“…Out of eight histone H1 subtypes (H1.a, H1.a′, H1.b, H1.b′, H1.c, H1.c′, H1.d, and H1.z) identified among avian erythrocyte histone H1 (Palyga 1991), five, including H1.a in duck (Anas platyrhynchos) (Kowalski et al1998), chicken (Gallus gallus) (Gornicka-Michalska et al 2006) and quail (Coturnix japonica) (Palyga 1998a), H1.a′ in grey partridge (Perdix perdix) (Kowalski et al 2008), H1.b in quail (Palyga 1998a), duck (Palyga et al 2000) and guinea fowl (Numidea meleagris) (Kowalski et al 2011a), H1.c in pheasant (Phasianus colchicus) (Kowalski et al 2010) and guinea fowl (Kowalski et al 2011a), and H1.z in duck (Palyga et al 1993) and quail (Palyga 1998a), have been recognized to be polymorphic due to the presence of two or three electromorphs differently migrating in the polyacrylamide gels as a result of variation in their net charges and/or apparent molecular weights. Both frequent and rare allelic isoforms for the avian polymorphic histone H1 subtypes were already observed in both conservative (Kowalski et al 1998;Palyga et al 2000;Kowalski and Palyga 2014) and breeding populations (Palyga et al 1993;Palyga 1998b;Kowalski and Palyga 2014).…”