Skip to Content

Postbac Seminar Series: April 20, 2021

Series: Science Skills; Speaking

Apr 20, 2021 12:30 pm - 1:30 pm

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: Ryan Stanton (NCI)

Title: RNA editors for functional microRNA target mapping

Summary: MicroRNAs regulate >60 percent of protein coding genes as components of the RNA Induced Silencing Complexes with Argonaut proteins. The mechanism by which microRNAs regulate mRNA has not been defined fully. Therefore, the target repertoires of each microRNA, and the regulatory networks of which they are a part, are not resolved. Bioinformatic and biochemical approaches for target mapping have supported some target identification. However, these methods produce large numbers of false positive results, and previous work demonstrated non-canonical targets are missed often in these approaches. We hypothesized a RNA editing enzyme associated to a target-bound RISC would metabolically alter the target, leading to target identification. Therefore, we generated fusion proteins with an Argonaut binding domain and an m6A editing domain. We aim to delineate the target repertoires of individual microRNAs using these editors and direct sequencing.

Bio: Ryan graduated from Swarthmore College in May 2020, earning a B.A. in Biology with a minor in Chemistry and Biochemistry. His thesis evaluated how different physiological states, and the higher nitrogen requirements associated with them, are correlated with differences in the gut microbiota of two hummingbird species. He joined Dr. Shuo Gu’s research group within the NCI’s RNA Biology Laboratory in August 2020. Since arriving, he has explored nucleic acid metabolism through the group’s studies in microRNA biogenesis, stability, and turnover.


Name: Una Karanovic (NIAID)

Title: Investigating the lytic exit phenotype in Chlamydia trachomatis infections.

Summary: Chlamydia trachomatis is an obligate intracellular pathogen that infects the human female genital tract. Serious complications of infection include ectopic pregnancy and infertility. Chlamydial species have a conserved plasmid that we know is required for persistence and encodes many important virulence factors. While surveying plasmid-regulated genes, we discovered a phospholipase D homolog that is highly regulated by the plasmid. Based on preliminary research, we know that lytic exit of chlamydial organisms from the host cell is a plasmid-dependent process. And, since phospholipases can function to break down lipid membranes we suppose that our target gene, CT084, may be responsible for the lytic exit phenotype. To confirm this function, we will create a knock-out mutant of CT084, then compare infection and lysis phenotypes to wild-type C. Trachomatis in vitro.

Bio: Una earned her B.S. in Microbiology in 2019 from the University of Nevada, Las Vegas. Her undergrad research, in conservation ecology, included an animal immunization trial against a deadly amphibian fungal pathogen. She joined the NIAID Chlamydial Diseases Section during the summer of 2020. Under the mentorship of Dr. Harlan Caldwell, she is creating genetic knock-out mutants to elucidate phenotypes of potential virulence genes in Chlamydia trachomatis.


Name: Lauren Thomas (NIMH)

Research Title: The Impact of Social Guidelines Under COVID-19 on Attentional Biases to Threat

Research Summary: Examining how COVID-19’s consequential social guidelines and distancing have impacted both healthy and anxious individuals’ attentional biases to threat, measured by a dot probe paradigm. 

Bio: Lauren graduated from University of Miami in 2020, with a B.A. in Psychology. She is now a postbac IRTA in the Section on Neurobiology of Fear and Anxiety under the supervision of Dr. Grillon and Dr. Ernst.



To request sign language interpreters or CART Services, you can contact NIH Interpreting Services by phone at 301-402-8180 or by using the Federal Relay Service at 1-800-877-8339, or by submitting a request online. If you have other, disability-related accommodation requests for this event, please contact Dr. Laura Marler at Requests should be made at least 5 days in advance of the Event.