Epigenetic DNA Modifications Are Correlated With B Chromosomes and Sex in the Cichlid Astatotilapia latifasciata

Autor(es)

Cardoso, Adauto Lima ; de Almeida Fantinatti, Bruno Evaristo ; Venturelli, Natalia Bortholazzi ; Carmello, Bianca de Oliveira ; de Oliveira, Rogerio Antonio ; Martins, Cesar

• Tipo de documento: Artigo Científico
• Fonte: FRONTIERS IN GENETICS; v. 10, p. 14-pg., 2019-04-12.

Resumo

Supernumerary B chromosomes are dispensable elements found in several groups of eukaryotes, and their impacts in host organisms are not clear. The cichlid fish Astatotilapia latifasciata presents one or two large metacentric B chromosomes. These elements affect the transcription of several classes of RNAs. Here, we evaluated the epigenetic DNA modification status of B chromosomes using immunocytogenetics and assessed the impact of B chromosome presence on the global contents of 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) and the molecular mechanisms underlying these variations. We found that the B chromosome of A. latifasciata has an active pattern of DNA epimarks, and its presence promotes the loss of 5mC in gonads of females with B chromosome (FB+) and promotes the loss of 5hmC in the muscle of males with the B element (MB+). Based on the transcriptional quantification of DNA modification genes (dnmt, tet, and tdg) and their candidate regulators (idh genes, microRNAs, and long non-coding RNAs) and on RNA-protein interaction prediction, we suggest the occurrence of passive demethylation in gonads of FB+ and 5hmC loss by Tet inhibition or by 5hmC oxidation in MB+ muscle. We suggest that these results can also explain the previously reported variations in the transcription levels of several classes of RNA depending on B chromosome presence. The DNA modifications detected here are also influenced by sex. Although the correlation between B chromosomes and sex has been previously reported, it remains unexplained. The B chromosome of A. latifasciata seems to be active and impacts cell physiology in a very complex way, including at the epigenetic level. (AU)

• Processo FAPESP: 12/21546-9 - Análises imunocitogenéticas no peixe ciclídeo Astototilapia latifasciata: inferências epigenéticas e suas contribuições no entendimento do papel biológico de cromossomos B
• Beneficiário: Adauto Lima Cardoso
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 13/04533-3 - Análise funcional de cromossomos B, utilizando o peixe ciclídeo Astatotilapia latifasciata como modelo
• Beneficiário: César Martins
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 15/16661-1 - Cromossomos sexuais, cromossomos B e seus enigmas: sistemas modelo para estudos de evolução cromossômica e genômica
• Beneficiário: César Martins
• Modalidade de apoio: Auxílio à Pesquisa - Temático