This report covers models in flies for the related diseases associated with the human gene Myosin VIIA (MYO7A). These diseases include Usher syndrome, type I (MIM:276900, FBhh0000469), deafness, autosomal dominant 11 (MIM:601317, FBhh0000470) and deafness, autosomal recessive 2 (MIM:600060, FBhh0000471). MYO7A encodes an unconventional myosin involved in intracellular transport and vesicle trafficking. There are two orthologous genes in Drosophila, ck, for which classical amorphic and hypomorphic alleles, RNAi-targeting constructs, and alleles caused by insertional mutagenesis have been generated, and Myo28B1, for which RNAi-targeting constructs and alleles caused by insertional mutagenesis are available. There is an additional paralogous gene in human, MYO7B.
The human MYO7A gene has not been introduced into flies.
Only the higher-scoring MYO7A ortholog in flies, ck, has been genetically characterized. Animals homozygous for amorphic alleles of ck are lethal during embryonic or larval stages. For several alleles that allow survival to adulthood, auditory transduction (assayed in the antenna) is impaired and the Johnston's organ (the auditory organ in the antenna) is morphologically abnormal. Genetic and physical interactions of Dmel\ck have been described; see below and in the gene report for ck.
[updated Jan. 2017 by FlyBase; FBrf0222196]
Myosins are actin-based motor molecules with ATPase activity; unconventional myosins serve in intracellular transport. Their highly divergent tails bind to membranous compartments, which are then moved relative to actin filaments. [from Gene cards, MYO7A; 2017.01.09]
The MYO7A gene encodes a protein classified as an unconventional myosin. Unconventional myosins are motor molecules with structurally conserved heads that move along actin filaments. Their highly divergent tails are presumed to be tethered to different macromolecular structures that move relative to actin filaments, thus enabling them to transport cargo (Weil et al., 1995; pubmed:7870171). [from MIM:276903; 2017.01.09]
Many to many: 2 human to 2 Drosophila; the other human gene is MYO7B.
Moderate- to high-scoring ortholog of human MYO7A and MYO7B (2 Drosophila to 2 human). Dmel\ck shares 59% identity and 75% similarity with MYO7A; it shares 46% identity and 64% similarity with MYO7B.
