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Trematode

qBio Seminar Series: Phillip Newmark

Event Details

When: February 22, 2017, 2:00 PM

Location: 3rd Floor Orchard View Room , Discovery Building

Contact: 608-316-4401, hstampfli@wisc.edu

Phillip Newmark

Phillip Newmark

Single-cell analysis of stem cells driving the life cycle of the parasitic flatworm, Schistosoma

Schistosomes are parasitic flatworms that infect hundreds of millions of people. Passage through their complex life cycle requires two distinct hosts and several different body plans. Our recent work has shown that both adult and larval schistosomes possess stem cells similar to those of planarians, free-living flatworms with amazing regenerative abilities. To characterize schistosome stem cells in greater detail, we have performed single-cell transcriptomic analysis on these cells isolated from larval-stage (i.e., intra-molluscan) schistosomes. We have identified three classes of larval stem cells based on gene expression signatures, and have validated these classes by in situ hybridization. Upon infecting a mammalian host, the larval schistosome “transforms” into the next stage of the life cycle. During this “juvenile” stage, schistosomes undergo extensive tissue remodeling, massive growth, and development of the reproductive system, enabling them to live in the host vasculature and reproduce sexually. We find that two classes of stem cells proliferate with different kinetics following this transformation: an early-proliferating population gives rise to the somatic stem cells, and a later-proliferating population gives rise to both germ cells and somatic stem cells. By performing single-cell gene expression analyses on stem cells from these juvenile schistosomes, we have identified a gene specific to the intra-mammalian stage that distinguishes the presumptive germ cell lineage in schistosomes. Thus, single-cell analysis has enabled us to characterize stem cell heterogeneity in schistosomes, revealing how different stem cell types contribute to distinct aspects of the animal’s developmental program.

All qBio sponsored talks take place on Wednesdays at 2:00 p.m. in the 3rd floor Orchard View room of the Discovery Building unless otherwise noted. Talks are open to the public. Access to the room is via the elevator behind Aldo’s Cafe in the Northeast corner of the building.