title: Characterization of two unrelated satellite DNA families in the Colorado potato beetle Leptinotarsa decemlineata (Coleoptera, Chrysomelidae).
abstract: The Colorado potato beetle (Leptinotarsa decemlineata, family Chrysomelidae),a phytophagous insect, which feeds preferably on potatoes, constitutes a serious pest of this crop and causes extensive damage to tomatoes and egg plants. It has a remarkable ability to develop resistance quickly against insecticides and shows a diversified and flexible life history. Consequently, the control of this pest has become difficult, requiring the development of new alternative biotechnology-based strategies. Such strategies require a thorough knowledge of the beetle’s genome,including the repetitive DNA. Satellite DNA (stDNA), composed of long arrays of tandemly arranged repeat units, constitutes the major component of heterochromatin and is located mainly in centromeric and telomeric chromosomal regions. We have studied two different unrelated satellite-DNA families of which the consensus sequences were 295 and 109bp in length, named LEDE-I and LEDE-II, respectively.Both were AT-rich (70.8% and 71.6%, respectively). Predictive models of sequence-dependent DNA bending and the study of electrophoretic mobility on non-denaturing polyacrylamide gels have shown that the DNA was curved in both satellite-DNA families. Among other features, the chromosome localization of both stDNAs has been studied. In situ hybridization performed on meiotic and mitoticnuclei showed chromosomes, including the X chromosome, with zero, one, or two stDNAs. In recent years, it has been proposed that the repetitive DNA may play a key role in biological diversification processes. This is the first molecular and cytogenetic study conducted on L. decemlineata repetitive DNA and specifically on stDNA, which is one of the important constituents of eukaryotic genomes.
authors: Departamento de Biología Experimental, Universidad de Jaén, 23071 Jaén, Spain.
authors: Pedro
authors: P
authors: Lorite
authors: M Isabel
authors: MI
authors: Torres
authors: Teresa
authors: T
authors: Palomeque
mesh_terms: D000818:Animals; D059006:Chromosomes, Insect; D001517:Coleoptera / Q000235:genetics*; D005260:Female; D049750:Genome, Insect; D008297:Male; D018895:Microsatellite Repeats