Histone H5 and H1 cross-reacting material is restricted to erythroid cells in chicken

Monoclonal H5 antibodies and a polyclonal antiserum, raised against the globular domain of chicken H5 (GH5) but which cross-reacts with histone H1(0) from mouse liver, were used to search for H5 or H1 (0)-like proteins in chicken embryo and adult tissue sections by indirect immunofluorescence. Chicken cell lines in culture were examined for H5 protein and H5 mRNA. Histone H5 was detected only in erythroid cells in tissue sections of chicken embryos or adult livers. H5 protein and H5 mRNA were found only in erythroid cells in culture. No cross-reacting proteins were detected in any other tissue or cell line examined.