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Updated: Feb 22, 2026

Genome Editing in Astyanax mexicanus Using Transcription Activator-like Effector Nucleases TALENs
Published on: June 20, 2016
Variability and evolutionary implications of repetitive DNA dynamics in genome of Astyanax scabripinnis (Teleostei,
Patrícia Barbosa1, Eliza Viola Leal2, Maelin da Silva2
1Programa de Pós-Graduação em Genética Evolutiva e Biologia Molecular, Universidade Federal de São Carlos, Rodovia Washington Luís Km 235, São Carlos, SP, 13565-905, Brazil.
Abstract:
DNA sequences of multiple copies help in understanding evolutionary mechanisms, genomic structures and karyotype differentiation. The current study investigates the organization and distribution of different repetitive DNA in the standard complement and B chromosomes in Astyanax scabripinnis (Jenyns, 1842) chromosomes from three allopatric populations in Campos do Jordão region, São Paulo State, Brazil. The location of microsatellite sequences showed different chromosome distribution between Lavrinha Farm Stream (LFS) and Lake of Pedalinho (LP) populations. However, the karyotype of these populations basically followed the pattern of dispersed distribution in the A complement, conspicuous in telomeric/interstitial regions and preferential accumulation in the B chromosome. The B chromosome showed heterogeneous location of microsatellite probes CA, CAC and GA. The H3 and H4 histone genes were isolated from the total genome of the species and then the chromosomal mapping was performed by fluorescence in situ hybridization (FISH). The FISH signals showed high similarity for the probes H3 and H4 mapping in genomes of the populations analyzed. The sequences (GATA) revealed a sex-specific trend between the chromosomal location in males and females at (LFS) and (LP) populations. Although species that comprise the Astyanax scabripinnis complex do not have morphologically differentiated sex chromosomes, the preferential GATA location - sex-associated - may represent a sex chromosome in differentiation.
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