Jilin He poses on a snowy overlook.

Name: Jilin He

Education: B.S. at Northwest A&F University in China, currently working on M.S. at CSU through a work-study grant.

Hometown: Beijing, China

Career goal: Jilin has always had a passion for animals. She plans on taking the knowledge and laboratory techniques she learns in her research at CSU into her future endeavors in the zoology field. When describing what kind of work she would like to do in the future, she says, “I really love animals. To work with animals in the future would make me very happy.”

Favorite Memory: Jilin expresses that she not only enjoys doing animal-related work, but she also likes doing experiments. She says that her favorite part of working in Dr. Mykles’ lab is she “gets to do something that is interesting,” and “also something [she] enjoys.”

Project: Identify, characterize and quantify the expression of TGF-beta signaling genes in the Y-organ over the molt cycle of the blackback land crab (Gecarcinus lateralis).

Thank Goodness For-beta proteins!

Jilin is studying a specific cell-signaling pathway that controls the growth and molting of the land crab. This growth pathway is initiated by a protein called myostatin, and Jilin is specifically interested in myostatin’s role in the molting cycle. Myostatin is a member of a family of proteins known as TGF-beta proteins; TGF stands for “transforming growth factor,” and all TGF-beta proteins regulate cell growth. There are a variety of different members of this one family, and they all preform different tasks in the cell by either positively or negatively regulating growth. Myostatin specifically is a negative regulator of growth and causes cells to either decrease in size or stop growing.

A Team Effort

The way myostatin causes negative growth is through a sequence of cellular signals that work together to elicit a response; this is known as a cell-signaling pathway. Cell signaling pathways work similarly to a team of relay runners. Each protein in the pathway is like a different runner that takes its turn racing the baton up to the next runner on the track. In the relay race, the second runner cannot start running until the first runner has passed the baton off to them. Similarly, in a cell-signaling pathway, the second protein in the sequence cannot act until the preceding protein activates it. It is in this way that the components of the cell work together in a timely manner to ensure successful cell processes.

The myostatin protein is the first runner in the race and carries the baton to the next protein in line. In the molting process, the proteins work together to send signals to the crab’s Y-organ–telling it to molt. The molt itself cannot occur without a decrease in muscle size, thus the process cannot occur without the myostatin protein that controls this. Jilin and her collaborators are aware of the fact that the protein myostatin plays a role in activating the Y-organ, they’re just “not entirely sure how it works” explains Jilin.

A Detective on the Case

Jilin investigates the role of the myostatin protein by examining the gene transcriptome, or full gene sequence, of the land crab. Having access to the animal’s genetic information gives Jilin the opportunity to analyze the genes expressed in its DNA. The investigation process in the lab is a thorough examination of the crab’s DNA using molecular techniques such as PCR and gel electrophoresis (these are common techniques used in several other research projects in the Crab Lab). These two techniques help uncover genetic clues for the researcher by replicating and highlighting specific regions of DNA. Transcriptome analysis helps the lab’s research team to gain a clearer picture of the proteins and cell pathways associated with molting.

Stepping-Stones in the Field of Science

Not only is transcriptome analysis a valuable tool in solving the mystery of molting in the land crab, but also serves as a stepping-stone in understanding other animals. Now that there is a growing availability of transcriptome data across different animal groups, comparisons of similar protein expressions in different species can be made. Comparing the role of a protein in a variety of different organisms can highlight its functional value while providing a new perspective on how it works. The Crab Lab’s transcriptome of the land crab will in the future serve as a significant comparison tool in other research and will contribute to the general knowledge base in the scientific field.