Fig. 6.

Schematic representation of the symbiont maintenance in Paraescarpia echinospica bacteriocytes. The gene names in a box indicate expansion in vestimentiferans. Grey arrows indicate pathways that could be blocked by serpin genes. The symbionts are located inside vacuoles surrounded by the bacteriocyte cytosol (pink). An overview of major processes is provided in the main text. ABC transporter, ATP-binding cassette transporter; AP3D1, adaptor-related protein complex 3 subunit delta-1; BPIP, bactericidal/permeability-increasing protein; C1q, C1q-domain-containing protein; M6P, Mannose 6-phosphate receptor; NLR, NOD-like receptor; PGRP, peptidoglycan recognition protein; TLR, Toll-like receptor.