Fourteen babies born after round spermatid injection into human oocytes
- Atsushi Tanakaa,1,
- Motoi Nagayoshia,
- Youichi Takemotoa,
- Izumi Tanakaa,
- Hiroshi Kusunokib,
- Seiji Watanabec,
- Keiji Kurodad,
- Satoru Takedad,
- Masahiko Itoe, and
- Ryuzo Yanagimachif,1
- aSaint Mother Obstetrics and Gynecology Clinic, Institute for ART, Fukuoka 807-0825, Japan;
- bFaunal Diversity Sciences, Graduate School of Agriculture, Kobe University, Kobe 657-8501, Japan;
- cDepartment of Anatomical Science, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562, Japan;
- dDepartment of Obstetrics and Gynecology, Juntendo University School of Medicine, Tokyo 113-0033, Japan;
- eDepartment of Infectious Diseases, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan;
- fDepartment of Anatomy, Physiology, and Biochemistry, University of Hawaii Medical School, Honolulu, HI 96822
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Contributed by Ryuzo Yanagimachi, September 25, 2015 (sent for review July 20, 2015; reviewed by J. Michael Bedford and Martin M. Matzuk)
Significance
Men without spermatozoa or elongating spermatids in their testes have been considered sterile and are advised to consider using a sperm donor. However, these men may have round spermatids. We have been able to accurately identify these cells based on their structural and physical characteristics (verified by karyotyping and FISH). Round spermatid injection was effectively used in our clinic and resulted in the birth of 14 healthy babies. Although the current success rate of round spermatid injection is not very high compared with intracytoplasmic sperm injection, this procedure can be the last resort for men who cannot produce spermatozoa but wish to use their own genetic material to produce offspring.
Abstract
During the human in vitro fertilization procedure in the assisted reproductive technology, intracytoplasmic sperm injection is routinely used to inject a spermatozoon or a less mature elongating spermatid into the oocyte. In some infertile men, round spermatids (haploid male germ cells that have completed meiosis) are the most mature cells visible during testicular biopsy. The microsurgical injection of a round spermatid into an oocyte as a substitute is commonly referred to as round spermatid injection (ROSI). Currently, human ROSI is considered a very inefficient procedure and of no clinical value. Herein, we report the birth and development of 14 children born to 12 women following ROSI of 734 oocytes previously activated by an electric current. The round spermatids came from men who had been diagnosed as not having spermatozoa or elongated spermatids by andrologists at other hospitals after a first Micro-TESE. A key to our success was our ability to identify round spermatids accurately before oocyte injection. As of today, all children born after ROSI in our clinic are without any unusual physical, mental, or epigenetic problems. Thus, for men whose germ cells are unable to develop beyond the round spermatid stage, ROSI can, as a last resort, enable them to have their own genetic offspring.
Footnotes
- ↵1To whom correspondence may be addressed. Email: incho{at}stmother.com or yana{at}hawaii.edu.
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Author contributions: A.T. designed research; A.T., M.N., Y.T., I.T., S.W., and S.T. performed research; K.K. contributed new reagents/analytic tools; A.T., H.K., M.I., and R.Y. analyzed data; and A.T. and R.Y. wrote the paper.
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Reviewers: J.M.B., Weill Medical College, Cornell; and M.M.M., Baylor College of Medicine.
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The authors declare no conflict of interest.
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This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1517466112/-/DCSupplemental.
Freely available online through the PNAS open access option.
