United States and British researchers announced Monday they have found a defective gene that makes it impossible for cats to taste sugar or other sweets.
Researchers at Philadelphia's Monell Chemical Senses Center in collaboration with Britain's Waltham Center for Pet Nutrition found a defect in a gene coding for part of the mammalian sweet taste receptor can account for cats' indifference to sweets.
Xia Li, a molecular geneticist at Monell, said the mammalian sweet receptor is composed of two protein subunits, known as T1R2 and T1R3. Each is coded for by a separate gene.
In the study, reported in the July inaugural issue of PLoS (Public Library of Science) Genetics, the researchers show a defect in the gene encoding the T1R2 protein in domestic cats.
Monell researchers also detected the same gene defect in tigers and cheetahs, suggesting it is common throughout the cat family.
"This type of gene is known as a pseudo gene and is somewhat like a molecular fossil," said Li. "It presumably once coded a functional protein, but no longer does so."
The data will be presented during the Waltham International Nutritional Sciences Symposium scheduled for September in Washington.
Copyright 2005 by United Press International
