CSIRO Publishing blank image blank image blank image blank imageBooksblank image blank image blank image blank imageJournalsblank image blank image blank image blank imageAbout Usblank image blank image blank image blank imageShopping Cartblank image blank image blank image You are here: Journals > Reproduction, Fertility and Development   
Reproduction, Fertility and Development
  Vertebrate reproductive science and technology
blank image Search
blank image blank image
blank image
  Advanced Search

Journal Home
About the Journal
Editorial Structure
Online Early
Current Issue
Just Accepted
All Issues
Special Issues
Research Fronts
Virtual Issues
Sample Issue
For Authors
General Information
Submit Article
Author Instructions
Open Access
Awards and Prizes
For Referees
Referee Guidelines
Review an Article
Annual Referee Index
For Subscribers
Subscription Prices
Customer Service
Print Publication Dates
Library Recommendation

blue arrow e-Alerts
blank image
Subscribe to our email Early Alert or RSS feeds for the latest journal papers.

red arrow Connect with us
blank image
facebook twitter logo LinkedIn

red arrow Connect with SRB
blank image
facebook TwitterIcon

Affiliated Societies

RFD is the official journal of the International Embryo Transfer Society and the Society for Reproductive Biology.

Article << Previous     |     Next >>   Contents Vol 22(1)


I. Carvalhais A, M. Faheem A, A. Habibi A, A. Geraldo A, R. Agrícola A, A. Chaveiro A and F. Moreira da Silva A

University of the Azores, 9700 Angra do Heroísmo Portugal

Export Citation


Many factors act together to prepare the immature oocyte for successful development to a competent embryo after fertilization. Defects in oocyte maturation and further development can possibly be caused by the oocyte quality or an inadequate nuclear maturation or even by a failure of both. In the present study, the effect of COCs quality on meiotic development and further embryo-development after in vitro fertilization was evaluated. A total of 3604 COCs was separated according to their morphological aspect and were classified as A, B, and C categories. Briefly, in class A, oocytes possessed compact layers of cumulus cells, being difficult to evaluate their number having a homogenous ooplasm with uniform color. In class B, oocytes show more or equal to five layers of cumulus cells, easily identifiable under a stereomicroscope and/or granulations in the ooplasm. In class C, some granulation was observed in oocytes with about three layers of cumulus cells. The total number of oocytes was divided into two groups (I and II) in which in the group I, COCs (n = 540) were fixed 0, 6, 12, 18, 24, and 30 h following ovarian aspiration, DNA was stained with aceto-orcein, and the nucleus were observed under a phase contrast microscope. In the Group II, COCs (n = 3064) were fertilized with frozen/thawed bull semen after 24 h of maturation, which was made in M199 medium (Sigma, St, Louis, MO, USA). The development of the embryos was evaluated on the third and seventh day after fertilization. Embryos were co-cultured with monolayers of granulosa cells in 45 μL droplets of B2 medium (CCD Laboratory, Paris, France), supplemented with 10% serum under mineral oil, at 39°C and 5% CO2 in air. It was observed that, other than the oocytes achieved metaphase II at 24 h was greater for the oocytes classified as A (65.4%), and B (61.0%) greater than C (51.2%), no statistical difference was observed between oocyte quality and capability to maturation. As far as the embryonic development is concerned, the same tendency was observed for the cleavage and for the morulae/blastocyst stage after 7 days after fertilization (P < 0.001). The percentages of cleaved oocytes classified as A, B, and C, were respectively 65.2%, 58.4%, and 48.0%. The development to the morulae/blastocyst stage of the cleaved embryos was A = 38.5%/27.4%, B = 33.6%/25.0%, and C = 30.9%/17.2% (Table 1). The results of our study clearly demonstrate that the morphology of the oocytes plays an important role on the in vitro embryonic developmental competence after fertilization.

The first author is supported by the Regional Foundation for Science and Technology of the Azores Government. This study was supported by the IBBA Institute grant number M2.1.2/I/022/2008 CITA-A is fully acknowledged.

Reproduction, Fertility and Development 22(5305) 322–323   http://dx.doi.org/10.1071/RDv22n1Ab333
Published online: 08 December 2009

Top  Email this page

Legal & Privacy | Contact Us | Help


© CSIRO 1996-2016