Author Information

DeAnna E. CuelloFollow

Presentation Type

Poster

Faculty Mentor’s Full Name

Ekaterina Voronina

Faculty Mentor’s Department

Department of Biological Science

Abstract / Artist's Statement

Stem cells are essential to establish tissue via proliferation and differentiation. We study stem cells of Caenorhabditis elegans germline as a model for development and differentiation. The distal tip cell (DTC) houses the stem cell niche which contains ~200 mitotically dividing cells. As germline stem cells move proximally the cells begin to differentiate while entering meiotic division (Austin and Kimble, 1987). Amongst the stem cells, previous research distinguished two populations, those that are naïve stem cells and others that are committed to differentiation (Cinquin, et. al, 2010).

We study stem cell regulation by two RNA-binding proteins, FBF-1 and FBF-2 that are both essential for stem cell maintenance (Zhang et al., 1997; Crittenden et al., 2002). FBF-1 and FBF-2 have different effects, FBF-1 restricts meiotic entry and FBF-2 promotes meiotic entry and cell division (Wang, et al. 2020) thus regulating mitotic stem cell population in an antagonistic fashion. However, previous studies did not distinguish FBF effects on naïve stem cells from the differentiating cells. Therefore, it remains unclear how the faster differentiation in fbf-1 mutant doesn’t deplete stem cell population (Wang et al. 2020). We hypothesize that fbf-1(lf) mutant maintains a relatively normal number of naïve stem cells protected from differentiation. By using a temperature sensitive assay that arrests cells in mitotic division (Cinquin, et al., 2010) we aim to count naïve stem cells from these different fbf (lf) backgrounds as compared to the wild type germlines. Upon temperature up-shift, naïve stem cells arrest in the M-phase of the cell cycle. Then they are detected with antibodies against phospho-Histone H3, and DNA is stained with DAPI. After imaging, naïve arrested stem cells are counted in the distal tip region of the germline. Our preliminary results confirmed protection of naïve stem cells in the fbf-1 mutant and revealed dramatic expansion of naïve stem cells in fbf-2 mutant. In future research, we will investigate molecular regulators of naive stem cell state in fbf-1 and fbf-2 mutants.

Category

Life Sciences

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Apr 21st, 11:00 AM Apr 21st, 12:00 PM

Investigating Naïve Stem Cell Maintenance with fbf Mutants in C. elegans Germline

UC South Ballroom

Stem cells are essential to establish tissue via proliferation and differentiation. We study stem cells of Caenorhabditis elegans germline as a model for development and differentiation. The distal tip cell (DTC) houses the stem cell niche which contains ~200 mitotically dividing cells. As germline stem cells move proximally the cells begin to differentiate while entering meiotic division (Austin and Kimble, 1987). Amongst the stem cells, previous research distinguished two populations, those that are naïve stem cells and others that are committed to differentiation (Cinquin, et. al, 2010).

We study stem cell regulation by two RNA-binding proteins, FBF-1 and FBF-2 that are both essential for stem cell maintenance (Zhang et al., 1997; Crittenden et al., 2002). FBF-1 and FBF-2 have different effects, FBF-1 restricts meiotic entry and FBF-2 promotes meiotic entry and cell division (Wang, et al. 2020) thus regulating mitotic stem cell population in an antagonistic fashion. However, previous studies did not distinguish FBF effects on naïve stem cells from the differentiating cells. Therefore, it remains unclear how the faster differentiation in fbf-1 mutant doesn’t deplete stem cell population (Wang et al. 2020). We hypothesize that fbf-1(lf) mutant maintains a relatively normal number of naïve stem cells protected from differentiation. By using a temperature sensitive assay that arrests cells in mitotic division (Cinquin, et al., 2010) we aim to count naïve stem cells from these different fbf (lf) backgrounds as compared to the wild type germlines. Upon temperature up-shift, naïve stem cells arrest in the M-phase of the cell cycle. Then they are detected with antibodies against phospho-Histone H3, and DNA is stained with DAPI. After imaging, naïve arrested stem cells are counted in the distal tip region of the germline. Our preliminary results confirmed protection of naïve stem cells in the fbf-1 mutant and revealed dramatic expansion of naïve stem cells in fbf-2 mutant. In future research, we will investigate molecular regulators of naive stem cell state in fbf-1 and fbf-2 mutants.