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 [2]. Neuropeptidergic bag cells of the marine mollusk Aplysia californica synthesise 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) [1].

1: Egg-laying hormone peptides in the aplysiidae family. Li L, Garden RW, Floyd PD, Moroz TP, Gleeson JM, Sweedler JV, Pasa-Tolic L, Smith RD; J Exp Biol 1999;202:2961-2973. PMID:10518477

2: Proteolytic processing of the Aplysia egg-laying hormone prohormone. Garden RW, Shippy SA, Li L, Moroz TP, Sweedler JV; Proc Natl Acad Sci U S A 1998;95:3972-3977. PMID:9520477