Genetic Identification and Phylogeny of Three Species of the Genus <Emphasis Type="Italic">Trachurus</Emphasis> Based on Mitochondrial DNA Analysis

The genetic identification and the phylogenetic relationships of 3 European species of the genus Trachurus (T. trachurus, T. mediterraneus, and T. picturatus) across their geographical distribution, have been investigated by mitochondrial DNA analysis. Both cytochrome b and 16S ribosomal DNA sequence analysis revealed the existence of several species-specific positions that distinguish the 3 studied species. Genetic distances between the species indicated that T. mediterraneus and T. picturatus are more closely related than T. trachurus. Similar topologies have been produced by neighbor-joining, maximum-likelihood, and maximum-parsimony trees, and they were in accordance with previous taxonomic classification. Internucleotide and intranucleotide diversity of T. picturatus was 2 times higher than that of T. mediterraneus and T. trachurus, possibly owing to the low levels of fishing pressure for T. picturatus. This is the first report of the phylogenetic relationships of the 3 Trachurus species and provides a possible scenario of the time of divergence related to the closure of the Gibraltar Straits. In addition, the present results can be used for genetic identification of the 3 species, even from the early stage of eggs, and for detection of commercial fraud.     

Instability of the insertional mutation inCftr TgH(neoim)Hgu cystic fibrosis mouse model

Background

There have been inconsistent results from case-control studies assessing the association of the PON1 Q192R polymorphism with coronary heart disease (CHD). Most studies have included predominantly men and the association in women is unclear. Since lipid levels vary between the sexes the antioxidant effect of PON1 and any genes associated with it may also vary by sex. We have examined the association of the PON1 Q192R polymorphism with CHD in a large cohort of British women and combined the results from our cohort study with those from all other published studies.

Results

The distribution of genotypes was the same among women with CHD and those without disease. The odds ratio (95% confidence interval) of having CHD comparing those with either the QR or RR genotype to those with QQ genotype (dominant model of association) was 1.03 (0.89, 1.21) and the per allele odds ratio was 0.98 (0.95, 1.01). In a meta-analysis of this and 38 other published studies (10,738 cases and 17,068 controls) the pooled odds ratio for the dominant effect was 1.14 (1.08, 1.20) and for the per allele effect was 1.10 (1.06, 1.13). There was evidence of small study bias in the meta-analyses and the dominant effect among those studies with 500 or more cases was 1.05 (0.96, 1.15). Ethnicity and reporting of whether the genotyping was done blind to the participants clinical status also contributed to heterogeneity between studies, but there was no difference in effect between studies with 50% or more women compared to those with fewer women and no difference between studies of healthy populations compared to those at high risk (with diabetes, renal disease of familial hypercholesterolaemia).

Conclusion

There is no robust evidence that the PON1 Q192R polymorphism is associated with CHD risk in Caucasian women or men.     

CYP46 T/C Polymorphism is not Associated with Alzheimer’s Dementia in a Population from Hungary

Multiple genetic and environmental factors regulate the susceptibility to Alzheimer’s disease (AD). Recently, several independent studies have reported that a locus on chromosome 14q32.1, where a gene encoding a cholesterol degrading enzyme of the brain, called 24-hydroxylase (CYP46A1) is located, has been linked with AD. The single nucleotide polymorphism (T/C) in intron 2 of CYP46 gene has been found to confer the risk for AD. The water soluble 24(S)-hydroxysterol is the product of the CYP46A1, and elevated plasma and cerebrospinal fluid hydroxysterol concentrations have been found in AD, reflecting increased brain cholesterol turnover or cellular degradation, due to the neurodegenerative process. A case–control study was performed on 125 AD and 102 age- and gender-matched control subjects (CNT) from Hungary, to test the association of CYP46 T/C and apolipoprotein E (ApoE) gene polymorphisms in AD. The frequency of the CYP46 C allele was similar (χ²=0.647, df=1, P=0.421, exact P=0.466, OR=0.845; 95% CI: 0.561–1.274) in both groups (CNT: 27%; 95% CI: 21.3–33.4; AD 30%; 95% CI: 25.0–36.3). The ApoE ɛ4 allele was significantly over-represented (χ²=11.029, df=2, P=0.004) in the AD population (23.2%; 95% CI: 18.2–29.0) when compared with the CNT (11.3%; 95% CI: 7.4–16.6). The presence or absence of one or two CYP46C alleles together with the ApoE ɛ4 allele did not increase the risk of AD (OR=3.492; 95% CI: 1.401–8.707; P<0.007 and OR=3.714; 95% CI: 1.549–8.908; P<0.003, respectively). Our results indicate that the intron 2 T/C polymorphism of CYP46 gene (neither alone, nor together with the ɛ4 allele) does not increase the susceptibility to late-onset sporadic AD in the Hungarian population.     

Vertical nutrient and phytoplankton distribution in relation to physical stability

The vertical distribution of nutrients and phytoplankton in relation to water stability in Saronicos Gulf, Greece, was examined during mixing and during water stratification. Phosphate, nitrate and phytoplankton were stratified during mixing (February), and phytoplankton was well stratified, mainly in April. Thus nutrient and phytoplankton vertical distribution do not always follow the motion of the water and eutrophic conditions favour nutrient and phytoplankton stratification.     

Ii-Key/HER-2/<Emphasis Type="Italic">neu</Emphasis>(776-90) hybrid peptides induce more effective immunological responses over the native peptide in lymphocyte cultures from patients with HER-2/<Emphasis Type="Italic">neu</Emphasis>+ tumors

We have demonstrated that coupling an immunoregulatory segment of the MHC class II-associated invariant chain (Ii), the Ii-Key peptide, to a promiscuous MHC class II epitope significantly enhances its presentation to CD4+ T cells. Here, a series of homologous Ii-Key/HER-2/neu(776-790) hybrid peptides, varying systematically in the length of the epitope(s)-containing segment, are significantly more potent than the native peptide in assays using T cells from patients with various types of tumors overexpressing HER-2/neu. In particular, priming normal donor and patient PBMCs with Ii-Key hybrid peptides enhances recognition of the native peptide either pulsed onto autologous dendritic cells (DCs) or naturally presented by IFN-gamma-treated autologous tumor cells. Moreover, patient-derived CD4+ T cells primed with the hybrid peptides provide a significantly stronger helper effect to autologous CD8+ T cells specific for the HER-2/neu(435-443) CTL epitope, as illustrated by either IFN-gamma ELISPOT assays or specific autologous tumor cell lysis. Hybrid peptide-specific CD4+ T cells strongly enhanced the antitumor efficacy of HER-2/neu(435-443) peptide-specific CTL in the therapy of xenografted SCID mice inoculated with HER-2/neu overexpressing human tumor cell lines. Our data indicate that the promiscuously presented vaccine peptide HER-2/neu(776-790) is amenable to Ii-Key-enhancing effects and supports the therapeutic potential of vaccinating patients with HER-2/neu+ tumors with such Ii-Key/HER-2/neu(776-790) hybrid peptides.     

Effect of heavy metals on the glutathione status in different ectomycorrhizal <Emphasis Type="Italic">Paxillus involutus</Emphasis> strains

The glutathione (GSH) status and heavy metal tolerance were investigated in four Paxillus involutus strains isolated from different heavy-metal-polluted and non-polluted regions of Europe. The heavy metal burden in the habitats did not affect significantly either the heavy metal (Cr₂O₇²⁻, Cd²⁺, Hg²⁺, Pb²⁺, Zn²⁺, Cu²⁺) tolerance and accumulation or the GSH production of the strains tested. Exposures to heavy metals increased the intracellular GSH concentrations in 12 from 24 experimental arrangements (four strains exposed to six heavy metals) independently of the habitats of the strains. The importance of GSH in heavy metal tolerance (high MIC values, ability to accumulate heavy metals and to grow in the presence of heavy metals) was thus demonstrated in this ectomycorrhizal fungus.     

Lack of c-kit receptor promotes mammary tumors in N-nitrosomethylurea-treated Ws/Ws rats

Background  

c-kit is expressed in various cell types during development and it has been linked to the promotion of cellular migration, proliferation and/or survival of melanoblasts, hematopoietic progenitors and primordial germ cells. Several reports have proposed a role for the c-kit gene on carcinogenesis. Gain-of-function mutations are associated with diseases such as mastocytosis and gastrointestinal stromal tumors among others. However, very little is known about pathologies associated with loss-of-function mutations. Regarding breast cancer, c-kit protein and mRNA are highly expressed in normal breast but their expression decreases or is absent in the presence of breast cancer. We studied the role of c-kit in mammary carcinogenesis in the Ws/Ws rats carrying spontaneous lack-of-function mutation in the c-kit gene. Fifty day-old virgin female Ws/Ws rats and their wild type counterparts were injected with either 50 mg/kg body weight of the chemical carcinogen N-nitrosomethylurea or with vehicle. The animals were followed-up for 6 months. Fisher 344 rats were used as positive controls for tumor development.     

Competition with a host nestling for parental provisioning imposes recoverable costs on parasitic cuckoo chick's growth

Chicks of the brood parasitic common cuckoo (Cuculus canorus) typically monopolize host parental care by evicting all eggs and nestmates from the nest. To assess the benefits of parasitic eviction behaviour throughout the full nestling period, we generated mixed broods of one cuckoo and one great reed warbler (Acrocephalus arundinaceus) to study how hosts divide care between own and parasitic young. We also recorded parental provisioning behaviour at nests of singleton host nestlings or singleton cuckoo chicks. Host parents fed the three types of broods with similar-sized food items. The mass of the cuckoo chicks was significantly reduced in mixed broods relative to singleton cuckoos. Yet, after the host chick fledged from mixed broods, at about 10-12 days, cuckoo chicks in mixed broods grew faster and appeared to have compensated for the growth costs of prior cohabitation by fledging at similar weights and ages compared to singleton cuckoo chicks. These results are contrary to suggestions that chick competition in mixed broods of cuckoos and hosts causes an irrecoverable cost for the developing brood parasite. Flexibility in cuckoos' growth dynamics may provide a general benefit to ecological uncertainty regarding the realized successes, failures, and costs of nestmate eviction strategies of brood parasites.     

Study of Caprine β-casein using Reversed-phase High-performance Liquid Chromatography and Mass Spectroscopy: Identification of a New Genetic Variant

The genotypes and the main phosphorylation levels of β-casein of goat milk were studied using RP-HPLC/ESI-MS. A new variant of caprine β-casein named E has been characterized using RP-HPLC/ESI-MS, MALDI-MS and NanoESI MS/MS methods. Its sequence differed from that of variant A in the mono amino acid substitution D47 → Y47, which resulted in a 48 Da experimental mass difference between them. The calculated molecular mass of the new variant E 6 P was estimated as 23,869 Da. Its phosphorylation pattern was similar to that of variant A, the most abundant types being those with 5 and 6 P in similar quantities.