title: Repetitive DNAs highlight the role of chromosomal fusions in the karyotype evolution of Dascyllus species (Pomacentridae, Perciformes).
abstract: The Dascyllus genus consists of 11 species spread over vast regions of the Indo-Pacific, showing remarkable reductions in the diploid chromosome numbers (2n). The present study analyzed the karyotypes and other chromosomal characteristics of D. trimaculatus (2n = 48; 2st + 46a; NF = 50), D. carneus (2n = 48; 2st + 46a; NF = 50) and D. aruanus (2n = 30; 18m + 2st + 10a; NF = 50) from the Thailand Gulf (Pacific Ocean) and D. melanurus (2n = 48; 2st + 46a; NF = 50) from the Andaman Sea (Indian Ocean), employing conventional cytogenetic analyses and the chromosomal mapping of repetitive DNAs, using 18S and 5S rDNA, telomeric sequences and (CA)15, (GA)15, and (CAA)10 microsatellites as probes. The C-positive heterochromatin was found in the centromeric regions of most chromosomal pairs and 18S rDNA phenotypes were single in all species. However, in D. aruanus (2n = 30), which harbors nine metacentric pairs; the 5S rDNA sites were located in the centromeric region of the shortest one. The mapping of the telomeric sequences in D. aruanus revealed the presence of interstitial telomeric sites (ITS) in the centromeric region of four metacentric pairs, with one of these pairs also displaying an additional ITS in the long arms. Distinct chromosomal markers confirmed the reduction of the 2n by chromosomal fusions, highlighting the precise characterization of these rearrangements by the cytogenetic mapping of the repetitive DNAs.
authors.affiliation: Department of Biology, Faculty of Science, Khon Kaen University, Muang District, Khon Kaen, Thailand.
authors.forename: Nuntaporn
authors.initials: N
authors.lastname: Getlekha
authors.affiliation: Departamento de Biologia Celular e Genética, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil.
authors.forename: Wagner Franco
authors.initials: WF
authors.lastname: Molina
authors.affiliation: Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, São Paulo, Brazil.
authors.forename: Marcelo
authors.initials: M
authors.lastname: de Bello Cioffi
authors.affiliation: Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, São Paulo, Brazil.
authors.forename: Cassia Fernanda
authors.initials: CF
authors.lastname: Yano
authors.affiliation: Department of Biology, Faculty of Science, Khon Kaen University, Muang District, Khon Kaen, Thailand.
authors.forename: Nuntiya
authors.initials: N
authors.lastname: Maneechot
authors.affiliation: Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, São Paulo, Brazil.
authors.forename: Luiz Antonio Carlos
authors.initials: LA
authors.lastname: Bertollo
authors.affiliation: Department of Fisheries, Faculty of Applied Science and Engineering, Khon Kaen University, Nong Khai Campus, Muang, Nong Khai, Thailand.
authors.forename: Weerayuth
authors.initials: W
authors.lastname: Supiwong
authors.affiliation: Department of Biology, Faculty of Science, Khon Kaen University, Muang District, Khon Kaen, Thailand. tanomtong@hotmail.com.|Toxic Substances in Livestock and Aquatic Animals Research Group, Khon Kaen University, Muang, Khon Kaen, 40002, Thailand. tanomtong@hotmail.com.
authors.forename: Alongklod
authors.initials: A
authors.lastname: Tanomtong
mesh_terms: D000818:Animals; D002874:Chromosome Mapping; D004171:Diploidy; D019143:Evolution, Molecular; D005260:Female; D019156:Indian Ocean; D059785:Karyotype; D008297:Male; D018895:Microsatellite Repeats; D010140:Pacific Ocean; D010473:Perciformes / Q000235:genetics*; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D012341:RNA, Ribosomal, 5S / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid; D017422:Sequence Analysis, DNA; D016615:Telomere / Q000235:genetics
chemical_list: D012337:RNA, Ribosomal, 18S; D012341:RNA, Ribosomal, 5S
keywords: Chromosomal rearrangements; Chromosome evolution; Damselfishes; Telomeric sequences