Ultrastructure analysis of bovine oocytes and blastocysts produced in vitro after oocyte maturation with cAMP modulators

• Grant number: 15/02557-8
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: May 01, 2015
• End date: October 10, 2015
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Marcelo Fábio Gouveia Nogueira
• Grantee: Eduardo Montanari Razza
• Supervisor: Poul Hyttel
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Institution abroad: University of Copenhagen, Copenhagen, Denmark
• Associated to the scholarship: 12/23409-9 - Differential gene expression, ultrastructural analysis and evaluation of the lipid profile of in vitro produced bovine blastocysts from oocytes matured conventionally or via SPOM system, BP.DR

Abstract

In vitro maturation (IVM) does not use superstimulatory hormones in vivo, thereby preventing, overspending and animal handling, in addition to the harmful iatrogenic effects of ovarian overstimulation. However, the efficiency of IVM systems do not meet full expectations due to the inability to simulate the physiological events that occur in vivo (i.e. synchronization between nuclear and cytoplasmic maturation of the oocyte). For this reason, the increment of IVM media is a target sought increasingly in reproductive studies. Evaluation and characterization of the cell features by morphology and organelle distribution, provides consistent results on the characterization of the embryo when it is examined for ultrastructure. This technique can be applied in order to identify in vitro oocytes and blastocysts with better quality (morphological and physiological) and competence for subsequent implantation and development. Therefore, this study aims to compare the conventional IVM system with a system that uses a prematuration with drugs that modulate cAMP in order to provide synchronization between nuclear and cytoplasmic maturation (briefly: forskolin and IBMX on prematurity for 2 h followed by 22 h of maturation with FSH). After prematuration, either oocytes or produced blastocysts will be evaluated for ultrastructure (transmission electron microscopy, University of Copenhagen, Denmark). The Department of Veterinary and Animal Clinical Sciences, along with Professor Poul M. Hyttel, is a world reference in the field of this research, hence the academic gain of this internship, previously proposed in the original project, comprises both the regular project (2012/23409-9) and the bilateral thematic project between Brazil and Denmark "GIFT" (2012/50533-2). The communion between the data to be obtained with this project with those obtained through the research in Brazil (data of in vitro performance from different maturation systems, lipid profile analysis of blastocysts by MALDI-MS, differential gene expression of 45 genes related to embryo quality) could provide general and reliable indicator of embryo quality, covering the implantation, development and cryopreservation of embryos in commercial routines of IVP. (AU)