title: Effect of age, sex and nutrition on discontinuous traits of rat skull.
abstract: The effect of biological (age and sex) and environmental factors (protein-calorie malnutrition and protein deficit) on 24 discontinuous cranial traits was investigated in Holtzman rats. The traits affected were (a) the interfrontal fusion, by age and nutrition; (b) the double posterior palatine foramen, by sex and nutrition, and (c) the double maxillary foramen, by nutrition. It is concluded that most of the traits studied were fairly stable. Nevertheless, it must be pointed out that taxonomic studies based on discontinuous cranial traits should be interpreted with care due to the influence of environmental and biological factors on the phenotypic expression of some of them.
mesh_terms: D000367:Age Factors; D000818:Animals; D001846:Bone Development; D005260:Female; D008297:Male; D009748:Nutrition Disorders / Q000503:physiopathology*; D010012:Osteogenesis; D051381:Rats; D011919:Rats, Inbred Strains; D012737:Sex Factors; D012886:Skull / Q000254:growth & development*