Widespread male-female expression imbalance of X-linked genes across phrynosomatid lizards.

Male-female expression imbalance of X-linked genes is widespread across phrynosomatid lizards, with females overexpressing ancestral X genes and males underexpressing neo-X genes.

• Why it matters: Understanding dosage compensation and sex-biased gene expression is crucial for insights into sex chromosome evolution and gene regulation. This work addresses the gap in knowledge about how these processes vary across different lizard species and their evolutionary implications.
• What they did: The study analyzed gene expression in Sceloporus undulatus and ten other phrynosomatid species, examining multiple tissues and developmental stages, revealing conserved female-biased expression on the ancestral X and male underexpression on neo-X regions.
• The result: Findings suggest that male-female expression imbalance is common in this family, driven by overexpression in females of ancestral X genes and underexpression in males of recently formed neo-X regions, highlighting complex dosage regulation evolution.