Figure 3.

Normal levels of TLC1 expression are observed in haploid strains with the tlc1-human allele. (A) TLC1 gene expression by Northern hybridization. A Northern blot of total RNA was hybridized with a full-length TLC1 probe, then stripped and reprobed with an ACT1 probe as a control for loading. Expression levels were quantitated by using a PhosphorImager. Diploid yeast, diploid strain NM1 (AB1380 × YPH925); Pop-in, clone C6 that was generated by pTLC1h plasmid insertion into NM1; Pop-out, clone C6.1, a 5-fluoroorotic acid-resistant derivative of C6 that has one copy each of the wild-type TLC1 and the tlc1-human alleles; 7A to 8D, haploid strains from two tetrad dissections of C6.1. (B) Allele-specific oligonucleotide hybridization distinguishes expression of the tlc1-human allele from the wild-type TLC1 allele. A Northern blot of total RNA was hybridized first with an oligonucleotide specific for the human template sequence (hT), then stripped and reprobed with an oligonucleotide specific for the yeast template sequence (yT), and finally stripped and reprobed with an ACT1 probe to control for loading. 7A to 8D, haploid strains from tetrads 7 and 8.