The Test Case is related to the Bioinformatic work / and Biostatistics needed to collect gather and analyze molecular info data from a project aiming at studying reproductive robustness in dairy cattle. In this project data will originate from different sets of biological material obtained in an in vitro model related to oocyte and granulosa cell culture. Biological material will be issued from genital tracts of cows of 2 genetic origins. After aspiration of cells from follicles, oocytes and granulosa cells will be challenged with metabolic mediators (inslulin or NEFA ) and then cultivated for 24hrs. Part of the oocytes will be used for molecular analyses before and after the 24 hours maturation while others will be in vitro fertilized and zygotes cultivated up to the blastocyst stage (day 7 of culture). Oocytes, granulosa cells and embryos will be studied for gene expression and epigenetics. This is part of 2 projects , one granted by FORMAS in 2010 and the other one presented this year. Collection of material has started for the first project. Phenotypic analysis and molecular analysis should be produced during beginning of 2013. Bioinformatic analyses should take place middle /end of 2014.

Dairy cow fertility has been decreasing for a long time due to genetic selection mainly orientated towards milk production. Metabolic imbalance is affecting around 70% or more of dairy cows during the period following parturition. Some cows recover from metabolic imbalance rather rapidly while others remain in negative energy balance that Induces reproductive disorders such as delayed resumption of ovarian activity and poor fertility / embryo quality. This induces longer intervals between calving and conception due mainly to conception failures and early embryonic death. There may be also differences in relation with genetic origin, in the way cows suffer from the disease and in the way reproduction is affected. The proposed projects (submitted to FORMAS in 2010 and 2012) aims to integrate phenotypic and molecular information to understand, predict and find solutions to lower the impact of metabolic stress in cows. One of the aims is to find molecular markers from oocytes, granulosa cells or embryos which may be related to different phenotypic expression and which may be differentially expressed in relation with genetic origin of cells.

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