Dr. Sarah Fahle
Reproduction and development are the requisites of life and researchers continue to be amazed by the different ways in which organisms solve these problems. Species in the family Drosophilidae (fruit flies) vary in sperm length, but the significance of this variation is unknown. Previous studies suggest that the variation in sperm length is necessary for the sperm to form a species-specific three dimensional (3D) conformation within the egg. We are testing whether this conformation is needed to correctly align structures, such as the male and female pronucleus, within the egg allowing development to proceed. The confirmation of this hypothesis and characterisation of the 3D sperm conformations would be another important step in understanding fertilization and development and would suggest a previously ignored mechanism crucial to sperm function.
Fruit fly eggs are collected, fixed (i.e., development is arrested), and stained (using antibody targeted against sperm-tail) and viewed on a confocal microscope. Images are collected of the 3D conformation of the sperm at the pronuclei (very earliest) stage of development and, by developing computer applications and utilising virtual reality technology, we will quantify the shape, size, and orientation of sperm inside eggs and compare this among species. The results will be used, in conjunction with a systems biology approach, to model gamete interactions (Figure 1). This will enable us to predict whether development in the early stages has been successful and to develop more realistic models of development and fertilisation.
Figure1. An example of an image which has been produced of
This work is funded by The Leverhulme Trust. The PI is Dr Rhonda R. Snook and the project collaborates with the Computer Science Department’s Professor Mike Holcombe and Ph.D student Duncan Payne (http://www.dcs.shef.ac.uk/~dpayne/).