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Apolipoprotein E4 (APOE4) is the strongest risk allele associated with the development of late onset Alzheimer’s disease (AD). Across the CNS, astrocytes are the predominant expressor of The online version contains supplementary material available at 10.1186/s12974-026-03698-2. Show less

Late-onset Alzheimer's disease (AD) is a complex and heterogeneous neurodegenerative disease with significant genetic components implicated in at least 97 loci from AD genome-wide association studies. While various distinct AD subtypes have been identified based on brain or CSF molecular profiling, contribution of the genetic signatures in distinguishing the AD subtypes is lacking. Here, we leveraged large snRNA-seq postmortem brain data with an empirical Bayes matrix factorization (EBMF) approach to study common effects of 197 AD risk variants on neuronal and glial cell transcriptome, enabling factor-based polygenic score (fPGS) and patient clustering based on their functional genetic profiles. We confirmed that each factor captures specific AD risk variant influences on cell types and known AD-associated biological processes, such as mitochondrial activity, endo-lysosomal activity, mRNA processing, neuroinflammation, or calcium signaling. Further, we found that most fPGS were predicting a certain neuropathological or AD-associated molecular condition. Notably, fPGS3 predicts somatic mutation burden in excitatory neurons, and fPGS7 predicts epigenome erosion in excitatory neurons associated with lipid transport disorders, increased mitochondrial activity, and increased Tau pathology. Finally, unsupervised clustering analysis of individuals with mild cognitive impairment and AD based on their fPGS profiles enable us to identify seven clusters, which are differentiated by the Show less

Here we show that emb-30 is required for metaphase-to-anaphase transitions during meiosis and mitosis in Caenorhabditis elegans. Germline-specific emb-30 mutant alleles block the meiotic divisions. Mutant oocytes, fertilized by wild-type sperm, set up a meiotic spindle but do not progress to anaphase I. As a result, polar bodies are not produced, pronuclei fail to form, and cytokinesis does not occur. Severe-reduction-of-function emb-30 alleles (class I alleles) result in zygotic sterility and lead to germline and somatic defects that are consistent with an essential role in promoting the metaphase-to-anaphase transition during mitosis. Analysis of the vulval cell lineages in these emb-30(class I) mutant animals suggests that mitosis is lengthened and eventually arrested when maternally contributed emb-30 becomes limiting. By further reducing maternal emb-30 function contributed to class I mutant animals, we show that emb-30 is required for the metaphase-to-anaphase transition in many, if not all, cells. Metaphase arrest in emb-30 mutants is not due to activation of the spindle assembly checkpoint but rather reflects an essential emb-30 requirement for M-phase progression. A reduction in emb-30 activity can suppress the lethality and sterility caused by a null mutation in mdf-1, a component of the spindle assembly checkpoint machinery. This result suggests that delaying anaphase onset can bypass the spindle checkpoint requirement for normal development. Positional cloning established that emb-30 encodes the likely C. elegans orthologue of APC4/Lid1, a component of the anaphase-promoting complex/cyclosome, required for the metaphase-to-anaphase transition. Thus, the anaphase-promoting complex/cyclosome is likely to be required for all metaphase-to-anaphase transitions in a multicellular organism. Show less