bioRxiv Science⌕ Search

Biology subjects

Wenda, J.

Publications and source records attributed to Wenda, J..

2 recordsLinked to original sources

Cell Painting morphological profiles can complement QSAR models for rat acute oral toxicity prediction

Early de-risking decisions in the development of new chemical compounds, enable the identification of novel chemical candidates with improved safety profiles. In vivo studies are traditionally conducted in the early assessment of acute oral toxicity of crop protection products to avoid compounds which are considered "very acutely toxic", with an in vivo Lethal Dose of 50% (LD50) [≤] 60 mg/kg bodyweight. Those studies are lengthy, costly, and raise ethical concerns, catalyzing the use of non-animal alternatives. The objective of our analysis was to assess the predictive efficacy of read-across approaches for acute oral toxicity in rats, comparing the use of chemical structure information, in vitro biological data derived from the Cell Painting profiling assay on U2OS cells or the combination of both. Our findings indicate that the classification of compounds as very acute oral toxic (LD50 [≤] 60 mg/kg) or not is possible using a read-across approach, with chemical structure information, morphological profiles, or a combination of both. When classifying compounds structurally similar to those in the training set, chemical structure was more predictive (balanced accuracy of 0.82). Conversely, when the compounds to be classified were structurally different from those in the training set, the morphological profiles were more predictive (balanced accuracy of 0.72). Combining the two models allowed for the classification of compounds structurally similar to those in the training set, to slightly improve the predictions (balanced accuracy of 0.85). O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=102 SRC="FIGDIR/small/591123v2_ufig1.gif" ALT="Figure 1"> View larger version (29K): org.highwire.dtl.DTLVardef@d7d4fcorg.highwire.dtl.DTLVardef@1e00a92org.highwire.dtl.DTLVardef@1d60fccorg.highwire.dtl.DTLVardef@a72961_HPS_FORMAT_FIGEXP M_FIG For Table of Contents Only C_FIG

pharmacology and toxicology↗

Trans-generational inheritance of centromere identity requires the CENP-A N-terminal tail in the C. elegans maternal germ line

Centromere protein A (CENP-A) is a histone H3 variant that defines centromeric chromatin and is essential for centromere function. In most eukaryotes CENP-A-containing chromatin is epigenetically maintained, and centromere identity is inherited from one cell cycle to the next. In the germ line of the holocentric nematode Caenorhabditis elegans, this inheritance cycle is disrupted. CENP-A is removed at the mitosis-to-meiosis transition and is established de novo on chromatin during diplotene of meiosis I. Here we show that the N-terminal tail of CENP-A is required for the de novo establishment of centromeres, but dispensable for centromere maintenance during embryogenesis. Worms homozygous for a CENP-A tail deletion maintain a functional centromere during development, but give rise to inviable offspring because they fail to re-establish centromeres in the maternal germ line. We identify the N-terminal tail of CENP-A as a critical domain for the interaction with the conserved kinetochore protein KNL-2, and argue that this interaction plays an important role in setting centromere identity in the germ line. We conclude that centromere establishment and maintenance are functionally distinct in C. elegans.

genetics↗