Fig 3.

The tva^r3 and tva^r4 alleles in chicken line P and G. g. murghi contain deletions in the first intron. (A) PCR amplification of the whole tva coding sequence from G. g. murghi (GGM), L15, and line P CEFs. Two forms of normal tva transcripts in L15 420 bp and 569 bp in length and two forms with retained intron 1 in G. g. murghi and line P 604 bp and 753 bp in length are shown. Lane M, DNA marker 100-bp ladder. (B) Partial sequence of the chicken tva intron 1 and junctions with exons 1 and 2. The region of the branch point with respective deletions in tva^r3 and tva^r4 alleles are highlighted below, and deleted bases are indicated with dashes. The deduced branch-point signal is boxed, and the 3′ splice signal (yAG) is indicated. The putative alternative branch-point signals are underlined. The intron-exon junctions are indicated by vertical bars; exon sequences are in italics.