Amy, Amylase, α-amylase, alpha-amylase distal, Amy6
Gene model reviewed during 5.50
Gene model reviewed during 5.56
There is only one protein coding transcript and one polypeptide associated with this gene
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\Amy-d using the Feature Mapper tool.
Amy-d3 transcript levels are higher in the anterior midgut than in the posterior midgut and are repressed by dietary glucose in both. The tissue specific effects of mapP alleles are restricted to the posterior midgut.
Amy-d6 transcript levels are higher in the anterior midgut than in the posterior midgut and are repressed by dietary glucose in both. The tissue specific effects of mapP alleles are restricted to the posterior midgut.
Glucose-fed larvae were shown to have less than 1% of the level of Amylase transcripts found in non-glucose-fed control larvae.
The amylase transcript levels were estimated to vary between 0.01 to 1.0% of poly(A)+ RNA depending on the presence or absence of added glucose in the diet.
Glucose was shown to have a repressing effect on amylase levels in the anterior end of the posterior midgut in mapP00 flies but not in mapP12 flies. Levels of amylase were generally higher in the anterior midgut than in the posterior midgut. The analysis of amylase activity and protein levels yielded the same results.
GBrowse - Visual display of RNA-Seq signalsView Dmel\Amy-d in GBrowse 2
Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see GBrowse for alignment of the cDNAs and ESTs to the gene model.
For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.
Eight electrophoretic variants of α-amylase have been recorded; they have been numbered, in order of decreasing rates of migration toward the anode, from "-1" through "+7" (FBrf0039664). Phenotypes usually represented as haplotypes according to the electrophoretic mobilities of the products of the Amy-d and Amy-p alleles. Bahn recovered one Amy1,3 and two Amy2 recombinants from Amy-p1 Amy-d-/Amy-p2 Amy-d3 heterozygotes and one Amy4,3 and two Amy2,6 recombinants from Amy-p4 Amy-d6/Amy-p2 Amy-d3 heterozygotes. From these observations it was concluded that the amylase locus is duplicated and the two copies are separated by 0.008 cm; furthermore, flanking marker segregations indicated that determinants of forms 1, 2 (thermostable) and 4 are to the left (from Amy-p) of those for 3 (thermostable) and 6 (from Amy-d); see also Gemmill et al. (FBrf0045142). Amy1 monomorphic phenotype in Oregon-R has been shown to be Amy-p1 Amy-d1.
In a sample of 79 genes with multiple introns, 33 showed significant heterogeneity in G+C content among introns of the same gene and significant positive correspondence between the intron and the third codon position G+C content within genes. These results are consistent with selection adding against preferred codons at the start of genes.
Molecular evolution of the Amy multigenes in Drosophila has been investigated.
Quantifying rates of protein sequence divergence within and between species reveals that the Drosophila genome harbors a substantial proportion of genes with a very high divergence rate.
Amylase enzyme activity has been measured in D.melanogaster lines in which spontaneous mutations have accumulated over approximately 300 mutations.
Amy-d is not correlated with geotaxis score in high and low hybrid derived lines.
The enzymological features of α-amylase from six species of the D.melanogaster species subgroup have been compared.
Comparison of CpG distribution in the coding region of 121 genes from six species supports the mCpG mutational hotspot explanation of CpG suppression in methylated species at position II-III and III-I.
In lines selected over 700 generations for high (negative) and low (positive) geotaxis, different variants of Amy found to have segregated out.
Rapid rates of gene conversion were observed between the duplicated Amy coding sequences. There is virtual sequence identity between the coding regions of the two genes. Flanking, noncoding regions are much more highly diverged and are not subject to gene conversion. The results conclude that recurrent gene conversion does lead to concerted evolution.
Glucose repression of gene expression reflects a change in the transcriptional activity of the Amylase gene in larvae.
Northern blot analysis demonstrates that amylase mRNA is repressed by dietary glucose: the mRNA can be estimated to vary from 0.01% of poly(A)+RNA to greater than 1% poly(A)+RNA depending on the diet.
Flies or larvae from a food medium containing starch show higher levels of activity than individuals from a food containing simple sugars. This is shown to be due to repression of activity by sugars rather than enhancement of activity by starch. The changes in enzyme activity are due to a change in enzyme quantity rather than efficiency. Flies carrying a duplication of the amylase structural gene have differential repression of the two isozymal forms by dietary sugars.
Structural gene for α-amylase. Most strains of D.melanogaster are duplicated for this gene, with distal (Amy-d) and proximal (Amy-p) genes being about 4-kb apart and divergently transcribed. Amylase is a monomeric protein based on failure to form hybrid enzyme molecules of intermediate mobility in heterozygotes for alleles coding for electrophoretic variants. Activity mainly in midgut and hemolymph with smaller amounts in other tissues; activity found in anterior or posterior, or both, but not middle, region of midgut; three spatial patterns of adult posterior midgut activity encountered on standard medium; controlled by the trans-regulatory effects of mapP (FBrf0032374;); adult anterior midgut activity under regulation of another separable regulatory locus, mapA (FBrf0034443). Larval midgut activity affected by closely linked cis-acting regulatory elements (FBrf0044421). Amylase activity is glucose repressible (FBrf0044516); the degree of repression can be greater than one hundred fold in larvae and occurs at the level of transcript initiation (FBrf0042684; FBrf0045840; FBrf0058599).