PEXgének

PEXgének refer to a class of genetic elements that are part of the broader category of transposable elements (TEs), specifically those found in certain plant genomes, including those of the *Pennisetum* genus, such as pearl millet (*Pennisetum glaucum*). These elements are characterized by their ability to move or "jump" to new positions within the genome, contributing to genomic diversity and evolution. PEXgének are often associated with the Pennisetum excludable (PEX) system, a type of retrotransposon that belongs to the Ty3/gypsy superfamily, which is known for its long terminal repeats (LTRs).

These genetic elements are significant in plant genomics due to their role in shaping genome structure and function. Retrotransposons like PEXgének replicate via an RNA intermediate and integrate back into the genome through reverse transcription, potentially causing insertional mutations, gene disruptions, or genomic rearrangements. Their activity can influence traits such as disease resistance, stress tolerance, and developmental processes, making them relevant in both evolutionary studies and agricultural breeding programs.

PEXgének have been studied extensively in pearl millet, a drought-resistant crop of great importance in arid regions. Their presence in the genome can contribute to genomic instability, but they also provide raw material for genetic variation, which may enhance adaptability to environmental changes. Researchers often analyze these elements to understand their impact on genome evolution, gene expression regulation, and the overall genetic architecture of plant species.

The study of PEXgének is part of a broader field examining the dynamics of transposable elements in plant genomes. By mapping and sequencing these elements, scientists can gain insights into their activity patterns, evolutionary history, and potential applications in crop improvement. Their research helps bridge the gap between genomic structure and functional genomics, offering valuable tools for both basic and applied biological studies.