Biology subjects

JIANG, H.

Publications and source records attributed to JIANG, H..

4 recordsLinked to original sources

bioRxiv2024

Secretory trafficking maintains the organelle band for spindle separation during Arabidopsis meiosis

Ploidy reduction is a critical aspect of meiosis, essential for the successful development of haploid germline cells. Notably, cellular processes during male meiosis vary between the major groups of flowering plants, with eudicots exhibiting simultaneous cytokinesis without an interkinesis phase, unlike monocots. Recent studies on the Arabidopsis jason (jas) mutant revealed that an organelle band plays a key role in spindle separation during simultaneous cytokinesis, though the mechanism is not fully understood. Here we identify a novel jas suppressor mutant, peleus (pele), which restores haploid pollen production in the jas background. PELE encodes a vacuole-localized protein that contributes to spindle separation by balancing the vacuolar pathway and secretory trafficking to the organelle band. JAS, PELE, and the ubiquitin-like protein UBQL coordinate the delivery of proteins and membrane components to the organelle band. Specifically, PELE and UBQL antagonistically fine-tune trafficking to the vacuole, while JAS adjusts the flow of secretory trafficking towards the organelle band. Our findings underscore the critical role of secretory trafficking in maintaining organelle band integrity and in ensuring precise spindle positioning during meiosis II. Our work provides novel insights into the regulation of the organelle band and spindle separation, enhancing our understanding of polyploidy generation in plants.

plant biology↗

bioRxiv2024

PDS5s control the Arabidopsis 3D genome by suppressing the formation of TAD-like domains

One key structural element in the three-dimensional (3D) chromatin organization is the Topologically Associating Domain (TAD), which facilitates the formation of distinct chromatin compartments and fosters specific chromatin interactions. Similar chromatin compartments, known as TAD-like domains, have been identified in many plant species. However, the model plant Arabidopsis thaliana has been an exception. In this study, we address this long-standing issue by presenting evidence that Arabidopsis PDS5 proteins play a crucial role in preventing the formation of TAD-like domains.

molecular biology↗

bioRxiv2023

Suppression of piriform cortex alters brain-wide dynamics and alleviates seizures in temporal lobe epilepsy

BackgroundTemporal lobe epilepsy (TLE) involves aberrant changes in the brain at molecular, cellular and circuitry levels, leading to recurrent seizures. Approximately one-third of patients develop drug resistance. Circuit-based interventions show promise for alleviating the drug-resistant seizures. This study explored the efficacy of chemogenetic stimulation on specific neuronal populations in piriform cortical microcircuits in a mouse TLE model. ObjectiveThe anterior piriform cortex (APC) is a limbic area closely associated with TLE but is understudied. Our previous study demonstrated that in the APC, parvalbumin-expressing (PV+) interneurons provide strong inhibition and help maintain excitation-inhibition balance. Here, we examined whether and how APCPV neurons can ameliorate seizure symptoms in TLE. MethodsWe used a chronic intrahippocampal kainic acid (IHKA) mouse model that develops hippocampal pathology and spontaneous recurrent seizures (SRSs). APCPV neurons were chemogenetically activated, and local field potentials were recorded longitudinally from multiple regions. Seizure metrics, spectral power and functional connectivity were compared between APCPV-activated and control samples. ResultsLoss of PV+ synapses emerged in the APC during epileptogenesis. Selective activation of APCPV neurons reduced the frequency and duration of hippocampal SRSs and modified long-range dynamics, with region- and frequency-specific changes in interictal band power and functional connectivity. ConclusionAPCPV chemogenetic activation exerts a robust anti-seizure effect and identifies the APC as a promising cortical node for seizure network control. The associated spectral and connectivity signatures suggest that targeted modulation of APC microcircuits can rebalance distributed seizure networks and lower seizure recurrence.

neuroscience↗

bioRxiv2023

Chromatin attachment to the nuclear matrix represses hypocotyl elongation in Arabidopsis thaliana

The nuclear matrix is a nuclear compartment that has diverse functions in chromatin regulation and transcription. However, how this structure influences epigenetic modifications and gene expression in plants is largely unknown. In this study, we showed that a nuclear matrix binding protein, AHL22, together with the two transcriptional repressors FRS7 and FRS12, regulates hypocotyl elongation by suppressing the expression of a group of genes known as SMALL AUXIN UP RNAs (SAURs) in Arabidopsis thaliana. The transcriptional repression of SAURs depends on their attachment to the nuclear matrix. The AHL22 complex not only brings these SAURs, which contained matrix attachment regions (MARs), to the nuclear matrix, but it also recruits the histone deacetylase HDA15 to the SAUR loci. This leads to the removal of H3 acetylation at the SAUR loci and the suppression of hypocotyl elongation. Taken together, our results indicate that MAR-binding proteins act as a hub for chromatin and epigenetic regulators. Moreover, we present a novel mechanism by which nuclear matrix attachment to chromatin regulates histone modifications, transcription, and hypocotyl elongation.

plant biology↗