Anti-stress activity of Propionibacterium freudenreichii: identification of a reactivative protein

Propionibacterium freudenreichii subsp. shermanii is known to prevent mutations caused by various agents such as N-methyl-N'-nitro-N-nitrosoguanidine, 9-aminoacridine, 4-nitro-quinoline-1-oxide and by UV radiation in both prokaryotic and eukaryotic cells. It was also shown to prevent or repair damage caused by H(2)O(2) or UV radiation in Salmonella typhimurium and Escherichia coli, a characteristic previously designated as reactivative effect. In order to characterise this effect at the molecular level, we have purified the active component from a P. freudenreichii cell-free extract using a combination of ammonium sulfate precipitation, anion-exchange and size-exclusion chromatography. The isolated 35 kDa protein was then identified using both N-terminal and internal peptide sequencing as a cysteine synthase. The latter was localised in the P. freudenreichii proteomic map. It is constitutively expressed but also clearly induced during adaptation to detergent and heat, but not acid, stresses. The biological meaning of cysteine synthase in the context of adaptation to oxidative and non-oxidative stresses is discussed.     

Allelic polymorphism of the CGG repeat region in the <Emphasis Type="Italic">FMR1</Emphasis> gene in patients with impaired natural and stimulated ovulation

The frequency of heterozygote carriers of risk zone alleles of the FMR1 gene (40–47 CGG repeats) was significantly higher in the group of patients with ovarian dysfunctions compared to control group I. The frequency of these alleles shows an increasing tendency in patients poorly responding to superovulation induction in IVF cycles. The average number of oocytes and follicles obtained from the stimulation of superovulation was significantly decreased in FMR1 gene heterozygous risk zone allele carriers as compared to patients with normal alleles of the FMR1 gene. The general average dosage of exogenous gonadotrophin necessary for superovulation induction was significantly higher in heterozygote carriers of FMR1 gene risk zone alleles than in patients with normal genotype. As well, the FMR1 gene risk zone alleles can be one of the hereditary susceptibility factors of impaired natural and stimulated ovulation.     

A case of deletion of the short arm of the chromosome 21 (21p-) (christchurch chromosome) discovered prenatally:clinical and cytogenetic data

Results of cytogenetic research of placental villi and amniotic fluid cells culture of the 22-weeks-old fetus with multiple congenital malformations (MCM) are presented. The absence of the short arm in one of the homologue of the chromosome 21 was revealed. Cytogenetic analysis of the fetus father's blood lymphocytes determined the similar chromosome. Further research of the father's karyotype made by FISH-method using specific DNA samples had discovered the absence of subtelomeric parts in the short arm of the chromosome 21 that might be considered as a deletion. It was suggested that the effect of position and interaction of genes could play a key role in appearing of MCM in the fetus in the case when the 21p-chromosome was transferred to it from the healthy parents.     

Diversity and Prevalence of Hereditary Diseases among Nogais of the Karachay-Cherkess Republic

The diversity and prevalence of hereditary diseases (HDs) among Nogais of the Karachay-Cherkess Republic (KChR) are described. The size of the surveyed KChR population was 387231 individuals, including 3.81% Nogais (14741 individuals). We revealed 36 nosological forms of HDs (110 patients from 81 families): 22 with autosomal dominant (AD) inheritance, 10 with autosomal recessive (AR) inheritance, and 4 with X-linked inheritance. The prevalence of HDs in Nogais was 1: 134. The features of HD diversity in Nogais were determined in comparison with the previously surveyed populations of Russia. The accumulation of Ehlers–Danlos syndrome (1: 388), AD amelogenesis imperfecta (1: 3685), AD ichthyosis (1: 4914), AR nonsyndromic mental retardation (1: 1340), AR Gilbert syndrome (1: 4914), and X-linked inherited deficit of glucose-6-dehydrogenase (1: 1774 males) was established. The analysis of heterozygous carriage of mutations “major” for Russia in the genes of the four following AR diseases in 118 unrelated clinically healthy Nogais (236 analyzed chromosomes) was performed: cystic fibrosis (13 mutations in the CFTR gene: CFTRdele2,3 (21 kb), F508del, I507del, 1677delTA, 2184insA, 2143delT, 2183AA>G, 2184delA, 394delTT, 3821delT, L138ins, E92K, W1282X); phenylketonuria (six frequent mutations in the PAH gene: R261X, R408W, R413P, F331S, P211T, P211L); nonsyndromic sensorineural hearing loss (35delG mutation in the GJB2 gene); and Gilbert syndrome (an increase in the number of TA repeats in the UGT1A1 gene). Allelic specificity for all studied genes in the Nogai people was revealed.     

ATP-induced shrinkage of DNA with MukB protein and the MukBEF complex of Escherichia coli

Fluorescence microscopic observation of individual T4 DNA molecules revealed that the MukBEF complex (bacterial condensin) and its subunit, the MukB (a member of the SMC [structural maintenance of chromosomes] superfamily) homodimer, of Escherichia coli markedly shrunk large DNA molecules in the presence of hydrolyzable ATP. In contrast, in the presence of ADP or ATP-gammaS, the conformation of DNA was almost not changed. This suggests that the ATPase activity of subunit MukB is essential for shrinking large DNA molecules. Stretching experiments on the shrunken DNA molecules in the presence of ATP and MukBEF indicated a cross-bridging interaction between DNA molecules.     

Population study of the Udmurt population: Analysis of ten polymorphic DNA loci of the nuclear genome

Genetic structure of Southern and Northern ethnographic groups of the Udmurt population from six regions of the Republic of Udmurtia has been studied. All the samples were examined using ten polymorphic DNA loci: VNTR/PAH, VNTR/ApoB, VNTR/DATI, VNTR/eNOS, ACE, CCR5 Δ32, KM19, IVS6a, THOI, and FABP2. Allelic and genotype frequencies were estimated for each of the six populations. The average heterozygosity for these ten polymorphic loci varied from 0.47 in Udmurts from Glazovskii region to 0.53 in Udmurts from Malopurginskii region. The level of genetic variation (F _ST) between populations of Udmurts was 0.0048. Ethnographic subdivision of the population into Northern and Southern Udmurts is in good agreement with the values of genetic distances and phylogenetic analysis.     

Point amino acid substitutions in the Ca2+-binding centers of recoverin. I. Mechanism of successive filling of Ca2+-binding centers

The molecule of photoreceptor Ca(2+)-binding protein recoverin contains four potential Ca(2+)-binding sites of the EF-hand type, but only two of them (the second and the third) can actually bind calcium ions. We studied the interaction of Ca2+ with recoverin and its mutant forms containing point amino acid substitutions at the working Ca(2+)-binding sites by measuring the intrinsic protein fluorescence and found that the substitution of Gln for Glu residues chelating Ca2+ in one (the second or the third) or simultaneously in both (the second and the third) Ca(2+)-binding sites changes the affinity of the protein to Ca2+ ions in different ways. The Gln for Glu121 substitution in the third site and the simultaneous Gln substitutions in the second (for Glu85) and in the third (for Glu121) sites result in the complete loss of the capability of recoverin for a strong binding of Ca(2+)-ions. On the other hand, the Gln for Glu85 substitution only in the second site moderately affects its affinity to the cation. Hence, we assumed that recoverin successively binds Ca(2+)-ions: the second site is filled with the cation only after the third site has been filled. The binding constants for the third and the second Ca(2+)-binding sites of recoverin determined by spectrofluorimetric titration are 3.7 x 10(6) and 3.1 x 10(5) M-1, respectively.     

Lipoxygenase inhibitors suppress intracellular calcium rise induced by ionomycin in rat thymocytes

The lipoxygenase (LO) inhibitors nordihydroguaiaretic acid (NDGA) and 15S-hydroxy-5,8,11,13-(Z,Z,Z,E)-eicosatetraenoic acid (15-HETE) have been found to suppress the rise in free cytoplasmic Ca2+ concentration [( Ca2+]i) induced by the Ca2+ ionophores ionomycin and A23187 in rat thymocytes. Bromophenacyl bromide (BPB), a phospholipase A2 (PLA2) inhibitor, produced a much weaker inhibitory effect, and indomethacin, a cyclo-oxygenase inhibitor, practically did not influence the [Ca2+]i response to ionomycin. These findings implicate the involvement of LO product(s) in the [Ca2+]i rise triggered by the Ca2+ ionophores. The contribution of the NDGA-sensitive component to the ionomycin-induced [Ca2+]i rise was significant in the ionomycin concentration range of 0.1 nM to 0.1 microM whereas at higher doses of the ionophore it gradually diminished. By contrast, the [Ca2+]i rise induced by exogenous arachidonic acid (AA) or melittin, a PLA2 activator, was not suppressed but potentiated by NDGA. Ionomycin and exogenous AA also elicited opposite changes in thymocyte cytoplasmic pH (pHi): the former elevated the pHi while the latter induced a pronounced acidification of the cytoplasm. This difference in the pHi responses may account for the different sensitivity of ionomycin- and AA-elicited [Ca2+]i signal to LO inhibitors.     

Study of the Role of the Main Factors of Population Dynamics in the Mechanism of Differentiation and Formation of Diversity and Genetic Load of Hereditary Diseases in Subpopulations of the Karachay-Cherkess Republic

Russian Journal of Genetics - The generalized results of the genetic and epidemiological study of the genetic structure of various ethnic groups of the Karachay-Cherkess Republic (KChR) through...     

Saline rivers provide arid landscapes with a considerable amount of biochemically valuable production of chironomid (Diptera) larvae

Saline rivers are supposed to be ‘hot spots’ of high biological productivity in arid landscapes. To test this, we quantified the production of chironomid larvae, because river production is known to be transferred to arid landscapes primarily by birds fed on these larvae. In addition, we studied the potential biochemical quality of the larvae for birds based on the essential highly unsaturated fatty acid (HUFA) contents in their biomass. We studied species composition and measured production of chironomid larvae in two saline rivers (Volgograd region, Russia). We also evaluated the fatty acid composition and contents of the dominant taxa and estimated the flux of HUFA from the studied saline rivers to land via chironomid potential emergence. Average monthly production of chironomids measured for only 1 month, August, was quite comparable to annual production in some freshwater rivers. All the dominant chironomid larvae had comparatively high essential eicosapentaenoic acid contents, especially Cricotopus salinophilus, which showed the highest value, reported for Chironomidae. The monthly flux of HUFA from the studied rivers to land due to the chironomid potential emergence was roughly comparable to the global average estimation of annual water–land HUFA export via emerging insects.