The we gene is a modifier of the wal gene in mice

Interaction of gene wellhaarig (we) with genes waved alopecia (wal) and hairless (hr) was studied in mice. The mutant gene we is responsible for the development of a specific waved coat in homozygotes. Homozygous mice carrying mutant gene wal also have a wavy coat, though a partial alopecia develops with time in these animals. In homozygotes for the hr gene, hair loss is observed beginning from the age of ten days. A series of crosses we/we and wal/wal yielded animals with we/+wal/wal and we/we wal/wal genotypes. In mice we/+wal/wal carrying gene we at a single dose, alopecia is accelerated significantly as compared to the single-dose homozygotes +/+wal/wal. In we/we wal/wal mice, alopecia starts earlier than in we/+wal/wal mice; by the age of one month, the double homozygotes are almost hairless except for small body areas covered with a sparse coat. In addition, curliness of the first-generation hair in mice we/we wal/wal is much more expressed than in +/+wal/wal and we/we+/+ mice. The obtained evidence suggests that the we gene is a modifier of the wal gene because the former enhances the effects of the wal gene, which is confirmed by the earlier onset of alopecia and progression of the latter in mice having the we/+wal/wal genotype and especially in we/we wal/wal animals. The we/we hr/+ mice do not differ in coat from we/we+/+ mice; in both cases, the coat is wavy. The coat of double homozygotes we/we hr/hr, is similar to that of we/we+/+ mice until ten days of age, when the signs of alopecia appear. By the age of 21 days, mice we/we hr/hr have lost their coat completely like mice +/+ hr/hr. Hence, the we gene is a modifier of the wal gene though it does not interact with hr gene during the coat formation.     

Evaluation of polymorphism at microsatellite loci of spring durum wheat (Triticum durum Desf.) varieties and the use of SSR-based analysis in phylogenetic studies

Polymorphism at 28 SSR loci was analyzed and described in 45 cultivars of spring durum wheat created in the former USSR and Russia during the last 80 years. Each cultivar was shown to have a unique allele combination. This allows SSR markers to be used to identify durum wheat varieties. Meanwhile, these markers can hardly be used to detect phylogenetic relationships among varieties and to specify their pedigrees, because genetic distances calculated on the basis of these markers do not correlate with the distance calculated by coefficient of parentage.     

Genetically encoded fluorescent indicators for live cell pH imaging

Background

Intracellular pH underlies most cellular processes. There is emerging evidence of a pH-signaling role in plant cells and microorganisms. Dysregulation of pH is associated with human diseases, such as cancer and Alzheimer's disease.

Species Identification of Multimammate Rats of the Genus <Emphasis Type="Italic">Mastomys</Emphasis> (Rodentia: Muridae) in Eastern Africa Using PCR Typing of Cytochrome <Emphasis Type="Italic">b</Emphasis> Gene Fragments

The multimammate rats of the genus Mastomys are widespread throughout sub-Saharan Africa. They are the major agricultural pests and reservoirs of many infections dangerous to humans. A simple and accurate species identification of multimammate rats is crucial in ecological and epidemiological studies; however, it is complicated by the absence of pronounced morphological differentiation between Mastomys species. We describe a simple molecular assay based on PCR typing of the cytochrome b gene fragments as a method that allows fast genotyping of a large number of samples without sequencing to distinguish Mastomys species of East Africa.     

Comparison of Amplification Methods of Single Trophoblast Cells for Their Subsequent Analysis Using Metaphase Comparative Genomic Hybridization

Single trophoblast cells circulating in the bloodstream of pregnant women are potential objects for noninvasive prenatal diagnosis. Owing to the very low concentration of cells of a fetal nature in the peripheral maternal blood, the choice of the method for whole genome amplification of the genetic material becomes topical. The key point in the use of single cells of a fetal nature for noninvasive prenatal diagnosis is to obtain DNA in an amount and of a quality acceptable for the analysis. In order to select the optimal method for whole genome amplification, a model experiment was conducted. We compared three different methods of whole genome amplification: linker-adaptor polymerase chain reaction (LA-PCR), degenerate oligonucleotide- primed PCR (DOP-PCR), and multiple displacement amplification (MDA). Subsequent analysis of the amplification products was performed by metaphase comparative genomic hybridization in order to evaluate the molecular karyotype of cells of a fetal nature with the known chromosome complement. As a result, an optimal method for whole genome amplification of the genetic material of single cells in a model experiment was determined by linker-adaptor PCR, which showed a more uniform representation of the genome regions compared with the other methods used.     

Analysis of the Distribution of <Emphasis Type="Italic">Triticum timopheevii</Emphasis> Zhuk. Genetic Material in Common Wheat Varieties (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)

The database of the world gene pool of wheat was scanned by pedigree and the participation of genetic material from T. timopheevii in the creation of 3088 varieties of common wheat was established. The spatial and temporal dynamics of the propagation of these varieties was studied. Using the analysis of pedigrees, a diversity of T. timopheevii donors was studied. The specificity of donors of the genetic material T. timopheevii for the regions of wheat breeding was established. The main source of resistance genes for most varieties is accession D-357-1 from the Georgian variety-population of Zanduri. This significantly reduces the diversity of the genetic material of T. timopheevii used in wheat breeding. In 369 varieties and 184 lines, the genes for resistance to pathogens from T. timopheevii were identified. The genes of T. timopheevii are distributed mainly in winter varieties, as well as spring varieties sown in autumn. The value of donors as sources of T. timopheevii genes is ambiguous, despite the fact that most of them come from the same D-357-1 accession. The Sr36 gene is most commonly found in the United States, Western Europe, and Australia; it was transferred from the Wisconsin-245 line through Arthur or TP-114-1965a. The Pm6 gene is distributed in Western Europe; it was transferred from the pre-breeding line Wisconsin 245/5*Cappelle-Desprez//Hybrid- 46/Cappelle Desprez. The gene Lr18 is more common in the United States; it was transmitted by the Blueboy or Vogel 5 varieties from the Coker-55-9 line. The extremely limited set of genes for resistance to pathogens from T. timopheevii used in commercial varieties and the specificity of their geographical distribution are possibly associated with the uniqueness of the G subgenome and plasmon in this species, its low potential for plasticity, and tolerance to drought. In addition, the imperfection of the methods of pre-breeding and recombination breeding prevents the elimination in translocation of close linkage of target genes with undesirable ones.     

Influence of plasma pedestal profiles on access to ELM-free regimes in ITER

The influence of current density and pressure gradient profiles in the pedestal on the access to the regimes free from edge localized modes (ELMs) like quiescent H-mode in ITER is investigated. Using the simulator of MHD modes localized near plasma boundary based on the KINX code, calculations of the ELM stability were performed for the ITER plasma in scenarios 2 and 4 under variations of density and temperature profiles with the self-consistent bootstrap current in the pedestal. Low pressure gradient values at the separatrix, the same position of the density and temperature pedestals and high poloidal beta values facilitate reaching high current density in the pedestal and a potential transition into the regime with saturated large scale kink modes. New version of the localized MHD mode simulator allows one to compute the growth rates of ideal peeling-ballooning modes with different toroidal mode numbers and to determine the stability region taking into account diamagnetic stabilization. The edge stability diagrams computations and sensitivity studies of the stability limits to the value of diamagnetic frequency show that diamagnetic stabilization of the modes with high toroidal mode numbers can help to access the quiescent H-mode even with high plasma density but only with low pressure gradient values at the separatrix. The limiting pressure at the top of the pedestal increases for higher plasma density. With flat density profile the access to the quiescent H-mode is closed even with diamagnetic stabilization taken into account, while toroidal mode numbers of the most unstable peeling-ballooning mode decrease from n = 10?40 to n = 3?20.     

Genealogical analysis of the use of two wheatgrass (<Emphasis Type="Italic">Agropyron</Emphasis>) species in common wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.) breeding for disease resistance

During the last 80 years, in order to increase the genetic variability of wheat, translocations containing nine elongated wheatgrass (Agropyron elongatum) and eight intermediate wheatgrass (Agropyron intermedium) genes, which control resistance to pathogens, were transferred to this crop culture. Genealogical and statistical analysis of 1500 varieties developed using the wheatgrass gave evidence of the continuing increase in the proportion of such varieties in the total number of wheat varieties over the last half-century. Translocations from Ag. elongatum most commonly occur in the pedigrees of the varieties from the United States, less frequently they can be found in Australian and Chinese varieties, and they are extremely rare—in European and African ones. Ag. intermedium most frequently occurs in the pedigrees of the Eastern European varieties, mainly in those from Russia, as well as in the varieties from China. The observed uneven distribution of such varieties may be associated with either the effectiveness of the translocation in the development of resistance to the local populations of pathogens or with the effect of the translocation on the adaptive traits of plants. By computer tracking of pedigrees, we performed an inventory of the translocation donors from Ag. elongatum and Ag. intermedium used in the breeding programs in the United States, Russia, Australia, India, and China. The most widely occurring combinations of the gene complex Lr24/Sr24 of Ag. elongatum with other resistance genes were revealed. In Russia, there were developed varieties in which the 6D chromosome was substituted by the 6Ai chromosome of Ag. intermedium, which controls disease resistance and the adaptivity of plants. The identification and introgression of new translocations indicates that the possibilities of using wheatgrass species for broadening of genetic variability of wheat are far from being exhausted.     

Chromophore aspartate oxidation-decarboxylation in the green-to-red conversion of a fluorescent protein from Zoanthus sp. 2

The red fluorescence of a Discosoma coral protein is the result of an additional autocatalytic oxidation of a green fluorescent protein (GFP)-like chromophore. This reaction creates an extra pi-electron conjugation by forming a C=N-C=O substituent. Here we show that the red fluorescence of a protein from Zoanthus sp. 2 (z2FP574) arises from a coupled oxidation-decarboxylation of Asp-66, the first amino acid of the chromophore-precursory DYG sequence. Comparative mutagenesis of highly homologous green (zFP506) and red (z2FP574) fluorescent proteins from Zoanthus species reveals that an aspartate at position 66 is critical for the development of red fluorescence. The maturation kinetics of wild-type z2FP574 and the zFP506 N66D mutant indicates that the "green" GFP-like form is the actual intermediate in producing the red species. Furthermore, via maturation kinetics analysis of zFP506 N66D, combined with mass spectrometry, we determined that the oxidation-decarboxylation of Asp-66 occurs without detectable intermediate products. According to mass spectral data, the minor "red" chromophore of the z2FP574 D66E mutant appears to be oxidized and completely decarboxylation deficient, indicating that the side chain length of acidic amino acid 66 is critical in controlling efficient oxidation-decarboxylation. Substitutions with aspartate at the equivalent positions of a Condylactis gigantea purple chromoprotein and Dendronephthya sp. green fluorescent protein imply that additional oxidation of a GFP-like structure is a prerequisite for chromophore decarboxylation. In summary, these results lead to a mechanism that is related to the chemistry of beta-keto acid decarboxylation.     

Polymorphism of the <Emphasis Type="Italic">Avr2</Emphasis> gene of oomycete <Emphasis Type="Italic">Phytophthora infestans</Emphasis> (Mont.) de Bary in the population of Moscow region

The goal of the present study was to investigate the nucleotide sequence polymorphism of the Avr2 virulence gene in the population of P. infestans from Moscow region. The SSCP technique was applied for estimation of this polymorphism. As a result, the Avr2 gene was shown to have a high degree of polymorphism of the primary structure. In particular, seven variants of genotypes associated with the Avr2 gene polymorphism were identified. It was also found that the distribution of these genotypes among the samples of the studied population had a spatially dependent manner.