1. PTC Testing ofTasters vs. Non-Tasters Taster allele = dominant (T) Non-taster allele = recessive (t) What are the possible genotypes of PTC tasters? What are the possible genotypes of non-tasters?
2. 1 atgttgactctaactcgcatccgcactgtgtcctatgaagtcaggagtacatttctgttc 61 atttcagtcctggagtttgcagtggggtttctgaccaatgccttcgttttcttggtgaat 121 ttttgggatgtagtgaagaggcaggcactgagcaacagtgattgtgtgctgctgtgtctcC145G 49 pro/ala 181 agcatcagccggcttttcctgcatggactgctgttcctgagtgctatccagcttacccac 241 ttccagaagttgagtgaaccactgaaccacagctaccaagccatcatcatgctatggatg 301 attgcaaaccaagccaacctctggcttgctgcctgcctcagcctgctttactgctccaag 361 ctcatccgtttctctcacaccttcctgatctgcttggcaagctgggtctccaggaagatc 421 tcccagatgctcctgggtattattctttgctcctgcatctgcactgtcctctgtgtttgg 481 tgcttttttagcagacctcacttcacagtcacaactgtgctattcatgaataacaataca 541 aggctcaactggcagaataaagatctcaatttattttattcctttctcttctgctatctg 601 tggtctgtgcctcctttcctattgtttctggtttcttctgggatgctgactgtctccctg 661 ggaaggcacatgaggacaatgaaggtctataccagaaactctcgtgaccccagcctggag 721 gcccacattaaagccctcaagtctcttgtctcctttttctgcttctttgtgatatcatcc 781 tgtgttgccttcatctctgtgcccctactgattctgtggcgcgacaaaataggggtgatgC785T 262 ala/val 841 gtttgtgttgggataatggcagcttgtccctctgggcatgcagccatcctgatctcaggcG886A 296 val/ile 901 aatgccaagttgaggagagctgtgatgaccattctgctctgggctcagagcagcctgaag 961 gtaagagccgaccacaaggcagattcccggacactgtgctga red bold = SNPsgreen = forward primer blue = reverse primer(complement) dark red = Fnu4H1 restriction site 5’-GCNGC-3’
3. The sequence shown in the figure is that of the common non-taster allele with: G at nucleotide position 145 (G145), T at position 785 (T785) A at position 886 (A886). This non-taster allele produces a polypeptide with Alanineat amino acid position 49, Valineat position 262 Isoleucineat position 296 referred to as the AVI allele.
4. The common taster allele has: C145, C785, G886, Which produces a polypeptide with: Proline at amino acid 49, Alanine at amino acid 262 and Valine at amino acid 296 in the protein referred to as the PAV allele.
5. The SNP at position 785 is of particular interest in genotyping Taster sequence in this region forms an Fnu4H1 restriction site Replacing C785 with T785 in the non-taster allele eliminates this restriction site. Fnu4H1 Taster allele C785 Non-taster allele T785
6. Two other Fnu4H1 restriction sites exist within the PTC gene. We have chosen primers (shown in green and blue in Figure 1) designed to specifically bind to regions flanking the one polymorphic Fnu4H1 site while excluding the other two. Forward Primer (10uM) 5’AACTGGCAGAATAAAGATCTCAATTTAT3’ Reverse Primer (10uM) 5’AACACAAACCATCACCCCTATTTT3’
7. 1 atgttgactctaactcgcatccgcactgtgtcctatgaagtcaggagtacatttctgttc 61 atttcagtcctggagtttgcagtggggtttctgaccaatgccttcgttttcttggtgaat 121 ttttgggatgtagtgaagaggcaggcactgagcaacagtgattgtgtgctgctgtgtctcC145G 49 pro/ala 181 agcatcagccggcttttcctgcatggactgctgttcctgagtgctatccagcttacccac 241 ttccagaagttgagtgaaccactgaaccacagctaccaagccatcatcatgctatggatg 301 attgcaaaccaagccaacctctggcttgctgcctgcctcagcctgctttactgctccaag 361 ctcatccgtttctctcacaccttcctgatctgcttggcaagctgggtctccaggaagatc 421 tcccagatgctcctgggtattattctttgctcctgcatctgcactgtcctctgtgtttgg 481 tgcttttttagcagacctcacttcacagtcacaactgtgctattcatgaataacaataca 541 aggctcaactggcagaataaagatctcaatttattttattcctttctcttctgctatctg 601 tggtctgtgcctcctttcctattgtttctggtttcttctgggatgctgactgtctccctg 661 ggaaggcacatgaggacaatgaaggtctataccagaaactctcgtgaccccagcctggag 721 gcccacattaaagccctcaagtctcttgtctcctttttctgcttctttgtgatatcatcc 781 tgtgttgccttcatctctgtgcccctactgattctgtggcgcgacaaaataggggtgatgC785T 262 ala/val 841 gtttgtgttgggataatggcagcttgtccctctgggcatgcagccatcctgatctcaggcG886A 296 val/ile 901 aatgccaagttgaggagagctgtgatgaccattctgctctgggctcagagcagcctgaag 961 gtaagagccgaccacaaggcagattcccggacactgtgctga red bold = SNPsgreen = forward primer blue = reverse primer(complement) dark red = Fnu4H1 restriction site 5’-GCNGC-3’
