title: Polymorphism of rRNA gene loci in the dog.
abstract: We examined the number of ribosomal gene (rDNA) loci in the metaphase spreads of 54 dogs by FISH method. We found that in 16 dogs (30%) one or two loci were missing. The total number of rDNA loci was varied from 5 to 7 in males and from 4 to 6 in females. As the male dog consistently bears the rDNA on the Y chromosome, the polymorphism of the rDNA locus was ascribed to the absence of autosomal rDNA loci. Indeed, the frequency of polymorphism is almost equivalent in both sexes in the beagle. In one female beagle dog, remarkable intense fluorescence signals were observed at the four autosomal loci, indicating the in situ amplification of rDNA.
authors.affiliation: Laboratory of Veterinary Anatomy, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan.
authors.forename: Motoki
authors.initials: M
authors.lastname: Goto
authors.forename: Asuka
authors.initials: A
authors.lastname: Sube
authors.forename: Soushi
authors.initials: S
authors.lastname: Mikashima
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kaneda
authors.forename: Hideshi
authors.initials: H
authors.lastname: Shibata
authors.forename: Naotoshi
authors.initials: N
authors.lastname: Kanda
mesh_terms: D000818:Animals; D002875:Chromosomes / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics*; D004285:Dogs / Q000235:genetics*; D005260:Female; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008297:Male; D008677:Metaphase; D011110:Polymorphism, Genetic
chemical_list: D004275:DNA, Ribosomal