Rats, Zucker

**Definition:** Two populations of Zucker rats have been cited in research--the fatty or obese and the lean. The fatty rat (Rattus norvegicus) appeared as a spontaneous mutant. The obese condition appears to be due to a single recessive gene.

**Tree numbers:** - B01.050.150.900.649.313.992.635.505.700.550.700

**Synonyms:** - Zucker Rat - Zucker Rats