Now, evolutionary and developmental biologists at the University of Georgia and the Hebrew University of Jerusalem have uncovered evidence that after fruit flies mate, the presence of sperm and male proteins in the female's reproductive tract sets off an amazing cascade of heretofore undescribed gene activity. Understanding how this works will give scientists new insights into reproduction, but it could also provide methods to safely control the spread of insect pests by interfering with their reproduction.
"We have been able to define a large number of mating-responsive genes that are activated in Drosophila," said Michael Bender, a developmental biologist in the department of genetics at UGA. "There is a lot of potential in this work for uncovering basic aspects of reproductive biology that will be useful in pest-control approaches."
The research was just published in the online edition of the Proceedings of the National Academy of Sciences. The work resulted from a collaboration between Bender, Paul Mack, a postdoctoral fellow in the Bender lab at UGA, Yael Heifetz of Hebrew University and Anat Kapelnikov, a graduate student in the Heifetz lab. A number of undergraduates at UGA also worked on the research.
Drosophila has been used as a model animal for nearly a century. It is easy to manipulate in a lab, lives only a few weeks and begins mating soon after hatching. Its entire genetic map or genome has also been sequenced, giving researchers a powerful tool in understanding intricate biological processes and the genes that direct them.
Bender's team, using both the established genomic background of Drosophila and studies of mating insects, showed that the sperm and proteins transferred from males to females during mating have "profound effects" on female gene expression. Most surprising is that gene activity rapidly escalates about six hours after mating--something previously unknown.
"We looked at the reproductive tracts of females at three, six and 24 hours post-mating," said Mack. "Just getting enough material through dissection is extremely difficult and time-consuming, but this kind of time-based evaluation of post-mating gene expression in Drosophila had never been done."
Perhaps surprisingly, very little is known about how gene expression in female reproductive tissues changes in response to the presence of sperm and male molecules. The study compared 3-day-old mated and unmated females and discovered the presence in mated females of a startling 539 genes whose activity changes after mating.
"One novel feature of this research was Paul's decision to look at what happens over time," said Bender. "That's how we found out that the activity hits a peak six hours after mating. This indicates quite a large genetic response in the female tract to male-derived molecules and sperm."
Though considerable research has been done on male Drosophila over the years, relatively little had focused on females. Just why the array of gene expression peaks at 6 hours is not yet clear, but revealing this timing could help in controlling insect pests. That is one reason the research was funded by the Binational Agricultural Research and Development (BARD) Fund, a joint program between the United States and Israel. Since 1979, BARD has funded nearly 900 research projects in almost all 50 states. Support for the research also came from The National Institutes of Health.
The Bender and Heifetz teams weren't operating in the dark, since earlier studies had examined some post-mating gene expression in Drosophila, but that earlier work did not examine expression over a set time period and involved examining the whole bodies of mated insects, not just their reproductive tracts.
The researchers' double approach using genomics and proteomics--the study of proteins and the products they turn on--was especially productive because it allowed them to identify genes they would not have found using a single approach.
"The next step will be to choose a few of the most promising genes and to explore their function in females," said Bender.
Once the gene functions are known, then scientists can begin to examine how to manipulate them--both to study the biology involved and to find potential targets for pest control.
Kim Carlyle | EurekAlert!
How circadian clocks communicate with each other
30.05.2017 | Julius-Maximilians-Universität Würzburg
Reptile vocalization is surprisingly flexible
30.05.2017 | Max-Planck-Institut für Ornithologie
The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.
The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
30.05.2017 | Life Sciences
30.05.2017 | Power and Electrical Engineering
29.05.2017 | Earth Sciences