Analysis of Transposable Elements in Coccidioides Species

Area of Science:

• Mycology
• Genomics
• Bioinformatics

Background:

• Coccidioides immitis and C. posadasii are pathogenic fungi endemic to arid regions of the Americas.
• Transposable elements (TEs) are mobile genetic sequences found in most genomes, including fungi.
• Understanding TE distribution and impact is crucial for comprehending fungal gene regulation and evolution.

Purpose of the Study:

• To conduct a detailed bioinformatic analysis of transposable elements (TEs) in Coccidioides spp.
• To investigate the potential influence of TEs on gene expression and evolution within Coccidioides.
• To identify specific TE families and their genomic distribution and association with host genes.

Main Methods:

• Identification and classification of Class I and Class II transposons in Coccidioides genomes.
• Phylogenetic analysis of integrase and reverse transcriptase sequences from Gypsy superfamily elements.
• Analysis of gene expression data in relation to proximity of TEs, specifically hAT and Gypsy elements.
• Examination of TE association with genes annotated with protein kinase gene ontology terms.

Main Results:

• Class I and Class II transposons were identified, with the LTR Gypsy superfamily being the most prevalent.
• Phylogenetic analysis suggests extensive transposition after the speciation of C. immitis and C. posadasii.
• Protein-coding genes near hAT or Gypsy TEs showed reduced expression in C. immitis and C. posadasii.
• TEs were preferentially associated with genes encoding protein kinases in both species.

Conclusions:

• Transposable elements, particularly Gypsy elements, are abundant and show species-specific clustering in Coccidioides.
• TEs appear to influence gene expression, with proximity to TEs correlating with lower gene expression levels.
• The preferential association of TEs with protein kinase genes suggests a potential role in Coccidioides gene regulation and evolutionary adaptation.