Their discovery, which appears in the journal PloS Biology, could lead into a range of innovations pertaining to insect life, from curbing the growth of mosquitos to bolstering the population of honey bees.
The researchers, part of NYU’s Center for Genomics and Systems Biology, studied spermathecal secretory cells (SSCs), a set of cells in the female reproductive tract whose existence had previously been determined but whose function was unknown.
To explore the role of SSCs, the NYU researchers studied female Drosophila melanogaster, a fruit fly. Fruit flies have rapid developmental time, allowing biologists to examine genetic and physical changes over a relatively short period. In addition, many of the genetic processes identified in flies are conserved in humans.
In order to isolate the role SSCs play, the researchers used a genetic technique to eliminate SSCs in a sample of flies and monitored how their reproductive process was affected. This method did not alter the function of these flies’ other cells.
Their results indicated that SSCs have two fundamental roles in the reproductive process: they are necessary for moving fertlized eggs through the reproductive tract and they assist in storing sperm.
Normal female fruit flies store sperm in two different organs–the seminal receptacle and two mushroom-shaped spermathecae. However, in flies missing SSCs, sperm never reached the spermathecae, and those that reached the seminal receptacle subsequently lost their motility—i.e., they stopped swimming. Lacking SSCs, D. melanogaster loses its ability to move fertilized eggs through the reproductive tract and, as a result, will hatch eggs internally—in utero—rather than outside the body.
“We are excited to see whether our findings apply to insects that are important to human health or agriculture,” said Mark Siegal, the study’s senior author and a professor of biology at NYU. “For instance, future work could explore boosting the reproduction of honeybees or, conversely, curbing this same process in disease-transmitting insects such as mosquitoes.”
The study’s other authors were Sandra Schnakenberg, an NYU doctoral candidate who led the study, and Wilfredo Matias, an NYU undergraduate at the time of the study and now a student at Harvard Medical School.