Identification of subtelomeric cluster-genes associated to sexual stage in Toxoplasma gondii.

• Clusters of Toxoplasma subtelomeric (ST) genes are upregulated in merozoite. • Clustered sex-associated ST genes encode short and alkaline hypothetical proteins. • Subtelomeric upregulated genes can be associated to stress adaptation. Toxoplasma gondii is an obligate intracellular parasite with sexual reproduction in the intestinal epithelium of felines. The depletion of two gene repressors, AP2XI-2 and AP2XII-1, induces merozoite formation and gene expression towards sexual commitment. Based on RNA-seq datasets of AP2XI-2 and AP2XII-1 knock downs we identified subtelomeric (ST) TgB12 and hypothetical (HP) genes upregulated. Some of the differentially expressed genes (DEGs) are arranged in ST clusters. These DEG products are characterized by high isoelectric points (pI) and may encode small proteins. The potential roles of these clusters of DEG ST genes in environmental resistance or parasite sexual development of T. gondii is discussed. [ABSTRACT FROM AUTHOR]