"The fact that we can override an existing force pattern is important, because the set of instructions or steps that an embryo follows during development is very robust, and to perturb them, we usually need methods like genetic mutations or drug injections," Herrera-Perez said. "Achieving such perturbations using optogenetics and light opens up a pathway to flexibly target cellular forces at the precise location and time point we want during development."

Specifically, the researchers studied the process of axis elongation in the fruit fly, where a tissue narrows in one direction and extends along the other direction to rapidly elongate the head-to-tail axis of the embryo. "A similar process occurs in humans as well," Herrera-Perez said. "We showed that modifying the mechanical forces in the tissue affects the way cells behave, for example, how they change shape and how they pack themselves into the tissue. This is helping us to understand how the tissue changes shape and elongates so rapidly and efficiently during normal development."

"The next step is to use these optogenetic tools both to explore how mechanical forces help regulate tissue development in the embryo and to control the mechanics and shape of tissues cultured in the laboratory for a wide range of applications in engineering, biology, and medicine," Kasza said.

Columbia Engineering

Columbia Engineering, based in New York City, is one of the top engineering schools in the U.S. and one of the oldest in the nation. Also known as The Fu Foundation School of Engineering and Applied Science, the School expands knowledge and advances technology through the pioneering research of its more than 220 faculty, while educating undergraduate and graduate students in a collaborative environment to become leaders informed by a firm foundation in engineering. The School’s faculty are at the center of the University’s cross-disciplinary research, contributing to the Data Science Institute, Earth Institute, Zuckerman Mind Brain Behavior Institute, Precision Medicine Initiative, and the Columbia Nano Initiative. Guided by its strategic vision, “Columbia Engineering for Humanity,” the School aims to translate ideas into innovations that foster a sustainable, healthy, secure, connected, and creative humanity.

ABOUT THE STUDY

The study is titled "Using optogenetics to link myosin patterns to contractile cell behaviors during convergent extension."

The study appeared in Biophysical Journal on July 20, 2021.

Authors are: R. Marisol Herrera-Perez, Christian Cupo, Cole Allan, Annie Lin, and Karen E. Kasza.

Department of Mechanical Engineering, Columbia Engineering

This work was supported by NSF Civil, Mechanical, and Manufacturing Innovation Grant 1751841. Karen E. Kasza holds a Career Award at the Scientific Interface from the Burroughs Wellcome Fund, a Clare Boothe Luce Professorship, and a Packard Fellowship.

ISS Liftoff: Introducing our NASA Student Payload Experiment

T-minus seven days and counting: In just under a week, Columbia Space Initiative (CSI) will board the International Space Station (ISS). Sort of.

A CSI team of 20 Columbia undergraduates will fly an experiment they designed on SpaceX’s resupply mission to the ISS. Lift off will take place before dawn on Dec. 21 from NASA’s Kennedy Space Center in Florida and be livestreamed on its website.

Dubbed SPOCS, which stands for Student Payload Opportunity with Citizen Science, the experiment is led by Kalpana (Kal) Ganeshan ’22SEAS and Swati Ravi ’22CC, seniors studying operations research and astrophysics, respectively. CSI was invited to participate as part of a NASA competition honoring twenty years of the ISS. Five student teams, including Columbia’s, received funding to build experiments, fly it up to ISS, and share their project with local K-12 schools.

Each of the experiments will focus on bacteria resistance or sustainability research. The Columbia team is working with two of five NASA-designated “medically important microorganisms”: Pseudomonas aeruginosa and Staphylococcus aureus, bugs commonly found together that are a common cause of chronic wound infections and that are themselves resistant to certain drugs. The team hopes to record how biofilm forms on the bacteria in a low gravity experiment. After thirty days in orbit, the bacteria will return to Columbia to have their DNA analyzed and see whether they respond to antibiotics and antibiotic testing.

ISS Liftoff: How Bacteria Impacts Space Travel

The students hope that studying how different microorganisms interact in space and become antibiotic resistant will help improve antibiotic treatments for astronauts of NASA’s Artemis program, to land the first woman on the moon by 2024. 

“We hope to contribute significantly to the impact of microgravity environments on bacterial genomes, given that there are fewer than five comparable pre-existing datasets for any and all bacteria,” said Theo Nelson ’24CC, a team member who serves as both outreach lead and protocol biologist. “We will be able to hypothesize the new rules of the road for these bacteria in space.” 

Their payload operates and conducts the experiment autonomously. The experiment is able to run without human intervention via a microcontroller connected to custom printed circuit boards. “Currently, most ISS experiments require an astronaut’s time, which is a very limited resource,” says Ganeshan. “Our project is a great opportunity to explore autonomous experimentation.” 

Another challenge involved designing a device to inject a preservative into petri dishes to protect samples from contamination. The team created a system optimized for low gravity while remaining fully sterile and sealed against any contamination, according to Alfonso Ussia ’22SEAS, who serves as the team’s mechanical co-lead. “It’s been especially exciting to put our classroom skills to practice in a project that’s allowed us to work with NASA to answer pressing questions in space exploration that will help astronauts on future long-term spaceflight,” says Ravi. 

The group is advised by Michael Massimino, a former NASA astronaut and current professor of practice in mechanical engineering, as well as Lars Dietrich, an associate professor of biological sciences. Founded in 2015, CSI is a student space technology and outreach club housed within Columbia Engineering’s Department of Mechanical Engineering. It serves as an umbrella organization for mission teams involved in everything from nanosatellite mechanical design to hosting space policy forums. 

Follow CSI as they take over the Columbia Engineering Instagram account on Thursday, December 16.