Project FAQs

Why is the project named "Pleiades"?

In Greek mythology the Pleiades are the seven daughters of the Titan god Atlas. The Pleiades Promoter Project is a spin-off (daughter) of the Mouse Atlas Project (www.mouseatlas.org). The Pleiades is also a 7-star constellation and coincidently the Pleiades Promoter Project has seven principal investigators!

What are MiniPromoters?

Within the Pleiades Promoter Project, MiniPromoters contain less than 4 kb of human genomic DNA. Segment(s) of genes are selected with the intention to direct transcription in a cell-type specific or regionally selective manner, potentially recapitulating all or a portion of the expression of the endogenous source gene.

How were the genes of the Pleiades Project chosen?

Our gene choosing strategy was to start with SAGE-identified genes ranked on the basis of specificity and expression level, and confirm this with supporting evidence from the literature (http://www.ncbi.nlm.nih.gov/sites/entrez/) and/or Allen Brain Atlas (ABA; http://www.allenbrainatlas.org/) or GENSAT (http://www.gensat.org/). For the small number of brain regions for which we had no SAGE data we interrogated the literature and ABA directly. We used several expression indicators including SAGE tag abundance and specificity, in situ hybridization, promoter-reporter fusion data etc. to assess candidacy of genes.

Aside from criteria used to rank SAGE-identified genes, other selection criteria included region specificity, strength of signal and cell-type specificity. Although we prioritized finding genes displaying absolute regional specificity (no detectable background expression), for practicality we did not limit ourselves to this level of stringency - especially for the brain nuclei e.g. Basal Nucleus of Meynert, Barrington's Nucleus etc. Other factors considered in gene selection include studies of promoters in the literature, bioinformatics analysis of promoter feasibility by the Wasserman group, mouse mutant phenotype pertinent to the region of interest from Mouse Genome Informatics (http://www.informatics.jax.org/), and disease association of the gene from post-mortem brain studies.