Том 52, № 2 (2018)

Electrophoretic mobility (EM) and molecular weight (MW) of some allelic variants of α- and β-gliadins contrlled by Gli-2 loci were compared by means of two-dimensional (APAGE × SDS) electrophoresis. Comparison of α-gliadins of the alleles Gli-A2b and Gli-A2p, of β-gliadins of the Gli-B2b and Gli-B2c, and of β-gliadins of the Gli-D2b, Gli-D2c, Gli-D2j, and Gli-D2r indicated that a gliadin with lower EM had, as a rule, bigger MW which is known to depend on the length of the polyglutamine domain of gliadin of α-type. However, allelic variants of the α-gliadin encoded by Gli-D2b and Gli-D2e differ in EM but not in apparent MW. It might be caused by a substitution of some charged/uncharged aminoacids in the polypeptide of gliadin. Allele Gli-B2o which is very frequent in up-to-date common wheat germplasm originated probably by means of unequal crossingover. Some alleles at Gli-A2 is found to control completely different blocks of gliadins and therefore might come to common wheat from different genotypes of the polymorphic diploid donor of the A genome. The results indicate that the reason of the known more vast polymorphism of gliadins controlled by Gli-2 loci as compared with Gli-1 loci is the considerable difference of the structure, first, of Gli-1 and Gli-2 loci (Gli-2 loci have more expressed genes per locus) and, second, of genes encoding gliadins of α- and γ-types (α-gliadins are shown to contain a long polyglutamine sequences highly variable in their length).

Results of classical and structural bioinformatical research allow to predict casein kinase 2 dependent phosphorylation of conservative residues of Ser94 and Ser419 in Trypanosoma and Arabidopsis α-tubulin. Location of these residues in the region of internal contact of α-/β-tubulin heterodimer has been demonstrated. It is hypothesized that phosphorylation of Ser94 can affect dimerization of α-/β-tubulin in Trypanosoma and Arabidopsis. Most likely, potential phosphorylation of Ser419 does not have a direct effect on microtubule structure but is related to interaction with associated proteins, in particular with kinesins.

The effects of exogenous phytohormones–gibberellic acid (GA3) and benzyl-aminopurine (BAP)–on the spore germination and morphogenesis of Polystichum aculeatum (L.) Roth gametophyte in vitro culture were studied. In the control, four stages of gametophyte morphogenesis were determined and their periods were established. Spore germination and protonema formation of P. aculeatum occurred according to the Vittaria-type and prothalium development according to the Aspidium-type. The spore germination percentage depended on the storage time duration. It was found that 80–95% of freshly collected spores germinated. Spore viability was within the range of 68–95% after 4–6-month storage under lab conditions and did not exceed 20% after 1.5 year of the storage period. High concentrations of exogenous GA3 (10^–5 and 10^–6 M) and BAP (10–5 M) significantly inhibited spore germination, whereas low concentrations (GA3 10^–7–10^–8 M) had an insignificant stimulating effect or did not affect germination at all (BAP 10^–6, 10^–7, 10^–8 M). All concentrations of exogenous BAP were demonstrated to inhibit the development of P. aculeatum gametophyte at the protonema stage, which might be due to the removal of apical dominance. The inhibiting effect directly depended on BAP concentrations. The formation of abnormal thalli of the P. aculeatum gametophyte in the response to exogenous GA3 treatments occurred as a result of impairment of cell growth by elongation. A direct interrelationship between GA3 concentrations and level of morphological abnormalities and grade of thalli underdevelopment was demonstrated.

The polymorphic variants G919A and A2039G of the FSHR gene in men with azoospermia were investigated. In the nonobstructive form of azoospermia, the frequency of homozygotes GGAA, GGGG, and AAAA was 1.8–3.2 times higher than theoretically expected. In men with nonobstructive azoospermia, the highest level of follicle stimulating hormone (FSH) in serum was observed in homozygotes for the polymorphic variant G919A of gene FSHR; heterozygotes were characterized by intermediate values; wild-type homozygotes showed a low level, r_s = 0.49. The FSH level in some patients with the nonobstructive form was at the upper limit or higher compared with the normal values, 19.07–33.42 mIU/mL, and the FSH level was in the normal range in the obstructive form. For obstructive azoospermia, the actual frequency of heterozygotes GGGG, GAAG, and AAAA was 2–5.1 times higher than expected; no homozygotes GGAA were found.

Precise assessment of diversity in available breeding germplasm helps to preempt epidemics and abrupt environmental changes. Spring wheat germplasm consisting of 84 accessions including cultivars, breeding lines and landraces from various origins was scanned with 44 SSRs. For allele frequencies, allelic patterns, heterozygosity and polymorphism the selected population was divided in three subpopulations: (i) pre-green revolution (pre-1965), (ii) post-green revolution (post-1965), (iii) post-veery (post-2000). Alleles produced in pre-1965, post-1965 and post-2000 subpopulations were 115, 144 and 131, respectively. Mean PIC values for pre-1965, post-1965 and post-2000 subpopulations were 0.48, 0.52 and 051, respectively. Allelic patterns showed no locally common alleles in any of the subpopulation. The pre-1965 subpopulation had also no private allele, however, average number of private alleles decreased from post-1965 to post-2000 subpopulation. In case of effective alleles and Shannon’s information index trend was increasing from pre-1965 to post-1965 and then decreasing from post-1965 to post-2000. The decreasing trend alarms the reduced genetic diversity in wheat varieties developed after 2000. PCA and cluster analysis didn’t clearly differentiated subpopulations, though pre-1965 genotypes showed higher genetic distance from post-1965 and post-2000 subpopulations. The decreasing measures of genetic diversity in post-2000 wheat genotypes should be a concern for wheat breeders, therefore, all sources of broadening genetic diversity should be exploited.