Assignment of maltase glucoamylase (MGAM) gene to bovine chromosome 4q34 by in situ hybridization and confirmation by radiation hybrid mapping

Abstract

In mammals, hydrolysis of the nonreducing ends of oligosacharide chains is carried out by an enzyme complex involving sucrase-isomaltase and maltase-glucoamylase which is anchored in the mucosa of the small intestine brush border (Semenza and Aurichino, 1989). It has been hypothesized that the human MGAM activity is an alternate pathway for starch digestion when luminal ·-amylase activity is reduced because of immaturity and malnutrition and that MGAM plays a unique role in the digestion of malted oligosaccharides (Nichols et al., 1998). The MGAM gene has been cloned and sequenced in man (AF016833) and partially sequenced in mouse (BC025509.1) Human MGAM has been mapped to human (HSA) chromosome 7 (Nichols et al., 1998), but as yet, the bovine MGAM gene has not been mapped. We used the human MGAM gene sequence to design specific primers to partially amplify the bovine gene. We report the localization of the bovine MGAM gene on bovine chromosome BTA4q34 by fluorescence in situ hybridization and radiation hybrid mapping.