Sperm Ribosomal DNA: Exploration into Male Factor Infertility

In the United States, 15% of heterosexual couples are affected by clinical infertility. Male factor infertility is the sole or contributing factor in approximately 50% of these couples, affecting approximately 7% of men. A multifaceted disorder, the complex mechanisms of male infertility remain largely unknown. In an attempt to explore one possible mechanism, the number of copies of ribosomal genes in 140 men were assessed and compared to semen parameters. A triplex qPCR approach was used to assess the copy numbers of two ribosomal subunits, the 5S and 18S. Using p53 as a single copy comparative gene, it was found that while the copy number of the 5S is not associated with semen quality, the 18S is inversely related to semen quality, with increased copies of the ribosomal gene being reflective of decreased count, concentration, motility, and morphology.