Vol 53, No 9 (2017)

Apomixis is defined as the asexual plant reproduction through seeds that results in the production of genetically uniform progeny. In fact, apomixis could be considered as a natural way of cloning. Currently there are more than 400 plant species known to use apomixis as a strategy for their propagation. The primary fundamental aspects of apomixis are the bypassing of meiosis and parthenogenetic development of the embryo without fertilization Apomixis attracts special attention because of its potential value for agriculture, as it could be harnessed for plant breeding programs enabling the permanent fixation of heterosis in crop plants. A better understanding of the molecular and genetic regulation of apomixis is important for developmental and evolutionary perspectives but also for implementation of engineering of apomixis traits into agricultural crop plants. Despite apomixis is considered as one of the key technologies for the improving agriculture, it is currently not fully known how the genetic and molecular regulation of this important trait occurs. In this review, an up to date information on the biology of apomixis and the known genes and genetic loci associated with regulation of different components of apomixis is provided.

Using ISIAH rat strain, an animal model for stress-sensitive form of arterial hypertension, a comparison of the brain stem, hypothalamus, adrenal gland, and kidney transcriptomes for identification of the key genes involved in the development of the stress-sensitive form of arterial hypertension was conducted. Our studies revealed Ephx2 gene encoding soluble epoxide hydrolase (sEH), whose transcription level was significantly higher in all the examined organs. On the basis of other studies and our previous investigations, we concluded the necessity of further studies of Ephx2 gene and an encoded sEH protein as a potential target for pharmacological treatment of stress-sensitive arterial hypertension.

The EAST protein is a component of nuclear matrix. In the interphase cells, EAST is localized in the extrachromosomal nuclear domain. Increased EAST concentration leads to a change in spatial chromatin structure. However, previously, it was not known whether this protein played any role in the regulation of transcription. This study examines the mechanism of the EAST protein effect on the yellow gene transcription. It was demonstrated that the EAST-dependent repression observed in a model system of the yellow gene could occur not only in the presence of the Su(Hw) insulator sequence but also in the presence of the long terminal repeat sequence of the gypsy retrotransposon. In the LTR, a 92-bp sequence involved in the mechanism of EAST-dependent repression was detected. These results suggest that the found DNA motif is the place of the assembly of a protein complex, which functionally interacts with the EAST protein. This complex either independently suppresses the yellow gene expression in bristles or moves the transgene in the nuclear region with a high concentration of transcription repression factors.

A collection of Puccinia triticina isolates was characterized for polymorphism of microsatellite loci and estimated for their differentiation by geographic origin. The collection included 20 isolates from the Ural region, 31 from West Siberia, 53 from Central Europe, 32 from the Northwest region, 32 from the Volga region, and 40 from the North Caucasus (24 from Dagestan and 16 from Krasnodar and Stavropol). The studied isolates were represented by 65 virulence phenotypes. In the polymorphism analysis of 18 microsatellite loci, 69 genotypes were determined. The index values of genetic distances (F_st, R_st, KB_c) between populations for microsatellite loci indicated differentiation of P. triticina isolates according to geographical origin, and they were clustered into three groups: (1) Asian, (2) European, and (3) North Caucasian. The North Caucasian isolates from Krasnodar and Stavropol regions were closer in similarity to European isolates than the Dagestan ones. Current analysis confirmed the assumption made earlier on the basis of the virulence analysis about the existence of several geographic fungi populations in Russia.

In this study, 12 samples of chum salmon from the southern and central parts of Primorye were studied with ten microsatellite loci. All studied localities of chum salmon of Primorye formed three main genetically different groups: (1) the Narva–Barabashevka–Ryazanovka cluster of southern Primorye, (2) Kievka River, and (3) Avvakumovka River. The revealed genetic heterogeneity of chum salmon showed clear population structure in accordance with the geographical location of the samples. The study suggests that, for the purposes of artificial reproduction of chum salmon, it is desirable to perform egg planting with regard to the described population structure of chum salmon of Primorye.

Molecular genetic and karyological analyses of antlered sculpin, Enophrys diceraus, from the Sea of Japan and the Sea of Okhotsk were carried out. The karyotype of this species was studied for the first time. On the basis of karyological analysis, it was established that E. diceraus from the Sea of Japan and the Sea of Okhotsk was polymorphic in terms of the number of chromosomes and their morphology (2n = 36, 35, and 37, NF = 40). It was suggested that the karyotype with 35 chromosomes could have been produced as a result of Robertsonian translocation; the karyotype with 37 chromosomes could have been produced by crossing of individuals with different number of chromosomes. On the basis of the molecular genetic analysis of the mitochondrial COI and 16S rRNA genes, considerable differences between E. diceraus from the Sea of Japan and the Sea of Okhotsk corresponding to the level of interspecies genetic variability were established. It is concluded that E. diceraus from the Sea of Japan belongs to another species, most likely, E. namiyei.

A search for association of polymorphisms in loci rs2981582, rs2420946, rs17102287, rs1219648, rs2981578, and rs17542768 in fibroblast growth factor receptor 2 (FGFR2) gene was performed using the “case-control” method among the major ethnic groups of Kazakhstan. Restriction fragments length polymorphism analysis of DNA obtained from 495 Kazakh and 195 Russian women with breast cancer (BC) revealed no statistically significant differences compared with the control group (190 Kazakhs, 170 Russians). An assessment of combination associations of alleles and genotypes (patterns) with BC was performed using the APSampler algorithm. Association of risk type (OR > 1.4; P_Fischer < 0.05; P_permutation < 0.05) in the Kazakh group identified two patterns, including allele C at site rs2420946, while the T allele was present in four protective patterns (OR < 0.70). No significant association of the examined polymorphisms with BC risk in the Russian group was revealed.

Data of draft genome sequencing of Streptomyces fradiae-АТСС19609-Olg4R strain, resistant to (33S)-33-deoxy-33-thiocyanatooligomycin A, are presented. Comparative analysis of the genomes of S. fradiae wild-type strain ATCC19609 and S. fradiae strain ATCC19609-Olg4R showed the single nucleotide substitution that led to A(600)T change in the conservative P-loop NTPase region of class IV helicase gene, which, probably, promoted the resistance of S. fradiae strain ATCC19609-Olg4R to (33S)-33-deoxy-33-thiocyanatooligomycin A.

Female predominance among carriers of reciprocal translocations (rec) has been commonly explained by male sterility, although appropriate comparative studies had not been carried out. The objectives of this study were comparative analysis of rates of carriers of balanced chromosomal rearrangement among patients with infertility and among patients with recurrent miscarriages and comparative analysis of maleto-female ratio (sex ratio, SR) in the carriers. Metaanalysis of data from 34 publications on prevalence of chromosomal rearrangements in couples with reproductive failures showed that among couples with infertility, a carrier of reciprocal translocation was found in 0.48% (74/15306) of males and in 0.41% (64/15456) of females, SR =1.17, not different statistically from the population value of 1.06 (p = 0.36). Carriers of Robertsonian translocations (rob) were detected in 0.58% of males and in 0.11% of females, SR = 5.3 (p = 5 × 10^–13). Carriers of an inversion (inv) were found at a slightly lower rate among infertile males compared to females, 0.16% vs 0.27%, SR = 0.59 (p = 0.020). Among patients with miscarriages, carriers of rec were detected at a significantly higher rate compared to patients with infertility, in 0.78% (151/19353) of males and in 1.42% (281/19737) of females, SR = 0.55 (p = 1 × 10^–9). Carriers of rob were found in 0.33% of male patients and in 0.6% of female patients, SR = 0.56 (p = 9.7 × 10–5). Rates of male and female carriers of inv were 0.17 and 0.20%, respectively. The data obtained corroborate with the observation of female predominance among fertile carriers of rob due to male sterility. However, female predominance among fertile carriers of rec cannot be explained by the same reason. Firstly, there is no significant male prevalence among infertile carriers, secondly, the rate of rec carriers among infertile males is lower compared to that among fertile patients. This phenomenon might be explained by factors inherent to oogenesis affecting meiotic segregation of rearranged.