Cytoplasmic distribution of poly(A)‐containing RNA in developing Necturus maculosus oocytes with reference to annulate lamellae

Abstract

The cytoplasmic distribution of poly(A)+ mRNA and its relationship to annulate lamellae were examined in developing Necturus maculosus oocytes by in situ hybridization with [3H]poly(U). The specificity of [3H]poly(U) binding was tested by incubating control ovarian sections with either KOH or RNase A before in situ hybridization. In both experiments, the silver grain densities were markedly reduced. Poly(A)+ RNA is uniformly distributed in the cytoplasm until the mid-growth phase and then later in vitellogenesis becomes localized in the subcortical ooplasm. The silver grain density in the cytoplasm varied during oogenesis and was greatest in previtellogenic oocytes. Annulate lamellae commonly are observed with the light microscope in oocytes prior to vitellogenesis. In such oocytes, the labeled mRNA probe is observed over cytoplasmic regions of annulate lamellae. The results suggests that a differential localization of messenger RNA occurs during oogenesis in Necturus maculosus. Furthermore, poly(A)+ RNA is present in cytoplasmic regions of annulate lamellae.

Imaging-associated stress causes divergent phase transitions of RNA-binding proteins in the Caenorhabditis elegans germ line

“…Proper regulation of phase transitions is critical, as dysregulation of RNP granules is associated with disease states such as cancer, cardiovascular disease, and neurodegenerative diseases ( Riggs et al 2020 ; Davis et al 2022 ). For example, in ALS (amyotrophic lateral sclerosis) mutations, the FUS protein phase separates into abnormal neuronal granules, and ectopic aggregates of FMRpolyG protein in ovarian stromal cells are associated with Fragile-X-associated primary ovarian insufficiency ( Ganion 1991 ; Buijsen et al 2016 ; Friedman-Gohas et al 2020 ). While a growing number of in vivo studies have started to build on in vitro observations that demonstrate a role for multivalent interactions in driving the condensation and decondensation of proteins, the precise regulation and function of phase transitions in oogenesis is not well understood.…”

Imaging-induced stress causes divergent phase transitions of RNA binding proteins in the C. elegans germ line

“…Proper regulation of phase transitions is critical, as dysregulation of RNP granules is associated with disease states such as cancer, cardiovascular disease, and neurodegenerative diseases (Wang et al, 2022). For example, in ALS mutations, the FUS protein phase separates into abnormal neuronal granules, and ectopic aggregates of FMRpolyG protein in ovarian stromal cells are associated with Fragile-X-associated primary ovarian insufficiency (Ganion 1991; Buijsen et al 2016; Friedman-Gohas et al 2020). While a growing number of in vivo studies started to build on in vitro observations that demonstrate a role for multivalent interactions in driving the condensation and decondensation of proteins, the precise regulation and function of phase transitions in oogenesis is not well understood.…”