A heterogeneity of the pheasant (Phasianus colchicus L.) erythrocyte histone H1 subtype H5.

In a previous work (Górnicka-Michalska et al. (1998)), an occurrence of genetic variants in the chicken erythrocyte histone H5 has been presented. Here, the pheasant histone H5 heterogeneity is characterized to verify if the interspecies variability of this protein is caused by the analogous determinants. During screening histone H1 preparations isolated from the pheasant erythrocytes, histone H5 was identified as differently located in the electrophoretic gels. According to the rate of electrophoretic migration, two histone H5 phenotypes (H5a and H5b) possessing similar quantitative proportion (P>0.05) were distinguished. A rare phenotype H5a (frequency 0.26) migrating faster in the SDS-PAGE was low mobile in the AU-PAGE, in contrast to the frequent phenotype H5b (frequency 0.74) that moved slowly in the SDS-PAGE and roamed faster in the AU-PAGE. The electrophoretic properties of histone H5 phenotypes may reflect disparities in their net charge and molecular weight. Peptide maps of histone H5 phenotypes, obtained by partial chemical cleavage (NBS) and limited enzymatic digestion (α-chymotrypsin), revealed their C-peptides possessing the same electrophoretic mobility and the N-peptides having variable rate of the electrophoretic migration. Based on this, the identified phenotypic variation seems to be determined by a histone H5 phenotype-specific amino acid sequence region situated in the N-terminal portion of its molecule. According to the identified varied sequence stretches, histone H5 phenotype may induce specific effects related to the organization and/or function of the pheasant chromatin.