ASSOCIATION OF MATRIX METALLOPROTEINASES GENE POLYMORPHISM WITH CLINICAL MANIFESTATIONS OF BRONCHIAL ASTHMA IN CHILDREN

In the present study, we have examined association between different polymorphic variants of metalloproteinases genes and clinical manifestations of bronchial asthma in children. We observed 103 patients including 42 children with an established diagnosis of asthma. Moreover, 61 persons were examined in the control group. All patients underwent genetic testing by allele-specific polymerase chain reaction. In particular, 320A>C polymorphic locus of ММР20 gene; Val275Ala ММР20, and -8202A>G gene ММР9 were analyzed.We have found that 30 patients (71.4% of total) had bronchial asthma of mild severity, 9 children (21.4%) exhibited moderate degree, and 3 patients (7%) had severe-grade disease. Homozygous C/C variant of the polymorphic ММР20 gene, 320A>C heterozygous variant of the ММР20 Val275Ala polymorphism, and heterozygous locus of -8202A>G ММР9 gene were found to be most frequent among the children with asthma. Generally, we have observed that the frequencies of the studied alleles and genotypes did not significantly differ berween the asthma patients and children from the control group (p < 0.05). However, in patients with GGgenotype of -8202A>G ММР9 polymorphism combined with homozygosity for the C allele of ММР20 320A>C, a more severe disease was observed, being combined with polyvalent sensitization and high total IgE levels in blood serum.In conclusion, frequencies of alleles and genotypes among patients with asthma did not show any statistically significant differences from the group of healthy children. The patients homozygous for G allele of ММР9 -8202A>G polymorphism gene and for the C allele ММР20 gene (320A>C) seem to be predisposed for a more severe clinical course of the disease.

A FACS-Optimized Screen Identifies Regulators of Genome Stability in Candida albicans

ABSTRACTLoss of heterozygosity (LOH) plays important roles in genome dynamics, notably, during tumorigenesis. In the fungal pathogenCandida albicans, LOH contributes to the acquisition of antifungal resistance. In order to investigate the mechanisms that regulate LOH inC. albicans, we have established a novel method combining an artificial heterozygous locus harboring the blue fluorescent protein and green fluorescent protein markers and flow cytometry to detect LOH events at the single-cell level. Using this fluorescence-based method, we have confirmed that elevated temperature, treatment with methyl methanesulfonate, and inactivation of the Mec1 DNA damage checkpoint kinase triggered an increase in the frequency of LOH. Taking advantage of this system, we have searched forC. albicansgenes whose overexpression triggered an increase in LOH and identified four candidates, some of which are known regulators of genome dynamics with human homologues contributing to cancer progression. Hence, the approach presented here will allow the implementation of new screens to identify genes that are important for genome stability inC. albicansand more generally in eukaryotic cells.

Infectious Endogenous Retroviruses in Cats and Emergence of Recombinant Viruses

Endogenous retroviruses (ERVs) comprise a significant percentage of the mammalian genome, and it is poorly understood whether they will remain as inactive genomes or emerge as infectious retroviruses. Although several types of ERVs are present in domestic cats, infectious ERVs have not been demonstrated. Here, we report a previously uncharacterized class of endogenous gammaretroviruses, termed ERV-DCs, that is present and hereditary in the domestic cat genome. We have characterized a subset of ERV-DC proviral clones, which are numbered according to their genomic insertions. One of these, ERV-DC10, located in the q12-q21 region on chromosome C1, is an infectious gammaretrovirus capable of infecting a broad range of cells, including human. Our studies indicate that ERV-DC10 entered the genome of domestic cats in the recent past and appeared to translocate to or reintegrate at a distinct locus as infectious ERV-DC18. Insertional polymorphism analysis revealed that 92 of 244 domestic cats had ERV-DC10 on a homozygous or heterozygous locus. ERV-DC-like sequences were found in primate and rodent genomes, suggesting that these ERVs, and recombinant viruses such as RD-114 and BaEV, originated from an ancestor of ERV-DC. We also found that a novel recombinant virus, feline leukemia virus subgroup D (FeLV-D), was generated by ERV-DCenvtransduction into feline leukemia virus in domestic cats. Our results indicate that ERV-DCs behave as donors and/or acceptors in the generation of infectious, recombinant viruses. The presence of such infectious endogenous retroviruses, which could be harmful or beneficial to the host, may affect veterinary medicine and public health.

Heterokaryon formation in Coprinus lagopus

1. The four possible kinds of heterokaryon of Coprinus lagopus with no, one or both mating-type factors in common (dikaryon, common A, common B and common AB) were produced. Analysis of hyphal tips of common A and common AB heterokaryons has shown that both nuclei may be present in the same hypha.2. All four heterokaryons are prototrophic when synthesized from two auxotrophic components with different requirements.3. When synthesized in this way compatible heterokaryons were stable in all tests, but the other heterokaryons showed different degrees of stability. Common B heterokaryons were the most stable and rarely gave rise to monokaryotic mycelia. Dissociation of the common A and the common AB heterokaryon into either component took place much more easily.4. Comparisons of the growth-rates of wild-type heterokaryons on complete medium show that common A heterokaryons are less vigorous, and dikaryons more vigorous than their monokaryon components. On minimal medium both compatible and common A heterokaryons are less vigorous than their wild-type monokaryon components. The possible reasons for this are discussed.5. Fruit-bodies have been obtained from both common A and common B heterokaryons. Both types showed normal segregation at the heterozygous locus (B or A), but showed in addition the segregation of new reactions at the ‘homozygous’ locus.