In humans, multiple genes have been implicated in muscular dystrophy (MD); in addition, in most cases, any specific gene is implicated in multiple forms of the disease. This report describes fly models of muscular dystrophy related to the human gene POMT1 (protein-O-mannosyltransferase 1); see the OMIM report for the POMT1 gene (OMIM:607423). There is a single fly ortholog, Dmel\rt, for which for which classical hypomorphic alleles, RNAi-targeting constructs, and alleles caused by insertional mutagenesis have been generated.
The human POMT1 gene has not been introduced into flies.
Hypomorphic mutations of rt are semi-lethal; muscle defects are observed in larvae; progress locomotion defects are observed in adults. Genetic interactions with other MD-associated fly orthologs (tw and Dg) have been characterized.
[updated Mar. 2016 by FlyBase; FBrf0222196]
A form of limb-girdle muscular dystrophy-dystroglycanopathy (type C1; MDDGC1; OMIM:609308) is caused by homozygous or compound heterozygous mutation in the POMT1 gene. Several more severe types of muscular dystrophy are also associated with the POMT1 gene (OMIM:613155, OMIM:236670). [from OMIM:607423; 2016.03.16]
The POMT1 and POMT2 proteins are O-mannosyltransferases that catalyze the first step in the synthesis of the O-mannosyl glycan found on alpha-dystroglycan (DAG1) (summary by van Reeuwijk et al., 2005; pubmed:15894594). [from OMIM:607439; 2016.03.16]
Transfers mannosyl residues to the hydroxyl group of serine or threonine residues; requires interaction with the product of the POMT2 gene for enzymatic function; localizes to the membrane of the endoplasmic reticulum. [from Gene Cards; POMT1; 2016.03.25]