Hybrids between the red abalone (Haliotis rufescens; RR) and green abalone (H. fulgens; GG) were produced at the Abalone Laboratory of CICESE with the goa l to increase survival and thermal tolerance under culture conditions. Therefore, this study aims at investigating the genetic contribution of each pure species to the transcriptome of the hybrid.
Both parental (RR and GG) and the hybrid abalone (RG) were cultivated under identical conditions for 4 months . At the end of the experiment, whole-fresh tissue of three individuals per replicate were preserved in RNAlater®. Total RNA was isolated with Trizol (Thermo Fisher) . After quality checking, three libraries per abalone cross were produced by pooling RNA from 3 – 4 individuals. Samples were sequenced in an Illumina NovaSeq 6000 (2 x 100 bp). The reference transcriptome was generated following the genome-guided protocol from Trinity v. 2.4.0 using the H. rufescens genome. Transcript abundance was calculated with Salmon v 1.4.0 and differential expression analysis was made with DeSeq2. Transcripts with an FDR corrected P values < 0.05 and log2FC > |1| were considered significantly expressed.
A multivariate analysis with normalized counts displays a clear separation of RR from RG and GG (Fig. 1) , suggesting that the transcriptomic profile of the hybrid RG is more similar GG than to RR. This is supported by the number of differentially expressed transcripts (DET) between each contrast, were the lowest numbers of DETs is observed between RG and GG (Fig. 2). Overall, results suggest a larger genetic contribution of H. fulgens to the hybrid than the red H. rufescens .