Metaphase II karyoplast transfer from human in-vitro matured oocytes to enuclueated mature oocytes

Tanaka, Atsushi; Nagayoshi, Motoi; Awata, Shoichiro; Himeno, Norio; Tanaka, Izumi; Watanabe, Seiji; Kusunoki, Hiroshi

doi:10.1016/j.rbmo.2009.06.004

« Previous Next »Reproductive BioMedicine Online
Volume 19, Issue 4 , Pages 514-520, October 2009

Metaphase II karyoplast transfer from human in-vitro matured oocytes to enuclueated mature oocytes

Atsushi Tanaka
- Saint Mother Obstetrics and Gynecology Clinic and Institute for ART, 4-9-12, Orio, Yahata-Nishi, Kitakyushu, Fukuoka 807-0825, Japan
- Correspondence:
Motoi Nagayoshi
- Saint Mother Obstetrics and Gynecology Clinic and Institute for ART, 4-9-12, Orio, Yahata-Nishi, Kitakyushu, Fukuoka 807-0825, Japan
Shoichiro Awata
- Saint Mother Obstetrics and Gynecology Clinic and Institute for ART, 4-9-12, Orio, Yahata-Nishi, Kitakyushu, Fukuoka 807-0825, Japan
Norio Himeno
- Saint Mother Obstetrics and Gynecology Clinic and Institute for ART, 4-9-12, Orio, Yahata-Nishi, Kitakyushu, Fukuoka 807-0825, Japan
Izumi Tanaka
- Saint Mother Obstetrics and Gynecology Clinic and Institute for ART, 4-9-12, Orio, Yahata-Nishi, Kitakyushu, Fukuoka 807-0825, Japan
Seiji Watanabe
- Department of Anatomy, Hirosaki University School of Medicine, Hirosaki, Japan
Hiroshi Kusunoki
- Faunal Diversity Sciences, Faculty of Agriculture, Kobe University, Kobe, Japan

Received 27 November 2008; received in revised form 12 December 2008; accepted 1 June 2009. published online 02 August 2010.

Declaration: The authors report no financial or commercial conflicts of interest.

Abstract

Metaphase II karyoplast transfer is believed to be a useful method to rescue aged oocytes. This study attempted karyoplast transfer of in-vitro matured metaphase II (MII) oocytes, as a model of aged oocytes, into enucleated freshly ovulated metaphase II oocytes with visualization of their chromosomes under an inverted microscope. Recipient karyoplasts derived from immature oocytes were cultured in-vitro until first polar body extrusion. After 1–2 days culture, 52.1% extruded a polar body, 95.5% had PSC, aneuploidy was very low (4.5%) and none had structural aberrations. Donor oocytes were obtained from IVF or intracytoplasmic sperm injection (ICSI) patients. Chromosomes were easily confirmed in 92.3% and 95.0% of in-vivo and in-vitro matured oocytes respectively. Thirty-one karyoplasts were placed in the perivitelline space of enucleated donor oocytes, and 25 (80.6%) fused to form a reconstituted oocyte. Fertilization, cleavage and blastocyst formation rates following ICSI were 76.0%, 64.0% and 28.0% respectively for reconstructed oocytes and 59.2%, 48.0% and 3.1% respectively for control (in-vitro matured) oocytes. Chromosomal analysis of five embryos developed after karyoplast transfer and ICSI showed normal diploid sets of 46 chromosomes. In conclusion, this metaphase II karyoplast transfer technique can be applied to the solution of chromosomal abnormalities related to oocyte ageing.

Keywords: aged oocytes, embryo development, karyoplast transfer, metaphase II, oocyte maturation

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Dr Atsushi Tanaka is one of the pioneers of Japanese private infertility clinic. He obtained his PhD in 1981 at the Juntendo University (Tokyo, Japan), where he worked from 1975 to 1981 in the Department of Obstetrics and Gynaecology. After working at the Koshigaya Municipal Hospital (Saitama, Japan), where he performed the first successful GIFT (gamete intra-Fallopian transfer) in Japan, he started the Saint Mother Obstetrics and Gynecology Clinic and Institute for ART (Fukuoka, Japan) in 1988. His current interest lies in a wide range of human infertility.Dr Atsushi Tanaka