Skip to Content

Postbac Seminar Series: February 23, 2021

Series: Science Skills; Speaking

Feb 23, 2021

This event is recommended for: Postbacs.

Science isn't complete until the results have been shared with others, and talking about your results is one of the important ways of making them public. The Postbac Seminar Series provides a unique opportunity for two Postbacs each month to present their research to a diverse audience of their peers.  The atmosphere is relatively informal and non-threatening.  The series allows Postbacs who attend to learn about the different types of biomedical research being conducted at the NIH while meeting other postbacs.  Read more about the seminar series.


The meeting information will be shared by email. If you have questions, please contact Ryan Bertoli <> and Madaleine Niznikiewicz <>.


This month's presenters are:

Name: Maryam Yamadi (NCI)

Title: Ga13 signaling in germinal center B cells suppresses lymphomagenesis in the mesenteric lymph node.

Summary: To generate high affinity antibodies, germinal center B-cells execute signaling pathways to maintain the necessary proliferation, apoptosis, random mutation, and migration. All of these components are also classical hallmarks of cancer cells, making the signaling pathways of the germinal center likely targets in the development of B-cell lymphoma. It has been shown that Ga13 signaling in germinal center B-cells is required for suppressing their outgrowth in the mesenteric lymph node. Disruption of this pathway results in the loss of germinal center confinement and proliferation leading to large tumors almost exclusively of the mesenteric lymph node. My project aims to further characterize aspects of the tumor microenvironment that may be promoting the outgrowth of germinal center B-cells in the mesenteric lymph node and by what mechanism is Ga13 able to suppress it.

Bio: I did my BS in Biochemistry and MS in Biology from American University where I studied protein complexes maintaining proper organ development in the model organism Arabidopsis thaliana. After studying development, I became interested in immunology and the instructions required for the development of tumors. I then came to do a postbac in NCI before applying to PhD programs. My hobbies include playing piano, drawing, and exploring DC.


Name: Daniel Brock (NEI)

Title: A Multi-Omics Study of how Dietary Choices Modulate the Epigenome of Aging Mouse Retinas

Summary: Photoreceptors are postmitotic cells responsible for light detection.  Aging photoreceptors accumulate damage, resulting in gradual vision impairment and increased disease disk.  Prior work revealed aging-related epigenomic alterations in retinal photoreceptors targeting energy metabolism genes, resulting in altered mitochondrial function including a small but significant shift towards using fatty acids as fuel.  Nutrients and metabolites are being increasingly realized to influence the cellular epigenome, which led us to hypothesize that dietary habits can potentially impact the health of the aging retina.  We formulated experimental mouse diets for use in an aging cohort of mice to investigate the impact of dietary supplements and nutrient composition on the retinal epigenome.  Experimental diets include the Mediterranean diet (rich in antioxidants and polyunsaturated fatty acids) and a high-fat hyperglycemic diet.  Our study aims to elucidate the potential of diet as a non-pharmaceutical alternative to promote health of the aging retina.

Bio: Daniel graduated from the University of Washington with a B.S. in biochemistry where he studied mitochondrial biogenesis in response to circadian rhythm in photoreceptors.  He joined Dr. Anand Swaroop’s lab at the NEI and is currently investigating the interactions between diet, metabolism, and epigenetics.  Daniel aspires to become a physician scientist.


Name: Ethan Baratz (NIDDK)

Research Title: The iron chaperone PCBP1 protects the liver from lipid peroxidation and steatosis

Research Summary: Iron is essential yet also highly chemically reactive and toxic. The

mechanisms that allow cells to use iron safely are not clear, and defects in iron management are a causative factor in the cell‚Äźdeath pathway known as ferroptosis. Poly rC binding protein 1 (PCBP1) is a cytosolic iron chaperone that binds and transfers iron to recipient proteins in mammalian cells. Although PCBP1 distributes iron in cells, its role in managing iron in

mammalian tissues remains open for study, especially in the liver, which is the primary storage organ for iron. Our project evaluated mice lacking PCBP1 in hepatocytes, and the mechanism of how mismanaged, labile iron caused them to develop fatty liver disease. 

Bio: I graduated from Vassar College in 2017 with a B.A. in Neuroscience and Behavior. While an undergrad, I used a computational approach to study statistical learning in human participants. After graduating, I joined the Genetics and Metabolism section of the NIDDK Liver Disease Branch, where we primarily study the cellular biology and systemic physiology of iron-related diseases. I also conduct research as a Special Volunteer for the NCI Pediatric Oncology Branch, where I study the pharmacokinetics of chemotherapies in patients and non-human primates.