Analysis of Drosophila proboscipedia mutant alleles.

Proboscipedia (PB) is a HOX protein required for adult maxillary palp and proboscis formation. To identify domains of PB important for function, 21 pb point mutant alleles were sequenced. Twelve pb alleles had DNA sequence changes that encode an altered PB protein product. The DNA sequence changes of these 12 alleles fell into 2 categories: missense alleles that effect the PB homeodomain (HD), and nonsense or frameshift alleles that result in C-terminal truncations of the PB protein. The phenotypic analysis of the pb homeobox missense alleles suggests that the PB HD is required for maxillary palp and proboscis development and pb - Sex combs reduced (Scr) genetic interaction. The phenotypic analysis of the pb nonsense or frameshift alleles suggests that the C-terminus is an important region required for maxillary palp and proboscis development and pb-Scr genetic interaction. PB and SCR do not interact directly with one another in a co-immunoprecipitation assay and in a yeast two-hybrid analysis, which suggests the pb-Scr genetic interaction is not mediated by a direct interaction between PB and SCR.     

Indigenous domestic breeds as reservoirs of genetic diversity: the Argentinean Creole cattle

Contrary to highly selected commercial breeds, indigenous domestic breeds are composed of semi-wild or feral populations subjected to reduced levels of artificial selection. As a consequence, many of these breeds have become locally adapted to a wide range of environments, showing high levels of phenotypic variability and increased fitness under natural conditions. Genetic analyses of three loci associated with milk production (alpha(S1)-casein, kappa-casein and prolactin) and the locus BoLA-DRB3 of the major histocompatibility complex indicated that the Argentinean Creole cattle (ACC), an indigenous breed from South America, maintains high levels of genetic diversity and population structure. In contrast to the commercial Holstein breed, the ACC showed considerable variation in heterozygosity (H(e)) and allelic diversity (A) across populations. As expected, bi-allelic markers showed extensive variation in He whereas the highly polymorphic BoLA-DRB3 showed substantial variation in A, with individual populations having 39-74% of the total number of alleles characterized for the breed. An analysis of molecular variance (AMOVA) of nine populations throughout the distribution range of the ACC revealed that 91.9-94.7% of the total observed variance was explained by differences within populations whereas 5.3-8.1% was the result of differences among populations. In addition, the ACC breed consistently showed higher levels of genetic differentiation among populations than Holstein. Results from this study emphasize the importance of population genetic structure within domestic breeds as an essential component of genetic diversity and suggest that indigenous breeds may be considered important reservoirs of genetic diversity for commercial domestic species.     

Effect of marinobufagenin on the primary reinforcing effect of ethanol]

Intraperitoneal administration of marinobufagenin resulted in a reliable and dose-dependent suppression of ethanol self-administration in drug- and experimentally naive DBA/2 mice. The findings suggest that Na/K-ATPase contributes to both mediation of the ethanol reinforcing properties and the mood regulation.     

Biosynthesis and use of coproporphyrins and uroporphyrins and their metal complexes in immune analysis and diagnostic methods]

Methods of synthesis of coproporphyrin and uroporphyrin by using bacteria of the genus Arthrobacter are proposed. Metal complexes of coproporphyrin and uroporphyrin with Pt, Pd, and Zn were synthesized. Their structures were identified by spectrophotometry, IR spectrometry, 1H-NMR, mass spectrometry, and HPLC. Data showing the possibility to use coproporphyrin III-metal complexes as luminophores for fluorescence detection of tumors. The current and prospective uses of metal complexes of water-soluble natural porphyrins in advanced immunofluorescence assays are discussed.     

Changes in Wheat Leaf Extracellular Proteolytic Activity after Infection with Septoria tritici

The proteolytic activity of the leaf extracellular space of wheat cultivars Pigüé and Isla Verde was estimated after inoculation of either detached leaves or plants with the fungus Septoria tritici. Pigüé is resistant, whereas Isla Verde is susceptible to the disease caused by S. tritici. Viable conidiospores of the fungus caused similar increases in both hydrogen peroxide production and chitinase activity of the cultivars studied. In contrast, they caused a decrease in the extracellular serine proteinase activity of Isla Verde and a significant increase in that of Pigüé. Independently of the cultivar from which it was extracted, the extracellular serine proteinase inhibited the germination of Septoria tritici conidiospores. These results suggest that the proteolytic activity of the leaf extracellular space can participate in the defence of wheat plants against Septoria tritici. Its regulation may be controlled by specific defence components of each cultivar.     

Expression, regulation, and function of P2X4 purinergic receptor in human cervical epithelial cells

Micromolarconcentrations of ATP stimulate biphasic change in transepithelialconductance across CaSki cultures on filters, an acute transientincrease (phase I response; triggered by P2Y₂ receptor and mediated by calcium mobilization-dependent cell volume decrease) followed by a slower decrease in permeability (phase II response). Phase II response is mediated byaugmented calcium influx and protein kinase C-dependent increase intight junctional resistance. The objective of the study was todetermine the role of P2X₄ receptor as a mediator ofphase II response. Human cervical epithelial cells expressP2X₄ receptor mRNA (1.4-, 2.2-, and 4.4-kb isoforms byNorthern blot analysis) and P2X₄ protein. Depletion ofvitamin A reversibly downregulated P2X₄ receptor mRNA andprotein and ATP-induced calcium influx. Depletion of vitamin Aabrogated phase II response, and the effect could bepartially reversed only with retinoic acid receptor (RAR)-selectiveretinoids but not retinoid X receptor (RXR) agonists. Depletion ofvitamin A also abrogated protein kinase C increase in tight junctionalresistance, and the effect could not be reversed with retinoids.Depletion of vitamin A also abrogated phase I increase inpermeability and reversibly downregulated P2Y₂ receptormRNA and ATP-induced calcium mobilization. However, in contrast tophase II response, both RAR and RXR agonists could fullyreverse those effects. These results suggest that phase IIresponse is mediated by a P2X₄ receptor mechanism.

     

Mitochondrial phylogeography and population history of pine martens Martes martes compared with polecats Mustela putorius

The flora and fauna of Europe are linked by a common biogeographic history, most recently the Pleistocene glaciations that restricted the range of most species to southern refugial populations. Changes in population size and migration, as well as selection, have all left a signature on the genetic differentiation. Thus, three paradigms of postglacial recolonization have been described, inferred from the patterns of DNA differentiation. Yet some species, especially wide-ranging carnivores, exhibit little population structuring between the proposed refugia, although relatively few have been studied due to the difficulty of obtaining samples. Therefore, we investigated mitochondrial variation in pine martens, Martes martes, in order to understand the extent to which they were affected by glacial cycles, and compared the results with an analysis of sequences from polecats, Mustela putorius. A general lack of ancient lineages, and a mismatch distribution that is consistent with an expanding population, is evidence that the present-day M. martes and Mu. putorius in central and northern Europe colonized from a single European refugium following a recent glaciation. There has also been interspecific mitochondrial introgression between M. martes and the sable M. zibellina in Fennoscandia.     

1-X-3 motif in inter-protein recognition: structures, widespreading and possible practical application.

Similarities in the discrete mode and size of contact areas of a wide range of protein complexes allows us to suggest the existence of a limited number of types of inter-protein interactions. Comparison of structures of bound determinants indicates that the double-module, 1-X-3 type of motif is widespread in recognition processes. Thus, in many cases, the sites of ligand recognition are formed by two significant amino acids and separated by insignificant ones. Typical examples of such motifs are the RGD sequence of some adhesive and haemostatic proteins, the primary sites for plasminogen sorption on the fibrin network, the reactive sites of protein inhibitors of serine proteinases, and the sites for activation of the hydrolysis of protein pro-forms and receptors. It is assumed that there is widespread double-module determinants in many inter-protein interactions.