Preprint Article Version 1 This version is not peer-reviewed

Structural and Functional Analysis of Transposable Elements Focusing on B Chromosomes of the Cichlid Fish Astatotilapia latifasciata

Version 1 : Received: 17 March 2018 / Approved: 19 March 2018 / Online: 19 March 2018 (08:33:48 CET)

How to cite: Coan, R.; Martins, C. Structural and Functional Analysis of Transposable Elements Focusing on B Chromosomes of the Cichlid Fish Astatotilapia latifasciata. Preprints 2018, 2018030145 (doi: 10.20944/preprints201803.0145.v1). Coan, R.; Martins, C. Structural and Functional Analysis of Transposable Elements Focusing on B Chromosomes of the Cichlid Fish Astatotilapia latifasciata. Preprints 2018, 2018030145 (doi: 10.20944/preprints201803.0145.v1).

Abstract

B chromosomes (B) are supernumerary elements found in many taxonomic groups. Most B chromosomes are rich in heterochromatin and composed of abundant repetitive sequences, especially transposable elements (TEs). Bs origin is generally linked to the A chromosome complement (A). The first report of a B chromosome in African cichlids was on Astatotilapia latifasciata, which can harbor 0, 1 or 2 B chromosomes. Classical cytogenetics studies found high TE content on the species B chromosome. In this study, we aim to understand TE composition and expression on A. latifasciata genome and its relation to the B chromosome. We use bioinformatics analysis to explore TEs genome organization and also their composition on the B chromosome. Bioinformatics findings were validated by fluorescent in situ hybridization (FISH) and real-time PCR (qPCR). A. latifasciata has a TE content similar to other cichlid fishes and several expanded elements on its B chromosome. With RNA sequencing data (RNA-seq) we showed that all major TE classes are transcribed in brain, muscle and male/female gonads. The evaluation of TE expression between B- and B+ individuals showed that few elements have differential expression among groups and expanded B elements were not highly transcribed. Putative silencing mechanisms may the acting on the B chromosome of A. latifasciata to prevent adverse consequences of repeat transcription and mobilization in the genome.

Subject Areas

repetitive elements; RNA-Seq; genomics; evolution; cytogenetics; supernumerary elements; extra chromosomes

Readers' Comments and Ratings (0)

Leave a public comment
Send a private comment to the author(s)
Rate this article
Views 0
Downloads 0
Comments 0
Metrics 0
Leave a public comment

×
Alerts
Notify me about updates to this article or when a peer-reviewed version is published.