Meiotic recombination during gametogenesis involves the exchange of segments of DNA between pairs of homologous chromosomes and guarantees the continual evolution of the species by ensuring genetic diversity in the off spring. Y-chromosome microdeletions were identified as a fairly common cause of non-obstructive azoospermia, being present in about 8-12% of men with non-obstructive azoospermia and a lesser percentage of men with oligospermia. This chapter discusses modulation of gene expression and its association with male infertility, modulation of RNA translation to proteins and its association with infertility, improvements in diagnosis of RNA transcription changes, and therapeutic advances of the future. To cure the infertile patients, rather than assist their fertility with assisted reproductive technology (ART) procedures, the continued application of basic research to define these control mechanisms is required. Knowledge of the cause of their infertility is gained as a result of new technologies.