A ripple effect: skipping a single exon in PTBP1 leads to changes in splicing and neural differentiation


What makes a human, human? Or a chicken, chicken?

The preeminent belief has been that the difference between species lies in their DNA—the number of genes an organism has, the function of those genes and when and where those genes are expressed. As it turns out, the answer is not quite so simple.

“There’s very high conservation of the total number of protein coding genes across different vertebrate species,” says Serge Gueroussov, a PhD student in Dr. Benjamin Blencowe’s lab at the University of Toronto. “When [researchers] compared gene expression across different organs in different species, there was also a lot of conservation. It suggests that organisms don’t differ so much in the genes they have and the extent to which they express [those genes].”

In other words, while we may look drastically different from a frog or a chicken, our repertoire of genes and when and where we express those genes are actually pretty similar. So where is the variation coming from?

The answer may lie, in part, in a process called alternative splicing. Continue reading


For fruit flies, sleep deprivation leads to less aggression and less sex

The common fruit fly - a small but mighty model organism for studying behaviour. (Credit: NASA)
The common fruit fly – a small but mighty model organism for studying behaviour. (Credit: NASA CC BY 2.0)

Sleep—it’s something that we all need but can’t seem to get enough of. Not getting enough sleep can turn the sweetest, most patient person into a short-tempered and irritable crank. When you’re tanky (tired + cranky), you might say and do things that you don’t really mean, kind of like when you’re hangry (hungry + angry). While the effects of sleep deprivation on mood and mental functioning have been well documented, less is known about how sleep loss affects aggressive behaviour.

Dr. Amita Sehgal, a professor at the Perelman School of Medicine at the University of Pennsylvania, studies behaviour and its relationship with the body’s internal clock. For her research, she uses the common fruit fly, Drosophila melanogaster, as a model to study the interactions between sleep and behaviour. In a paper published last month in eLife, Sehgal and colleagues showed that sleep deprivation in fruit flies leads to less aggression. Continue reading