Vol 54, No 3 (2018)

The review provides the latest achievements in the field of wheat transformation and analysis of the factors affecting transformation efficiency. A comparative analysis of the most commonly used methods of wheat transformation, i.e., direct gene transfer by biolistic transformation and by Agrobacterium tumefaciens in vitro and in planta, is carried out. The stages and components of methods that affect transformation efficiency are examined in detail. Since the first successful biolistic transformation of wheat in 1992 and Agrobacterium- mediated transformation in 1997, 25 to 20 years have passed. Since then, all physical and biological parameters for the heterologous DNA delivery to the wheat genome and regeneration of plant transformants in vitro have been investigated and described in detail. Information on the influence of key parameters and factors on increasing transformation efficiency of highly productive wheat varieties is presented.

Clubroot disease, which is caused by Plasmodiophora brassicae Wor., a soil-borne microorganism, is one of the most severe diseases of Brassica crops. Combining of two and more dominant resistance loci is an efficient method in breeding for clubroot resistance. Several clubroot resistance loci were earlier identified on linkage groups 1, 2, 3, 6, and 8 of Brassica rapa by different research groups. In our previous studies, we found a dominant monogenic resistance locus in an inbred line 20-2ccl of Chinese cabbage. In this study, a SCAR marker tau_cBrCR404 tightly linked to clubroot resistance locus (2.9 cM) was identified by a bulked segregant analysis (BSA) of a backcross population (BC₁). The position of this clubroot resistance locus, named CrrA5, was determined on the linkage group 5 of B. rapa genome using genetic mapping. The efficiency of the tau_cBrCR404 marker in marker-assisted selection was validated using a collection of different Chinese cabbage accessions.

Variation of the 838-bp fragment of the mitochondrial cytb gene was analyzed in Sylvaemus uralensis from the northern macroslope of the Western Caucasus. On the basis of two fixed nonsynonymous substitutions, cytb sequences of the population sample studied can be considered as a distinct Lago-Naki haplogroup, which is clustered in the European cytb lineage. As estimated on the basis of the known rate of substitutions per third codon position in S. sylvaticus, the population must have been isolated for all or a part of the last glaciation period (10000 to 100000 years ago). The observed differentiation of cytb haplotypes is indicative of the refugial distribution of S. uralensis in the northern macroslope of the Western Caucasus, as well as of a secondary contact between the Caucasian and the Russian Plain populations during the Holocene.

Genetic characteristics of the allele pool of four groups of the Yakut snow sheep subspecies (Ovis nivicola lydekkeri) inhabiting various parts of the Verkhoyansk Mountain Range such as Kharaulakh Ridge, Orulgan Ridge, ridges of the Central Verkhoyansk, and Suntar-Khayata Ridge is presented. Fragment analysis using 17 microsatellite loci was carried out using the ABI 3131xl genetic analyzer. Significant heterozygote deficiency was detected in all investigated snow sheep populations. Differentiation of the studied groups in accordance to their geographical origin was revealed.

The aim of this study is to investigate the polymorphism of the Pituitary transcription factor (PIT-1) and Prolactin (PRL) genes in Holstein Friesian cows (HF) bred in Vietnam and their effects on milk yields. For these purposes, 125 HF dairy cows of milking age from Da Lat Milk Farm located in Lam Dong, Vietnam were sampled. Phenotypic data of milk yields (calculated on 305-day of milking cycle; kg/day) of each individual milking cow were collected. The PIT-1.E2, PIT-1.E6, PRL.E3 and PRL.E4 genotypes were analyzed using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method with restriction enzymes TaqI, HinfI, RsaI, respectively. The significant effects of PIT-1.E6, PRL.E3 and PRL.E4 polymorphisms on milk yields were not observed in HF dairy cows (P > 0.05). However, results revealed statistically significant associations between PIT-1.E2 polymorphism and milk yields of HF dairy cows; individuals carrying the AA genotype yielded more milk compared to others. Our study suggests the potential use of PIT-1.E2 SNP in marker assisted selection (MAS) for improved milk yields of HF dairy cows bred in Vietnam.

Heat shock proteins (HSPs) are known as molecular chaperones, and they function in response to cell stress. HSPA13, also called STCH, is a member of the HSP70 family. In general, HSP70 family may play a protective role in prion diseases. In a recent study, the overexpression of HSPA13 was shown to shorten the incubation time of prion diseases. Although the exact role of HSPA13 in the pathogenesis of prion diseases remains unknown, the expression level of HSPA13 is significantly associated with the latent phase of prion diseases. It has been known that single nucleotide polymorphisms (SNPs) in promoter and open reading frame (ORF) region of genes can affect either gene expression or gene function. The purpose of this study was to investigate genotype and allele frequencies of SNPs found in the promoter and ORF of HSPA13 in healthy Korean population to obtain the information for subsequent population genetics and prion diseases studies. We observed four SNPs in the promoter region of HSPA13, of which two have previous identified (c.-608C>G; rs2242662 and c.-381G>A; rs2242661) and two are novel (c.-321C>T and c.-300A>G). Interestingly, we did not observe any polymorphisms in the ORF of this gene. To our knowledge, this is the first study of polymorphisms in the human HSPA13 gene.

In the middle of the 20th century, massive introductions of sables were performed to recover the area of this valuable fur species. In this work, genetic variation of a naturalized sable population from the Vakh River basin (Nizhnevartovskiy district, Khanty-Mansi Autonomous Okrug) was investigated. This population developed as a result of sable introduction from Cisbaikalia in 1952‒1957. The naturalized sable population of the Vakh basin occupies an intermediate position between two autochthonous sable populations from the Ob River area and Cisbaikalia, as assessed by variation of five microsatellite loci. Apparently, the genetic structure of the modern sable population from the Vakh basin was formed by mixing the gene pools of the original Cisbaikalian population and the neighboring autochthonous populations from the Ob River area which recovered their numbers in a natural way. Data on genetic variation in the naturalized sable population agree with the results of previous morphological studies and can be employed for long-term monitoring of the outcome of sable introduction.

The analysis of genetic polymorphism of Epischura chankensis from Lake Khanka, one of the key species of zooplankton, identified traces of geographical subdivision in the past in the current single population, probably owing to the formation of isolated reservoirs in the lake valley during its regression.