[Change in the level of casein mRNA in the mammary gland of rats and goats during lactation]. / Izmenenie soderzhaniia kazeinovykh mRNK v molochnoi zheleze krys i koz v protsesse laktatsii.

Cloned cDNAs for three distinct casein mRNAs (alpha s1-, beta- and chi) were used to determine the levels of individual mRNAs in total cell RNA preparations from both rat mammary glands in the course of natural lactation cycle and goat mammary glands at the most important lactation stages. Two maxima of active rat mRNA synthesis were shown to be closely associated with the particular developmental features of the progeny. A negative correlation between rat alpha s1-, and beta-casein mRNA levels was found. The length of goat casein mRNA was relatively increased at certain periods of the lactation cycle. The possible regulation mechanisms for the control of casein gene expression are discussed.