FIG 2.

Changes in the relative frequencies of FBNSV segments occur at early stages within aphids. (A) Aphids of the species A. pisum were fed together on a single source plant. Seven groups of five aphids each were removed after AAPs of 6 h (red box plots), 10 h (yellow box plots), 25 h (green box plots), 49 h (blue box plots), and 74 h (purple box plots) and analyzed for their viral contents. The standardized relative frequency of each segment shown here corresponds to the relative frequency of a segment within aphids relative to that within the source plant. The red dashed line represents the “zero line,” where the relative frequencies of a segment are equal in aphids and in the source plant. Deviations in the frequencies of segments in aphids from those in the source plant are evident from the first time point (red box plots), and the apparent additional changes for some of the segments at later time points were statistically analyzed and are described in detail in the text. For each box plot, the bottom and top of the box are the first and third quartiles, the horizontal line within the box plots represents the median value of the distribution, and the whiskers delineate 1.5 times the distance between the first and third quartiles of the distribution. (C) The absolute copy number of each segment in the same aphid pool samples as in panel A, for which the statistical testing of the effect of time on virus accumulation is described in the text. (B) Dissected guts (pink box plots) and heads (blue box plots) of 22 groups of 5 aphids each of the species A. pisum were analyzed for their viral content after a 3-day AAP on an infected plant and a 3-day IAP on a healthy plant. The relative segment frequencies shown here are not standardized and simply compare the FBNSV genome formulas in aphid guts and heads, regardless of that in the source plant. No statistical differences could be detected between the two aphid compartments, and the detailed results of the tests are described in the text. (D) Absolute copy number of each segment in the same head and gut pool samples as in panel B.