Meiotic self-pairing of the Psalidodon (Characiformes, Characidae) iso-B chromosome: A successful perpetuation mechanism

Author(s)

Duílio Mazzoni Zerbinato de Andrade Silva ^[1] ; Cristian Araya-Jaime ; Masakane Yamashita ^[3] ; Mateus Rossetto Vidal ^[4] ; Claudio Oliveira ^[5] ; Fábio Porto-Foresti ^[6] ; Roberto Ferreira Artoni ; Fausto Foresti ^[8]

Affiliation

^[1] Universidade Estadual Paulista (UNESP). Instituto de Biociências de Botucatu. Departamento de Biologia Estrutural e Funcional - Brasil

^[3] Hokkaido University. Faculty of Science. Department of Biological Sciences - Japão

^[4] Universidade Estadual Paulista (UNESP). Instituto de Biociências de Botucatu. Departamento de Biologia Estrutural e Funcional - Brasil

^[5] Universidade Estadual Paulista (UNESP). Instituto de Biociências de Botucatu. Departamento de Biologia Estrutural e Funcional - Brasil

^[6] Universidade Estadual Paulista (UNESP). Faculdade de Ciências. Departamento de Ciências Biológicas - Brasil

^[8] Universidade Estadual Paulista (UNESP). Instituto de Biociências de Botucatu. Departamento de Biologia Estrutural e Funcional - Brasil

• Document type: Journal article
• Source: GENETICS AND MOLECULAR BIOLOGY; v. 44, n. 3 2021-10-04.

Abstract

Abstract B chromosomes are non-essential additional genomic elements present in several animal and plant species. In fishes, species of the genus Psalidodon (Characiformes, Characidae) harbor great karyotype diversity, and multiple populations carry different types of non-essential B chromosomes. This study analyzed how the dispensable supernumerary B chromosome of Psalidodon paranae behaves during meiosis to overcome checkpoints and express its own meiosis-specific genes. We visualized the synaptonemal complexes of P. paranae individuals with zero, one, or two B chromosomes using immunodetection with anti-medaka SYCP3 antibody and fluorescence in situ hybridization with a (CA)15 microsatellite probe. Our results showed that B chromosomes self-pair in cells containing only one B chromosome. In cells with two identical B chromosomes, these elements remain as separate synaptonemal complexes or close self-paired elements in the nucleus territory. Overall, we reveal that B chromosomes can escape meiotic silencing of unsynapsed chromatin through a self-pairing process, allowing expression of their own genes to facilitate regular meiosis resulting in fertile individuals. This behavior, also seen in other congeneric species, might be related to their maintenance throughout the evolutionary history of Psalidodon. (AU)

• FAPESP's process: 17/15608-5 - Meiotic chromosomes in fish: synaptic behavior and transcriptional status visualized by immunofluorescence.
• Grantee: Fausto Foresti
• Support Opportunities: Regular Research Grants
• FAPESP's process: 17/22447-8 - Comparative Genetic Activity on B Chromosomes of Astyanax species (Teleostei, Characiformes)
• Grantee: Duílio Mazzoni Zerbinato de Andrade Silva
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 14/26508-3 - Phylogeny of the hyperdiverse order Characiformes (Teleostei: Ostariophysi) using ultraconserved elements
• Grantee: Claudio de Oliveira
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 16/09204-6 - Biodiversity and Biogeography in marine-estuarine fishes (Teleostei) from Brazil
• Grantee: Claudio de Oliveira
• Support Opportunities: Regular Research Grants
• FAPESP's process: 18/20610-1 - Study of the biogeography of the Brazilian coast using data population genetic data of marine catfish of the genera Cathorops and Genidens
• Grantee: Claudio de Oliveira
• Support Opportunities: Regular Research Grants
• FAPESP's process: 14/09634-5 - Functional and evolutionary analysis of b chromosomes using the Astyanax paranae fish (Characiformes Characidae) as model
• Grantee: Fausto Foresti
• Support Opportunities: Regular Research Grants