Kinesins in the Arabidopsis genome: A comparative analysis among eukaryotes

Background  

Receptor protein tyrosine phosphatase rho (RPTPρ, gene symbol PTPRT) is a member of the type IIB RPTP family. These transmembrane molecules have been linked to signal transduction, cell adhesion and neurite extension. The extracellular segment contains MAM, Ig-like and fibronectin type III domains, and the intracellular segment contains two phosphatase domains. The human RPTPρ gene is located on chromosome 20q12-13.1, and the mouse gene is located on a syntenic region of chromosome 2. RPTPρ expression is restricted to the central nervous system.     

Evasion of mammalian defense systems by orthopoxviruses

In the course of evolution, viruses have mastered various molecular mechanisms to evade defense reactions of the host organism. The understanding of these mechanisms would promote better comprehension of the crucial reactions directed against infectious agents and further insights into their organization and functioning. A considerable contribution to this field of study can be made by investigating orthopoxviruses pathogenic for humans, such as variola, monkeypox, cowpox, and vaccinia viruses. The experimental data reviewed here suggest that variola virus and other orthopoxviruses, in comparison to other virus families, possess an unsurpassed set of genes whose protein products efficiently modulate the diverse defense reactions of the host.     

Comparative analysis of variable regions in the variola virus genome

Two segments of the variable terminal regions of the variola virus (VARV) genome were sequenced in 22 strains from the Russian collection, including about 13.5 kb of the left segment and about 10.5 kb of the right segment. The total length of the sequences was over 540 kb. Phylogenetic analysis of the new and published data determined the relationships among 70 VARV strains, the character of their clustering, and the intergroup and intragroup variation of the strain clusters. Loci with the highest polymorphism rate were identified and proved to map to noncoding regions or to regions of damaged open reading frames, characteristic of the ancestral virus. These loci offer attractive possibilities for developing a strategy of VARV strain genotyping. Recombination analysis by different methods did not detect, except for a single case, significant recombination events in the VARV strains examined.     

The attitudes of riparian communities to the presence of water hyacinth in the Wouri River Basin,Douala, Cameroon

Since publication of the first record of Eichhornia crassipes in Cameroon in 1997, the weed has become highly invasive in the Wouri River Basin. Between June and September 2014, a socio-economic survey using participatory and qualitative methods was undertaken in the riparian villages of the Wouri River Basin to assess the perception of respondents to the presence of water hyacinth. The survey revealed that water hyacinth was a significant threat to activities along the river, which included fishing, sand extraction and river transportation. The presence of water hyacinth mats reduced catch rates of several common fish species, river transportation by 75%, and significantly reduced the income for sand extraction. Cameroon employs manual clearing of water hyacinth; however, respondents indicated they would consider other control methods, provided they do not have any negative impacts.     

Characteristics of the thermoregulatory reactions of mice and rats to mediator-active substances

The effect of dopaminomimetics (apomorphine, piribedil, bromocriptine), cholinomimetics (oxotremorine, arecoline, pylocarpine), and neuroleptics (chlorpromazine, haloperidol, triperidol) on rectal temperature (Tr) and temperature of different parts of the skin has been investigated in albino mice and rats of either sex. In rats these drugs cause the decrease of Tr and significantly increase tail temperature (Tt), as well as the temperature of the fore- and hindpaws (Tfp and Thp correspondingly). In mice the drug-induced fall of Tr is more significant than in rats; however, only neuroleptics essentially increase Tfp and Thp, the increase in Tt being inconsistent and small. Cholinomimetics and usually dopaminomimetics decrease Tt. Cholinomimetics do not affect and dopaminomimetics cause only transient and small rise in Tfp and Thp. The data do not confirm the key role of enhanced heat dissipation through the skin as a mechanism of hypothermic effect of cholino- and dopaminomimetic drugs in mice under the room temperature. In contrast to mice, thermoregulatory skin reactions to drugs in rats are much more pronounced, and together with palmar and plantar surfaces of the paws the same role in thermoregulationss is played by the skin of the tail.     

3D structure modeling of complexes formed by CrmB TNF-binding proteins of Variola and cowpox viruses with murine and human TNFs

Orthopoxviral genomes bear genes for a series of homologous secreted proteins binding tumor necrosis factor (TNF). Orthopoxvirus species have different sets of these proteins. Variola virus has only one protein of this series, CrmB. Although CrmB protein sequences are similar to each other, their physicochemical and biological properties show certain species-specific features. We constructed 3D models of complexes formed by TNF-binding domains of variola and cowpox viruses with murine and human TNFs. We also constructed corresponding models with a mutant human TNF. In this mutant TNF, the arginine residue at position 31 involved in receptor binding was replaced by glutamine, characteristic of murine TNF. Analysis of the models showed that the least stable complex should be that formed by cowpox virus CrmB with human TNF, and the Arg31/Gln substitution should significantly stabilize the interaction between cowpox CrmB and mutant human TNF. Experimental comparison of the abilities of recombinant variola and cowpox CrmB proteins to inhibit the cytotoxic action of TNFs confirmed the predictions.     

Micromethod of ultracentrifugation in cesium chloride]

The micromethod of ultracentrifugation in cesium chloride is described. Band destributions have been analysed by the direct scanning of microtubes with the differential doublewave micro-spectrophotometer at 260 nm. The 10(-8)-10(-9) g of DNA or ribosomes are enough for one analysis, tube volume is 2 mul. The method described permits the simultaneous centrifugation of several probe scores. The error of the beyoant density determination is 0.001 g/sm3 relatively internal standard. DNA's from 5 types of Acetabularia were analysed by the developed technique.