title: Effects of experimentally increased in ovo lysozyme on egg hatchability, chicks complement activity, and phenotype in a precocial bird.
abstract: In birds, spectrum of egg white proteins deposited into the egg during its formation are thought to be essential maternal effects. Particularly, egg white lysozyme (LSM), exhibiting great between and within species variability, is considered to be essential for developing avian embryos due to its physiological, antimicrobial, and innate immune defense functions. However, there have been few studies investigating effects of LSM on early post-hatching phenotype, despite its broad physiological and protective role during embryogenesis. Here, we test how experimentally increased concentrations of egg white LSM affect hatchability in Japanese quail (Coturnix japonica) and chick phenotype immediately after hatching (particularly body weight, tarsus length, plasma LSM concentration, and plasma complement activity). Chicks from eggs with increased LSM concentration displayed reduced tarsus length compared to chicks from control eggs while hatchability, body weight and plasma LSM concentration were unaffected. It is worth noting that no effect of increased in ovo lysozyme on eggs hatchability could be related to pathogen-free environment during artificial incubation of experimental eggs causing minimal pressure on embryo viability. While tangible in vivo mechanisms during avian embryogenesis remain to be tested, our study is the first to document experimentally that egg white LSM appears to have growth-regulation role during embryo development, with possible underlying phenotypic consequences in the early post-hatching period in precocial birds.
authors.affiliation: Department of Zoology, Biodiversity Research Group, Faculty of Science, Charles University in Prague, Prague 2, Czech Republic.|The Czech Academy of Sciences, Institute of Vertebrate Biology v.v.i., Brno, Czech Republic.
authors.forename: Veronika
authors.initials: V
authors.lastname: Javůrková
authors.affiliation: Department of Zoology, Biodiversity Research Group, Faculty of Science, Charles University in Prague, Prague 2, Czech Republic.
authors.forename: Eva
authors.initials: E
authors.lastname: Krkavcová
authors.affiliation: Department of Zoology, Biodiversity Research Group, Faculty of Science, Charles University in Prague, Prague 2, Czech Republic.|Department of Biodiversity and Molecular Ecology, Fondazione Edmund Mach, Research and Innovation Centre, Trentino, Italy.
authors.forename: Jakub
authors.initials: J
authors.lastname: Kreisinger
authors.affiliation: Department of Animal Physiology and Immunology, Institute of Experimental Biology, Masaryk University, Brno, Czech Republic.
authors.forename: Pavel
authors.initials: P
authors.lastname: Hyršl
authors.affiliation: Department of Genetics and breeding of farm animals, Institute of Animal Science, Prague, Czech Republic.
authors.forename: Ludmila
authors.initials: L
authors.lastname: Hyánková
mesh_terms: D000818:Animals; D001835:Body Weight; D003165:Complement System Proteins / Q000378:metabolism; D003370:Coturnix / Q000033:anatomy & histology / Q000196:embryology*; D004529:Egg White / Q000737:chemistry; D047108:Embryonic Development; D009113:Muramidase / Q000097:blood*; D010063:Ovum / Q000201:enzymology; D010641:Phenotype; D013643:Tarsus, Animal / Q000033:anatomy & histology*
chemical_list: D003165:Complement System Proteins; D009113:Muramidase