Periodic Reporting for period 3 - TE_INVASION (The evolutionary genetics of transposable element invasions)
Okres sprawozdawczy: 2022-05-01 do 2023-10-31
Transposable elements (TEs) are 'jumping genes'-- pieces of parasitic DNA that are not only inherited from parent to offspring, but which also replicate within genomes, producing copies that 'jump' from one location to another. TEs come in many different varieties which are possible to distinguish by their DNA sequences, suggesting that this kind of parasite has evolved successfully many times. In fact, the success of parasitic DNA is clear. TEs make up major part of genomes-- roughly half of the human genome, for example-- and is not possible to ignore-- they play major roles in genome evolution and also likely in genetic disease.
The harmful effects of TEs have driven hosts to evolve in response; most hosts can effectively suppress the jumping and proliferation of transposable elements. In fact, these mechanisms are so effective that particular kinds of TEs are thought to only survive long term by invading, new naïve species. Surprisingly-- these transposable element invasions appear to occur through crossing species boundaries, and can result in the rapid, selfish spread of the element through a species, like that of an epidemic disease. Understanding these issues benefits scientific knowledge by shedding light on genome evolution and genetic disease, but also on the processes that affect any introduction of new DNA to a species, such as genetic modifications aimed at controlling pest species.
Despite the importance of this invasion process to understanding evolution, we know very little about how it works, or how invasions affect their hosts. In this project, we aim to understand better what makes a successful TE invasion-- both from the perspective of the TE and that of the host. We will ask how TEs spread to new species, what factors impact their success, and how these TE invasions impact their hosts.
The harmful effects of TEs have driven hosts to evolve in response; most hosts can effectively suppress the jumping and proliferation of transposable elements. In fact, these mechanisms are so effective that particular kinds of TEs are thought to only survive long term by invading, new naïve species. Surprisingly-- these transposable element invasions appear to occur through crossing species boundaries, and can result in the rapid, selfish spread of the element through a species, like that of an epidemic disease. Understanding these issues benefits scientific knowledge by shedding light on genome evolution and genetic disease, but also on the processes that affect any introduction of new DNA to a species, such as genetic modifications aimed at controlling pest species.
Despite the importance of this invasion process to understanding evolution, we know very little about how it works, or how invasions affect their hosts. In this project, we aim to understand better what makes a successful TE invasion-- both from the perspective of the TE and that of the host. We will ask how TEs spread to new species, what factors impact their success, and how these TE invasions impact their hosts.
Thus far, we have worked on characterising the genomics of the host defense mechanisms, and on reconstructing the invasion of a transposable element in Drosophila. We have also made progress on understanding why the genes of some flies appear to resist the invasive transposable element more successfully than others.
By the conclusion of the project, we hope to better understand several key aspects of transposable element invasions, including aspects we currently don't understand. These include how hosts adapt rapidly to invasions of new TEs, how TEs cross species boundaries, and what makes a successful TE invasion.