DOI: 10.5061/dryad.bnzs7h49s
title: A reversal in sensory processing accompanies ongoing ecological divergence and speciation in Rhagoletis pomonella

description: Changes in behavior often drive rapid adaptive evolution and speciation.
 However, the mechanistic basis for behavioral shifts is largely unknown.
 The tephritid fruit fly Rhagoletis pomonella is an example of ecological
 specialization and speciation in action via a recent host plant shift from
 hawthorn to apple. These flies primarily utilize specific odors to locate
 fruit, and because they mate only on or near host fruit, changes in odor
 preference for apples versus hawthorns translate directly to prezygotic
 reproductive isolation, initiating speciation. Using a variety of
 techniques, we found a reversal between apple and hawthorn flies in the
 sensory processing of key odors associated with host fruit preference at
 the first olfactory synapse, linking changes in the antennal lobe of the
 brain with ongoing ecological divergence. Indeed, changes to specific
 neural pathways of any sensory modality may be a broad mechanism for
 changes in animal behavior, catalyzing the genesis of new biodiversity.
description: Uploaded as part of this dataset are raw files collected in
 pursuit of results part b (antennal lobe input), part c (activity in the
 antennal lobe), and part d (antennal lobe output) of our manuscript. All
 three of these types of files include both apple and hawthorn race flies,
 as we were interested in how they diverged at these different levels of
 olfactory processing, and are labeled by host race and, usually, odor
 stimulus given to cause response captured in the particular
 file. The data for part b, antennal lobe input,
 consists of 19 ".oib" files, labeled with "partB",
 then numerically as "OSN_1" through "OSN_19",
 according to supplementary table s1 in the manuscript, and with whether
 they came from an "Apple" or "Hawthorn" race fly. They
 are the raw stacks of images obtained via confocal microscopy, consisting
 of one channel capturing the neuropil marker at the 647 wavelength and one
 channel capturing the neurobiotin tracer backfilling an OSN that responded
 to 3MB and BH at the 488 wavelength. Magnification was 40x, using an oil
 objective. Files can by opened in FIJI (Fiji: an open-source platform for
 biological-image analysis. <i>Nat. Methods</i>
 <b>9</b>, 676–82). These files are raw files, before all
 processing. To replicate the results shown in the manuscript in Figure 3
 and Supplementary Figure S2, one should consult the methods and
 supplementary methods of the manuscript, or the uploaded ReadMe
 file. The data for part c, activity in the antennal
 lobe, consists of 26 ".tif" files, labeled "partC",
 then the numeric file name, followed by "Apple" or
 "Hawthorn" and then further followed by the odor stimulus during
 that particular trace "BH" or "3MB". Focused on the
 antennal lobe after it had been incubated with Calcium Green AM-ester,
 these traces show 10 seconds, recorded at 4 Hz on a CCD camera with a 20x
 water-immersion objective, wherein the given odor stimulus (BH or 3MB) was
 introduced at the 2 second time point. A peak of activity shown by the
 calcium-sensitive fluorescent dye can be seen for each of these traces
 within 2.5 seconds after the 2 second introduction of odor. Again, these
 are raw data files. To replicate results, corrections for movement and
 bleaching were undertaken, again using FIJI, as well as multi-step manual
 landmark registration, to produce Figure 4 and Supplementary Figures S3
 and S4. For details on processing and analysis, one should consult the
 methods and supplementary methods of the manuscript or the uploaded ReadMe
 file. The data for part d, antennal lobe output,
 consists of 10 ".oib" or ".oir" files, labeled with
 "partD", then the numerical file name, followed by
 "Apple" or "Hawthorn", then further described by the
 odor stimulus that the filled antennal lobe neuron responded to,
 "BH", or "3MB" and the glomerulus/i filled in that
 case, either "DM1", "VP1", or "VP2" or some
 combination thereof. This data for all 10 of these images is summarized by
 Supplementary Figures S5 and S6, with detailed analyses shown in Figure 5.
 Uploaded here are the raw data files, taken via confocal microscopy,
 showing one channel capturing the neuropil marker at the 647 wavelength
 and one channel capturing the neurobiotin tracer filling the ALN at the
 488 wavelength. Magnification was 40x, using an oil objective. For details
 on the processing and analysis of these raw files, one should consult the
 methods and supplementary methods in the manuscript or the uploaded ReadMe
 file.
description: Uploaded with these files is a master ReadMe file
 (ReadMe_Tait_2021) that describes all three main experimental parts
 included in this publication: part b, c, and d. This file includes all
 methods from the manuscript, pulled from both the main paper and the
 supplementary methods, which were used to collect and analyze the data, as
 well as a listing of each associated file name.