Deletion mutants of the B type natriuretic peptide receptor: cDNA expression and protein purification and characterization

The C type natriuretic peptide (CNP) is a peptide hormone stimulating vasorelaxation and inhibiting cell proliferation. CNP activates the type B natriuretic peptide receptor (NPR-B), known as the guanylate cyclase B membrane enzyme, which results in the cGMP release. To study functional properties of NPR-B, its gene fragments were expressed in methylotrophic yeastsPichia pastoris. Conditions were found providing for secretion of functionally active recombinant proteins NPR-Bs and NPR-Bl into the cultural medium in a yield of 25 mg/l culture. Their specific activity was 0.97 and 0.93 μmol cGMP min⁻¹ mg⁻¹ protein, respectively. It was shown that NPR-B belongs to the family of Ser/Thr protein kinases and can be autophosphorylated at the serine residues.     

Experimental models of transgenic plants promising for innovative biotechnologies

Transgenic potato plants have been created that express recombinant proteins that are analogues of spidroin 1, the protein of the cobweb dragline. Expression of spidroin 1 hybrid genes possessing some repeated sequences is retained on going from model test tube-grown plants to crops. The expression level of the synthetic spidroin 1 genes and the level of accumulation of their products in plants depend on the type of promoter, number of repeats, organ specificity, and plant species, but not on the duration of plant material storage. The results show that the strategy based on construction and expression of hybrid proteins including a reporter protein makes it easier to select and analyze the expression of hybrid proteins in transgenic organisms.     

Taxonomic relations between forms in evolutionary young complexes of lepidopterans (insecta, lepidoptera)

Morphological characteristics of the prototype wing pattern can be used in lepidopteran population studies as markers of population groups and interpopulation boundaries. The centers of phenotypic variation serving as speciation centers were recognized within the range of polytypic species. Revision of the polytypic complex Polyommatus icarus Rott. allowed us to recognize six specific and six subspecific taxa.     

Biometric variations and oxidative stress responses in juvenile Clarias gariepinus exposed to Termex®

The current study investigated the effects of termite insecticide, Termex® (imidacloprid 35.50% SC), on biometric variations and oxidative stress biomarkers in Clarias gariepinus. Fish were exposed to 4.00 and 6.00 µg l^–1 sublethal Termex® concentrations in 2017. The gill and liver tissues were sampled on days 7, 14, 21 and 28 and the results indicated that hepatosomatic index (HSI) decreased significantly when compared with the control on days 14, 21 and 28. The condition factor (CF) and viscera-somatic index (VSI) also decreased during the study period. The decrease was greater at 6.00 µg l^–1 Termex® concentration on days 21 and 28 for CF and days 14 to 28 for VSI, respectively. The lipid peroxidation (LPO) in both tissues was highest in the 6.00 µg l^?1 Termex® and increased with the duration. There was significant decrease (p < 0.05) in superoxide dismutase and glutathione peroxidase values, but significant increase in catalase activity in both tissues. The values of glutathione reductase in both tissues were comparable to the control, except on days 21 and 28 in the liver. There was negative correlation between the LPO in tissues and the HSI, CF and VSI values. The use of Termex® in the environment should be monitored to safeguard the health of aquatic organisms.