Figure 1.

Types of allorecognition entities in young colonies of Stylophora pistillata. (a) Single genotype (SG, age two months). (b) Bi-chimera (BC, age two months). (c) Bi-rejecting genotype (BR, age two weeks). Colony no. 2 has begun to overgrow colony no. 1. (d) Tri-chimera (TC, age 1.5 months). (e) Entity with three rejecting genotypes numbered 1, 2 and 3 (TR, age one month). Clear borderlines demarcate each genotype. (f) Aggregated colony composed of seven genotypes (MP = multi-partner entity, age four months). A necrosis developed between the left genotype and its two contacting confreres (out of the six fused partners), resulting in tissue separation. Asterisks indicate rejecting areas. Thick dotted lines depict presumed borders between genotypes. Thin dotted lines indicate no clear border between genotypes. Arrows point to the sites of founder polyps in each genotype. Scale bars = 1 mm.