Cell Biology & Molecular Genetics Research Works

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    Group active engagements for helping students learn major principles in introductory organismal biology
    (2022) Cooke, Todd J.; Jensen, Jeffrey S.
    This website in the Digital Repository at University of Maryland (DRUM) presents the resources for teaching group active engagements (GAE’s) for the introductory organismal biology (OrgBio) course taught at the University of Maryland. Each folder includes an instructor guide, student worksheet, and pptx presentation, and most include several homework assignments. Please read the “read me first” file for further information about these resources. Our version of the OrgBio course is described in the paper Cooke et al., “Group active engagements for facilitating principles-based learning in introductory organismal biology,” which was submitted to American Biology Teacher in October 2022. We’ll update the citation when/if the paper is published. All our resources on this website are copyrighted under a Creative Commons BY-NC-SA 4.0 license, which means that they can freely be used in biology courses and for other non-commercial purposes. The Cooke et al. paper and this DRUM website should be credited whenever any of these resources are used, redistributed, or adapted in any format.
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    Collaborative learning in an undergraduate life sciences living-learning program: case studies at multiple planes of analysis.
    (2017) Jardine, Hannah; Levin, Daniel; Quimby, B. Bryn; Cooke, Todd
    The authors report on a living-learning program (LLP) designed to transform life sciences education. One goal of the LLP is to engage students in collaborative learning. Little research describes interactions and experiences within an LLP that encourage collaborative learning. This qualitative ethnographic study explores the following questions: What are some of the ways in which collaborative learning occurs in an LLP? and What factors influence how, when, and to what extent collaborative learning occurs in an LLP? The authors aim to identify ways to promote collaborative learning in an LLP and provide insight for others wishing to construct LLPs with similar goals.
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    Examining the impact of student expectations on undergraduate biology education reform.
    (2011) Hall, Kristi; Watkins, Jessica; Coffey, Janet; Cooke, Todd; Redish, Edward
    The past 10-15 years have seen numerous calls for curricular reform in undergraduate biology education, most of which focus on changes to curriculum or pedagogy. Data collected from students in a large introductory undergraduate biology course indicate that student expectations about the nature of the knowledge they were learning influence how they interacted with reform efforts in that class. Given that student expectations influence the ways in which they participate in course activities, this paper (the first in a series that looks at student expectations in biology) argues that curriculum reform initiatives should consider student expectations in order to increase the chance for effective implementation.
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    Cytonemes coordinate asymmetric signaling and organization in the Drosophila muscle progenitor niche
    (Springer Nature, 2022-03-04) Patel, Akshay; Wu, Yicong; Han, Xiaofei; Su, Yijun; Maugel, Tim; Shroff, Hari; Roy, Sougata
    Asymmetric signaling and organization in the stem-cell niche determine stem-cell fates. Here, we investigate the basis of asymmetric signaling and stem-cell organization using the Drosophila wing-disc that creates an adult muscle progenitor (AMP) niche. We show that AMPs extend polarized cytonemes to contact the disc epithelial junctions and adhere themselves to the disc/niche. Niche-adhering cytonemes localize FGF-receptor to selectively adhere to the FGF-producing disc and receive FGFs in a contact-dependent manner. Activation of FGF signaling in AMPs, in turn, reinforces disc-specific cytoneme polarity/adhesion, which maintains their disc-proximal positions. Loss of cytoneme-mediated adhesion promotes AMPs to lose niche occupancy and FGF signaling, occupy a disc-distal position, and acquire morphological hallmarks of differentiation. Niche-specific AMP organization and diversification patterns are determined by localized expression and presentation patterns of two different FGFs in the wing-disc and their polarized target-specific distribution through niche-adhering cytonemes. Thus, cytonemes are essential for asymmetric signaling and niche-specific AMP organization.
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    Mating can initiate stable RNA silencing that overcomes epigenetic recovery
    (Springer Nature, 2021-07-09) Devanapally, Sindhuja; Raman, Pravrutha; Chey, Mary; Allgood, Samual; Ettefa, Farida; Diop, Maïgane; Lin, Yixin; Cho, Yongyi E.; Jose, Antony M.
    Stable epigenetic changes appear uncommon, suggesting that changes typically dissipate or are repaired. Changes that stably alter gene expression across generations presumably require particular conditions that are currently unknown. Here we report that a minimal combination of cis-regulatory sequences can support permanent RNA silencing of a singlecopy transgene and its derivatives in C. elegans simply upon mating. Mating disrupts competing RNA-based mechanisms to initiate silencing that can last for >300 generations. This stable silencing requires components of the small RNA pathway and can silence homologous sequences in trans. While animals do not recover from mating-induced silencing, they often recover from and become resistant to trans silencing. Recovery is also observed in most cases when double-stranded RNA is used to silence the same coding sequence in different regulatory contexts that drive germline expression. Therefore, we propose that regulatory features can evolve to oppose permanent and potentially maladaptive responses to transient change.