The 5S rDNA in two Abracris grasshoppers (Ommatolampidinae: Acrididae): molecular and chromosomal organization.
The 5S ribosomal DNA (rDNA) sequences are subject of dynamic evolution at chromosomal and molecular levels, evolving through concerted and/or birth-and-death fashion. Among grasshoppers, the chromosomal location for this sequence was established for some species, but little molecular information was obtained to infer evolutionary patterns. Here, we integrated data from chromosomal and nucleotide sequence analysis for 5S rDNA in two Abracris species aiming to identify evolutionary dynamics. For both species, two arrays were identified, a larger sequence (named type-I) that consisted of the entire 5S rDNA gene plus NTS (non-transcribed spacer) and a smaller (named type-II) with truncated 5S rDNA gene plus short NTS that was considered a pseudogene. For type-I sequences, the gene corresponding region contained the internal control region and poly-T motif and the NTS presented partial transposable elements. Between the species, nucleotide differences for type-I were noticed, while type-II was identical, suggesting pseudogenization in a common ancestor. At chromosomal point to view, the type-II was placed in one bivalent, while type-I occurred in multiple copies in distinct chromosomes. In Abracris, the evolution of 5S rDNA was apparently influenced by the chromosomal distribution of clusters (single or multiple location), resulting in a mixed mechanism integrating concerted and birth-and-death evolution depending on the unit.
Departamento de Biologia, Instituto de Biociências/IB, UNESP, Univ Estadual Paulista, Rio Claro, São Paulo, CEP 13506-900, Brazil.
Danilo
D
Bueno
Departamento de Biologia, Instituto de Biociências/IB, UNESP, Univ Estadual Paulista, Rio Claro, São Paulo, CEP 13506-900, Brazil.
Octavio Manuel
OM
Palacios-Gimenez
Laboratorio de Genética Evolutiva, IBS, Facultad de Ciencias Exactas, Químicas y Naturales, CONICET, Universidad Nacional de Misiones, 3300, Posadas, Argentina.
Dardo Andrea
DA
Martí
Departamento de Zoologia, Instituto de Biociências/IB, UNESP, Univ Estadual Paulista, Rio Claro, São Paulo, Brazil.
Tatiane Casagrande
TC
Mariguela
Departamento de Biologia, Instituto de Biociências/IB, UNESP, Univ Estadual Paulista, Rio Claro, São Paulo, CEP 13506-900, Brazil. mellodc@rc.unesp.br.
Diogo Cavalcanti
DC
Cabral-de-Mello
D000818:Animals; D002874:Chromosome Mapping / Q000379:methods*; D002875:Chromosomes / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics*; D019143:Evolution, Molecular; D005260:Female; D006110:Grasshoppers / Q000235:genetics*; D008297:Male; D011544:Pseudogenes; D012341:RNA, Ribosomal, 5S / Q000235:genetics*; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein
D004275:DNA, Ribosomal; D012341:RNA, Ribosomal, 5S
FISH; Genome; Multigene family; Non-transcribed spacer; Repetitive DNAs