Using these special tools, the researchers confirmed that one important role of reproductive tract secretions is to protect and store sperm. At least 25 secretory cells are required, and their products attract sperm to glands where they can remain safely while bathed in the secretory fluid. Similar storage takes place in a region of the human Fallopian tube known as the isthmus. Sperm are thought to persist in the isthmus for only a few days, but can be stored for a week or more in the case of fruit flies. When production of the secretion is compromised, sperm have difficulty getting to the gland and those that can make it undergo abnormal changes.
The secretory "machinery" studied in these experiments may allow the reproductive tract to signal the ovary when it is ready to receive an egg. Waiting for such a signal before releasing an egg could reduce the chance that an egg would fail to enter the reproductive tract or arrive before active sperm were available.
Interestingly, Spradling and Sun's work shows that different secretions are responsible for ovulation from those responsible for attracting and storing sperm. Identifying the specific secretory cell products (and the corresponding genes) that are required for successful ovulation would be an important step in understanding the mechanisms of this still-mysterious process.
This research has a possible connection to one of the most common forms of ovarian cancer, which was recently shown to derive from abnormalities in reproductive tract secretory cells. The genes and pathways that cells use in carrying out their normal functions are often the targets of the alternations that drive cancer cell growth. Thus, this work should stimulate investigation of the role played by genes such as Lrh1 in this deva
|Contact: Allan Spradling|