| First Author | Hjorth JP | Year | 1979 |
| Journal | Mouse News Lett | Volume | 61 |
| Pages | 25 | Mgi Jnum | J:13808 |
| Mgi Id | MGI:61987 | Citation | Hjorth JP (1979) Salivary amylase. Mouse News Lett 61:25 |
| abstractText | Full text of MNL contribution: Research News: Among 24 BxD recombinant inbred lines from Dr. B. Taylor, The Jackson Laboratory, one, no. 16, has a non-parental salivary amylase. The parental strains C57BL/6J and DBA/2J as well as the 23 RI lines all have the single-banded A phenotype in native gel electrophoresis. However, BxD16 has a co-dominant allele at the salivary amylase locus that codes for a single amylase protein form with electrophoretic mobility close to but different from, that of previously described B strains. The allele in BxDl6 at the closely linked pancreatic amylase locus codes for an electrophoretically A2 protein, the same as that in the parental strains. The salivary amylase of BxDl6 is more heat-labile than that of the parental strains. The patterns obtained by peptide analysis of purified salivary amylase from BxDl6 using s. aureus protease and CNBr digests followed by electrophoresis in polyacrylamide gels with SDS were of parental type. However, by isoelectric focusing of CNBr peptides some minor non-parental peptides were revealed. By these three techniques, salivary amylase from the B strain YBR gives different patterns. The pancreatic amylase from BxD16 had parental thermo-stability and parental peptide patterns when studied by the procedures mentioned above. No other strain or single mouse has (as yet) been found with the same amylase complex (combination of alleles at Amy-1 and Amy-2) as BxD16. It seems, therefore, very possible that the variant salivary amylase in this strain appeared as the result of a single mutation in one of the parental amylase complexes during the establishment of the BxD16 strain. The mutation has most probably occurred in the structural information because electrophoretic mobility as well as thermal-stability and pi of some CNBr peptides are changed by the mutation. In summary, an apparent single mutation has resulted in the change of all salivary amylase synthesized from one structural form to another. It is therefore concluded that BxDl6 has a single structural gene for salivary amylase. The allele in this strain will be used in future studies to define a baseline of amylase production. Genetic quantitative variation has previously been reported for salivary amylase. (Hjorth) |
