Fig. 3. tsr PCP defects in adult epithelia. tsr⁹⁶ flies rescued by tsr¹³⁹/tsr^V27Q or P[WHTG] have PCP defects in several epithelia. (A-C) The wing (anterior is upwards and distal is rightwards). (A) Wild-type wings always have a uniform and distally pointing hair orientation; (B) tsr¹³⁹/tsr^V27Q wing hairs have a non-distal orientation; and (C) a P[WHTG] wing has hairs oriented in swirls or non-distally (not shown). (D) The eye. A thin section through a heat-shocked P[WHTG] eye shows a field of ommatidia that have randomly adopted polarities. (E) The abdomen. A P[WHTG] cuticle shows a random orientation of fine hairs. A region of hairs with wild-type orientation that points posteriorly is shaded. (F-H) The leg. A wild-type leg (F) shows normal segmentation and bristle pattern. Blue, tarsal segment 3; yellow, the correct joint position and polarity. P[WHTG] legs (G,H) have aberrant tarsal segments. Blue, the equivalent of tarsal segment 3 (from tibia); yellow, aberrant joints with duplications. At higher magnification (I), some P[WHTG] leg bristles show reversed polarity as do the `bract-socket vectors' (Held et al., 1986). Bracts (purple) are fine hair-like structures at the base of each bristle: two bracts, one above the other, have the correct polarity: growing from the proximal side of the socket and point distally (to the right). The third bract has reversed polarity, growing from the distal side of the socket and points proximally. (J) The notum. A tsr¹³⁹/tsr^V27Q cuticle shows some of the fine hairs have lost the proper posterior-pointing orientation. Occasionally multiple hairs are observed (arrow).