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I’m crazy about plants and sustainability. In my home country of Portugal, I started “food gardens” with a friend on campus as an educational program for my peers. This provided me with an outlet for the math and physics-oriented studies I was undertaking. I wanted to be an aerospace engineer. Until I started thinking about what type of career I could have and I decided I wanted more creativity.

Worms are (relatively) simple

So, I switched to biology and here, I’ve found plenty of opportunity to be innovative – in worms. Not the ones from my garden (although plentiful), I mean Caenorhabditis elegans, more commonly known as C. elegans. These microscopic (1 mm in length) organisms are transparent; you can actually see individual cells and what’s happening to them. They’re easy and cheap to maintain, have lots of epithelial tissue and are adults within three to four days. It was also the first multicellular organisms to be fully sequenced and has a very reliable, annotated genome, making genetics easy to do.

CRISPR/Cas9 is (relatively) simple

CRISPR/Cas9 is another scientific staple in our lab. In fact, one of the first scientific publications using CRISPR/Cas9 on C. elegans comes from our lab. Therefore, we’re combining our solid foundation of knowledge of C. elegans together with the amazing technology of CRISPR/Cas9 in order to elucidate the diverse role of ERM proteins, which are critical for cell structure.

One of the first scientific publications using CRISPR/Cas9 on C. elegans comes from our lab

How cells change shape is complex

ERM (Ezrin, Radixin, Moesin) proteins are highly conserved. Interestingly, unicellular organisms do not contain ERMs, so their appearance coincides with the evolution of multicellular organisms and connections between cells. Multiple cells also mean that different cells have different shapes and functions. We’re looking at differences in cell shape, which enables specialized regions to be created within a cell. More specifically, we’re trying to understand how different (epithelial) cell types make specialized regions with basically the same building blocks of polarity and ERMs. 

These regions are important for a variety of functions, including cell shape, cell movement, cell binding and mediating molecular signaling from extracellular input. Dysfunction of ERMs may contribute to loss of cell shape, which is common in tumor cells, defects in immune cell activation and permissibility of invasive viruses. However, we know almost nothing about how these specialized regions work.

Cell polarity is highly dependent on tissue type, and we’re interested in phosphorylation, a chemical reaction which usually activates certain proteins or attaches proteins together to make them functional.  Altering the phosphorylation site on ERMs may have different effects in different tissues.

A simple organism + a basic technology may elucidate the unknown

Using CRISPR/Cas9, we’re making single mutations in phosphorylation regulatory sites in ERM genes that contain a fluorescent tag. Under a fluorescent microscope (and with other advanced imaging techniques) we can observe, in real time, what ERMs are doing, how they contribute to cell polarity and how to target and overcome defects in these proteins. 

João Ramalho, PhD candidate
Group: Mike Boxem, PhD
Faculty of Science,
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