title: Evidence of birth-and-death evolution of 5S rRNA gene in Channa species (Teleostei, Perciformes).
abstract: In higher eukaryotes, minor rDNA family codes for 5S rRNA that is arranged in tandem arrays and comprises of a highly conserved 120 bp long coding sequence with a variable non-transcribed spacer (NTS). Initially the 5S rDNA repeats are considered to be evolved by the process of concerted evolution. But some recent reports, including teleost fishes suggested that evolution of 5S rDNA repeat does not fit into the concerted evolution model and evolution of 5S rDNA family may be explained by a birth-and-death evolution model. In order to study the mode of evolution of 5S rDNA repeats in Perciformes fish species, nucleotide sequence and molecular organization of five species of genus Channa were analyzed in the present study. Molecular analyses revealed several variants of 5S rDNA repeats (four types of NTS) and networks created by a neighbor net algorithm for each type of sequences (I, II, III and IV) did not show a clear clustering in species specific manner. The stable secondary structure is predicted and upstream and downstream conserved regulatory elements were characterized. Sequence analyses also shown the presence of two putative pseudogenes in Channa marulius. Present study supported that 5S rDNA repeats in genus Channa were evolved under the process of birth-and-death.
authors.affiliation: College of Fisheries, Central Agricultural University, Lembucherra, Tripura (West), 799210, India. barman.anindya@gmail.com.
authors.forename: Anindya Sundar
authors.initials: AS
authors.lastname: Barman
authors.affiliation: College of Fisheries, Central Agricultural University, Lembucherra, Tripura (West), 799210, India.
authors.forename: Mamta
authors.initials: M
authors.lastname: Singh
authors.affiliation: National Bureau of Fish Genetic Resources (ICAR), Canal Ring Road, P.O. Dilkusha, Lucknow, 226002, India.
authors.forename: Rajeev Kumar
authors.initials: RK
authors.lastname: Singh
authors.affiliation: National Bureau of Fish Genetic Resources (ICAR), Canal Ring Road, P.O. Dilkusha, Lucknow, 226002, India.
authors.forename: Kuldeep Kumar
authors.initials: KK
authors.lastname: Lal
mesh_terms: D000818:Animals; D001482:Base Composition; D001483:Base Sequence; D019143:Evolution, Molecular; D010473:Perciformes / Q000235:genetics*; D012341:RNA, Ribosomal, 5S / Q000737:chemistry / Q000235:genetics*
chemical_list: D012341:RNA, Ribosomal, 5S
keywords: 5S rDNA; Channa; Evolution model; NTS