Comparative genomics presentation

Comparative Genomics and the Evolution of Genes

Based on 12 way comparison

Evolution of Genes and Genomes on the Drosophila phylogeny

Phylogenetic Tree of Drosophila

http://blast.ncbi.nlm.nih.gov

SHOTGUN SEQUENCING

It is named by analogy with the rapidly-expanding, quasi-random firing pattern of a shotgun.

The technique was developed in the 1970s by double Nobel prize laureate Frederick Sanger.

Craig Venter

W = dN/ds

dN (non synonymous)dS (synonymous)

Examined the ratio of non-synonymous to synonymous divergence to explain distribution

W = d

• A major question in evolutionary biology is how important tinkering with promoter sequences is to evolutionary change, for example, the changes that have occurred in the human lineage after separating from chimps.

Are evolution in promoter or regulatory regions more important than changes in coding sequences over such

time frames?

A key reason for the importance of promoters is the potential to incorporate endocrine and environmental signals into

changes in gene expression[1]: A great variety of changes in the extracellular or intracellular environment[2] may have

impact on gene expression, depending on the exact configuration of a given promoter [2]: the combination and arrangement of specific DNA sequences that constitute the promoter defines the exact groups of proteins that can be

bound to the promoter, at a given time [3].

Genetic Obstacles

Conclusion

• Demonstrated the ability to place every one of these genomic comparisons on a phylogeny with a taxon separation that is ideal for asking a wealth of questions about evolutionary patterns and processes.

• The use of multi-species orthology “provides” especially convincing evidence in support of particular gene models, not only for protein-coding genes, but also for miRNA and other ncRNA genes.

The methodology and principles are absolutely general and they are applicable

to any genome. The genomes of these species provide an excellent model for studying how conserved functions are

maintained in the face of sequence divergence. These genome sequences provide an unprecedented dataset to contrast genome structure, genome

content, and evolutionary dynamics across the well-defined phylogeny of the

sequenced species

• Species D. willistoni doesn’t appear to have genes to make proteins containing selenium – proteins that researches had thought were common to all animals.

• analysis suggests that “some” gene families expand of contract at a rate of 0.0012 gains and losses per gene per million years or roughly one fixed gene gain/ loss across the genome every 60,000 yr.

• Number of structural changes and rearrangements is much larger, for example, there are several different rearrangements of genes in the Hox cluster found in these Drosophila species

Brosius J, Erfle M, et al. (1985). "Spacing of the -10 and -35 regions in the TAC promoter - effect on its in vivo activity". Journal of Biological Chemistry 260 (6): 3539–3541.

Celniker SE, Drewell RA (2007). "Chromatin looping mediates boundary element promoter interactions". Bioessays 29 (1): 7–10

Vlahopoulos S, Zoumpourlis VC (2004). "JNK: a key modulator of intracellular signaling". Biochemistry (Mosc) 69 (8): 844–54.

http://en.wikipedia.org/wiki/Promoter_%28biology%29

Your mom

Works cited..