Mullins Lab

We Support Racial Equality!

We in the Mullins laboratory stand in solidarity with the Black community during this defining  time of confronting racial and social injustice. The murder of George Floyd by police is only one of many injustices experienced by Black Americans. For hundreds of years, institutional policies and individual actions have oppressed Black people. Today, we continue to see the widespread immoral and abhorrent treatment of racial and ethnic minority groups. These acts of oppression are unequivocally a result of the systemic racism in our society and cannot be ignored. We must proactively oppose these systems of oppression and take action against racism in our scientific community and beyond.

As a laboratory, we are committed to changing the environment that has led to the oppression of people of color in all sectors of our society. We will continue to educate ourselves about the challenges disproportionately affecting people of color so that we can help eliminate those barriers. We will challenge our worldview by continuing to learn about both the systemic oppression and implicit biases affecting people of color. Finally, we pledge to maintain and further cultivate a safe and supportive environment for people of color who join our laboratory.

Research Overview

We are studying the molecular mechanisms by which a BMP (Bone Morphogenetic Protein) signal transduction pathway establishes different aspects of the vertebrate body plan. Various zebrafish mutants of BMP pathway components, as well as antisense knockdown approaches are used to dissect the molecular mechanisms by which this pathway establishes different cell types. We are studying the formation, function, and temporal regulation of a BMP activity gradient, which is implicated in specification of diverse cell types along the dorsal-ventral axis. We have shown that this gradient is essential in neural crest specification and is linked to dorsal-ventral patterning of neural tissue. Moreover, a subset of our defined components also function in post-embryonic heart development. Misregulation of BMP signaling leads to a debilitating disease in humans called fibrodysplasia ossificans progressiva (FOP). We are currently trying to establish a model for FOP in the zebrafish.

Elaboration of the vertebrate body plan relies not only on zygotic processes, but also on maternally-controlled processes: that is, processes that depend on products derived from the mother that are deposited into the oocyte and are critical for proper development of the embryo. To this end, we performed a large-scale maternal-effect mutant screen, not previously performed in a vertebrate, to identify mutants of key genes specifically required in the mother for oocyte development, egg activation, fertilization, the mid-blastula transition, and establishment of the axes of the vertebrate embryo. We identified numerous mutants in these processes and are studying the molecular and cellular basis for the defects, including positional cloning of the mutated genes.

Latest News

  • Bakary Appointed to UPenn Genetics T32 Training Grant Thursday, July 14, 2022
    New graduate student Bakary Samasa has been appointed to UPenn's competitive Genetics T32 training grant! Congratulations on your new funding, Bakary!
  • Mullins Lab Members Present at International Zebrafish Conference 2022 Sunday, June 26, 2022
    Post-docs Manami and Jose and graduate student William presented at International Zebrafish Conference 2022 in Montreal, Quebec, from June 22-26, 2022! Manami and William joined Mary in Montreal to present in-person, while Jose presented virtually at the hybrid meeting. It was exciting to attend our first in-person conference in years due to the pandemic! Manami presented a 10-minute talk, William presented a 1-minute Rapid Fire talk, and William and Jose presented posters. William won a poster prize for his presentation!
  • Megan Guerin Joins the Mullins Lab! Tuesday, June 21, 2022

    The Mullins lab is excited to welcome a new graduate student, Megan Guerin! What an exciting year to get three new students in the lab! Megan joins us from the Developmental, Stem Cell, and Regenerative Biology Program and will be studying zebrafish mutants of Balbiani body components cirbpa and cirbpb. Welcome, Megan!

More News