### Description

This column shows the ratio of expression of each gene in a particular phase of the worm life cycle to expression of the gene in mixed wild-type N2 cultures. These experiments were replicated several times. This track shows the median value for each life cycle stage.

A gene that is more highly expressed in a life cycle phase is colored red, and a less expressed gene is shown in green. The values are colored on a logarithmic scale. This coloring is standard, but is the opposite of what an inexperienced user might expect: in this case, red means go and green means stop! Black indicates that a gene is neither over- nor under-expressed in a life cycle phase. Uncolored boxes (white on most browsers) represent missing data.

### Column Configuration

Column configuration options are available on the Configuration page, which can be accessed via the configure button in the top menu.

- Color scheme: Color-blind users can switch the coloring scheme from red/green to yellow/blue via the Expression ratio colors pulldown menu at the top of the Configuration page.
- Brightness: To increase or decrease the brightness of the expression colors, edit the number in the column's brightness text box. Values greater than 1.0 increase the brightness, while those less than 1.0 dim the color.

### Methods

The data in this column were collected as described in the paper Jiang M, et.al. (2001), "Genome-wide analysis of developmental and sex-regulated gene expression profiles in Caenorhabditis elegans", PNAS 98(1):218-23. We retrieved the data from the Stanford Microarray Database.

To associate particular genes with expression data we use a fairly simple-minded scheme. First we align the cDNA sequences around which the probes were designed to the genome. Then for each gene we pick the cDNA sequence with the alignment that most overlaps the gene as the source for expression data for that gene. Since many of the cDNA sequences and probes designed for the cDNA sequences just cover part of the gene, in most cases different splice varients of a gene will end up mapped to the same cDNA sequence.

### Credits

Many thanks to the Kim Lab for making the data available.