The fields of research: - The impact of genes SF-1 and StAR on growth and development (progress) - Embryo transfer - The impact of microcystin LR on gamete and embryo development - Freezing of semen - Postembryonal development of pigs - Characteristics of autochthonous domestic breeds and wild hare - The environmental impact of avermectin residua - Identification of immunogenic properties of dermatophyte proteins SF-1 knock out mice, demonstrating an excessive increase of body weight are an ideal model for studies of mechanisms for body weight regulation. According to our findings, the ventromedial nucleus in hypothalamus is responsible mainly for the activity of the animals and less for the feed uptake. StAR knock out mice can be kept alive by daily injections of corticosteroid hormones, however steroidogenous cells of suprarenal gland cortex, Leydig cells in testis and ovary granolous cells do not survive. Agonist-induced internalization of GnRH receptor proceed via clathrin-coated pits and it is beta-arrestin independent. That diferentiate it from most other G-protein coupled receptors (GPCR), which possess an intracellular carboxyl-terminal tail. This receptor is also unable to undergo agonist-induced phosphorylation and rapid desensitization. Results obtained with GnRH receptor chimeras demonstrated a role of casein kinase II sites in the carboxyl-terminal tail in determing beta-arrestin dependent pathway. Arrestin mutants that prevent rapid dissociation from the receptor yield an increased bioluminescence resonance energy transfer signal for the members of the Class A GPCRs. Using transrectal sonography of ovaries, follicles with diameter of 2mm and corpus luteum can be detected. Gravidity can be confirmed 16 days after ovulation with 83% and 20 days after ovulation with 100% certainty. The greatest embryonal survival potential was shown for embryos frozen in glycerol after 45 min of equilibration. The exposition of female rabbits in the firs half of pregnancy to the sublethal doses of microcistin-LR have no effect on rabbit embryo and foetal development and number of offspring, although increased plasma liver enzymes at the time of exposition and liver degeneration was found in females exposed to the microcistin. Growth, development and cytoskeleton organization of the embryos embedded in zona pellucida are not affected by microcystin-LR in concentrations used, while microcystin-LR profoundly in dose dependent manner affects actin and microtubule organization of the embryonic cells in culture. The method for isolation of membrane proteins from frozen semen was developed. The abnormalities were found mainly at tail and acrosomal region of sperm cells after freezing. Thyroid hormones affect pig testis development till the age of 8-12 weeks, division of Sertoli cells starts at 14 weeks. Giant cells in skeletal muscles appear because of acid-base disbalance. Giant cells are also present in muscles of pigs possessing wild RYR1 gene and containing glycolitic muscle fibers.