Recent Advances in the Genetic, Anatomical, and Environmental Regulation of the C. elegans Germ Line Progenitor Zone

Abstract

The C. elegans germ line and its gonadal support cells are well studied from a developmental genetics standpoint and have revealed many foundational principles of stem cell niche biology. Among these are the observations that a niche-like cell supports a self-renewing stem cell population with multipotential, differentiating daughter cells. While genetic features that distinguish stem-like cells from their differentiating progeny have been defined, the mechanisms that structure these populations in the germ line have yet to be explained. The spatial restriction of Notch activation has emerged as an important genetic principle acting in the distal germ line. Synthesizing recent findings, I present a model in which the germ stem cell population of the C. elegans adult hermaphrodite can be recognized as two distinct anatomical and genetic populations. This review describes the recent progress that has been made in characterizing the undifferentiated germ cells and gonad anatomy, and presents open questions in the field and new directions for research to pursue.

Caenorhabditis elegans septins contribute to the development and structure of the oogenic germline

“…Given the shortened germlines of septin loss‐of‐function animals and the GO Term clustering of cell cycle genes phenocopying C. elegans septins (Figures 3 and 4), we hypothesized that germline development was perturbed. In wild‐type C. elegans hermaphrodites, the germline arises from primordial germ cell (PGC) proliferation, which creates a population of germline stem cell compartments that can self‐renew and give rise to gamete progenitors (Gordon, 2020; Pazdernik & Schedl, 2013). These progenitors remain connected to each other via intercellular bridges within a syncytium (Bauer et al, 2021; Goupil et al, 2017).…”

Reproductive Toxicity of Furfural Acetone in Meloidogyne incognita and Caenorhabditis elegans

“…Whether the reduction of germ cells of C. elegans is caused by affecting gonadal development was studied further. The DTCs act as the germ line stem cell niche, and each DTC caps a pool of germ stem cells [37]. Because lag-2::gfp is expressed in the DTCs of C. elegans JK2868, the transgenic nematode qIs56 [lag-2::gfp] (JK2868) was used to check the quantity of DTCs after exposure to FAc.…”

Higher-order epistasis shapes natural variation in germ stem cell niche activity

“…This is controlled by a network of RNA regulatory proteins, PUF (Pumilio and FBF) RNA-binding proteins, which promote self-renewal downstream GLP-1/Notch, and RNA regulatory pathways (GLD-1, GLD-2, SCF PROM-1 ), which promote entry into meiosis (Chen et al, 2020; Crittenden and Kimble, 2008; Hansen and Schedl, 2013; Haupt et al, 2020; Hubbard and Schedl, 2019; Kimble and Crittenden, 2007). Additional signals from gonadal sheath cells may further modulate C. elegans germ cell proliferation and differentiation (Gopal et al, 2021; Gordon, 2020; Killian and Hubbard, 2005; Li et al, 2022; McCarter et al, 1997; Starich et al, 2014; Tolkin and Hubbard, 2021). Germline PZ cell number is thus determined by the interplay of distal proliferative activity and the spatio-temporal transition into the proximal meiotic state.…”

“…This is controlled by a network of RNA regulatory proteins, including PUF (Pumilio and FBF) RNA-binding proteins that promote self-renewal downstream GLP-1/Notch and other RNA regulatory proteins (GLD-1, GLD-2, SCF ) that promote entry into meiosis 17,37,38,[46][47][48] . Additional signals from gonadal sheath cells further modulate C. elegans germ cell proliferation and differentiation [49][50][51][52][53][54][55] . Germline PZ cell number is thus determined by the interplay of distal proliferative activity and the spatio-temporal transition into the proximal meiotic state.…”