Bassem Hassan
Neurogenetics
VIB Department of Molecular and Developmental Genetics, K.U.Leuven

PhD: Ohio State Univ., Ohio, USA, '96 Postdoc: Baylor Coll. of Medicine, Houston, Texas, USA, '96-'01 VIB Group leader since 2001 EMBO Young Investigator, 2003 EMBO Member since October 2009

e-mail phone +32 16 34 62 26 ADDRESS

Current team members
Group leader: Bassem Hassan
Postdoctoral scientists: Ariane Ramaekers, Marta Koch, Xiao-Jiang Quan
Ph.D. Students: Alessia Soldano, Duygu Esen Ozel, Laura Nicolaï, Marion Langen, Marlen Schlieder, Zeynep Okray
Support personnel: Agata Gawad, Annelies Claeys, Fatima Sharafeddine, Genia De Brauwer, Jiekun Yan, Martine Noblet, Natalie De Geest

Keywords
brain - neural circuit - genetics - Drosophila - neuronal cell biology

Science

How do you make a nervous system that works…and keep it that way?

Diversity is a beautiful thing and unity is a powerful thing. Put them together, and what do you get? You get the most beautiful and powerful of all things: Evolution! Much like human beings, cells of the nervous system are exquisitely diverse. They have diverse shapes and perform diverse functions. Yet, also like humans, underneath this bewildering diversity lies a profound unity: the genome. How can exactly the same genome produce so many different cells? The answer is that it depends on how a cell interprets its genome. Different cells extract differential information form their genomes using transcription factors that activate or repress different genes. Our lab is interested in understanding the contribution of the information encoded by cell type specific transcription factors to cell fate specification. For this we use the development and evolution of sensory organs- the eye, ear and nose- in the fruit fly Drosophila melanogaster as a model system. We compare the genetic programs of different sensor cells within one species, as well as the genetic programs of the same sensory organs across different Drosophila species. This way we hope to learn about the rules of cellular diversity and specialization. Because cellular specialization goes wrong in Cancer, these findings have profound implications for human health.

Making a brand new specialized nervous system cell is just the beginning. Now it has to grow axons and dendrites and begin its journey. Axons of young brain neurons have a promiscuous wanderlust! They like to travel, explore new environments, search for suitable partners and establish as many connections as they can. They cannot help it. Its an irresistible drive. Its in their genes, you could say! After a certain age however, they settle down, and, satisfied with the extensive network of connections they have made, stop searching for new ones. They devote their lives to their jobs, and generally perform exceptionally well, given the monumental task they have: making the formidable machine that is the organism live, behave and reproduce. This dedication however, comes at a price: the loss of their youthful sense of wanderlust. If their connections are cut, they are unable to get themselves to travel, make new connections and start all over again. Using the mighty fruit fly as a model organism, we study the genes that allow young axons to grow and establish connections. We also ask why the same axons, now older and wiser, are unable to grow again and re-establish lost connections if they are injured or struck down by disease. We combine powerful molecular genetic tools, innovative whole-brain culture approaches and high resolution imaging to search for genes and gene ensembles that control axonal growth during development. We also ask if the same genes might help injured or diseased axons to regenerate and survive.

Link to Group's website for more details.

Press releases
See also press release (23/02/2009): Anti-cancer gene discovered: perspective for therapy - based on a publication in PloS Biology (Bossuyt et al., PLoS Biology, 2009)

See also press release (04/06/2008): Microsurgery on the brain of the fruit fly leads to new insights into irreparable nerve injuries - based on a publication in The Journal of Neuroscience (Ayaz et al., The Journal of Neuroscience, 2008).

Bossuyt W, De Geest N, Aerts S, Leenaerts I, Marynen P, Hassan B
The atonal proneural transcription factor links differentiation and tumor formation in Drosophila
PLOS BIOL 7, e40, 2009



Choi C, Vilain S, Langen M, Van Kelst S, De Geest N, Yan J, Verstreken P, Hassan B
Conditional mutagenesis in Drosophila
SCIENCE 324, 54, 2009



Ayaz D, Leyssen M, Koch M, Yan J, Srahna M, Sheeba V, Fogle K, Holmes T, Hassan B
Axonal injury and regeneration in the adult brain of Drosophila
J NEUROSCI 28, 6010-21, 2008



Aerts S, Lambrechts D, Maity S, Van Loo P, Coessens B, De Smet F, Tranchevent L, De Moor B, Marynen P, Hassan B, Carmeliet P, Moreau Y
Gene prioritization through genomic data fusion
NAT BIOTECHNOL 24, 537-544, 2006



Srahna M, Leyssen M, Choi C, Fradkin L, Noordermeer J, Hassan B
A Signaling Network for Patterning of Neuronal Connectivity in the Drosophila Brain
PLOS BIOL 4, e348, 2006

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