title: Physical mapping of 5S rDNA in two species of Knifefishes: Gymnotus pantanal and Gymnotus paraguensis (Gymnotiformes).
abstract: Physical mapping of 5S rDNA in 2 species of knifefishes, Gymnotuspantanal and G. paraguensis (Gymnotiformes), was performed using fluorescence in situ hybridization with a 5S rDNA probe. The 5S rDNA PCR product from the genomes of both species was also sequenced and aligned to determine non-transcribed spacer sequences (NTS). Both species under study had different patterns of 5S rDNA gene cluster distribution. While in the karyotype of G. pantanal two 5S rDNA-bearing pairs were observed, the karyotype of G. paraguensis possessed as many as 19 such pairs. Such multiplication of 5S rDNA gene clusters might be caused by the involvement of transposable elements because the NTS of G. paraguensis was 400 bp long with high identity (90%) with a mobile transposable element called Tc1-like transposon, described from the cyprinid fish Labeo rohita.
authors.affiliation: Departamento de Biologia Estrutural, Molecular e Genética, Universidade Estadual de Ponta Grossa, Brasil.
authors.forename: M
authors.initials: M
authors.lastname: da Silva
authors.forename: D A
authors.initials: DA
authors.lastname: Matoso
authors.forename: M R
authors.initials: MR
authors.lastname: Vicari
authors.forename: M C
authors.initials: MC
authors.lastname: de Almeida
authors.forename: V P
authors.initials: VP
authors.lastname: Margarido
authors.forename: R F
authors.initials: RF
authors.lastname: Artoni
mesh_terms: D000818:Animals; D001483:Base Sequence; D004251:DNA Transposable Elements / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics*; D005260:Female; D014644:Genetic Variation; D023702:Gymnotiformes / Q000145:classification / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D020161:Physical Chromosome Mapping / Q000379:methods*; D012341:RNA, Ribosomal, 5S / Q000235:genetics*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D032681:Spectral Karyotyping
chemical_list: D004251:DNA Transposable Elements; D004275:DNA, Ribosomal; D012341:RNA, Ribosomal, 5S