Nuclear Proteins during Development: Incorporation of Leucine into Histones of Rainbow Trout during Early Development

Abstract

Nuclear histones of embryos of rainbow trout (Salmo gairdnerii) were isolated after incubation of cell suspensions with [4,5-3H]leucine. The incorporation of leucine into nuclei at 10 °C was found to occur linearly for 4 h. At all stages examined from very early blastula to [Formula: see text] epiboly, a component identical in mobility to histone I was found when a sensitive staining technique was employed. The relative proportion of histone IIId is higher at early blastula, and decreased by mid-blastula to a level which remains constant relative to other components during the remainder of the stages examined. The major proportion of the leucine incorporated into histones is found at all stages in histones IIb1 and IIb2, but as development occurs, the relative proportion of incorporation into histone IV increases until at [Formula: see text] epiboly, it is almost equal to either histone IIb1 or IIb2.