Dear Evolunchers,
It is our great pleasure to announce our next Evolunch seminar:
IMBA Vienna
How do genes venture into the unknown?
Mavericks—a new vector of horizontal gene transfer in animals
Wednesday,
8th May,
2024
11:00
CET
Mondi
2, Central Building, ISTA
Hybrid
Meeting (zoom link here)
Abstract:
Horizontal gene transfer (HGT)-the movement of genetic material between species-has been
reported across all major eukaryotic lineages. However, the underlying mechanisms of transfer and their impact on genome evolution are still poorly understood. While studying the evolutionary origin of a selfish element in the nematode C.
briggsae, we discovered that Mavericks, ancient virus-like transposons related to giant viruses and virophages, are one of the long-sought vectors of horizontal gene transfer. Mavericks-also
known as Polintons-are found in almost every major eukaryotic lineage. They are flanked by terminal inverted repeats and can readily jump and insert into genomes, like transposons. But like viruses, they code for a large number of proteins, including a typeB
DNA polymerase, a retroviral-like integrase, as well as major and minor capsid proteins. Using a combination of phylogenetics, structural predictions and genetic crosses, we discovered that two novel nematode gene families-wosp proteases
and krma kinases-are preferentially taken up as cargo genes by Mavericks and
have been extensively transferred between different nematode species on a global scale. We also found that nematode Mavericks captured
a novel fusogen, MFUS-1, which is structurally similar to the glycoprotein B from Herpes simplex virus 1. This event likely fueled their spread via the formation of enveloped infective particles, analogous to the inception of retroviruses from genomic retroelements.
Lastly, we show how the union between a horizontally transferred wosp protease, msft-1, and a
MULE transposon gave birth to a novel class of selfish gene in C. briggsae: a mobile toxin-antidote
element that causes genetic incompatibilities that drive in wild populations. Our results identify the first wide-spread vector of HGT in animals and highlight how the intertwined biology of viruses and transposons can ultimately impact gene flow between populations,
shaping the evolution of the species that carry them.
Biography
Alejandro Burga studied Biochemistry at the Pontifical Catholic University of Chile in Santiago. In 2012, he completed his Ph.D. in Systems Biology at the Centre for
Genomic Regulation in Barcelona under the guidance of Ben Lehner. Following this, he conducted postdoctoral research in quantitative genetics at Princeton University and UCLA with Leonid Kruglyak. Since 2019, he has been a Junior Group Leader at IMBA in Vienna.
If you wish to meet with Alejandro after his seminar, please sign-up for 1-1 meetings here here.
Looking forward to seeing you all there !
The Evolunch Team
(Upcoming seminars will be communicated in the reminder email next week)