Gypsy, RTE and Mariner transposable elements populate Eyprepocnemis plorans genome

Area of Science:

• Genomics
• Molecular Biology
• Evolutionary Biology

Background:

• Transposable elements (TEs) are mobile genetic sequences that can alter an organism's genome.
• Understanding TE distribution and abundance is crucial for comprehending genome structure and evolution.
• The grasshopper Eyprepocnemis plorans possesses a large genome, making it an interesting model for TE studies.

Purpose of the Study:

• To investigate the presence, abundance, and genomic location of Gypsy, RTE, and Mariner transposable elements in Eyprepocnemis plorans.
• To analyze the transcriptional activity of these transposable elements.
• To discuss the implications of TE distribution in euchromatin and their potential role in B chromosome dynamics.

Main Methods:

• Polymerase Chain Reaction (PCR) for amplification, cloning, and sequencing of TEs.
• Fluorescent In Situ Hybridization (FISH) to determine TE genomic localization.
• Quantitative PCR (qPCR) to estimate TE copy number.
• RNA isolation and RT-PCR to detect TE transcripts.

Main Results:

• Three TEs (EploGypI, EploRTE5, EploMar20) were identified and characterized.
• All TEs were predominantly found in euchromatic regions, avoiding pericentromeric and B chromosome heterochromatin.
• EploGypI was the most abundant, followed by EploRTE5, and then EploMar20, consistent across FISH and qPCR.
• Transcripts for all three TE families were detected, indicating their activity.

Conclusions:

• Transposable elements in E. plorans are preferentially located in euchromatic regions.
• The high abundance of TEs in this species' large genome may have significant evolutionary implications.
• A potential relationship between transposable elements and B chromosome mutability is suggested.