Cell line bioassay for measuring FSH bioactivity in pregnant mare serum

养牛者需要可靠的方法来增加有遗传价值的动物的产量，并通过选择来改善遗传性能性状。常见的方法是在“供体”奶牛中诱导多排卵，然后将产生的胚胎转移到受体奶牛的子宫中。诱导多排卵是昂贵和耗时的，结果可能是高度可变的;一些奶牛对治疗没有反应。最便宜和最少的劳动密集型药物诱导多排卵是马绒毛膜促性腺激素（eCG）。这是一种由马胎盘在怀孕期间产生的激素，并从马血清中纯化。有些细菌产生的eCG比其他细菌产生的eCG具有更高的生物活性。然而，在马场，当收集eCG用作诱导牛多排卵的药物时，没有考虑到两种药物之间的这种变异性。这导致了市售eCG批次的活性变化。此外，大量的马被保留用于eCG生产;如果只使用最好的生产马，这个数量可以减少。为了克服这些问题，需要在eCG收集现场使用快速检测高活性eCG的方法。本项目旨在开发这样一种方法。我们将使用一种卵巢细胞系，它是由不断分裂而不死亡的细胞组成的。使用基因工程，我们可以将这些细胞中的一个基因，当细胞被eCG刺激时，该基因就会被打开。eCG的活性越高，该基因的表达将越大。一旦基因被激活，就会产生一种酶，这种酶会导致培养介质中的化学物质改变颜色。因此，通过将细胞的颜色与标准化的比色表进行比较，可以容易地检测eCG的活性。这将使加拿大制药业能够生产更好的产品，并减少生产eCG所需的马匹数量。这将为加拿大养牛者节省大量的经济开支

Cattle breeders need reliable methods to increase production of genetically valuable animals, and to improvehereditary performance traits by selection. The common approach is inducing multiple ovulation in 'donor'cows followed by transfer of the resulting embryos into the wombs of recipient cows. Inducing multipleovulation is expensive and time-consuming, and the results can be highly variable; some cows do not respond to treatment.The cheapest and least labour-intensive drug for inducing multiple ovulation is equine chorionic gonadotropin (eCG). This is a hormone that is produced by the horse placenta during pregnancy, and is purified from horse serum. Some mares produce eCG which has a higher biological activity than that produced by other mares. However, on the horse farm this variability between mares is not taken into account when eCG is collected for use as a drug for inducing multiple ovulation in cattle. This contributes to the variation in activity of batches of commercially available eCG. Further, a large number of horsesare kept for eCG production; this number can be reduced if only the best producing mares are used.To overcome these problems, a rapid method of detecting highly active eCG is required for use at the site of eCG collection. This project aims to develop such a method. We will use an ovarian cell line, which is aculture of cells that divide continually and do not die. Using genetic engineering, we can incorporate into these cells a gene that is turned on when the cells are stimulated by eCG. The higher the activity of the eCG, the greater the expression of this gene will be. Once the gene is turned on, an enzyme is produced that will cause a chemical in the incubation medium to change colour. Thus the activity of eCG can be readily detected by comparing the colour of the cells to a standardized colour chart. This will enable the Canadian pharmaceutical industry to produce a better product, and to reduce the number of horses required to make eCG. This will result in significant economic savings for Canadian cattle breeders