This strain carries a targeted mutation of the Tas1r1 (taste receptor, type 1, member 1) gene which encodes a component of the heterodimeric G-protein coupled umami (monosodium L-glutamate, MSG) taste sensor. Homozygous mice lack expression of the gene and have normal viability, body weight, overall anatomy and general behavior. Taste receptor cells appear normal morphologically and numerically. Although the mice show robust neural responses to sour (citric acid), salty (NaCl), bitter (6-n-propylthiouracil, PROP), and sweet (D-amino acids, sucrose, maltose, glucose, saccharin) tastants, responses to umami L-amino acid tastants are lost. This strain may be useful in studies of taste and nutrient sensing.
