[Todos] Seminarios conjuntos IFIBYNE-DFBMC- Viernes 7/10 - Dr. Lutz Birnbaumer- RECORDATORIO

[Paula Felman]

Viernes 7 de octubre 13 Hs. en el aula de seminarios.

Dr. Lutz Birnbaumer

Titulo “Una metodología para analizar el metiloma en salud y enfermedad”.

SUMMARY : Methylation of CpG at position 5 of the 
cytosine ring is an epigenetic inheritable mark 
that changes with age, life experiences and 
diseases such as cancer and psychiatric 
disorders. CpGs are mostly methylated except at 
regions called CpG Islands or CGIs, where, for 
unknown reasons, their inter-CpG distance is 
small and they are mostly unmethylated. CGIs are 
defined by computer algorithms and are primarily 
found in the neighborhood of promoters where DNA 
methylation regulates gene expression.  The 
descripition of genome wide methylation patterns 
­ the methylomes ­ is extremely costly and time 
consuming.  By applying a 
methyl-sensitive-cut-counting approach we 
developed a cost-effective method to survey the 
methylation status of one out of every three CpGs 
at single CpG resolution. At CGIs, the  survey 
power is increased to one in two. This led to the 
discovery of thousands of patches of mostly 
unmethylated CpGs that are not predicted by 
algorithms and thus do not qualify as CGIs, but 
are enriched in binding sites for regulatory 
elements and in mammalian most conserved 
sequences.  These patches are not represented in 
genomic hybridization chips meant to survey 
changes in the methylome in health and disease.

By applying a multi-dimensional approach to 
estimate false discovery rates (mdFDR), we found 
that it is possible to compare the distribution 
of unmethylated CpGs among different tissues and 
among tissues from animals subjected to different 
treatments and identify tissue- and 
treatment-specific differentially methylated CpGs.

Studies are underway to explore changes in the 
metylome occurring with treatments such as high 
and low methylation promoting diets in normal and 
obese mice, to answer the question whether it is 
possible to associate obesity with specific changes in the methylome.

Host. Francisco Urbano