APPLICATION OF GENETIC METHODS OF RESEARCH IN CLINICAL DENTISTRY

Subject. The prevalence of dental diseases worldwide comes between 67% and 98% at an older age, regardless of gender. Many chronic dental processes take place with intoxication of the body. Thereby they cause significant health problems, disrupting the quality of life. They entail large financial investments both from the person and the state. Doctor’s prognosis and understanding on the possible development of the disease in the patient either completely helps to prevent it or facilitates its course, helping to recover and accelerate the rehabilitation period. Genetic tests are an extremely promising and modern solution to this prognosis. Knowledge of genetic characteristics allows dentists to determine the medical tactics, helps to build a plan of recommendations for the patient's lifestyle and the schedule of preventive examinations. In dentistry genetic tests determine the quality of the innate inflammatory immune response to the introduction of pathogenic flora. Such tests allow to find out the features of the regenerative processes in the body and the quality of the detoxification system. Thus, they help to predict a more aggressive and faster course of the disease. Purpose. The aim of the work is to study the relevance and possibility of using genetic testing in dentistry. It describes the most modern methods. The present study shows the function and interpretation of the effect of the most probable gene polymorphisms on clinical signs of dental diseases. Materials and methods. The analysis of 40 sources of domestic and foreign literature on the possibilities and availability of modern test systems in dentistry has been carried out. The information on possible associations of genetic predisposition to the most common dental diseases and conditions has been highlighted, summarized and analyzed. Conclusion. Having previously obtained the results of the patient's genetic characteristics of the metabolism of mineral and vitamin substances, confirmation of the propensity for excessive bacterial growth and other genetic characteristics, the doctor will be able to build a plan of preventive measures to preserve the patient's health or, if necessary, will prepare the patient for treatment to minimize negative effects.

Genetic diversity in wild populations of the restinga ecotype of the cashew (Anacardium occidentale) in coastal Piauí, Brazil

The cashew, Anacardium occidentale, is a globally important tropical fruit tree, but little is known about its natural infraspecific systematics. Wild Brazilian populations occur in the cerrado biome and coastal restinga vegetation. We investigated whether wild coastal and domesticated populations could be distinguished genetically using inter-simple repeat molecular markers (ISSRs). In total, 94 polymorphic loci from five primers were used to characterise genetic diversity, structure and differentiation in four wild restinga populations and four domesticated ones from eight localities in Piauí state (30 individuals per population). Genetic diversity was greater overall in wild (%P: 57.2%, I: 0.24, He : 0.15) than domesticated populations (%P: 49.5%, I: 0.19, He : 0.12). Significant structure was observed among the eight populations (between-population variance 22%, ΦPT = 0.217, P ≥ 0.001), but only weak distinctions between wild and domesticated groups. Cluster and principal coordinate analyses showed marked genetic disparity in populations. No correlation of genetic and geographical inter-population distance was found (Mantel test, r = 0.02032, P = 0.4436). Bayesian analysis found an eight-group optimal model (ΔK = 50.2, K = 8), which mostly corresponded to sampled populations. Wild populations show strong genetic heterogeneity within a small geographical area despite probable gene flow between them. Within-population genetic diversity of wild plants varied considerably and was lower where extractive activities by local people are most intense (Labino population). The study underlines the importance of wild populations as in situ genetic reserves and the urgent need for further studies to support their conservation.

Identification of a 2′-O-Methyluridine Nucleoside Hydrolase Using the Metagenomic Libraries

Ribose methylation is among the most ubiquitous modifications found in RNA. 2′-O-methyluridine is found in rRNA, snRNA, snoRNA and tRNA of Archaea, Bacteria, and Eukaryota. Moreover, 2′-O-methylribonucleosides are promising starting materials for the production of nucleic acid-based drugs. Despite the countless possibilities of practical use for the metabolic enzymes associated with methylated nucleosides, there are very few reports regarding the metabolic fate and enzymes involved in the metabolism of 2′-O-alkyl nucleosides. The presented work focuses on the cellular degradation of 2′-O-methyluridine. A novel enzyme was found using a screening strategy that employs Escherichia coli uracil auxotroph and the metagenomic libraries. A 2′-O-methyluridine hydrolase (RK9NH) has been identified together with an aldolase (RK9DPA)—forming a part of a probable gene cluster that is involved in the degradation of 2′-O-methylated nucleosides. The RK9NH is functional in E. coli uracil auxotroph and in vitro. The RK9NH nucleoside hydrolase could be engineered to enzymatically produce 2′-O-methylated nucleosides that are of great demand as raw materials for production of nucleic acid-based drugs. Moreover, RK9NH nucleoside hydrolase converts 5-fluorouridine, 5-fluoro-2′-deoxyuridine and 5-fluoro-2′-O-methyluridine into 5-fluorouracil, which suggests it could be employed in cancer therapy.

Managing Evidence from Multiple Gene Finding Resources via an XML-based Integration Architecture

SummaryWhile biological processes underlying gene expression are still under experimental research, computational gene prediction techniques have reached high level of sophistication with the employment of efficient intrinsic and extrinsic methods that identify protein-coding regions within query genomic sequences. Their ability though to delineate the exact exon boundaries is characterized by a trade off between sensitivity and specificity and still is prone to alternations in gene regulation during transcription and splicing and to inherent complexities introduced by the implemented methodology. Evaluation studies have shown that combinatorial approaches exhibit improved accuracy levels through the integration of evidence data from multiple resources that are further assessed in order to end up with the most probable gene assembly.In this work, we present an integration and information handling architecture that exploits evidence derived from multiple gene finding resources, in order to generate machine-readable representations of optimal/suboptimal gene structure predictions, signal features identification and high scoring similarity matches. Unlike most combinatorial techniques, which end up with the most probable gene assembly, the objective of this architecture is to support advanced information handling mechanisms that may give more in depth insights on the underlying gene expression machinery and the alternations that may occur. Technically, XML was adopted to build and interchange structured data among the architecture’s components together with relevant technologies offering graphical representations and queries formulation/execution over single/multiple information sources.

Genetic linkage map of fishes of the genus Xiphophorus (Teleostei: Poeciliidae).

Analysis of genotypes of 76 polymorphic loci in more than 2600 backcross hybrid individuals derived from intra- and interspecific genetic crosses of fishes of the genus Xiphophorus (Poeciliidae) resulted in the identification of 17 multipoint linkage groups containing 55 protein-coding loci and one sex chromosome-linked pigment pattern gene. Multipoint linkage analyses identified highly probable gene orders for 10 linkage groups. The total genome length was estimated to be approximately 18 Morgans. Comparisons of the Xiphophorus linkage map with those of other fishes, amphibians and mammals suggested that fish gene maps are remarkably similar and probably retain many syntenic groups present in the ancestor of all vertebrates.

Recessive Lethal Mutations and the Maintenance of Duplication-Bearing Strains of Dictyostelium discoideum

ABSTRACT Recessive lethal mutations have been isolated and used to maintain n + 1 aneuploid strains of Dictyostelium discoideum carrying a duplication of part or all of linkage group VII. The recessive lethal mutations, relA351 and relB352, arose spontaneously in diploids; no mutagenic treatment was used in the isolation of these mutations. The probable gene order on linkage group VII is: centromere, relB, couA, bsgB, cobA, relA . Maintenance of aneuploids disomic for linkage group VII was made possible by complementation of a rel mutation on each linkage group VII homologue by the corresponding wild-type allele on the other linkage group VII homologue. The duplication-bearing disomic strains were slow-growing and produced faster-growing sectors on the colony edge. Haploid sectors probably arise by a combination of mitotic recombination and subsequent loss of one homologue, diploid sectors may be formed by chromosome doubling to 2n + 2, followed by chromosome loss to return to 2n, and aneuploid sectors may arise by deletion or new mutation.

TWO FVIII GENE LESIONS DETECTED IN SEVERE AND MODERATE HAEMOPHILIA A

DNAs from 15 haemophilia A patients from different families have been hybridized to FVIII cDNA probes for the exons 14-26.In a severely affected patient (FVIII:C 2 %) the TaqI site of exon 24 is absent originating an abnormal band of 4.2 Kb. A C toT transition in the CG dinucleotide of the TaqI site (TCGA) is the probable gene mutation. Since the transition in the sense strand should originate an additional Hind III site, which is not detected in our patient, we infer that the mutation occurred in the antisensestrand causing an aminoacid change (CGA →CAA, Arg → Gin). This isin accordance with the low activity of FVIII and with the absence of inhibitor. Infact Gitschier et Al reported in a patient with ahigh titre of anti-FVIII antibody and with <1% FVIII activity a C → T transition in the coding strand, originating a nonsense codon in the TaqI site of exon 24.In the Hindlll pattern from a moderately affected patient (FVIII:C 4%) the fragment containing the exon 18 is 2.5 Kb in size (normal 2.6 Kb). Since the patterns with other restriction enzymes are indistinguishable from normal a small mutation originating a new Hind III site is likely. Both altered patterns have been detected in the patients' mothers.Work supported by Ricerca Sanitaria Finalizzata Regione Emilia Romagna