Unfortunately, the amount of data is a bit too low to draw conclusion, but if one look at the data for each fly:

Only one fly not learning and the median would be 0. It looks very similar in the d42xPKCi cross, suggesting that the flies will also show the phenotype.

This will need to be confirmed next year with a new cross.
Other data visible at https://figshare.com/preview/_preview/104549
and later at doi: 10.6084/m9.figshare.104549

Here is the data for first two crosses:

No changes from the first 4-6 tests. The most striking is the absence of learning for the control. It does not make sense. I also controlled that the genotypes were not inverted by looking at GFP fluorescence which is much weaker in the test line (due to the tubGal80ts presence) than in the control line. Could it be an effect of GFP presence in some neurons? The CS strain should be unguilty, since the CSx c380 had no phenotype in the previous cross…
A third cross is coming, with the elavGal4 control, maybe it is only bad luck… But the results were so reproductible so far, and so solid… it is strange. I got the parental lines out of the stock to get fresh flies for the next cross.
I should also cross new flies now. I am planning these groups (male-female):
UGFP;;d42gal4,chaGal80 x tubGal80ts,U-PKCi
CS x tubGal80ts,U-PKCi
UGFP;;d42gal4,chaGal80 x CS
UGFP,c380;;,chaGal80 x tubGal80ts,U-PKCi

I got mutant from Amita and will test them when out of quarantine. Then, we will have a clear answer about the compensatory mechanisms (the former mutant I tested was probably not null). There is also 2 other RNAi lines for PKC53e from the TriP project.

I am waiting for chrisi to be back and we will see what flies we need to order to bloomington in addition to these two. (There is also another RNAi against FoxP…)
The outcross of the RNAi is also running (3d cross, now).
We will then have 3 RNAi and one mutant, if the results are consistent, this would be enough to convince people that PKC53e is the PKC involved.