A transcriptomic analysis of gene expression patterns across phases of parental care in Nicrophorus vespilloides

Subsocial insects exhibit remarkable behavioural changes throughout their life cycle. During one part of their life cycle, these insects display solitary tendencies. However, during reproduction there is a transition to social behaviour with previously solitary individuals carrying out cooperative and parental care tasks thus boosting offspring survival. These behavioural shifts are regulated by distinct changes in molecular mechanisms. Therefore, elucidating the molecular mechanisms underlying such transitions is crucial for understanding the genetic basis of social behaviour. To this end, we performed a comprehensive transcriptome analysis by comparing the social phases during the reproductive cycle of the subsocial burying beetle N. vespilloides. This beetles reproduce on a highly nutritions but ephemeral substrate where they provide intensive pre-hatching care by preparing a vertebrate carcass and post-hatching care by larval feeding. RNA-seq data obtained from head and fat body tissues of females were analysed to elucidate changes in gene expression during the solitary phase as well as three distinct social phases: (i) early pre-hatching care, (ii) late pre-hatching care and (iii) post-hatching care. Our findings revealed that the changes in gene expression levels following the transition from the solitary to the social phase was greater than those observed following the transition between successive social phases. The majority of the differentially expressed genes are known to function in bacterial management and immune regulation, functions which are associated with the presence and preparation of the vertebrate carcass. We conclude that the key molecular mechanisms are govern to behaviours responsible for carcass management and offspring survival.