B chromosomes of multiple species have intense evolutionary dynamics and accumulated genes related to important biologic
- PDF / 5,975,884 Bytes
- 25 Pages / 595.276 x 790.866 pts Page_size
- 25 Downloads / 158 Views
RESEARCH ARTICLE
Open Access
B chromosomes of multiple species have intense evolutionary dynamics and accumulated genes related to important biological processes Syed F. Ahmad1, Maryam Jehangir1, Adauto L. Cardoso1, Ivan R. Wolf1, Vladimir P. Margarido2, Diogo C. Cabral-de-Mello3, Rachel O’Neill4,5, Guilherme T. Valente6 and Cesar Martins1*
Abstract Background: One of the biggest challenges in chromosome biology is to understand the occurrence and complex genetics of the extra, non-essential karyotype elements, commonly known as supernumerary or B chromosomes (Bs). The non-Mendelian inheritance and non-pairing abilities of B chromosomes make them an interesting model for genomics studies, thus bringing to bear different questions about their genetic composition, evolutionary survival, maintenance and functional role inside the cell. This study uncovers these phenomena in multiple species that we considered as representative organisms of both vertebrate and invertebrate models for B chromosome analysis. Results: We sequenced the genomes of three animal species including two fishes Astyanax mexicanus and Astyanax correntinus, and a grasshopper Abracris flavolineata, each with and without Bs, and identified their Blocalized genes and repeat contents. We detected unique sequences occurring exclusively on Bs and discovered various evolutionary patterns of genomic rearrangements associated to Bs. In situ hybridization and quantitative polymerase chain reactions further validated our genomic approach confirming detection of sequences on Bs. The functional annotation of B sequences showed that the B chromosome comprises regions of gene fragments, novel genes, and intact genes, which encode a diverse set of functions related to important biological processes such as metabolism, morphogenesis, reproduction, transposition, recombination, cell cycle and chromosomes functions which might be important for their evolutionary success. Conclusions: This study reveals the genomic structure, composition and function of Bs, which provide new insights for theories of B chromosome evolution. The selfish behavior of Bs seems to be favored by gained genes/sequences. Keywords: Supernumerary chromosome, Extra chromosome, Genome, Evolution, Next generation sequencing
* Correspondence: [email protected] 1 Department of Structural and Functional Biology, Institute of Bioscience at Botucatu, Sao Paulo State University (UNESP), Botucatu, SP 18618-689, Brazil Full list of author information is available at the end of the article © The Author(s). 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherw
Data Loading...
