Variation in transciptomic patterns between shallow and mesophotic corals was assessed using tag-based RNA-Seq (Tag-Seq) through analysis of natural populations across four regions in the Gulf of Mexico. Additionally, colonies were fate-tracked and repeatedly sampled to assess changes in gene expression through time in a transplant experiment between shallow and mesophotic depth zones at West and East Flower Garden Banks. This repository contains the raw .fastq.gz files for all sequenced samples. Overall design: Examination of gene expression between shallow and mesophotic depths across four sites for natural populations. Examination of gene expression through time between depth tratements for manipulative experiment. Please note that the isogroup notations (in the processed data files, e.g. Mcavernosa00001, Cladocopium100036 etc.) correspond to uniprot database annotations for the coral host (Montastraea cavernosa) and the dominant algal symbiont (Cladocopium sp.). Mcavernosa_Cladocopium_iso2geneName.tab is the corresponding isogroup-to-gene lookup table used for downstream analyses