Click here to close Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly. We suggest using a current version of Chrome, FireFox, or Safari.
XB-ART-32651
Chromosoma 1975 Nov 20;531:25-36. doi: 10.1007/bf00329388.
Show Gene links Show Anatomy links

Distribution of 18+28S ribosomal genes in mammalian genomes.

Hsu TC , Spirito SE , Pardue ML .


???displayArticle.abstract???
In situ hybridization with 3H 18S and 28S ribosomal RNA from Xenopus laevis has been used to study the distribution of DNA sequences coding for these RNAs (the nucleolus organizing regions) in the genomes of six mammals. Several patterns of distribution have been found: 1) A single major site (rat kangaroo, Seba's fruit bat), 2) Two major sites (Indian muntjac), 3) Multiple sites in centromeric heterochromatin (field vole), 4) Multiple sites in heterochromatic short arms (Peromyscus eremicus), 5) Multiple sites in telomeric regions (Chinese hamster). - The chromosomal sites which bind 3H 18S and 28S ribosomal RNA correspond closely to the sites of secondary constrictions where these are known. However, the correlation is not absolute. Some secondary constrictions do not appear to bind 3H ribosomal RNA. Some regions which bind ribosomal RNA do not appear as secondary constrictions in metaphase chromosomes. - Although the nucleolus organizing regions of most mammalian karyotypes are found on the autosomes, the X chromosomes in Carollia perspicillata and C. castanea carry large clusters of sequences complementary to ribosomal RNA. In situ hybridization shows that the Y chromosome in C. castanea also has a large nucleolus organizing region.

???displayArticle.pubmedLink??? 1104290
???displayArticle.link??? Chromosoma


Species referenced: Xenopus laevis
Genes referenced: kidins220

References [+] :
Funaki, Location of nucleolar organizers in animal and plant chromosomes by means of an improved N-banding technique. 1975, Pubmed