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.

Constant and Cycling Incubation Temperatures Have Long-Term Effects on the Morphology and Metabolic Rate of Japanese Quail

“…Hatching success was reduced by low temperature but not by cycling. In fact, the cyclical treatment had the highest hatching success at 71%, although this was not significantly different from that for the control treatment (60%), and both were similar to previously reported hatching successes in Japanese quail (Copur et al 2010;Javurkova et al 2015). This result mirrors what was found with even longer cycling periods (8 h off-bouts) of incubation in Japanese quail (Callebaut 1990).…”

Different incubation patterns affect selective antimicrobial properties of the egg interior: experimental evidence from eggs of precocial and altricial birds

“…Recent studies have identified more than 180 different egg white proteins in chicken eggs (Mann and Mann, 2011;Sun et al, 2017). Of these, lysozyme and ovotransferrin are the most abundant (Burley and Vadehra, 1989), having physiological (Giansanti et al, 2012;Javurkova et al, 2015; Krkavcová et al, 2018) and strong antimicrobial potential (Baron and Jan, 2011;Wellman-Labadie et al, 2008b). While lysozyme has significant bactericidal activity against Gram-positive as well as Gram-negative bacteria (Ibrahim et al, 2001;Wellman-Labadie et al, 2008a), ovotransferrin is primarily bacteriostatic via its iron-binding potential, forming an iron-deficient environment, inhibiting the growth of many microorganisms (Wu and Acero-Lopez, 2012).…”

The hidden function of egg white antimicrobials: egg weight-dependent effects of avidin on avian embryo survival and hatchling phenotype

“…Both the alkaline pH ( Grizard et al, 2015 ) and the presence of antimicrobial proteins ( Shawkey et al, 2008 ; Horrocks et al, 2014 ) have been shown to significantly reduce the growth of microorganisms ( Board and Fuller, 1974 ) able to penetrate the eggshell and fundamentally affect egg hatchability ( Pinowski et al, 1994 ) and/or offspring phenotype ( Javůrková et al, 2014 ). In addition, many egg white proteins are thought to be important modulators of embryogenesis and immune phenotype; though few correlative studies ( Saino et al, 2002 , 2007 ; Bonisoli-Alquati et al, 2010 ; D′Alba et al, 2010 ) and only one experimental study ( Javůrková et al, 2015 ) have examined the effect of egg white proteins on the development and post-hatching phenotype of birds. Many egg white proteins also have binding sites specific to metal ions, such as Fe 3+ , or to vitamins, such as biotin, riboflavin or thiamine ( Muniyappa and Adiga, 1979 ; White and Merrill, 1988 ).…”

“…Many egg white proteins also have binding sites specific to metal ions, such as Fe 3+ , or to vitamins, such as biotin, riboflavin or thiamine ( Muniyappa and Adiga, 1979 ; White and Merrill, 1988 ). Although the binding of these essential molecules to specific proteins prevents their use in the growth and proliferation of many pathogenic microorganisms, their presence is probably more important for proper development of the embryo ( Bonisoli-Alquati et al, 2010 ; Giansanti et al, 2012 ; Javůrková et al, 2015 ).…”