Embryonic and postnatal growth of the rat and mouse. VI. Prenatal growth of organs and tissues: individual organs; final remarks on parts I-VI, phase transitions.
The embryonic growth curves of 38 individual organs and tissues in the mouse and 19 in the rat are given. A method is presented for the estimation of the confidence interval of the time points of the breaks in the growth curves. In some instances, breaks in the organ curves in the mouse coincided with those noted for the whole embryo, at 10.7, 14.5 and 18.1 days, but they also occurred at other times, i.e., 9.4, 12.1, 13.3, and 16.9 days; we call these times 'phase transitions'. The relations between cell multiplication and other factors influencing volume increase are discussed, and also the relation between cell multiplication and changes in shape. Some implications of our work on growth for development in general are put forward.
D000818:Animals; D002455:Cell Division; D051379:Mice / Q000196:embryology*; D008954:Models, Biological; D051381:Rats / Q000196:embryology*