title: Differential distribution of poly(A)-containing RNA sequences between the nucleus and post-nuclear supernatant of the lactating guinea-pig mammary gland.
abstract: RNA complexity analysis of poly(A)-containing RNA isolated from the lactating guinea-pig mammary gland demontrates that the complexity within the nuclear population was three--four-fold greater than that in the equivalent post-nuclear polyribosomal population [see Craig et al., Biochem. J. (1979) 181, 737-756]. Up to 21 000 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 a 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.
mesh_terms: D000818:Animals; D001483:Base Sequence; D002467:Cell Nucleus / Q000032:analysis* / Q000648:ultrastructure; D005260:Female; D006168:Guinea Pigs; D007774:Lactation; D008321:Mammary Glands, Animal / Q000032:analysis*; D008970:Molecular Weight; D011061:Poly A / Q000032:analysis*; D011132:Polyribosomes / Q000032:analysis; D011247:Pregnancy; D012313:RNA / Q000032:analysis*
chemical_list: D011061:Poly A; D012313:RNA