‘Cs’ (D. melanogaster control strain). Data shown are the frequencies of courtship (with both intact and decapitated females) and of mating (with intact females), within a 1 h observation period and were calculated from the total number of tested pairs (shown in brackets). D. mauritiana males courted (χ2 = 16.81, P < 0.001) and mated…
Genetic elimination of known pheromones reveals the fundamental chemical bases of mating and isolation in Drosophila
1999
Overexpression of the UAS-tra transgene in Drosophila melanogaster females led to the complete elimination of their cuticular pheromones. According to current models of Drosophila behavior, these flies should induce no courtship. In fact, they are still attractive to conspecific males. Three classes of stimuli are shown to induce courtship, with different effects on male behavior: ( i ) known pheromones produced by control females, ( ii ) stimuli produced by living control and transgenic flies, and ( iii ) as-yet-undetermined pheromones present on both control and transgenic flies. Only the latter class of pheromones are required for mating. They appear to represent a layer of ancestral at…
HLA-A, -B and -DRB1 allele frequencies in Cyrenaica population (Libya) and genetic relationships with other populations.
2011
Abstract The frequencies of HLA-A, HLA-B and HLA-DRB1 alleles in 118 unrelated Libyans from Benghazi (Cyrenaica) were analysed using high resolution typing and compared with other populations. Their relatedness has been tested by correspondence analyses and principal component analysis. The most frequent HLA-A alleles were A ∗ 02:01:01:01 (15.7%), A ∗ 01:01:01:01 (11.4%) and A ∗ 03:01:01:01 (9.3%). For the HLA-B locus, the commonest allele was HLA-B ∗ 50:01:01 (14.4%) followed by B ∗ 51:01:01 (9.8%) and B ∗ 08:01:01 (6.4%). For the HLA-DRB1 locus, the commonest was HLA-DRB1 ∗ 07:01:01:01 (16.9%) followed by DRB1 ∗ 03:01:01:01 (13.6%) and DRB1 ∗ 13:02:01 (9.3%). The most frequent two-locus h…
A whole genome screen for linkage disequilibrium in multiple sclerosis performed in a continental Italian population
2003
We have systematically screened the genome for evidence of linkage disequilibrium (LD) with multiple sclerosis (MS) by typing 6000 microsatellite markers in case-control and family based (AFBAC) cohorts from the Italian population. DNA pooling was used to reduce the genotyping effort involved. Four DNA pools were considered: cases (224 Italian MS patients), controls (231 healthy Italians), index (185 index cases from trio families) and parents (the 370 parents of the patient included in the Index pool), respectively. After refining analysis of the most promising 14 markers to emerge from this screening process, only marker D2S367 retained evidence for association. © 2003 Elsevier B.V. All r…
Genetic identification of neurons controlling a sexually dimorphic behaviour
2000
0960-9822 (Print) Journal Article Research Support, Non-U.S. Gov't; In the fruit fly Drosophila melanogaster, locomotor activity is sexually dimorphic: female flies constantly modulate their activity pattern whereas males show a steadier, stereotyped walking pace [1]. Here, we mapped the area of the brain controlling this behavioural dimorphism. Adult male Drosophila expressing a dominant feminising transgene in a small cluster of neurons in the pars intercerebralis exhibited a female-like pattern of locomotor activity. Genetic ablation of these neurons prevented the feminisation of the locomotor activity of transgenic males. The results suggest that this cluster of neurons modulates sex-sp…
Genes involved in sex pheromone discrimination in Drosophila melanogaster and their background-dependent effect.
2012
International audience; Mate choice is based on the comparison of the sensory quality of potential mating partners, and sex pheromones play an important role in this process. In Drosophila melanogaster, contact pheromones differ between male and female in their content and in their effects on male courtship, both inhibitory and stimulatory. To investigate the genetic basis of sex pheromone discrimination, we experimentally selected males showing either a higher or lower ability to discriminate sex pheromones over 20 generations. This experimental selection was carried out in parallel on two different genetic backgrounds: wild-type and desat1 mutant, in which parental males showed high and l…
Exclusion of the Sonic Hedgehog gene as responsible for Currarino syndrome and anorectal malformations with sacral hypodevelopment.
1999
Anorectal malformations (ARMs) are common congenital anomalies that account for 1:4 digestive malformations. ARM patients show different degrees of sacral hypodevelopment while the hemisacrum is characteristic of the Currarino syndrome (CS). Cases of CS present an association of ARM, hemisacrum and presacral mass. A gene responsible for CS has recently been mapped in 7q36. Among the genes localized in this critical region, sonic hedgehog (SHH) was thought to represent a candidate gene for CS as well as for ARM with different levels of sacral hypodevelopment according to its role in the differentiation of midline mesoderm. By linkage analysis we confirmed the critical region in one large fam…
TBC1D24-TLDc-related epilepsy exercise-induced dystonia: rescue by antioxidants in a disease model
2019
Genetic mutations in TBC1D24 have been associated with multiple phenotypes, with epilepsy being the main clinical manifestation. The TBC1D24 protein consists of the unique association of a Tre2/Bub2/Cdc16 (TBC) domain and a TBC/lysin motif domain/catalytic (TLDc) domain. More than 50 missense and loss-of-function mutations have been described and are spread over the entire protein. Through whole genome/exome sequencing we identified compound heterozygous mutations, R360H and G501R, within the TLDc domain, in an index family with a Rolandic epilepsy exercise-induced dystonia phenotype (http://omim.org/entry/608105). A 20-year long clinical follow-up revealed that epilepsy was self-limited in…