Research activities

RESEARCH ACTIVITIES

In vitro production of bovine embryos

In vitro produced bovine embryos are obtained after maturation, fertilization in vitro and culture of embryos up to the blastocyst stage. This technique allows to dramatically increase the number of calves obtained from one female and can be used in breeding programmes or in order to save the genetics of infertile valuable cows.

It represents also an ideal tool for fundamental research on gamete interaction and early embryo development in mammals. The optimization of embryo production implies research on the three main steps of embryo production. It is also necessary to define quality markers for gametes and embryos at different stages of the procedure.

Our laboratory is mainly specialized in the study of :

  • The kinetics of development by time-lapse cinematography
  • Embryo metabolism, including markers of oxidative stress and apoptosis using microfluorimetry
  • Embryo sexing and gene expression by PCR

    

Key publications:

  • GEORGE F, DANIAUX Ch, GENICOT G., VERHAEGHE B., LAMBERT Ph, DONNAY I, Set up of a serum-free culture system for bovine embryos: embryo development and quality before and after transient transfer, Theriogenology, 69, 2008, 612-623
  • GENICOT G, LEROY J, VAN SOOM A, DONNAY I, The use of a fluorescent dye, Nile red, to evaluate the lipid content of single mammalian oocytes, Theriogenology, 63, 2005, 1181-1194.
  • FEUGANG J-M, DE ROOVER R, MOENS A, LÉONARD S, DESSY F, DONNAY I, Addition of Bêta-Mercaptoethanol or Trolox at the morula/blastocyst stage improves the quality of bovine blastocysts and prevents induction of apoptosis and degeneration by prooxidant agents, Theriogenology, 61, 2004, 71-90.
  • MAJERUS V, LEQUARRE A-S, FERGUSON E, KAIDI S, MASSIP A, DESSY F, DONNAY I, Characterization of embryos derived from calf oocytes: kinetics of cleavage, cell allocation to inner cell mass and trophectoderm and lipid metabolism, Molecular Reproduction and Development, 57, 2000, 346-352.

 

Gene expression and regulation in  oocytes and early embryos

Early embryonic development is under the control of proteins and mRNA accumulated in the oocyte before fertilization. The major onset of the embryonic genome occurs in the bovine between the 5-8 cell stage and the 9-16 cell stage, 3 days post-insemination. mRNA storage or degradation in the oocyte and the regulation of their translation is unique. Moreover, few are known about the regulation of the embryonic genome.

Our current researches in this area are related to:

  • The polyadenlation/deadenylation of transcripts and their translation during oocyte maturation
  • The kinetics of expression of specific genes during oocyte maturation and early embryonic development

    

Key publications:

  • PAUL D, BRIDOUX L, REZSOHAZY R, DONNAY I, Hox genes are expressed in bovine and mouse oocytes and early embryos, Mol Reprod Dev, 78, 2011, 436-449
  • TRAVERSO J, DONNAY I, LEQUARRE A-S, Effects of polyadenylation inhibition on meiosis progression in relation to the polyadenylation status of cyclins A2 and B1 during in vitro maturation of bovine oocytes, Molecular Reproduction and Development, 71, 5, 2005, 107-14.
  • LEYENS G, VERHAEGHE B, LANDTMETERS M, MARCHANDISE J, KNOOPS B, DONNAY I, Peroxiredoxin 6 is Up-Regulated in Bovine Oocytes and Cumulus Cells During in vitro Maturation: Role of intercellular Communication, Biology of Reproduction, 71, 5, 2004, 1646-1651.
  • LEQUARRÉ A-S, TRAVERSO J, MARCHANDISE J, DONNAY I, Poly(A) RNA Is Reduced by Half During Bovine Oocyte Maturation but Increases when Meiotic Arrest is Maintained with CDK Inhibitors, Biology of Reproduction, 71, 2004, 425-431.

 

Cryopreservation and cryobanking (gametes and embryos)

The widespread use of in vitro produced embryos is facilitated by their cryopreservation. However, such embryos are more sensitive to cryopreservation than their in vivo counterparts. Our research focuses on the improvement of the resistance of bovine IVP blastocysts to cryopreservation, by increasing their quality or by adapting the freezing procedures. Another applied project is related to the resistance to cryopreservation of bovine and equine  sperm, in collaboration with the Association wallonne de l'Elevage. We are also involved in a a project of creation of a cryobank to preserve the genetics of local breeds of domestic ruminant species in Belgium (in collaboration with Prof. Ph. Baret, Unité de Génétique).

    

Key publications:

  • GEORGE F, VRANCKEN M, VERHAEGHE B, VERHOEYE F, SCHNEIDER YJ, MASSIP A, DONNAY I, Freezing of in vitro produced bovine embryos in animal protein-free medium containing vegetal peptones, Theriogenology, 66, 2006, 1381-1390.
  • KAIDI S, BERNARD S, LAMBERT P, MASSIP A, DESSY F, DONNAY I, Effect of conventional controlled-rate freezing and vitrification on morphology and metabolism of bovine blastocysts produced in vitro, Biology of Reproduction, 65, 2001, 1127-1134.
| 31/01/2012 |