DOI: 10.5061/dryad.n8pk0p2t8
title: Relationships between immune gene expression and circulating cytokine levels in wild house mice

description: 1. Quantitative PCR (qPCR) has been commonly used to measure gene
 expression in a number of research contexts, but the measured RNA
 concentrations do not always represent the concentrations of active
 proteins which they encode. This can be due to transcriptional regulation
 or post-translational modifications, or localisation of immune
 environments, as can occur during infection. However, in studies using
 free-living non-model species, such as in ecoimmunological research, qPCR
 may be the only available option to measure a parameter of interest, and
 so understanding the quantitative link between gene expression and
 associated effector protein levels is vital. 2. Here we use qPCR to
 measure concentrations of RNA from mesenteric lymph node (MLN) and spleen
 tissue, and multiplex ELISA of blood serum to measure circulating cytokine
 concentrations in a wild population of a model species, Mus musculus
 domesticus. 3. Few significant correlations were found between gene
 expression levels and circulating cytokines of the same immune genes or
 proteins, or related functional groups. Where significant correlations
 were observed, these were most frequently within the measured tissue (i.e.
 the expression levels of genes measured from spleen tissue were more
 likely to correlate with each other rather than with genes measured from
 MLN tissue, or with cytokine concentrations measured from blood). 4.
 Potential reasons for discrepancies between measures, including
 differences in decay rates and transcriptional regulation networks are
 discussed. We highlight the relative usefulness of different measures
 under different research questions, and consider what might be inferred
 from immune assays.
description: Gene expression levels were obtained by qPCR from spleen and
 mesenteric lymph node tissue. Concentrations of circulating cytokines were
 measured by multiplex ELISA of blood serum. Groupings by functional arm of
 the immune system and inflammation type were done by PCA. All samples were
 from wild <em>Mus musculus domesticus</em> trapped on the Isle
 of May, Scotland between August 2014 and October 2016. For full details of
 methodology, please refer to: Young <em>et al</em>. 2020,
 "Relationships between immune gene expression and circulating
 cytokine levels in wild house mice", Ecology and Evolution.
description: <strong>Raw gene expression and circulating cytokine
 data</strong> all_genes_cytokines.csv contains
 gene expression data and circulating cytokine concentrations for all immue
 genes/cytokines measured. The "Cyt" prefix refers to circulating
 cytokines, "MLN" refers to gene expression data from mesenteric
 lymph node tissue, and "Spleen" refers to gene expression data
 from spleen tissue. Gene expression data is measured as
 ΔΔC<sub>T</sub>, circulating cytokines are measured as pg
 ml<sup>-1</sup>. "id" refers to the individual mouse
 from which samples came.  <strong>Inflammation
 type</strong> Immune genes and circulating
 cytokines were grouped by inflammation type (pro-inflammatory or
 anti-inflammatory) by PCA. inflamation_type.csv contains the PC1 scores of
 these groupings. Here, "Cyt.pro" refers to pro-inflammatory
 circulating cytokines, for example. For full details of these groupings,
 see Young <em>et al</em>. 2020, "Relationships between
 immune gene expression and circulating cytokine levels in wild house
 mice", Ecology and Evolution.
 <strong>Response type</strong> The
 genes and cytokines were further grouped according to the functional arms
 of the immune system. response_type.csv contains the PC1 scores of these
 groupings. Young <em>et al</em>. 2020, "Relationships
 between immune gene expression and circulating cytokine levels in wild
 house mice", Ecology and Evolution.