Open AccessDifferential Distribution of Poly(A)‐Containing RNA Sequences between the Nucleus and Post‐nuclear Supernatant of the Lactating Guinea‐pig Mammary Gland
Author(s) -
BATHURST Ian C.,
CRAIG Roger K.,
HERRIES David G.,
CAMPBELL Peter N.
Publication year - 1980
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1980.tb04783.x
Subject(s) - biology , cell nucleus , population , rna , nuclear localization sequence , microbiology and biotechnology , nucleus , messenger rna , nuclear protein , mammary gland , gene , genetics , transcription factor , demography , sociology , cancer , breast cancer
RNA complexity analysis of poly(A)‐containing RNA isolated from the lactating guinea‐pig mammary gland demonstrates that the complexity within the nuclear population was three–fourfold greater than that in the equivalent post‐nuclear polyribosomal population [see Craig et al., Biochem. J. (1979) 181 , 737–756]. Up to 21000 different sequences distributed in two abundance groups were detected in the nucleus, whereas 5000 sequences distributed in three abundance groups were present in the post‐nuclear population. All poly(A)‐containing RNA sequences present in the post‐nuclear fraction could be detected in the nuclear poly(A)‐containing population. Analysis of the relative distribution of the three post‐nuclear abundance populations within the nuclear poly(A)‐containing RNA population demonstrates that the abundant and moderately abundant post‐nuclear sequences were present at similar concentrations within the nucleus, and comprised the abundant nuclear population. The abundant and moderately abundant post‐nuclear sequences were present at 62200 and 785 copies of each sequence/cell in the post‐nuclear fraction respectively, and 44 and 118 copies of each sequence/cell in the nuclear fraction respectively. The scarce post‐nuclear sequences (18.5 copies of each sequence/cell) were also present at low levels in the nuclear fraction (0.1 copy of each sequence/cell). The results are discussed in terms of the post‐transcriptional regulation of gene expression in the lactating guinea‐pig mammary gland.