How can poo save the wētā?
South Auckland students are learning how to help endangered wētā by looking at plant DNA taken from the insects’ poo.
Poo is gross. But a bunch of 10- and 11-year olds at Dawson Primary School in Otara are using it to help protect wētā from extinction.
The wētā family includes one of New Zealand's largest creepy-crawlies but many are threatened or endangered. The schoolkids are helping to tackle this problem by finding out which plants wētā love eating, so they can make sure there is enough food for the bugs to survive.
The kids are looking at the poo in a very unusual way, though. They are analysing the genetic material from the digested plants.
Uncovering new ground
Stéphane Boyer, a scientist at Unitec who is leading the project, says that he has tried to grow the seeds found in the poo to see what plants would emerge but growing seeds takes a long time and it only works when weta have eaten fruits, not when they eat leaves.
Instead, he and the students are taking out the plant DNA in the poo and searching for patterns or ‘barcodes’ that show exactly which plants the wētā have eaten.
The exciting part is that no-one has any inkling as to what they might find - not even Stéphane.
“I expect there might be some berry plants, but really I’m in the dark just as much as the kids are. We just don’t know. We could have all sorts of different things in there,” Stéphane tells us.
Doing grown-up science
So far, the kids have learnt how to do what is known as ‘DNA extraction’ – a tricky technique normally only done by adult geneticists all over the world.
This involved using chemicals to break down the poo and then spinning the mix at high speed in a centrifuge.
This is so that the DNA gets separated from the rest of the poo – similar to how a washing machine uses spinning force to remove most of the water at the end of the laundry cycle.
The kids then kept adding different chemicals and using the centrifuge several times until only the DNA was left.
In the next step, the DNA is copied many times so that it becomes easier to see. This 'DNA amplification' process takes a long time, so to speed things up Stéphane pulled out an earlier batch of DNA extracted from wētā poo that he had already copied.
The kids then 'labeled' the copied DNA with a dye that glows under ultraviolet light. They injected this into one end of a tray of clear gel with an electrical current running through it, which separated the DNA further into bands that glowed purple.
Stéphane showed the students which bands were plant DNA and which were DNA from the wētā or other things it might have eaten.
Dawson Primary School student Skylar told us, “I liked using the pipettes and spinning thing, getting the DNA out of the poo and putting the labcoats on.”
From DNA to conservation
At the end of November, Stéphane is hoping to hold a video conference with the students and show them from his lab how to do DNA sequencing.
He says he will take the DNA the students got from their workshop and they will all find out together if the 'barcode' of their DNA matches the DNA code found in specific New Zealand plants.
Every time there is a match, they will know that the wētā have eaten that plant.
From their findings, the students will know which plants are favourites for wētā and they will use this information to create wētā-friendly gardens in their schools.
“My favourite part was working with Stéphane and using teamwork,” said Leon, another student at Dawson Primary. “It was cool doing the experimenting too.”
“We were quite nervous because we haven’t done it before, but we did it and I really liked it. I’m excited about the next part now!”
Read the students' blog for some great accounts in their own words!
Follow Dawson Primary on Twitter
About the project
The project, which also involves students from Rongomai and Bairds Mainfreight primary schools, is being supported by funding from the South Auckland Participatory Science Platform.
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