Fig. 4. Skeletal and soft tissue phenotypes due to retroviral misexpression of T. (A-D) Embryos harvested at day 9-10 were stained for cartilage. (A) Uninfected control leg with tarso-metatarsals (tm) and digits I-IV (anterior to posterior order) indicated. Digit identity was based on the number of phalangeal elements (1-4 for I-IV respectively). Skeletal phenotypes in infected legs (B-D) included partial (C) or complete (B,D) anterior digit duplications, and occasionally thickening (arrow, C) or duplication (arrow, D) of anterior tarsometatarsals. Some infected embryos at day 9-10 also showed changes in digital soft tissues in the infected (inf.) compared to contralateral control (con.) leg (panels E,F). These included digital soft tissue broadening (E,F arrowheads), ectopic cartilage condensations (D,E asterisk), and delayed loss of interdigital webbing (E, compare arrows). E, ventral side; F, dorsal side shown.