on Monday, August 7th, 2023 2:13 | by Ellie
The offspring of my first experimental fly cohort finally hatched! Below you find a few first pre-tests I ran last week :)
First, here are the results of a quick test to see if the offspring shows a preference for the parentally trained side after the first training period:
After that I played around with the laser a little bit to find the learning threshhold. I set the laser on 2,6V but the results I got look a bit weird:
-> untrained wtb flies
-> offspring of trained wtb flies
I´m optimistic however there is still a lot of work to do…
on Monday, August 7th, 2023 11:11 | by Isabel Stark
Via gDNA analysis and PCR was the specific area of the rsh gene extracted and amplified where the nucleotide substitution: C to T (Folkers et al., 2006) should be for the rsh1 mutation. The amplicon was Sanger sequenced which proved the nucleotide substitution.
on Monday, July 24th, 2023 2:22 | by Ellie
on Monday, July 24th, 2023 1:59 | by Björn Brembs
Despite very warm weather, some flies did fly, even though the learning performance of the control flies was really poor. At least for now, it looks like all stocks are learning and that rut and rsh flies learn at least equally well as the Berlin flies. I’ve also managed to fix the positive preference problem:
on Friday, July 7th, 2023 6:38 | by Isabel Stark
on Thursday, June 29th, 2023 5:25 | by Björn Brembs
Since the Canton S strain I used wasn’t a perfect genetic background strain anyway and didn’t fly properly, I kicked it out and replaced it with the wild type Berlin data I had collected just prior to the rut and rsh mutants. Now I can collect data for two projects in one go: I check the rut/rsh learning mutants if they still behave the way they should and with the wtb control strain and continue collecting data to evaluate their optomotor responses after training. So now the learning scores for the three strains look like this:
It still doesn’t look like rut is better than wtb, so I’m still skeptical that the strain is really what it should be. The rsh data also don’t look very promising, but I still need to get more flies with a negative preference before the training.
on Monday, June 26th, 2023 2:03 | by Björn Brembs
Suspicion: rut may not be rut
Carsten Duch is identifying the muscles involved in operant self-learning:
on Friday, June 16th, 2023 4:42 | by Björn Brembs
The first few rutabaga and radish mutants have been measured and so far it looks good: standard duration yaw torque learning – the situation all three groups should learn.
on Monday, June 5th, 2023 12:59 | by Ellie
Things are not going well…
Over the last week I have encountered numerous problems in carrying out the planned experiment, and the biggest of these is definitely the generation of offspring. Since it has been shown that long-term memory decays quickly in the first 24 hours after operant self-learning on the flight simulator (and with that possible epigenetic marker I suppose), I decided to mate the flies immediately after training and separate them again after 16-20 hours. However, I did not get any offspring by doing this. I tried mating virgin males/virgin females and also adult males/virgin females for 16-20 h, but no eggs could be found in the vials. I have not yet found out what prevents the flies from mating and am now trying again with older (3-4 days old) adult male flies.
Another problem is the training protocol for memory consolidation by S Xia, L Liu, C Feng et al. 1997. Although I have practiced gluing and inserting flies into the flight simulator, I don’t think I can train enough flies in one day. To maintain sufficient larval density after mating, I need at least 5 females and 2-3 males, and I would need to train them twice, giving a total of 16-18 training rounds per day (and that doesn’t include failed attempts…). Alternatively, I can use the standard protocol and see if the training is enough to reveal epigenetic inheritance of acquired habits, if any.
For now, I will continue to try to produce offspring and practice gluing and training the flies. I have started to do further research on inheritance mechanisms to see if it might also be possible to work with only the F0 generation and detect epigenetic markers (methylation of genes, e.g. foxP, siRNAs) in the trained flies and compare them with untrained flies. Here (1, 2) you can find a few interesting articles on this topic.
However there is also some good news to report: my ContonS line will be ready soon, so I don’t have to work with the wtb virgin flies anymore, which decease very quickly. I have also made some progress on the statistical background after talking to a friend of mine although I still need to do some research on how to set my effect size so I can finally calculate the sample size I need for the experiment.
on Monday, May 22nd, 2023 8:45 | by Ellie
Here is a brief overview of the topics I will be dealing with over the next few months:
This is the experiment by MD Ziv Williams I am trying to imitate ->
- Lamarckian inheritance following sensorimotor training and its neural basis in Drosophila – Williams, 2015
If you are further interested in transgenerational inheritance of behavioral traits and non synaptic memory storage check out these interesting links ->
- Can brain activity transmit transgenerationally? – Miska and Rechavi, 2021
- Is plasticity of synapses the mechanism of long-term memory storage? – Abraham, Jones and Glanzman, 2019
This week, for now, I will continue practicing to glue the flies and make a realistic estimate of the number of flies I need to get a significant result. Hopefully I can start trying out my experimental setup by the start of next week :)