FIG. 1.
Rejection behavior displayed by spin mutant females. (A) Typical repelling postures taken by spinP1 female flies. The pictures were selected from continuous videotape recordings. The picture illustrating extrusion was obtained using a wild-type fertilized female, as spinP1 females do not exhibit this behavior. (B) Relative contributions of different types of repelling actions compared among wild-type, spinP1, and spinP1/spinP2 females. The wild-type females were divided into three categories, 1-day-old virgin, 4-day-old virgin, and 4-day-old fertilized females. The females of spinP1, spinP1/spinP2, and spinR4 lines were 4 days old, and the males were all wild type. The behavior of single females was recorded on a video tape for 10 min after pairing, and the numbers of females exhibiting decamping (D), fending (Fe), flicking (F1), kicking (K), curling (C), spreading (S), extrusion (E), and punching (P) actions were counted and are shown as percentages with the respect to the total number of females observed. A value of 100% means that all of the females observed exhibited that action at least once during the recorded period, while 0% means that none of the females did so. The counts obtained from at least 20 females were summed and are illustrated as frequency histograms. CS, CS strain. (C) The percentage of mating success (dark columns) was decreased in spinP1 and spinP1/spinP2 females compared to that of CS wild-type and spinR4 females. The differences in levels of mating success between the wild-type and mutant (spinP1 and spinP1/spinP2) females were found to be statistically significant at a P of <0.001 using Student's t-test. No difference was detected between the four genotypes in the females' ability to elicit male courtship songs (SAPI, paler columns). The bars on the columns represent the standard errors of the mean values for SAPI. The numbers of flies observed in order to estimate the mating success were 114 (wild type), 62 (spinP1), 44 (spinP1/spinP2), and 44 (spinR4). The number of flies observed to calculate the SAPI was 20 for each of the three genotypes. Males were from the CS wild-type strain, and all flies were aged for 3 days following eclosion. (D) Longevity of adult flies. The percentage of survival after eclosion is plotted for wild-type (CS) females spinP1 females, and spinP1 males.