The present invention provides isolated and recombinant avian nucleic acid
molecules comprising at least one avian MAR and an avian nucleic acid
sequence encoding an ovalbumin transcriptional regulatory region. The
isolated nucleic acid of the present invention is useful for reducing
chromosomal positional effects upon the transcription of a transgene
operably linked to the ovalbumin transcriptional regulatory region and
transfected into a recipient avian cell The recombinant nucleic acid
molecules of the present invention may further comprise a polyadenylation
signal sequence or an avian 3' domain, and optionally, an internal
ribosome entry site for expression of an operably linked heterologous
nucleic acid insert in a transfected avian cell.