Biology subjects

Almog, Y.

Publications and source records attributed to Almog, Y..

3 recordsLinked to original sources

bioRxiv2025

Alterations in background ECoG activity and behavioral deficits in a mouse model of CHD2-related developmental delay

Heterozygous loss of function mutations in the CHD2 gene, encoding for chromodomain helicase DNA-binding protein 2, are associated with severe childhood-onset epilepsy, global developmental delay, and autistic features. Here, we characterized the behavioral and epileptic phenotypes of a mouse model harboring a frameshift truncating mutation in the Chd2 gene (Chd2WT/m and Chd2m/m mice). Genetic background dramatically affected the phenotypes. While no phenotypes were observed on the pure C57BL/6J background, crossing these mice onto the 129X1/SvJ genetic background gradually uncovered neurodevelopmental phenotypes. Transcriptomic analysis identified Kcnj11 as a potential genetic modifier. On the 129X1/SvJ background, Chd2m/m mice demonstrated growth retardation, and both Chd2WT/m and Chd2m/m showed motor deficits, including clasping behavior and reduced abilities to balance on a rotating rod. Autistic-like features were also observed, with Chd2m/m showing reduced nest-building abilities and Chd2WT/m demonstrating increased repetitive-like behavior in the marble burying test and altered social behavior. Quantitative analysis of electrocorticographic (ECoG) recordings revealed neuronal changes consisting of a global reduction in the total power of background activity in Chd2WT/m and Chd2m/m mice, as well as increased susceptibility to seizures induced by acute administration of 4-aminopyridine. Overall, this mouse model recapitulates multiple key phenotypes observed in CHD2 patients, providing a valuable platform to study the molecular basis and treatment options for this intractable disease.

neuroscience↗

bioRxiv2019

Early hippocampal hyperexcitability followed by disinhibition in a mouse model of Dravet syndrome

Dravet syndrome (Dravet) epilepsy begins with febrile seizures followed by worsening to refractory seizures, with some improvement and stabilization toward adolescence. The neuronal basis of Dravet is debatable, with evidence favoring reduced inhibition or enhanced excitation. Focusing on the firing properties of hippocampal CA1 pyramidal neurons and oriens-lacunosum moleculare (O-LM) interneurons, we provide a comprehensive analysis of the activity of both cell types through the febrile, worsening and stabilization stages. Our data indicate a temporary increase in the excitability of CA1 pyramidal neurons during the febrile stage, which is fully reversed by the onset of spontaneous seizures. In contrast, reduced function of O-LM interneurons persisted from the febrile through the stabilization stages, with the greatest impairment of excitability occurring during the worsening stage. Thus, both excitatory and inhibitory neurons contribute to Dravet, indicating complex and reciprocal pathophysiological neuronal changes during the different stages of the disease.\n\nGraphical abstract\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=90 SRC=\"FIGDIR/small/790170v2_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (15K):\norg.highwire.dtl.DTLVardef@220862org.highwire.dtl.DTLVardef@54840eorg.highwire.dtl.DTLVardef@a9d006org.highwire.dtl.DTLVardef@9854ec_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2019

The response to the DNA damaging agent methyl methanesulfonate in a fungal plant pathogen

DNA damage can cause mutations that in fungal plant pathogens lead to hypervirulence and resistance to pesticides. Almost nothing is known about the response of these fungi to DNA damage. We performed transcriptomic and phosphoproteomic analyses of Fusarium oxysporum exposed to a DNA alkylating agent (MMS). At the RNA level we observe massive induction of DNA repair pathways; the most surprising is the global genome nucleotide excision repair. Cul3, Cul4, several Ubiquitin-like ligases and other components of the protein degradation machinery are significantly induced. In agreement, we observed drug synergism between a proteasome inhibitor and MMS. While our data suggest that Yap1 and Xbp1 networks are similarly activated in response to damage in yeast and Fusarium we were able to observe Fusarium specific MMS-responsive modules. These include transcription/splicing modules that are upregulated and respiration that is down-regulated. In agreement, MMS treated cells are much more sensitive to a respiration inhibitor. At the phosphoproteomic level, Adenylate cyclase, which generates cAMP, is phosphorylated by MMS and forms a network of phosphorylated proteins that include cell cycle regulators and several MAPK pathways. Recently, there are many attempts to re-sequence isolates of fungal plant pathogens. These attempts often reveal changes in the genomes that may be explained by DNA damage exposure. Our analysis provides an important starting point in understanding how these genomic changes occur.

microbiology↗