Endogenous factors in regulating Na+,K+-ATPase in small intestinal mucosa

In the combination of gel- and ion exchange chromatography low-molecular weight (Mm < 1000 Da) fractions of tissue extracts of small intestine epithelium with high activity towards the Na+,K(+)-ATP-ase were obtained. The influence of these fractions on the Na+, K(+)-ATP-ase of small intestine epithelium and rat renal cortex is studied and discussed.     

A marker set for construction of a genetic map of the silver fox (Vulpes vulpes)

The silver fox, a variant of the red fox (Vulpes vulpes), is a close relative of the dog (Canis familiaris). Cytogenetic differences and similarities between these species are well understood, but their genomic organizations have not been compared at higher resolution. Differences in their behavior also remain unexplained. Two silver fox strains demonstrating markedly different behavior have been generated at the Institute of Cytology and Genetics of the Russian Academy of Sciences. Foxes selected for tameness are friendly, like domestic dogs, while foxes selected for aggression resist human contact. To refine our understanding of the comparative genomic organization of dogs and foxes, and enable a study of the genetic basis of behavior in these fox strains, we need a meiotic linkage map of the fox. Towards this goal we generated a primary set of fox microsatellite markers. Four hundred canine microsatellites, evenly distributed throughout the canine genome, have been identified that amplify robustly from fox DNA. Polymorphism information content (PIC) values were calculated for a representative subset of these markers and population inbreeding coefficients were determined for tame and aggressive foxes. To begin to identify fox-specific single nucleotide polymorphisms (SNPs) in genes involved in the neurobiology of behavior, fox and dog orthologs of serotonin 5-HT1A and 5-HT1B receptor genes have been cloned. Sequence comparison of these genes from tame and aggressive foxes reveal several SNPs. The close relationship of the fox and dog enables canine genomic tools to be utilized in developing a fox meiotic map and mapping behavioral traits in the fox.     

Combined prime-boost vaccination against tick-borne encephalitis (TBE) using a recombinant vaccinia virus and a bacterial plasmid both expressing TBE virus non-structural NS1 protein

Background  

Heterologous prime-boost immunization protocols using different gene expression systems have proven to be successful tools in protecting against various diseases in experimental animal models. The main reason for using this approach is to exploit the ability of expression cassettes to prime or boost the immune system in different ways during vaccination procedures. The purpose of the project was to study the ability of recombinant vaccinia virus (VV) and bacterial plasmid, both carrying the NS1 gene from tick-borne encephalitis (TBE) virus under the control of different promoters, to protect mice against lethal challenge using a heterologous prime-boost vaccination protocol.     

Folliculogenesis, onset of puberty and fecundity of mink (Mustela vision Schreb) selectively bred for docility or aggressiveness

It has been suggested that selective breeding of animals for docile behavior is correlated with early onset of puberty and improved fertility. We wished to test the hypothesis that mink bred for docility would show earlier onset of puberty and greater fecundity than mink bred for aggressiveness. We used farm-raised, 7-mo-old mink females that had been selectively bred for 7 to 10 generations on the basis of behavior towards humans. Onset of puberty was estimated once (between 15 and 20 December) by vaginal smears and was said to start wtih preponderance of cornified epithelial cells in the cytological specimen. Fecundity was measured by litter size and rate of folliculogenesis, with and without hCG stimulation, by histomorphometric examination of ovaries and uteri. A total of 43/100 (43%) docile females achieved proestrus and estrus as compared to 16/136 (12%) of the aggressive ones. Overall pregnancy rate, survival to 5 d after whelping and litter size did not differ between the docile and aggressive females. Docile females showed significantly higher numbers (P < 0.05 and < 0.001) of growing, maturing and atretic follicles than the aggressive ones, however the latter showed a highly significant (P < 0.001) folliculogenic response to hCG. The response of the ovary of aggressive females to hCG is particularly dramatic because in most aggressive females the ovaries contained none or only few follicles of any kind. The inhibition of folliculogenesis in aggressive mink is similar to that reported in Silverblue and Sapphire mink homozygous for the Stuart factor. The paradoxical response to hCG may be an indication that selective breeding for aggression may be correlated with the disturbance at the early stages of folliculogenesis which creates a deficiency of follicles that are sensitive to LH-type stimulation.     

Activation of morphogenesis and proliferation by low specificity chemical effectors

Activation of highly specific biochemical processes by simple chemical agents is demonstrated for morphogenesis (anlage and development of female gametophyte in cereal) and mitosis (in cell cultures and animal and plant tissues). The effects of these agents are tissue-specific. Structure--activity relationship is analyzed in this group of compounds. Thus, the phenomenon reveals the exact pathways of the influence of allelopathic and anthropogenic chemical agents on evolution of plant biocenoses.     

Organization of fusicoccin receptor in higher plant plasma membrane: relationship between affinity and molecular mass

Higher plant plasma membranes carry receptors of different affinity for the phytotoxin fusicoccin. Reception of fusicoccin involves proteins belonging to the highly conserved 14-3-3 family, but the complete structure of the fusicoccin receptor (FCR) is unknown. Using radiation inactivation analysis, we estimated the molecular masses of low-affinity and high-affinity FCR at 63 +/- 7 and 130 +/- 15 kD, respectively. The dose dependences of receptor inactivation indicate that microsomal specimens contain "silent" FCRs of 420 +/- 90 kD in amounts commensurate with that of the active FCRs. Both low- and high-affinity FCRs are inactivated by hydrolytic enzymes from the outer surface of the plasma membrane, and impairment of protoplast integrity causes an irreversible transition of the low-affinity binding site into the high-affinity one. A scheme is proposed for the organization of different types of FCR in the plasma membrane, implying that the membrane affinity for fusicoccin reflects the interaction between proteins in the FCR complex.     

Secretion of endogenous regulators of Na K ATPase by isolated rat duodenum in osmotic stimulation of its mucous membrane]

The experiments in vitro have shown that perfusion of the isolated duodenum cavity in rats by hypotonic (20 mosmol/l H2O) or hypertonic (500 mosmol/l H2O) solutions of NaCl and mannitol during 10 min stimulates secretion of endogenic factors (activators or inhibitors of enterocytes of Na+, K(+)-ATPase) into the serous incubation solution. Contact of the duodenum mucose surface with isotonic (300 mosmol/l H2O) solutions does not stimulate the secretion of this enzyme regulators. Endogenic substance are thermostable: they retain activity relative to Na+, K+ ATPase of enterocytes after heating (100 degrees C, 10 min duration) of serous incubation solutions.     

Genetic regulation of canine skeletal traits: trade-offs between the hind limbs and forelimbs in the fox and dog

Genetic variation in functionally integrated skeletal traitscan be maintained over 10 million years despite bottlenecksand stringent selection. Here, we describe an analysis of thegenetic architecture of the canid axial skeleton using populationsof the Portuguese Water Dog Canis familiaris) and silver fox(Vulpes vulpes). Twenty-one skeletal metrics taken from radiographsof the forelimbs and hind limbs of the fox and dog were usedto construct separate anatomical principal component (PC) matricesof the two species. In both species, 15 of the 21 PCs exhibitedsignificant heritability, ranging from 25% to 70%. The secondPC, in both species, represents a trade-off in which limb-bonewidth is inversely correlated with limb-bone length. PC2 accountsfor approximately 15% of the observed skeletal variation, 30%of the variation in shape. Many of the other significant PCsaffect very small amounts of variation (e.g., 0.2–2%)along trade-off axes that partition function between the forelimbsand hind limbs. These PCs represent shape axes in which an increasein size of an element of the forelimb is associated with a decreasein size of an element of the hind limb and vice versa. In mostcases, these trade-offs are heritable in both species and geneticloci have been identified in the Portuguese Water Dog for manyof these. These PCs, present in both the dog and the fox, includeones that affect lengths of the forelimb versus the hind limb,length of the forefoot versus that of the hind foot, musclemoment (i.e., lever) arms of the forelimb versus hind limb,and cortical thickness of the bones of the forelimb versus hindlimb. These inverse relationships suggest that genetic regulationof the axial skeleton results, in part, from the action of genesthat influence suites of functionally integrated traits. Theirpresence in both dogs and foxes suggests that the genes controllingthe regulation of these PCs of the forelimb versus hind limbmay be found in other tetrapod taxa.