Výsledky projektu Sekvenční a expresní variabilita antimikrobiálních peptidů u kura domácího

While haematological variation is well known in birds, variation in avian breeds (distinct morphotypes of the
same species) remains unexplored. Poultry breeds, in particular, may show interesting evolutionary patterns and
economically-relevant physiological differences. We performed a comparative examination of blood cellular
composition in five chicken (Gallus gallus domesticus) breeds: Araucana, Booted bantam, Czech, Minorca and
Rosecomb bantam. In standard-environment-reared hens whole-blood flow cytometry revealed remarkable
differences in most erythrocyte- and leukocyte-related parameters. We identified two extremes: Czech, a
European breed, with a low heterophil/lymphocyte (H/L) ratio and high CD4+ levels, and Araucana, a South-
American breed, with a high H/L ratio and high relative monocyte count. Such variation may reflect a
combination of artificial and natural selection acting on health- and stress-related traits in domestic populations.
Different breeds have evolved different immunological adaptations reflecting their original need to fight
pathogens and physiological constraint resulting from dissimilar physiological trade-offs.

Avian egg white is essential for protecting and nourishing bird embryos during their development. Being produced in the female magnum, variability in hen oviduct gene expression may affect egg white composition in domestic chickens. Since traditional poultry breeds may represent a source of variation, in the present study we describe the egg white proteome (mass spectrometry) and corresponding magnum transcriptome (high-throughput sequencing) for twenty hens from five domestic fowl breeds (Araucana, Booted bantam, Czech golden pencilled, Minorca and Rosecomb bantam). In total, we identified 189 egg white proteins and 16391 magnum-expressed genes. The majority of egg white protein content comprised proteins with an antimicrobial function. Between-class Principal Component Analysis revealed significant breed-specific variability in protein composition, differentiating especially small and large breeds. Though we found strong association between magnum mRNA expression and egg white protein content across genes, co-inertia analysis revealed no transcriptome/proteome co-structure at the individual level. Our study is the first to show proteomic variation in egg white composition across chicken breeds with potential effects on egg quality, biosafety and chick development. The observed inter-individual variation probably results from post-transcriptional regulation creating a discrepancy between proteomic and transcriptomic data