Cell line bioassay for measuring FSH bioactivity in pregnant mare serum

牛饲养者需要可靠的方法来增加具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”奶牛身上诱导多次排卵，然后将产生的胚胎移植到“受体”奶牛的子宫中。诱导多个排卵是昂贵和耗时的，结果可能非常不稳定；一些奶牛对治疗没有反应。最便宜、劳动强度最低的多次排卵药物是马绒毛膜促性腺激素(CG)。这是一种荷尔蒙，由怀孕期间的马胎盘产生，从马血清中提纯。一些母马产生的心电比其他母马产生的心电信号具有更高的生物学活性。然而，在马场，当收集心电作为一种药物来诱导牛的多次排卵时，不考虑母马之间的这种差异性。这导致了商业上可获得的心电批次活动的差异。此外，大量的马被饲养用于心电生产；如果只使用最好的生产母马，这个数字可以减少。为了克服这些问题，需要在心电采集现场使用一种快速检测高活跃心电的方法。本项目旨在开发这样一种方法。我们将使用卵巢细胞系，这是一种持续分裂且不会死亡的细胞培养。利用基因工程，我们可以将一种基因整合到这些细胞中，当细胞受到心电刺激时，这种基因就会被打开。心电图的活跃度越高，这个基因的表达就越大。一旦基因被激活，就会产生一种酶，使孵化介质中的一种化学物质改变颜色。因此，通过将细胞的颜色与标准化的色表进行比较，可以容易地检测到心电活动。这将使加拿大制药业能够生产出更好的产品，并减少制作心电所需的马匹数量。这将为加拿大的养牛者带来显著的经济节约。

Cattle breeders need reliable methods to increase production of genetically valuable animals, and to improve hereditary 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 multiple ovulation 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 horses are 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 a culture 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