Transposable elements in vertebrates: From invasive crowd to emerging stars
Event details
| Date | 13.09.2013 |
| Hour | 10:15 › 11:15 |
| Speaker |
Domitille Chalopin Institut de Génomique Fonctionelle de Lyon (IGFL) |
| Location |
SV 3.510
|
| Category | Conferences - Seminars |
Transposable elements (TEs), commonly named mobile DNA, are one of the major components of vertebrate genomes. They largely contributed to shape genomes by driving recombination, deletion or insertion, but also by generating new functions through molecular domestication processes. To better understand the roles of TEs in genomes, a large amount of mobilomes is necessary to accumulate and annotate in many lineages. Nowadays, except many studies done in mammals, chicken and some reptiles, few information are available in other vertebrate lineages.
We automatically and manually re-annotated TEs in 10 non-tetrapod genomes and used available tetrapod data to compare diversity, abundance and bursts of TE activity in all vertebrate lineages. Analyses of TEs in vertebrate genomes bring new insights into genome dynamics and evolution. As a general tendency, TE diversity tends to gradually decrease from fish to tetrapods, with the poorest diversity observed in mammals. On the contrary, the copy numbers of TE families tend to increase. Our analyses also show that vertebrate genomes contain a high proportion of small or degenerated sequences. The question that arises is why small remnants are not rapidly eliminated from genomes.
To tackle this last question, we analyzed a gene, called Gin-2, which encodes an integrase similar to the ones of retrotransposons. We show that this gene is highly expressed during adult life in fish and also during embryogenesis. In situ hybridization in zebrafish embryo showed that Gin-2 is highly expressed during the whole gastrulation process, suggesting a role during the involution and the extension of the embryo. Altogether, through the process of molecular domestication, TEs can be sources of new genes and new regulatory sequences becoming beneficial and helpful for the host.
We automatically and manually re-annotated TEs in 10 non-tetrapod genomes and used available tetrapod data to compare diversity, abundance and bursts of TE activity in all vertebrate lineages. Analyses of TEs in vertebrate genomes bring new insights into genome dynamics and evolution. As a general tendency, TE diversity tends to gradually decrease from fish to tetrapods, with the poorest diversity observed in mammals. On the contrary, the copy numbers of TE families tend to increase. Our analyses also show that vertebrate genomes contain a high proportion of small or degenerated sequences. The question that arises is why small remnants are not rapidly eliminated from genomes.
To tackle this last question, we analyzed a gene, called Gin-2, which encodes an integrase similar to the ones of retrotransposons. We show that this gene is highly expressed during adult life in fish and also during embryogenesis. In situ hybridization in zebrafish embryo showed that Gin-2 is highly expressed during the whole gastrulation process, suggesting a role during the involution and the extension of the embryo. Altogether, through the process of molecular domestication, TEs can be sources of new genes and new regulatory sequences becoming beneficial and helpful for the host.
Practical information
- Informed public
- Free
Organizer
- Anamaria Necsulea
Laboratory of Developmental Genomics
ISREC, EPFL
Contact
- Anamaria Necsulea
[email protected]
Laboratory of Developmental Genomics
ISREC, EPFL