Drosophila wing images from a phenotypic selection gradient experiment with lineages evolved with predators.

2018-03-01T22:16:05Z (GMT) by Michael DeNieu Ian Dworkin
These are images of wings from populations of Drosophila melanogaster experimentally evolved in the presence (or absence for controls) of juvenile Chinese mantids (Tenodera aridifolia sinensis) for 32 generations.
There are two control lineages and two selection lineages (i.e. 2 replicate populations for each of the predator treatment and the control).
Flies were reared in a common garden for two generations prior to the experiment used for the phenotypic selection gradient analysis.
These experiments were done by Dr. Michael DeNieu in the lab of Ian Dworkin at Michigan State University in 2010.
Each zipped folder contains a subset of the images. This was done to help with uploading to Figshare.


Assaying Phenotypic Selection: Evolved populations
To examine how the fitness function changed as a result of experimental evolution, we
repeated phenotypic selection (as described above) during generations 31 and 32 of the
experiment. Given the large size of this experiment, it was performed in four blocks,
with two blocks for each generation. At generation 31 of experimental evolution, we set
up 14 arenas each of PredR1 females & males and ConR1 females & males. Five days
later, we set up 14, 14, 8, and 9 arenas for PredR2 females & males and ConR2 females &
males respectively. At generation 32, we set up 14 arenas each of PredR1 females & males
and ConR1 females & males . Five days later we set up 13, 13, 14, and 14 arenas for
PredR2 females & males and ConR2 females & males respectively. As before, we collected
all surviving flies and unconsumed wings and stored them in ethanol. Overlapping egg
cases were used for this experiment, and egg case of origin was used as a covariate in the
model (see below). We distributed mantids so as not to confound predation effects across
replicates and treatments.

Wing imaging
Wings were dissected and mounted on slides in 70% glycerol. When available, both
wings from an individual were mounted. Wings were also dissected from 25 flies that
were stored from the initial generation of experimental evolution, and from every 10 generations following up to generation 30 to estimate the trajectory of size and shape
change. Wings were imaged with a total 40X magnification on an Olympus DP30BW camera
mounted on a Olympus BX51 microscope using ‘DP controller’ V3.1.1 software. All
images were saved in greyscale as tiff files.

** Note ** in preparing these images for upload to figshare I noticed a small set were saved as .jpg.

See the pre-print
https://www.biorxiv.org/content/early/2014/05/19/005322.short for more details about the experimental protocol.


Naming convention for the images. Variables are seperated by underscore

SEL/CON - selection or control treatments. This refers to the experimental evolution lineages.
M/F - Sex of individuals
R1/R2 - Replicate lineage for experimental evolution
B1/B2 - Block one or block two. These are the experimental blocks used for performing the phenotypic selection analysis.
S/D - Whether the individual survived the predation assay for phenotypic selection or died (was preyed upon by the mantid).
number - unique number for each fly (I believe)
L/R - Left or Right wing. We don't have this for most flies that were preyed upon (i.e. had a code of D).

So
CON_F_R2_B2_D_4520_L.tif

would be control lineage female replicate 2 block 2 dead left wing.

and
SEL_M_R1_B1_S_2120_R.jpg
Would be selection lineage male replicate 1 block 1 survivor right wing.