Actb^tm1Bhr

A promoterless hygromycin-lacZ fusion gene with a splice acceptor was introduced into the first intron of the beta actin locus. The presence of normal transcript in homozygous mutants suggests that the fusion gene is sporadically excised during splicing, resulting in a hypomorphic allele. Expression analysis indicated that the integration event does not result in ubiquitous expression of Beta galactosidase. (J:46634)