Monthly Archives: June 2018

Growing in a changing environment

By: Jason Wang

Imagine climbing a staircase, but with every 5th step you took, you slid back down 4 steps. For many marine larvae, the process of growing seems just as inefficient and “wasteful”. Proteins are the building blocks of life – all living things must synthesize them to function. However, some animals may spend more than half of their energy building proteins while only keeping a small portion of them as growth. Whether you’re a larva growing in a dangerous and changing ocean or one being grown for food in aquaculture, this inefficient growth is a concern.

This summer will be my third summer as a Wrigley Summer Fellow, and I plan to continue researching the physiological processes that drive growth rates in marine larvae. As a PhD student in the Manahan lab at USC, I have a unique opportunity this summer to work with genetic lines of Pacific oysters that we created two summers ago. Pacific oysters are one of the most aquacultured animals in the world, and can be farmed more sustainably than other species.

The parental generation of oysters used two years ago to create dozens of G0 (generation zero) families. The G0 families have since grown to adulthood, and are ready this summer to create the next generation.

The parental generation of oysters used two years ago to create dozens of G0 (generation zero) families. The G0 families have since grown to adulthood, and are ready this summer to create the next generation.

However, the larval form of the oyster is quite susceptible to mortality, and the growth and recruitment of larvae to the adult stages is often a bottleneck in their production. We believe that understanding the dynamics of synthesizing and degrading proteins may be a key to understanding what drives growth and success in early larval stages.

Two day old oyster larvae next to a human hair for scale. These larvae have already built their first shell and are just beginning their month-long journey of growing and finding a place to settle down. The faster they can get there, the better their chances may be.

Two day old oyster larvae next to a human hair for scale. These larvae have already built their first shell and are just beginning their month-long journey of growing and finding a place to settle down. The faster they can get there, the better their chances may be.

Why wouldn’t a larva just keep all of the proteins that it synthesizes and thus grow with perfect efficiency? The answer to this question is perhaps a bit philosophical. Life is constantly changing and eliciting a proper response from our bodies. When it’s hot outside, we sweat. When we run long distances, we breathe faster. Behind all of these reactions are a chain of biochemical reactions taking place using proteins. The ability to break down, repackage, and repurpose proteins is fundamental to living in a dynamic environment. It’s not surprising then that our cells spend so much time and energy building and tearing down proteins. Now add to this cost of maintenance an additional need to grow, and we begin to see why growth might be inefficient.

Growing separate families of oyster larvae to examine the genetic basis for differences in growth rates and protein metabolism.

Growing separate families of oyster larvae to examine the genetic basis for differences in growth rates and protein metabolism.

Having begun the process of breeding genetically distinct families of oysters two years ago, we are now positioned to examine the genetically determined processes that regulate protein metabolism and growth rate, and to examine how these processes interact with changes in the environment. Using a suit of integrative methods, this summer I hope to “balance the budget” of protein intake, synthesis, turnover, and excretion to see whether certain families of oysters are able to grow more efficiently than others.

Beginning the Summer REU Program

By: Madeleine King (REU student, Bowdoin College)

Greetings from the Wrigley Institute’s NSF Research Experiences for Undergraduates (REU) program! We are just now wrapping up the end of the first week of the REU program in LA and getting ready to leave early tomorrow morning for Catalina Island. The week has gone by quickly as we have all worked to get to know one another, connect with our mentors and grad students, and begin our projects for the summer. Each day has been split between time working on our projects and time spent exploring the city. Since USC’s campus is directly across the street from both the Los Angeles Natural History Museum and the Science Center, we spent many hours exploring both of them. Additionally, of course, we have also been taking advantage of LA’s food scene by having at least daily dinners all together. It’s been great getting to know everyone and learning about everyone’s different passions in the science realm and beyond.

REU students at the Hollywood sign, and walking to the CA Science Center

REU students at the Hollywood sign, and walking to the CA Science Center

It has also been very exciting to learn about our projects for summer. This summer I will be working with Dr. Will Berelson, his lab tech, Nick, and his grad student, Abby, to carry out two different projects. The first project is to look at how atmospheric pCO2 fluctuates over time on Catalina Island and to determine what factors control the different fluctuations we observe. The data I collect will then be paired with data compiled here at USC’s main campus about pCO2 fluctuations in LA in the hopes of determining how the two influence each other and why they differ.

My other project is to look at the distribution and activity of carbonic anhydrase in the ocean. Carbonic anhydrase (CA) is an enzyme present in all living beings that speeds up the reaction that turns CO2 to HCO3- (bicarbonate) and vice versa. This is incredibly important in biology as it turns the HCO3- in our blood into CO2 so we can exhale it. However, it is also important for climate science as CA can increase the rate of calcium carbonate dissolution in the ocean, allowing for greater sequestration of CO2. As CO2 levels continue to rise in our atmosphere, it is essential to find more sinks for it. If we can identify places in the ocean with high CA, they can serve as indicators of environments where a lot of CO2 sequestration is happening. Studies on this subject have been limited, so it’s very exciting to be able to learn more about this process.

REU student, Sam, in lab with her mentor, Lynn Dodd.

REU student, Sam, in lab with her mentor, Lynn Dodd.

We’re all excited to head out to Catalina tomorrow and to continue working on our projects! I feel very lucky to be able to work on these projects with amazing people in a very beautiful place. We all can’t wait to continue our research, as well as hike and swim Catalina Island soon.

Stay tuned for more blogs from the REU students this summer!