Identification of alpha-tropomyosin of the human myocardium by two-dimensional electrophoresis, and sequencing]

Two-dimensional electrophoresis of total cardiac muscle extracts allows the detection of about 200 protein fractions. In preliminary studies the fraction D-10 protein was characterized in terms of relative molecular mass, isoelectric point and quantitative composition as alpha-tropomyosin. The similarity of the protein to human alpha-tropomyosin was confirmed by the results of analysis of the N-terminal sequence of the D-10 protein eluate in a gas-phase sequencer.     

A two-dimensional map of proteins from left ventricle of the human heart

A two-dimensional map of human heart left ventricular proteins for 213 polypeptide fractions has been constructed. A quantitative analysis of variability of the fraction position at 60 selected spots with the use of a CVIT computer system revealed a high reproducibility of the material distribution on electrophoregrams. Differences were found in the protein composition of eight heart muscle atrial and ventricular polypeptide fractions. Left ventricular proteins were shown to be represented by six electrophoretical variants. The methodological peculiarities of construction at the two-dimensional map of heart muscle proteins are discussed.     

Mapping of meiotic genes in rye (Secale cereale L.): Localization of sy19 mutation, impairing homologous synapsis, by means of isozyme and microsatellite markers

The sy19 mutation, which impairs the homology of meiotic chromosome synapsis in rye, were mapped using a specially created F₂ population by means of isozyme Acph1 locus and microsatellite (SSR) markers. The sy19 gene was localized in the chromosome 7R in the pericentromeric region of long arm based on the linked inheritance with the Acph1 locus. The locus was linked with five rye SSR markers, with the Xrems1234 locus being located closest to the sy19 gene (6.4 cM). The genetic map of the analyzed chromosome 7R region includes ten markers and the sy19 locus. A possible function of the Sy1 and Sy19 genes based on the data on comparative genomics is discussed.     

Distribution of amiloride-sensitive sodium channels in the oral cavity of the hamster

The distribution of amiloride-sensitive sodium channels (ASSCs) in taste buds isolated from the oral cavity of hamsters was assessed by patch clamp recording. In contrast to the case for rats, taste cells from the fungiform, foliate and vallate papillae and from the soft palate all contain functional ASSCs. The differential distribution of ASSCs between the hamster and the rat may be important for understanding the physiology underlying the differing behavioral responses of these species to sodium salts.      

Antimicrobial effects of α-defensins from leukocytes of the hamadryas baboon <Emphasis Type="Italic">Papio hamadryas</Emphasis>

To understand the emergence and evolutionary selection of the efficient mechanisms of innate immunity it is necessary to accumulate knowledge about the structural and functional properties of antimicrobial peptides in different animal species. The cationic antimicrobial peptides, α-defensins, were isolated from leukocytic extracts of the lower narrow-nosed monkey, hamadryas baboon Papio hamadryas, using ultrafiltration, preparative electrophoresis and reverse-phase highperformance liquid chromatography. Analysis of the antimicrobial properties of α-defensins showed that they display a wide spectrum of antimicrobial activity, comparable with that of human α-defensin HNP1, and exert bactericidal and fungicidal effects at micromolar concentrations. A study of the influence of different medium conditions on antimicrobial activity of α-defensins revealed that a higher ionic strength or the presence of blood serum leads to a marked decrease in antimicrobial activity of α-defensins, while pH has no appreciable effect on it. We found that hamadryas baboon α-defensins are able to increase the permeability of the outer and inner membranes of E. coli, suggests that the bacterial membrane is one of the major targets of the antimicrobial effects of these peptides. The revealed differences in antimicrobial activity of α-defensins may result from their structural heterogeneity, which reflects different pathways of evolution of α-defensins in primates and underlies the selectivity of their antimicrobial effect.     

Physical properties of membrane fractions isolated from human platelets: implications for chilling induced platelet activation.

In previous studies, it has been suggested that chilling induced activation of human platelets is related to a lipid phase transition seen in membrane lipids. Those studies showed a single, surprisingly cooperative transition in human platelets, as determined by Fourier transform infrared (FTIR) spectroscopy, findings that are confirmed here with calorimetric measurements. Such transitions have now been studied in membrane fractions obtained from the platelets and it is reported that all fractions and purified phospholipids show similar transitions. In order to obtain these data it was necessary to develop means for separating these fractions. Therefore, a novel method for isolation and separation of dense tubular system (DTS) and plasma membranes in human platelets is described here. Lipid analysis showed that phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were the dominant phospholipids in both fractions, whereas cholesterol and sphingomyelin (SM) were predominantly located in the plasma membranes. Thermotropic phase transitions in the two membrane fractions, determined by differential scanning calorimetry (DSC) and FTIR spectroscopy were found to occur at about 15 degrees C, similar to the Tm of intact human platelets. These data are discussed in relation to the role of the DTS and plasma membranes in the cold-induced activation of human platelets.     

The Effect of Parental Genotypes of Rye Lines on the Development of Quantitative Traits in Primary Octoploid Triticale: Plant Height

When breeding the primary spring octoploid triticale derived from crosses of various inbred rye lines to wheat Chinese Spring, the effects of the rye genotype and growth conditions on the plant height and proportion of the first, second, and final (pedicle) internodes to the entire stem length were studied. Two triticale groups were examined: homozygotes for the dominant (Ddw1) and recessive (ddw1) alleles of the gene responsible for short stem in rye. In the short stem triticale lines carrying the Ddw1 alleles, the plants were 20 cm shorter on average than those in the ddw1-carrying lines, and the distribution of the two triticale groups overlapped significantly. In both groups, the lines significantly differing in plant height could be differentiated, because of allelic diversity of the additional genes controlling this trait along with the Ddw gene. In most triticale lines, especially in theDdw1-carrying ones, the plant height was much reduced under unfavorable growth conditions. At the same time, a short-stem line was isolated, which is characterized by ecological plasticity, like the maternal wheat cultivar. In the triticale studied, the stem structure depended on the short-stem rye genotype. The two-year study showed that in the triticale carrying the dominant allele of this gene, the first internode is significantly extended, whereas the upper (pedicle) internode is reduced, which increases plant lodging resistance. The differences revealed between the rye lines as well as their effect on the quantitative triticale traits are discussed in view of a variant of the hybridological analysis, which had been previously proposed for identification and mapping of the correspondent rye genes.     

Dispermic androgenesis in sturgeons with the help of cryopreserved sperm: production of androgenetic hybrids between Siberian and Russian sturgeons

Dispermic androgenesis was used to produce, for the first time, an androgenetic progeny of the Siberian sturgeon (Acipenser baerii) and the androgenetic nuclear cytoplasmic hybrids (Siberian sturgeon, A. baerii x Russian sturgeon, A. gueldenstaedtii) using cryopreserved sperm. Microsatellite DNA analysis confirmed exclusively paternal inheritance in the androgenetic progeny of Siberian sturgeon. Heterozygotes for certain microsatellite loci were detected among the androgenetic hybrids, thereby confirming a dispermic nature of androgenesis. According to the data of comparative morphological analysis, the obtained androgenetic hybrid, by the age of 15 months old, was completely identical to the paternal species. Both a female and a male were detected in the androgenetic sturgeon progenies, which is of interest for producing bisexual progenies via androgenesis. The data of this study confirm the feasibility of dispermic androgenesis using cryopreserved sperm to preserve and recover the gene pools of endangered sturgeon species.     

Effects of double ligation of Stensen's duct on the rabbit parotid gland

Salivary gland duct ligation is an alternative to gland excision for treating sialorrhea or reducing salivary gland size prior to tumor excision. Duct ligation also is used as an approach to study salivary gland aging, regeneration, radiotherapy, sialolithiasis and sialadenitis. Reports conflict about the contribution of each salivary cell population to gland size reduction after ductal ligation. Certain cell populations, especially acini, reportedly undergo atrophy, apoptosis and proliferation during reduction of gland size. Acini also have been reported to de-differentiate into ducts. These contradictory results have been attributed to different animal or salivary gland models, or to methods of ligation. We report here a bilateral double ligature technique for rabbit parotid glands with histologic observations at 1, 7, 14, 30, 60 days after ligation. A large battery of special stains and immunohistochemical procedures was employed to define the cell populations. Four stages with overlapping features were observed that led to progressive shutdown of gland activities: 1) marked atrophy of the acinar cells occurred by 14 days, 2) response to and removal of the secretory material trapped in the acinar and ductal lumens mainly between 30 and 60 days, 3) reduction in the number of parenchymal (mostly acinar) cells by apoptosis that occurred mainly between 14–30 days, and 4) maintenance of steady-state at 60 days with a low rate of fluid, protein, and glycoprotein secretion, which greatly decreased the number of leukocytes engaged in the removal of the luminal contents. The main post- ligation characteristics were dilation of ductal and acinar lumens, massive transient infiltration of mostly heterophils (rabbit polymorphonuclear leukocytes), acinar atrophy, and apoptosis of both acinar and ductal cells. Proliferation was uncommon except in the larger ducts. By 30 days, the distribution of myoepithelial cells had spread from exclusively investing the intercalated ducts pre-ligation to surrounding a majority of the residual duct-like structures, many of which clearly were atrophic acini. Thus, both atrophy and apoptosis made major contributions to the post-ligation reduction in gland size. Structures also occurred with both ductal and acinar markers that suggested acini differentiating into ducts. Overall, the reaction to duct ligation proceeded at a considerably slower pace in the rabbit parotid glands than has been reported for the salivary glands of the rat.