The analysis of chromatin organisation allows selection of mouse antral oocytes competent for development to blastocyst.
Mouse antral oocytes can be classified in two different types termed SN or NSN oocytes, depending on the presence or absence, respectively, of a ring of Hoechst 33342-positive chromatin surrounding the nucleolus. The aim of the present study was to test the developmental competence to blastocyst of the two types of oocytes. Here we show that following isolation, classification and culture of cumulus-free antral oocytes, 14.7% and 74.5% of NSN and SN oocytes, respectively, reached the metaphase II stage. When fertilised and further cultured none of the metaphase II NSN oocytes developed beyond the 2-cell stage whilst 47.4% of the metaphase II SN oocytes reached the 4-cell stage and 18.4% developed to blastocyst. The findings reported in this paper may contribute to improved procedures of female gamete selection for in vitro fertilisation of humans and farm animals. Furthermore, the selection of oocytes with better developmental potential may be of interest for studies on nuclear/cytoplasm interaction, particularly in nuclear-transfer experiments.
Zuccotti
Maurizio
M
Università degli Studi di Parma, Italy. maurizio.zuccotti@unipv.it
Ponce
Rubén H
RH
Boiani
Michele
M
Guizzardi
Stefano
S
Govoni
Paolo
P
Scandroglio
Renato
R
Garagna
Silvia
S
Redi
Carlo Alberto
CA
D000818:Animals; D001562:Benzimidazoles; D001755:Blastocyst / Q000166:cytology* / Q000502:physiology; D002454:Cell Differentiation; D002466:Cell Nucleolus / Q000502:physiology; D002843:Chromatin / Q000502:physiology*; D046508:Culture Techniques; D005260:Female; D008297:Male; D008540:Meiosis / Q000502:physiology; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D009865:Oocytes / Q000166:cytology*
D001562:Benzimidazoles; D002843:Chromatin; C017807:bisbenzimide ethoxide trihydrochloride