Isolation and characterization of free haem from the shell gland of quail and hen

Abstract

Free haem was isolated from the shell gland of the quail, Coturnix coturnix japonica, and of the fowl, Galinus domesticus, and characterized by HPLC-ESI-MS/MS. Quantification by HPLC gave values of 1.17-1.40 nmol/mg quail shell gland protein for haem, 1.66-2.17 nmol/mg protein for protoporphyrin and 0.25-0.40 nmol/mg protein for biliverdin. Possible implications of this previously unreported finding are discussed but they are not considered incompatible with the conclusion that all eggshell pigments are endogenously synthesized in the oviduct system.

Egg Recognition in Japanese Quail

“…P-values were calcu-lated as the proportion of 10 6 Monte Carlo simulations (in which the second egg of each pair was randomly allocated among females, and a new set of MDP distances computed) with mean distances greater than the observed distance (Good, 2005).…”

“…P-values were calculated by comparing the full model to a reduced model lacking the factor of interest using likelihood ratio tests (Crawley, 2002). None of the three egg phenotypic variables were inter-correlated (all P40:2).…”

“…Pattern and texture is primarily perceived using achromatic (luminance) vision (Jones and Osorio, 2004;Osorio and Vorobyev, 2005), which in birds is likely to be encoded by the double cones (Osorio and Vorobyev, 2005). Both the basal colouration and the regions of maculation of Japanese quail eggs are predominantly produced by deposition of protoporphyrin at varying concentrations (Gorchein et al, 2011), and so egg background and maculation colour remains remarkably constant across eggs (even white eggs contain some protoporphyrin; cf. Kennedy and Vevers, 1976) while there is marked variation in luminance (Pike, unpublished data).…”

An evaluation of different methods for assessing eggshell pigmentation and pigment concentration using great tit eggs

“…In some species, both biliverdin and protoporphyrin are found in the eggshell, but often one exceeds the other many times (Kennedy and Vevers ). Biliverdin and protoporphyrin concentrations are often negatively correlated, and since protoporphyrin is a precursor and biliverdin a metabolite of heme, a strong link has been suggested (Gorchein et al , , Wang et al ). Both originate most likely from within the oviduct system (Kennedy and Vevers , Sparks , Gorchein et al ).…”

“…Biliverdin and protoporphyrin concentrations are often negatively correlated, and since protoporphyrin is a precursor and biliverdin a metabolite of heme, a strong link has been suggested (Gorchein et al , , Wang et al ). Both originate most likely from within the oviduct system (Kennedy and Vevers , Sparks , Gorchein et al ). Protoporphyrin IX, as found in eggshells, is not bound to an iron molecule and can therefore be harmful by oxidising other molecules (Ryter and Tyrrell ), while biliverdin has antioxidant properties, which has been the basis for the assumption that eggshell pigmentation may be linked to female physiological condition.…”