PEOPLE

DR Priya Sivaramakrishnan, MSc., PhD.

Assistant Professor of Pathology and Laboratory Medicine
Perelman School of Medicine at the University of Pennsylvania

Contact InformationColket Translational Research Building
Room 9022 (Office), 9200 (Lab)
3501 Civic Center Blvd


Philadelphia, PA, 19104

Email: psiv@pennmedicine.upenn.edu

Research Expertise

Research Interests

We are interested in understanding how the dynamics of fundamental cellular processes are fine-tuned in developing cells; and apply single-cell imaging and sequencing approaches to uncover principles that drive cell identity establishment and how these can be dysregulated in disease states.

Keywords

Gene regulation, development, cell fate programming, transcriptomics, single-cell imaging

Research Details

In rapidly growing and dividing cells, precise spatio-temporal coordination of basic processes such as transcription and DNA replication is essential for cellular decision making. We use the C. elegans embryo as a model to capture and quantify the dynamics of these processes during developmental cell fate programming. C. elegans embryonic development is invariant, proceeding through highly reproducible division patterns, resulting in an identical set of 558 terminal cells at the time of hatching. We can track the development of each individual cell, identify lineage trajectories, and characterize detailed fate changes in mutant and perturbed individuals, allowing us to directly link molecular dysregulation with developmental defects.

Gene expression programs that control when genes are turned ON are central to cellular programing. The steps involved in these programs are complex and dynamic, occurring in a crowded nuclear space. We are working towards systematically investigating each step and examining their impact on cellular fate decisions in individual cells. Current projects include looking at how the spatial organization and the different stages of transcription contribute to overall dynamics and mRNA accumulation, studying the patterns of replication origin firing and its role in preventing replication-transcription conflicts, connecting mechanisms that buffer transcription noise to invariant fate decisions, and generating humanized C. elegans to investigate the molecular basis of transcription-associated developmental disorders.

Rotation Projects

(1) Contributions of different transcription steps to total RNA dynamics. Test the impact of initiation (using CRISPR, synthetic arrays), elongation (DRB-seq, mutants) and spatial organization (imaging) to mRNA output and developmental outcomes

(2) Can we connect noisy transcription to specific fate defects? Developing combined live RNA imaging (MS2 or RNAi-based) and lineage tracing methods (confocal imaging followed by automated lineage analysis) to investigate mechanisms that buffer transcription noise and promote high-fidelity fate decisions

(3) Coupling cell size to transcription dynamics. Test the hypothesis that cell size might control transcription rates of cell fate regulators using RNAi and degron alleles to manipulate cell size and characterize transcriptome changes by single-cell RNA sequencing and single molecule FISH.

(4) Understanding variable expressivity and penetrance using worm models of human transcription-associated developmental disorders. Mutations in gene associated with general transcription factors show a range of phenotypes, but the molecular mechanisms are not known. By generating humanized worms and knocking-in a human variant of interest, we can connect transcriptome changes with cell fate defects.


(5) Examining replication-transcription conflicts in the rapidly dividing embryo. Mapping the dynamics of replication origin firing in connection with high-rate transcription of cell fate regulators.

Education

BSc. (Zoology), Stella Maris College (University of Madras), 2006
MSc. (Human Genetics ), Sri Ramachandra University , 2008
PhD. (Molecular and Human Genetics ), Baylor College of Medicine , 2017

Specialty Certification

Postgraduate Training

Postdoctoral Research - Genetics, University of Pennsylvania, 2017-2020
Postdoctoral Research - Genetics, University of Pennsylvania, 2020-2023

Awards and Honors

Dr. Dharmarajan Award (Class First in Genetics, 2003-2006) - BSc. Zoology, Stella Maris College, 2003-2006
Dr. Shiranee Pereira Award (for 2003-2006) - BSc. Zoology, Stella Maris College, 2003-2006
Jayanth Family Gold Medal for highest marks in MSc. Human Genetics awarded (for 2006-2008) - Sri Ramachandra University, 2006-2008
John R. Kelsey Student Speaker Award (October 2012) – Graduate Student Symposium, Baylor College of Medicine, 2012
First Place Student Speaker Award (January 2014) - Department of Molecular and Human Genetics Retreat, Baylor College of Medicine, 2014
Best Teaching Assistant Award (October 2015) - Genetics A Core Course, Baylor College of Medicine, 2015
Best paper from a graduate student in 2017 - Department of Molecular and Human Genetics, Baylor College of Medicine, 2017
Society for Developmental Biology Travel Award, 2018
BPP Achievement Award for Excellence in Leadership, 2022

Memberships and Professional Organizations

American Society for Microbiology, 2012 - 2017
Society for Developmental Biology, 2018 - 2020
Genetics Society of America, 2018 - Present

Web Links


Selected Publications

Transcript accumulation rates in the early Caenorhabditis elegans embryo

Sivaramakrishnan P, Watkins C, Murray JI.  Sci Adv 9(34):eadi1270, Aug 2025. doi: 10.1126/sciadv.adi1270. Epub 2023 Aug 23. PMID: 37611097; PMCID: PMC10446496.

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The transcription fidelity factor GreA impedes DNA break repair in Escherichia coli

Sivaramakrishnan P, Sepúlveda LA, Halliday JA, Liu J, Núñez MAB, Golding I, Rosenberg SM, Herman C. Nature 550(7675):214-218, Oct 2017. doi: 10.1038/nature23907. Epub 2017 Oct 4. PMID: 28976965; PMCID: PMC5654330.

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A lineage-resolved molecular atlas of C. elegans embryogenesis at single-cell resolution

Packer JS, Zhu Q, Huynh C, Sivaramakrishnan P, Preston E, Dueck H, Stefanik D, Tan K, Trapnell C, Kim J, Waterston RH, Murray JI. Science 365(6459):eaax1971, Sep 2019. doi: 10.1126/science.aax1971. Epub 2019 Sep 5. PMID: 31488706; PMCID: PMC7428862.

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Modulation of RNA polymerase processivity affects double-strand break repair in the presence of a DNA end-binding protein

Sivaramakrishnan P, Bradley CC, Artsimovitch I, Hagstrom KM, Ramirez LD, Wen AC, Cooke MB, Shaulsky M, Herman C, Halliday JA. bioRxiv 2022.02.08.479637; doi: https://doi.org/10.1101/2022.02.08.479637

The anterior Hox gene ceh-13 and elt-1/GATA activate the posterior Hox genes nob-1 and php-1 to specify posterior lineages in the C. elegans embryo

Murray JI, Preston E, Crawford JP, Rumley JD, Amom P, Anderson BD, Sivaramakrishnan P, Patel SD, Bennett BA, Lavon TD, Hsiao E, Peng F, Zacharias AL. PLoS Genet 18(5):e1010187, May 2022. doi: 10.1371/journal.pgen.1010187. PMID: 35500030; PMCID: PMC9098060.

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Microbial Genetic Composition Tunes Host Longevity

Han B, Sivaramakrishnan P, Lin CJ, Neve IAA, He J, Tay LWR, Sowa JN, Sizovs A, Du G, Wang J, Herman C, Wang MC. Cell 169(7):1249-1262.e13, Jun 2017. doi: 10.1016/j.cell.2017.05.036. Erratum in: Cell. 2018 May 3;173(4):1058. doi: 10.1016/j.cell.2018.04.026. PMID: 28622510; PMCID: PMC5635830.

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Escherichia coli Metabolite Profiling Leads to the Development of an RNA Interference Strain for Caenorhabditis elegans

Neve IAA, Sowa JN, Lin CJ, Sivaramakrishnan P, Herman C, Ye Y, Han L, Wang MC. G3 (Bethesda). 10(1):189-198, Jan 2020. doi: 10.1534/g3.119.400741. PMID: 31712257; PMCID: PMC6945014.

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K3K9me2 orchestrates inheritance of spatial positioning of peripheral heterochromatin through mitosis

Poleshko A, Smith CL, Nguyen SC, Sivaramakrishnan P, Wong KG, Murray JI, Lakadamyali M, Joyce EF, Jain R, Epstein JA. Elife 8:e49278, Oct 2019. doi: 10.7554/eLife.49278. PMID: 31573510; PMCID: PMC6795522.

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DksA guards elongating RNA polymerase against ribosome-stalling-induced arrest

Zhang Y, Mooney RA, Grass JA, Sivaramakrishnan P, Herman C, Landick R, Wang JD. Mol Cell 53(5):766-78, Mar 2014. doi: 10.1016/j.molcel.2014.02.005. PMID: 24606919; PMCID: PMC4023959.

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R-loops and nicks initiate DNA breakage and genome instability in non-growing Escherichia coli

Wimberly H, Shee C, Thornton PC, Sivaramakrishnan P, Rosenberg SM, Hastings PJ. Nat Commun 4:2115, 2013. doi: 10.1038/ncomms3115. Erratum in: Nat Commun. 2014;5:2762. PMID: 23828459; PMCID: PMC3715873.

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