Biomedical subjects

Julia Ferrari

Publications and source records attributed to Julia Ferrari.

3 recordsLinked to original sources

PubMed2007

The Thr715Pro polymorphism of the P-selectin gene is not associated with ischemic stroke risk.

BACKGROUND AND PURPOSE: A Thr>Pro polymorphism at codon 715 in the coding region of the P-selectin gene has recently been described. Individuals carrying the Pro715 allele were reported to have a reduced risk of myocardial infarction. A possible association of this polymorphism with the risk of ischemic stroke is currently under discussion. METHODS: We investigated the prevalence of the 715 Thr>Pro polymorphism in 450 patients aged younger than 60 years with ischemic stroke or transient ischemic attack and in 450 controls without vascular disease matched for age and gender. We also investigated possible interactions of the polymorphism with other vascular risk factors, stroke severity and stroke etiology. RESULTS: The distribution of the two allelic variants of the 715Thr>Pro polymorphism did not differ significantly between patients and control subjects (78% versus 81% for Thr/Thr, 21% versus 18% for Thr/Pro and 1% versus 1% for Pro/Pro in patients and controls, respectively; adjusted odds ratio for carriers of the C allele: 1.0 [0.8 to 1.2; P=0.695]). We found no significant interaction of this polymorphism with vascular risk factors, stroke severity, or stroke etiology. CONCLUSIONS: Our study supports results from previous investigation showing that the 715Thr>Pro polymorphism of the P-selectin gene was not associated with a risk or clinical characteristics of ischemic stroke.

Alleles↗

PubMed2006

Population differentiation and genetic variation in host choice among pea aphids from eight host plant genera.

Habitat choice plays a critical role in the processes of host range evolution, specialization, and ecological speciation. Pea aphid, Acyrthosiphon pisum, populations from alfalfa and red clover in eastern North America are known to be genetically differentiated and show genetic preferences for the appropriate host plant. This species feeds on many more hosts, and here we report a study of the genetic variation in host plant preference within and between pea aphid populations collected from eight genera of host plants in southeastern England. Most host-associated populations show a strong, genetically based preference for the host plant from which they were collected. Only in one case (populations from Vicia and Trifolium) was there little difference in the plant preference spectrum between populations. All populations showed a significant secondary preference for the plant on which all the aphid lines were reared: broad bean, Vicia faba, previously suggested to be a "universal host" for pea aphids. Of the total genetic variance in host preference within our sample, 61% could be attributed to preference for the collection host plant and a further 9% to systematic differences in secondary preferences with the residual representing within-population genetic variation between clones. We discuss how a combination of host plant preference and mating on the host plant may promote local adaptation and possibly ecological speciation, and whether a widely accepted host could oppose speciation by mediating gene flow between different populations.

Animals↗

PubMed2005

Aphid protected from pathogen by endosymbiont.

Aphids are associated with several facultative bacterial endosymbionts that may influence their interactions with other organisms. We show here that one of the three most common facultative symbionts of pea aphid (Acyrthosiphon pisum), the bacterium Regiella insecticola, has a major effect on host resistance to a fungal pathogen. Experimental establishment of the bacterium in uninfected aphid clones led to higher survival after fungal attack. The bacteria also increased the aphid's inclusive fitness, because the presence of the symbiont reduced the probability of fungal sporulation on aphid cadavers, hence lowering the rate of transmission of the disease to nearby related aphids.

Animals↗