Objective
The objective was to obtain basic information on the growth and development of early cattle embryos and their environment in the female reproductive tract. Such information is essential to address the problem of early embryo loss, to improve the quality of embryos produced in vitro and ultimately, to enable genome mapping results be placed in a functional context. The main focus was on signal transduction systems, the second messengers which mediate the action of growth factors essential for normal development. Protein content was measured to provide basic data on embryo growth. The energy metabolism of early embryos and the provision of nutrients in oviduct and uterine fluids were also examined since both are crucial for embryo survival.
There was a dramatic increase in embryo size and protein content; length increased by 500-fold and protein content by 2,600-fold between blastocyst formation (day 8) and elongation (day 16). The signal transduction system involving cyclic AMP (cAMP) and cyclic GMP (cGMP), was present, and capable of activation, from the 2-cell to the elongated stage, with a marked decrease in cGMP content between days 13 and 16. Surprisingly, embryos at these stages exported both cAMP and cGMP, possibly as a means of embryo-maternal signalling. Components of the system involving phosphatidylinositol (PI) were present and active and were affected by growth factors. Significantly, the uptake of inositol and its incorporation into phosphoinositides and inositol phosphates was dramatically increased at blastocyst formation and elongation. Epidermal Growth Factor (EGF) stimulated PI turnover in day 16 but not in day 14 embryos. The tyrosine kinase growth factor receptor system was present in 7 to 16 day-old embryos, with a shift in localisation from the apical, at day 13 and 14, to the basal, at day 15 and 16, sides of the plasma membrane of the embryo. The receptor for all members of the EGF family was expressed from day 13 -16. Intracellular calcium [Ca(2+)]I was localised in embryos but no effects of external growth factors were demonstrated, making a role for [Ca(2+)]I unlikely at these early stages. An ATP- stimulated [Ca(2+)]I signalling system was, however, demonstrated in bovine oviduct and uterine epithelia.
BREAKTHROUGHS:
The results provide comprehensive, basic information, most of it for the first time, on the cellular mechanisms controlling early cattle embryo growth and development. Significant, qualitative and quantitative shifts in growth factor expression and signal transduction systems were apparent at the time of greatest embryo loss in vivo.
The first, comprehensive profile of energy metabolism in early cattle embryos was obtained, in terms of glucose, pyruvate, amino acid and oxygen consumption and lactate production. Blastocyst formation was associated with a dramatic increase in energy turnover.
This new information on protein content, signal transduction systems and embryo metabolism will allow major questions to be addressed, such as how environmental factors like nutrition, energy balance and metabolism affect embryonic biochemical and physiological mechanisms and in turn, embryo quality and/or embryo loss.
Fields of science (EuroSciVoc)
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques. See: The European Science Vocabulary.
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques. See: The European Science Vocabulary.
- natural sciences biological sciences biochemistry biomolecules proteins
- medical and health sciences health sciences nutrition
- agricultural sciences animal and dairy science domestic animals animal husbandry
- natural sciences chemical sciences organic chemistry amines
- medical and health sciences clinical medicine embryology
You need to log in or register to use this function
Programme(s)
Multi-annual funding programmes that define the EU’s priorities for research and innovation.
Multi-annual funding programmes that define the EU’s priorities for research and innovation.
Topic(s)
Calls for proposals are divided into topics. A topic defines a specific subject or area for which applicants can submit proposals. The description of a topic comprises its specific scope and the expected impact of the funded project.
Calls for proposals are divided into topics. A topic defines a specific subject or area for which applicants can submit proposals. The description of a topic comprises its specific scope and the expected impact of the funded project.
Call for proposal
Procedure for inviting applicants to submit project proposals, with the aim of receiving EU funding.
Data not available
Procedure for inviting applicants to submit project proposals, with the aim of receiving EU funding.
Funding Scheme
Funding scheme (or “Type of Action”) inside a programme with common features. It specifies: the scope of what is funded; the reimbursement rate; specific evaluation criteria to qualify for funding; and the use of simplified forms of costs like lump sums.
Funding scheme (or “Type of Action”) inside a programme with common features. It specifies: the scope of what is funded; the reimbursement rate; specific evaluation criteria to qualify for funding; and the use of simplified forms of costs like lump sums.
Coordinator
4 DUBLIN
Ireland
The total costs incurred by this organisation to participate in the project, including direct and indirect costs. This amount is a subset of the overall project budget.