DOI: 10.5281/zenodo.13380553
title: Cadmium ingestion does not disrupt the social transmission of microbiome in juveniles of a subsocial insect

description: READ ME

This repositery contains all dataset that allow to reproduce this study (16S rRNA sequences in .fastq format, the R script and the informative file related with the samples (env_succession.txt). It also contains Supplemental material to complete the related manuscript.

1) The file "cd_data.txt" 

It contains the informations regarding the samples. The description of the variables follows:



ID: The identifiant of the sample (host)

Clutch: The name of the family

Treatment: The cadmium doses that had been administered (0, 25 or 100 mg/L)

Group_nymph: social environment of the nymph where nymph are either isolated, with sibling (10 nymphs) or in family (10 nymphs with their mother).


2) The file "Cadmium_script.R" 

This script allows to perform all the bioinformatical process and analyses that were made for this study. It was made on R version 4.4. This script needs the source code provided by the "make_biom.R" code that will need to be downloaded in the "reference_database" the script creates (but see the Cadmium_script).

3) The RData objects

We publish the R objects (phyloseq objects) that allow to perform all statistical analyses from the initial object "ps_proka.RData" or directly after the core calculation "core.RData". It avoids to perform all bioinformatical steps to process the sequences.

4) The file "R1R2.zip"

This folder zip contains all sequence at fastq format. These sequences are from the V3-V4 of the 16S rRNA genes sequenced by Illumina MiSeq 2x250 bp.

5) The file "Supplemental Material.docx"

This document contains all supplemental tables and figures related with our study. Specifically,



Table S1: Results of the DESeq2 analysis regarding the effects of the cadmium ingestion and the social environment.

Figure S1: Electrophoresis gel (agarose 1.5%) of the 16S rRNA amplicons.

Figure S2: Species-Abundance Distribution (SAD) patterns for the microbial ASVs of the European earwig nymphs.

Figure S3: Rarefaction curves for each nymph microbiome, depending on its social environment.

Figure S4: Beta-diversity of the nymph microbiomes.
description: Symbiotic microbes play a critical role in the health and fitness of their host. In family-living species, these microbes are typically acquired through vertical transmission from parents and horizontal transmission from siblings. A growing body of research suggest that environmental stressors, such as chemical pollution, can disrupt microbial diversity from these sources and impair the ability of family members to effectively transfer microorganisms. However, the effects of pollutants on the relative contributions of parents and siblings to the juvenile microbiome are not well understood. To address this, we tested the main and interactive effects of social environment and cadmium ingestion - a common heavy metal pollutant - on the microbiome of juvenile European earwigs. We reared 900 juveniles either alone, with siblings or with siblings plus the mother, exposed them to cadmium at 0, 25 or 100mg/L, and analysed the composition and diversity of their microbiome. Our results showed that both social environment and cadmium independently influenced the phylogenetic beta-diversity of the juvenile microbiome. However, none of these factors affected alpha-diversity, and there was no interaction between them. Notably, we observed a turnover of specific bacterial taxa in the social groups, including the overabundance of pathogenic (Serratia) and mutualistic (Lactobacillus) symbionts in juveniles reared with family members. Overall, our findings indicate that while cadmium exposure does not impede social transmission of gut microbiota, both social environment and pollution influence the juvenile microbiome. More generally, they show that family life does not necessarily amplify the costs of chemical exposure on microbiota.