This family consists of egg-laying hormone (ELH) precursor and atrial gland peptides form little and California sea hare. The family also includes ovulation prohormone precursor from great pond snail. This family thus represents a conserved gastropoda ovulation and egg production prohormone. Note that many of the proteins present are further cleaved to give individual peptides. Neuropeptidergic bag cells of the marine mollusk Aplysia californica synthesize an egg-laying hormone (ELH) precursor protein which is cleaved to generate several bioactive peptides including ELH, bag cell peptides (BCP) and acidic peptide (AP).
Jiyao W et al.(2023). "The conserved domain database in 2023.",