PiRNA actuation in transposable elements silencing on B chromosome presence of the Astatotilapia latifasciata (Cichlidae)

Abstract

The supernumerary chromosomes B (Bs) are found in several eukaryotic organisms, does not follow the mendelian heritage and has its own transmission mechanism (drive), which is less understood under molecular point view. The Bs genomic constitution shows a mosaics sequences, which includes repetitives DNA, genes and pseudogenes. Preview studies had related this element to several functions, as genetic variability among populations, fertility effects, adaptation and evolutive link to sexual chromosomes origin. It is know which in Astatotilapia latifasciata African cichlid fish the B chromosome is enriched of repetitive DNA sequences, mainly Transposable Elements (TEs), being that some this are differentially expressed. Additionally, to this cichlid transcriptome and microRNome large scale data had revealed differential transcriptional activity among sexes and, among B minus and B plus individuals. Further, a copy of pdl6 with high integrity was identified in B chromosome. This gene is involved piwiRNAs biogenesis (piRNAs), which promote transposable elements silencing and ensure the integrity of genome in gonads tissue. Therefore, either one TEs or the other B chromosome are known as selfish elements it is suggested which piRNAs activity be differentially regulated in B presence. Thus, the perspectives to investigation under functional focus shows quite promising to the understanding of B chromosome behavior and influences in environmental cell. This work proposes to investigate the piRNAs and TEs activity in gonads tissue of the A. latifasciata in B chromosome presence. Therefore, using the transcriptome, small RNAs sequencing and genome of A. latifasciata existing data will be performed in silico prediction analysis, piRNAs and protein expression assay related to piRNAs biogenesis and transposition. Lately, the in silico analysis obtained results are validated by expression and physics localization analysis. (AU)