Factors affecting cattle fertility
Infertile cattle are becoming an increasing problem for European dairy farmers. One of the major causes of infertility in female cattle is poor-quality reproductive egg cells called oocytes. The EU-funded PRO-OVUM (Role of progesterone receptor membrane component-1 in oogenesis and mammalian fertility) initiative aimed to improve cattle fertility by studying factors that affect oocyte quality. An oocyte undergoes several developmental stages before it becomes a healthy egg cell that can be fertilised by sperm. In the first stage, the oocyte splits into two, with each new 'daughter' cell receiving half the complement of chromosomes from the original cell. This process, called oocyte maturation, occurs within follicles in the ovary until finally, at the time of ovulation, it is released as a fertilisable egg. Scientists suspected that a protein called progesterone receptor membrane component-1 (PGRMC1) is key to oocyte production. Confirming its essential role, the blocking of PGRMC1 production interferes with oocyte maturation. In addition, researchers found that PGRMC1 may help to form the follicles that house and release the eggs through the control of the proper proliferation of the cells that form the follicle wall. Knowing how PGRMC1 affects processes and structures pivotal to female fertility will help scientists to improve the reproductive success rate of dairy cattle. This will increase farmer profits while satisfying consumer demand for dairy products. Finally, this can provide a model to advance in understanding causes and in treating female infertility.
Keywords
Cattle fertility, oocytes, PRO-OVUM, progesterone receptor membrane component-1, follicles
