Last night, I headed down to the beautiful Bell House in the Gowanus section of Brooklyn for a Secret Science Club event that featured a film clip and a discussion of fruit flies by Cold Spring Harbor Laboratories neuroscientist Dr Josh Dubnau. Dr Dubnau studies neurodegenerative disorders such as amyotrophic lateral sclerosis and temporal lobe dementia using fruit flies as a lab subject. Dr Dubnau likened Drosophila melanogaster to the genetic Swiss army knife- they have been the go-to organism used to study genetics for about a century.
Drosophila is a good lab subject because it has manipulable genes and manipulable neurons. Flybase is a database of Drosophila genetics and Flycircuit is a database of Drosophila neurons. Enhancer traps are inserted into the genome of a subject to produce genetic markers, with the GAL4 gene (obtained from yeast) being commonly inserted in Drosophila.
Dr Dubnau made a humorous comparison between Drosophila behavior and human behavior, noting that Drosophila was highly motivated to mate with opposite sex parters (and sometimes with same-sex partners, most appropriate for a Pride Day lecture), and that they enjoyed alcohol (with unsuccessfully mating flies seeking out alcohol after their amatory failure). Those little flies are enough like us genetically and behaviorally to make good models for human genetics and neurology.
Dr Dubnau then went on to discuss the role of transposons or "jumping genes". Transposons were first described by Dr Barbara McClintock, who, while researching the genetics of corn (Zea mays), discovered that there were genes which could change locations on a chromosome, and such changes in location could alter the expression of nearby genes. She was specifically describing the genes which control the pigmentation of corn kernels. McClintock originally described these "jumping genes" as "controlling elements" because she hypothesized that these movable genes regulated development. In humans, about 44% of the genome is composed of transposons.
In Drosophila, transposons have been implicated in intra-specific infertility among two strains of flies (the Harwich and Canton-S populations- Harwich males mating with Canton-S females would result in a lack of fertility)- in the Q&A session, some bastard in the audience asked Dr Dubnau about the role of transposons in speciation, and Dr Dubnau responded that they probably played a major role in the inability of populations to mate successfully, thus leading to a "separation".
Dr Dubnau then moved on to the topic of fruit fly neurology, and his specialty, the study of neurological degenerative diseases. Structures in the fruit fly brain, the mushroom bodies are connected to olfactory learning and memory. Dr Dubnau showed us a video of flies which had been subjected to a mild electric shock while being exposed to a particular fragrance. They learned to associate the fragrance with the shock, so continued exposure to that fragrance would cause them to behave so that they would avoid an expected shock. The flies are then put in a T-maze and subjected to different odors... here's a video featuring Dr Dubnau, explaining this experiment:
Neurological damage may result from a "storm of tansposons", with the accumulation of a protein called TDP-43 playing a role in ALS. In patients with neurodegenerative diseases, these transposons avoid the regulatory affects of piwi-interacting RNA, which "tamps down" transposons.
Besides Dr Dubnau's lecture, the 1910 short film The Acrobatic Fly was shown:
The main news of the night, though, came from Friend of the Bastard Dr Alexis Gambis, who announced that he has finished filming his first feature film, The Fly Room. He will be spending the next few months editing the film, and hopes to shop it around to the major film festivals. The Fly Room will tell the tale of pioneering geneticist Calvin Bridges through the eyes of his daughter Betsey (who, **SPOILER ALERT** makes an appearance in the film). In discussing the film shoot, Dr Gambis told me that filming took place in upstate New York during the emergence of the 17-year cicada brood so, appropriately, **SPOILER ALERT**, insects make their presence known in the film.
All told, it was a great night, and the news of Dr Gambis' first feature film has me overjoyed. I always love to see the good guys succeed and Dr Gambis (who I have known since 2006, before he was a Doktor) is one of the goodest of good guys. Here's video of a TED talk that Dr Gambis gave back in 2011, so you can get an idea of where he's coming from:
Rest assured, I'm going to make it to the theater when The Fly Room is released. GO DR GAMBIS!!!