Similar to how a balance between water pressure and gravity determines the height of a fountain’s stream, a balance of assembly and disassembly speed determines cilia’s length. When growing and shrinking happen simultaneously cilia length remains constant.
Cilia cellular structure similar to humans’
Pond scum’s algae make good lab models for analyzing this because they reproduce quickly, and they have cellular structure and cilia that closely parallel ours. Quarmby and Hilton have been mucking about with pond scum for years and recently started studying algae cilia with defective CNK2 and LF4 genes.
After discovering that cilia with either defective gene are abnormally long, they created an algae cell with four cilia, instead of the normal two, with two of the four engineered to glow green.
Along with two SFU undergrad students and a University of Toronto undergrad, Quarmby and Hilton watched as the fluorescent green tag began to appear at the tip of the untagged pair of cilia.
Cilia mutations unlike anything seen before
“We were able to deduce how the mutations affected the cilia’s assembly and disassembly by measuring how much and how quickly green fluorescence appeared at the tip of the untagged cilia,” explains Quarmby.
“We knew that we had something important when we saw that cells bearing mutations in both CNK2 and LF4 had the most extraordinarily long cilia. They were unlike anything anyone had ever seen before.
Further investigation will shed light on progression of diseases
“My student Laura ran this experiment and oversaw our undergrad researchers. It gave us unique insights into the potentially key role disassembling cilia have in deciding the tails’ length. Further investigation will help us understand how ciliary malfunction causes a progression of diseases.”
The SFU undergrads working with Quarmby and Hilton were Kavisha Gunawardane and Marianne Schwarz. The UofT student was Joo Wan (James) Kim.