Investigating vertebrate jaw evolution using the sea lamprey as a model
Megan Martik, Professor
Molecular and Cell Biology
Closed. This professor is continuing with Fall 2024 apprentices on this project; no new apprentices needed for Spring 2025.
The huge diversity of animal lifeforms that occupy virtually every ecological niche on our planet are all produced through the transformation of a single-celled zygote to a multicellular, fully functional organism via the processes encompassed by embryogenesis. It is through tweaks and changes to these developmental mechanisms that new morphologies and characters are acquired in evolution. A major objective of the field of evolutionary developmental biology (evo-devo) is to uncover the developmental mechanisms that underlie novel structures and anatomical features in evolution. One such character that has drawn particular interest is the vertebrate jaw: while 99% of extant vertebrate species possess jaws, ancestral vertebrates did not have jaws and occupied filter-feeding niches.
Around the same time as the jaw emerged in evolution, a new embryonic cell type called the neural crest, also emerged. The neural crest contributes to the craniofacial skeleton including the jaw and so has been proposed to have facilitated the evolution of the jaw. However, there are a few existing species of jawless vertebrates that have neural crest in their embryos but do not produce a jaw, including the sea lamprey. We are using the sea lamprey to understand what is different about the neural crest in lamprey (in comparison with jawed vertebrates) that precludes the production of a jaw or jaw-like structures.
Role: The student will be initially tasked with molecular cloning of lamprey genes to validate cell type specific gene expression in embryonic tissues on the basis of existing single-cell transcriptomics data. This will involve molecular cloning, bacterial work, and DNA sequence analysis. When genes have been successfully cloned, antisense RNA probes will be synthesized and used to probe gene expression in fixed lamprey embryos (in situ hybridization). There will also be opportunities for the student to learn histology techniques including tissue sectioning and staining. The student may also contribute to cloning of tissue-specific enhancers and assembly of enhancer reporter constructs for injection into live lamprey embryos later in the year (please note that there is a possibility for research to continue into the summer if the student is interested, as this is when live lamprey are available and breeding, but no live work with lamprey will occur during the spring semester).
Students will interact directly with their mentor, Dr. Lara Busby, for day-to-day tasks and will meet with Dr. Martik weekly to discuss research progress.
Qualifications: We are looking for a committed and focused student with an interest in cellular and developmental biology. They should have familiarity with basic molecular cloning approaches (wet lab experience not required, but helpful). The ideal candidate for this position would have genuine interest and curiosity in the questions being investigated in the laboratory, and a clear vision for how a URAP experience will contribute toward their own career goals. It is very important that they take lab research seriously and have the time to commit to the project.
MCB or IB Major – Required
Bio 1A – Required
Genetics 104 or 140 – Highly desirable but not essential
Biochemistry 102 or equivalent (e.g., C110) – Highly desirable but not essential
Developmental Biology 141 – Desirable but not essential
Day-to-day supervisor for this project: Lara Busby, Post-Doc
Hours: 12 or more hours
Related website: https://www.martiklab.org
Biological & Health Sciences