Unusual splice sites revealed by mutagenic inactivation of an authentic splice site of the rabbit β-globin gene

Abstract
Only one of six point mutations of the sequence around one end of the larger of the introns of the rabbit β-globin gene seriously affects the normal removal of the intron and splicing of the gene. That mutation converts a GT sequence, invariably found at the 5′ end of introns, into an AT, which is no longer recognized as a signal for intron removal Instead, three normally unused (cryptic) sites are used, leading to aberrant gene transcripts. One of the cryptic sites is an exception to the invariable GT sequence.