Growth curve and morphometric variables in rats: are they related?
Four growth curve variables were measured in a population of rats in order to assess their association, if any, with a suite of morphometric characters. The growth curve variables (A = asymptotic weight, R = growth rate, P = percentage of asymptotic size at inflection, and G = time to grow from 10 to 90% of asymptotic size) were derived from Richards' curves applied to longitudinal body weight data, and the morphometric characters (measured in 189-day-old rats) consisted of 4 tooth and 7 bone variables. As assessed by a canonical correlation analysis, there was a significant association between the two sets of variables, especially between A and the skeletal variables. It was hypothesized that associations of the bone characters should be greater with A but less with R compared with those for the tooth characters, and this was shown to be the case. The canonical correlation analysis also showed a strong association of P with G in each sex, although in a factor analysis these two variables associated with R.
Leamy
L
L
Department of Biology, California State University, Long Beach 90840.
Bradley
D
D
D000375:Aging; D000818:Animals; D001699:Biometry; D001835:Body Weight; D001846:Bone Development; D005260:Female; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains / Q000254:growth & development*; D012737:Sex Factors; D014070:Tooth / Q000254:growth & development