Laboratory of Molecular Systematics & Evolutionary Genetics

A simplified example of how spike‐in standards can be used during read normalization to enable comparisons of expression level at different biological scales between a hypothetical diploid–polyploid pair with differing cell density. The large circles represent a unit of biomass and contain a number of cells (green squares). Beneath each circle is a depiction of how the read normalizations are calculated. Under a per transcriptome normalization, the ratio of target transcripts to the total transcriptome is compared. The per biomass normalization uses the ratio of the transcript of interest to the spike‐in transcripts. The per cell normalization also uses the ratio of the transcript of interest to spike‐in transcripts, but scales the spike‐in transcript abundance by cell density, represented here by multiplying the spike‐in abundance by the number of contributing cells. Whether the transcript of interest would be found as not differentially expressed (=) or upregulated (<) in the polyploid under each normalization is indicated (downregulated not included). DE: differential expression.

Global resources can be spatially, taxonomically or temporally subset to serve focused needs, as shown. The top rows in the inset show needed data resources, and the bottom row shows synthetic products, such as regional assessments of evolutionary diversity that inform about community processes and conservation priorities.