Transposable elements as a potential source for understanding the fish genome

A new dispersed element in the genome of the catfish Hisonotus leucofrenatus (Teleostei

“…13 In this study, the retroelements Rex1 and Rex3 were analyzed and presented dispersed patterns of distribution in the genome, in a similar way to that found for the HLBam transposable element. This feature reinforces the hypothesis proposed by Ferreira et al 4 that all transposable elements behave similarly within a family or subfamily. In the case of the transposable elements studied in the subfamily Hypoptopomatinae so far, they are scattered throughout the genome.…”

“…There are only a few studies on the identification and chromosome location of these elements in fish, and the data on physical genome mapping are still restricted to 15 transposable elements mapped onto the genome of 32 species. 4 The dispersed pattern of marks evidenced by FISH technique with the single HLBam element in H. leucofrenatus has been described before in the Antarctic Perciformes 12 and in individuals of the subfamily Hypoptopomatinae by Ferreira et al 13 when studying the retrotransposons Rex1 and Rex3. The finding on the genomic organization of this element supports the hypothesis that the isolated HLBam sequence is a dispersed transposon type element.…”

“…Results in the literature suggest that these elements are differently organized among different groups of fish. 4 They can be found scattered throughout the genome in the species Oreochromis niloticus, [14][15][16] Antarctic Perciformes 12 and also in species of the subfamily Hypoptopomatinae. 13 However, in species like Tetraodon nigroviridis [17][18][19] and in most species of cichlids 16,20 they can be with accession numbers JN368463, JN368464, JN368465, JN368466, JN368467.…”

“…In this sense, the study of these repeat sequences of DNA is a means to generate information on the genomic organization of fish, as well as on the dynamic processes by which the sequences have evolved in these organisms. 4 The fish species Hisonotus leucofrenatus presents a karyotype composed of 54 chromosomes and a chromosomal polymorphism, Eight restriction enzymes were used in the prospection and isolation of repetitive sequences in the genome of the catfish Hisonotus leucofrenatus, a siluriform fish species that presents a large heterochromatic block in the W chromosome. In the tested enzymes, only the BamHI enzyme revealed a distinct band of 224 bp G+C value of 37%.…”

Construction and Characterization of a Repetitive DNA Library in Parodontidae (Actinopterygii: Characiformes): A Genomic and Evolutionary Approach to the Degeneration of the W Sex Chromosome

“…The REX retrotransposon element and the Tc1-Mariner transposon are involved in the differentiation of sex chromosomes in Chionodraco hamatus. 49 LTR elements, LINEs, SINEs, and MITEs were also isolated from the sex chromosomes of Xiphophorus maculatus. 50 Importantly, the accumulation of the Helitron element in the W chromosome can promote gene degeneration and can also cause nucleation sites, promote insulation, generate siRNAs, and exert other effects.…”