- TEX11 (Testis-Expressed Gene 11) is a gene located on the X chromosome that encodes a protein critically involved in meiotic recombination and germ cell development.
- As its name suggests, TEX11 is predominantly expressed in the testis, specifically in spermatocytes during meiosis, where it plays a central role in the formation and repair of DNA double-strand breaks, synapsis of homologous chromosomes, and crossover formation. Because proper meiotic recombination is essential for genetic diversity and accurate chromosome segregation, TEX11 is indispensable for male fertility.
- At the molecular level, TEX11 is classified as a meiosis-specific factor that interacts with components of the recombination machinery. It is known to associate with meiotic chromosome axis proteins and is required for the repair of programmed double-strand breaks through homologous recombination. TEX11 helps regulate crossover frequency and distribution, ensuring that homologous chromosomes exchange genetic material in a balanced manner. Loss of TEX11 function leads to a marked reduction in meiotic crossovers, defects in synaptonemal complex formation, and subsequent meiotic arrest.
- Clinically, mutations in TEX11 are a recognized cause of male infertility, particularly non-obstructive azoospermia (NOA), a condition in which sperm are absent from the ejaculate due to failed spermatogenesis rather than blockage. TEX11 mutations can result in meiotic arrest, where spermatocytes cannot progress beyond prophase I of meiosis. This phenotype has been observed in both humans and mouse models, underscoring its essential role in spermatogenic progression. As TEX11 is located on the X chromosome, pathogenic mutations can exert profound effects in males, who carry only a single copy of the gene. In contrast, females with a heterozygous mutation are usually unaffected due to the presence of a second functional allele, though TEX11 is less critical for oogenesis compared to spermatogenesis.
- In addition to its role in male infertility, TEX11 has attracted interest in reproductive medicine and genetic counseling. Screening for TEX11 mutations has become an important diagnostic step in men with idiopathic azoospermia or severe oligozoospermia. Identifying TEX11-associated infertility can help avoid unnecessary interventions, such as repeated surgical sperm retrieval attempts, since meiotic arrest due to TEX11 deficiency is typically irreversible. Furthermore, genetic counseling is critical because TEX11 mutations can be inherited by daughters as carriers and potentially passed to future generations.
- Research into TEX11 also highlights broader insights into the biology of meiosis and chromosomal stability. Because TEX11 governs recombination, its study informs understanding of how meiotic defects can contribute not only to infertility but also to chromosomal abnormalities and aneuploidy. Although TEX11 has not been strongly implicated in cancer, its function in DNA repair suggests potential connections to broader genome maintenance pathways.
