Application of iPS in assisted reproductive technology: sperm from somatic cells?

Infertility is an emotionally charged problem, and it is a condition of increasing incidence. In addition, in 40% to 60% of all infertile couples, it was the male who had a problem that led to infertility. Among the male fertility problems, non-obstructive azoospermia (NOA) (caused by testis failure or impaired spermatogenesis) is the most prevalent. Despite enormous clinical and experimental efforts, treatment of this disorder--assistant reproduction technique (ART) with donor spermatozoa remains controversial. We present the hypothesis that induced pluripotent stem (iPS) cell derived spermatozoa can be a potential source for male gametes for patients with NOA; we support this with the following three evidence: the first is the generation of viable, live-born, fertile mature organism from iPS cells; the second is the successful induced differentiation of male gametes from pluripotent cells in vitro; and the last is the wide use of intracytoplasmic sperm injection (ICSI) in human assisted reproduction. If the hiPS derived spermatozoa prove practical in the generation offspring with ICSI, this method might be able to grant a new chance for NOA patients to have their genetic children with fewer emotional, ethical and legislative problems. To ensure the safety of the technology itself and the production of healthy offspring, further investigations are needed. We also suggest several laboratory and clinical approaches for testing our hypothesis.