Many of our students get real world, hands-on experience at a top medical facility. And this is as undergraduates!

Leocadia Paliulis

Regardless of what species you happen to be, your chromosomes and the DNA within them form your blueprint for life. Under normal conditions, humans have 46 chromosomes – 23 from each parent. But what happens when something goes wrong?

In genetic translocations, for example, a chromosomal segment breaks off and rejoins in an unexpected location. "In a best-case scenario, it swaps places with other material without any damage or loss of  information. In other cases, things aren't so pretty," says Leocadia Paliulis, who studies these events and others like them in her lab, which is home to plastic tubs of larvae and live spiders – including, at times, black widows.

"In moths and butterflies," explains Paliulis, "cellular abnormalities occur quite frequently. It's as if their chromosomes are designed to missegregate, especially during meiosis." Understanding these events in moths and other species can have important implications when it comes to human health, she says, with applications as varied as infertility solutions and the treatment of a wide range of cancers.

Paliulis is also looking at how chromosomes communicate where they are in a cell. During meiosis in black widow spiders, the sex chromosomes always move together, even though they're not connected. How is that possible? To find out, Paliulis has her student researchers – who work alongside her in her lab every semester and during the summer – use a micromanipulator to isolate chromosomes in spider cells. They observe how the altered cells attempt to correct themselves and at what point similar control cells seem to stop recognizing them.

Paliulis says her students routinely move on to top graduate and medical schools where they are among the best prepared. "Bucknell students really have an important advantage," she explains. "Our labs are state-of-the-art, and because of our close proximity and connections to Geisinger Health System, many of our students get real world, hands-on experience at a top medical facility. And this is as undergraduates!"

Posted October 3, 2013