Reevaluating the relationship between EGL-43 (EVI1) and LIN-12 (Notch) during C. elegans anchor cell invasion

• Published in: Biology open Vol. 11; no. 12
• Main Authors: Martinez, Michael A Q, Mullarkey, Angelina A, Yee, Callista, Zhao, Chris Z, Zhang, Wan, Shen, Kang, Matus, David Q
• Format: Journal Article
• Language: English
• Published: England The Company of Biologists Ltd 15.12.2022; The Company of Biologists
• Subjects: aid; anchor cell invasion; Animals; Basic Helix-Loop-Helix Transcription Factors - metabolism; c. elegans; Caenorhabditis elegans - genetics; Caenorhabditis elegans - metabolism; Caenorhabditis elegans Proteins - genetics; Caenorhabditis elegans Proteins - metabolism; dhb; egl-43; Female; Humans; Indoleacetic Acids - metabolism; lin-12; Receptors, Cytoplasmic and Nuclear - metabolism; Receptors, Notch - genetics; Receptors, Notch - metabolism; Transcription Factors - genetics; Transcription Factors - metabolism; Vulva - metabolism; Anchor cell invasion; EGL-43; C. elegans; LIN-12; AID; DHB
• ISSN: 2046-6390; 2046-6390
• DOI: 10.1242/bio.059668

Development of the Caenorhabditis elegans reproductive tract is orchestrated by the anchor cell (AC). This occurs in part through a cell invasion event that connects the uterine and vulval tissues. Several key transcription factors regulate AC invasion, such as EGL-43, HLH-2, and NHR-67. Specifically, these transcription factors function together to maintain the post-mitotic state of the AC, a requirement for AC invasion. Recently, a mechanistic connection has been made between loss of EGL-43 and AC cell-cycle entry. The current model states that EGL-43 represses LIN-12 (Notch) expression to prevent AC proliferation, suggesting that Notch signaling has mitogenic effects in the invasive AC. To reexamine the relationship between EGL-43 and LIN-12, we first designed and implemented a heterologous co-expression system called AIDHB that combines the auxin-inducible degron (AID) system of plants with a live cell-cycle sensor based on human DNA helicase B (DHB). After validating AIDHB using AID-tagged GFP, we sought to test it by using AID-tagged alleles of egl-43 and lin-12. Auxin-induced degradation of either EGL-43 or LIN-12 resulted in the expected AC phenotypes. Lastly, we seized the opportunity to pair AIDHB with RNAi to co-deplete LIN-12 and EGL-43, respectively, which revealed that LIN-12 is not required for AC proliferation following loss of EGL-43.