Development of genetic research in the USSR

Two periods of the development of genetic research in the USSR with reference to its current trends of plant and animal genetics, cytogenetics, and molecular genetics are reviewed. A short list of priority areas is established: the maintenance and use of unique gene pools of plants and animals; the domestication of animals and cultivation of new plants; the development of programmes for mathematical treatment of genetic data banks. It is suggested to consider them within the framework of international projects. The idea is to promote the collaborative efforts of scientists on an international scale.     

Localization of the α2-macroglobulin gene and Lpm gene family on mink chromosome 9

Summary Using cloned cDNA for human ₂-macroglobulin (A2M) as a probe, mink-Chinese hamster hybrid cells were analysed. The results allowed us to assign a gene for A2M to mink chromosome 9. Breeding tests demonstrated that the Lpm-locus coding for other related -macroglobulin protein and the gene for peptidase B (PEPB) are linked 11±3 cm apart. The PEPB gene is located on mink chromosome 9, and hence, the Lpw-locus is on the same mink chromosome. The relationship of the genetic systems controlling the isotypically different -macroglobulins in mink serum are discussed.     

Development and study of spring bread wheat variety Pamyati Maystrenko with introgression of genetic material from synthetic hexaploid Triticum timopheevii Zhuk. × Aegilops tauschii Coss.

Synthetic hexaploids are bridges for transferring new genes that determine resistance to stress factors from wild-type species to bread wheat. In the present work, the method of developing the spring bread wheat variety Pamyati Maystrenko and the results of its study are described. This variety was obtained using one of the immune lines produced earlier via the hybridization of the spring bread wheat variety Saratovskaya 29 with the synthetic hexaploid T. timopheevii Zhuk. × Ae. tauschii Coss. The C-staining of chromosomes in the Pamyati Maystrenko variety revealed substitutions of 2B and 6B chromosomes by the homeologous chromosomes of the G genome of T. timopheevii and the substitution of chromosome 1D by an orthologous chromosome of Ae. tauschii. It was found that this variety is characterized by resistance to leaf and stem rust, powdery mildew, and loose smut as well as by high grain and bread-making qualities. The role of the alien genetic material introgressed into the bread-wheat genome in the expression of adaptive and economically valuable traits in the Pamyati Maystrenko variety is discussed.     

Comparative characteristic of Triticum aestivum/Triticum durum and Triticum aestivum/Triticum dicoccum hybrid lines by genomic composition and resistance to fungal diseases under different environmental conditions

The genetic diversity of common wheat hybrid lines Triticum aestivum/Triticum durum and Triticum aestivum/Triticum dicoccum (2n = 42, F_6–7) using chromosome-specific microsatellite (SSR) markers and C-banding of chromosomes was studied. Cluster analysis of data obtained by 42 SSR markers indicated that the hybrid lines can be broken into three groups according to their origin. There were two cases of complete genetic similarity between lines 183₂-2/184₁-6 and 208-3/213-1, which were obtained using common wheat as the parental plants. In cross combinations, when the stabilization of the nuclear genome of hexaploid lines occurred against a background of the cytoplasmic genome of tetraploid wheats, there was a high level of divergence between sister lines, in some cases exceeding 50%. The evaluation of the degree of susceptibility of the lines to powdery mildew, leaf and stem rust, and septoria leaf blotch was performed under different environmental conditions. It was shown that resistance to powdery mildew and leaf rust significantly depended on the region where assays were conducted. An evaluation of the field data showed that the lines 195-3, 196-1, and 221-1 with T. durum genetic material displayed complex resistance to fungal pathogens in Western Siberia and the Republic of Belarus. For lines 195-3 and 196-1, one shows a possible contribution of chromosomes 4B and 5B in the formation of complex resistance to diseases. Hybrid lines with complex resistance can be used to expand the genetic diversity of modern common wheat cultivars for genes of immunity.     

The inheritance of endosperm storage proteins by the line of the Saratovskaya 29 cultivar of common wheat from its parental forms

We ran a comparative analysis of storage proteins (gliadins, high(HMW) and low-molecularweight (LMW) glutenins, puroindolines, and exogenous pest alpha-amylase inhibitors) in the Saratovskaya 29 cultivar line from the collection of a genetic engineering laboratory, its parental forms (Albidum 24 and Lutescens 55/11), and distant ancestors (Poltavka, Selivanovskiy Rusak, Sarroza, and tetraploid Beloturka). It was confirmed that the allelic states of storage proteins in the Gli-1, Gli-2 and Glu-1 loci originate from ancestral forms from the collection of the Vavilov Institute of Plant Industry. Moreover, new alleles were found in Lutescens 55/11 (Glu-A1a) and Selivanovskiy Rusak (Glu-B1b) cultivars from the collection of the Institute of Cytology and Genetics. A new allelic state, Ha, was observed in the loci of the Poltavka cultivar as a soft-grain cultivar, and the ha allele was found in the hard-grain Albidum 24 and Sarroza cultivars. It was found that the expression rate of exogenous pest alpha-amylase inhibitors in the Saratovskaya 29 cultivar line is lower than that of ancestral cultivars (Albidum 24, Sarroza, Poltavka, and Beloturka). Such inhibitors are absent in the paternal form Lutescens 55/11. A high expression rate of protein pest inhibitors for exogenous α-amylases and puroindolines was observed in the Poltavka cultivar. The allelic composition of Glu-1 loci was newly studied in the Sarroza cultivar, which has some promising features. The Saratovskaya 29 cultivar line, on the basis of which a wide range of diverse lines were created in the Institute of Cytology and Genetics, is isogenic for all of the studied traits.     

Peculiarities of cytomixis in pollen mother cells of transgenic tobacco plants (Nicotiana tabacum L.) with mutant phenotype

The frequency characteristics and cytological picture of cytomixis in the course of male meiosis are described in transgenic tobacco plants (Nicotiana tabacum L.) with altered flower morphology and male sterility. Effects of cytomixis on qualitative composition of meiotic products are studied (formation of cytoplasts and polyads). Doubling of the chromosome number was established to increase frequency of cytomixis in the studied plants.     

Specific features of vector sequences insertion in the genome of transgenic plants

Upon processing of T-DNA, both borders may be recognized incorrectly. A number of transgenic plants containing, apart from a fragment of vector DNA adjacent to the left border of T-DNA, a vector fragment inserted irrespective of it were identified. Sequence analysis confirmed that genes located beyond the boundaries of T-DNA are transferred and inserted in the genome of transgenic plants. Recombination of vector DNA was discovered among plants of the first generation after self-pollination of the original transformants.     

T-DNA-induced mutations in transgenic plants

The review surveys experimental data on changes of individual traits in genetically modified (transgenic) plants. The attention is focused on mutations induced by T-DNA insertions upon Agrobacterium-induced transformation of dicotyledonous plants. The character of mutation appearance in transgenic plants is examined. The prospects of mutations induced by T-DNA insertions are considered.     

Tobacco transformants expressing antisense sequence of proline dehydrogenase gene possess tolerance to heavy metals

Analysis of resistance of genetically modified tobacco plants bearing antisense suppressor of proline dehydrogenase gene and characterized with higher content of proline to elevated concentrations of heavy metals was performed. It was demonstrated that progeny of transgenic plants have high resistance to lead, nickel and cadmium ions.