Recent results 2014

Adrenergic receptors in preimplantation embryos

Catecholamines play an important role in embryogenesis, and data obtained in the rodent model indicate that they can act even during the preimplantation period of development. Using RT-PCR with specific oligonucleotide primers distinguishing among all members of the adrenergic receptor family, we examined expression of adrenergic receptors in bovine and rabbit oocytes, morulas, and blastocysts. We found several profiles of adrenoceptor mRNA expression. Transcripts for some receptor subtypes (bovine alpha 2 receptors, rabbit α2A, α2C, β1 and β2 receptors) were detected at all examined stages, which suggests receptor expression throughout (or at most stages) of the preimplantation developmental period. Expression in oocytes but not at later stages was found in only one adrenoceptor subtype (rabbit α1B). In contrast, mRNA for several adrenoceptors was found in embryos but not in oocytes (bovine beta adrenoceptors and rabbit α1A). Nucleotide sequences of our PCR products amplified in rabbit oocytes and preimplantation embryos represent the first published mRNA sequences (partial sequences coding at least one transmembrane region) of rabbit α2C, β1 and β2 adrenoceptors. Our results suggest that expression of adrenergic receptors can be a general feature of mammalian oocytes and preimplantation embryos. On the other hand, comparison of three mammalian species (cattle, rabbit, mouse) revealed possible inter-species differences in the expression of particular adrenoceptor subtypes. Our results support the opinion that stress mediators can act directly in cells of preimplantation embryos.

ČIKOŠ, Štefan – CZIKKOVÁ, Soňa – CHRENEK, P. – MAKAREVICH, A.V. – BURKUŠ, Ján – JANŠTOVÁ, Žofia – FABIAN, Dušan – KOPPEL, Juraj. Expression of adrenergic receptors in bovine and rabbit oocytes and preimplantation embryos. In Reproduction in Domestic Animals, 2014, vol. 49, no. 1, p. 92-100.

Fermentation of fungal substrates in rumen

Enrichment of cereal agro-industrial substrates with Cunninghamella echinulata as a source of fungal gamma-linolenic acid (GLA) could open new perspectives in animal nutrition of livestock. Examined cereal-enriched diets with fungal GLA did not affect biohydrogenation of fatty acids, but significantly influenced the concentration of GLA in rumen fluid. Substrates enriched by C. echinulata were used for first time in sheep nutrition.

WENCELOVÁ, M. – VÁRADYOVÁ, Z. – MIHALIKOVÁ, K. – GUOTHOVÁ, L. – JANŠTOVÁ, J. – ČERTÍK, M. – HOMOĽOVÁ, L. – PRISTAŠ, P. – JALČ, D. – KIŠIDAYOVÁ, S.: Substrates enriched by the fungus Cunninghamella echinulata: an in vitro study of nutrient composition, sheep rumen fermentation and lipid metabolism. In Journal of Applied Microbiology, 2014, vol., 117, p. 930-939. doi:10.1111/jam.12594.

Evaluation of rumen ciliates and archaea relationship

The development and testing the fluorescence in situ hybridization (FISH) based technique and identifying and quantifying simultaneously the methanogenic populations colonizing Entodinium spp. in the rumen of cows fed different forages was carried out. New FISH probes targeting protozoal Entodinium spp. were designed and used together with FISH probes for methanogens in the cow rumen. Phylogenetically closely related Entodinium spp. were colonized by similar methanogenic populations regardless of the forage fed. Methanogens including Methanobrevibacter thaueri, Methanobrevibacter millerae and Methanobrevibacter smithii, and members of Methanomicrobium and Methanosphaera were generally the predominant colonizers of protozoa. Simultaneous FISH probing appears to be a reliable and effective approach to investigate the dynamics of symbiotic relationships between ruminal protozoa and methanogens at a single cell level. This is the first report of the methanogenic archaeal populations that specifically colonize Entodinium spp. as identified using simultaneous FISH probing.

XIA, Y. – KONG, Y.H. – SEVIOUR, R. – FORSTER, R.J. – KIŠIDAYOVÁ, S. – MCALLISTER, T.A. Fluorescence in situ hybridization probing of protozoal Entodinium spp. and their methanogenic colonizers in the rumen of cattle fed alfalfa hay or triticale straw. In Journal of Applied Microbiology, 2014, vol. 116, no.1, p. 14-22.doi: 10.1111/jam.12356