Biology subjects

Pezza, R.

Publications and source records attributed to Pezza, R..

5 recordsLinked to original sources

bioRxiv2026

ZCWPW1 organizes telomeric architecture to drive meiotic chromosome movements

Meiotic homolog pairing relies on programmed DNA recombination and large-scale chromosome movements, yet, how these genetic and mechanical events are coordinated remains unclear. ZCWPW1 is a histone reader that recognizes PRDM9-deposited chromatin marks. We identify an unexpected role for ZCWPW1 as a regulator of rapid prophase movements (RPMs). Using super-resolution imaging, we show that ZCWPW1 is strongly enriched at subtelomeric regions of mouse spermatocytes, where it stabilizes TRF1, LINC complex components, dynein, and meiosis-specific cohesin (STAG3). Loss of ZCWPW1 disrupts telomere architecture, weakens telomere-LINC- motor coupling, and abolishes chromosome movement, leading to defective synapsis and pairing, and persistence of DSBs. These defects are more severe than, and mechanistically independent of, those observed in Prdm9-/- spermatocytes. Together, our findings reveal that ZCWPW1 acts independently of PRDM9 as a chromatin-based intranuclear regulator of telomere architecture and telomere-led chromosome movements, thereby linking telomeric chromatin state to nuclear force transmission required for faithful meiotic progression. Significance StatementMeiotic pairing requires recombination and telomere-led chromosome movements, yet no chromatin factor has been shown to regulate both. We identify ZCWPW1 as the first chromatin-based regulator of rapid prophase movements. ZCWPW1 organizes telomeric chromatin and promotes cohesin and motor assembly at telomeres that for force transmission across the nuclear envelope. Loss of ZCWPW1 disrupts the telomere-nuclear envelope mechanical coupling, impairing motion and altering recombination. This function doesnt rely on PRDM9 despite their co-evolution and co-expression, challenging the prevailing view that ZCWPW1 only acts downstream of PRDM9 in DNA repair. Our findings show that chromatin readers can function as structural regulators of genome organization, revealing a conserved mechanism integrating chromosome structure, motion, and repair to ensure proper pairing and fertility.

cell biology↗

bioRxiv2025

A novel CHD4-CTCF regulatory axis drives key developmental programs and transitions in male germ cells.

Sustained gamete production and testis development relies in developmental programs and transitions such as spermatogonia differentiation, meiosis, and spermiogenesis. Chromatin remodeling complexes and CTCF are key regulators of these processes by controlling specific patterns of gene expression across gamete development. Although the CHD4 chromatin remodeler and CTCF have been implicated in spermatogonia development, a mechanism explaining their cooperation is missing. We also do not know CHD4 and CTCF role in later stages of spermatogenesis. Our studies reveal that germ cell-specific deletion of CHD4 results in spermatogonia development defects and affects meiotic-specific functions such as homologous chromosome synapsis. Combined analysis of genome-wide chromatin binding and single cell gene transcription showed that CHD4 controls specific gene expression programs important for spermatogonia differentiation, transition into meiosis, and meiotic specific processes. Mechanistically, this can be explained by a pervasive role for CHD4 in controlling CTCF chromatin binding and transcriptional function. The discovery of a functional interplay between CHD4 and CTCF reveals a novel axis of gene expression control, integrating chromatin structure and transcriptional outcomes. This interaction is essential in orchestrating early testis development and meiotic processes, ensuring that the correct number of chromosomes is faithfully transmitted to the next generation.

developmental biology↗

bioRxiv2024

Low fidelity DNA polymerase IV accelerates genome evolution in Pseudomonas aeruginosa

Specialized DNA polymerases are crucial for bypassing lesions and facilitating various cellular processes. Despite extensive research, the mutagenic effects of these error-prone enzymes on genomes are still not fully understood. In this study, we examined the genomic instability caused by Pol IV in the bacterial pathogen Pseudomonas aeruginosa. Pol IV mutagenesis primarily involved the misincorporation of oxidized guanine nucleotides opposite template adenine. This activity led to a distinctive mutational signature, characterized by A to C transversions occurring preferentially at AT sites flanked by a 5G and/or 3C. Furthermore, Pol IV preferentially targeted specific chromosomal locations near the replication termination region and rRNA-encoding operons. Several genes associated with virulence, motility, antibiotic resistance and chemotaxis are located in these difficult-to-replicate regions, making them hotspots for Pol IV-mutagenesis. Notably, half of the mutation events catalyzed by Pol IV effectively impaired gene function. This can be attributed to the strong bias of Pol IV for mutating specific codons with its preferred sequence contexts, leading to substitutions primarily to the unreactive Ala and Gly residues. Remarkably, mutation signatures identified for Pol IV were also present in genomes from clinical isolates of P. aeruginosa, providing compelling evidence for its role in genetic diversification during pathogen adaptation.

genomics↗

bioRxiv2022

Efficient enrichment of synchronized mouse spermatocytes suitable for genome-wide analysis.

Chromatin-based mechanisms regulating developmental transitions during meiosis are fundamental but understudied aspects of male gametogenesis. Indeed, chromatin undergoes extensive remodeling during meiosis, leading to specific patterns of gene expression and chromosome organization, which ultimately controls fundamental meiotic processes such as recombination and homologous chromo-some associations. Recent game-changing advances have been made by analysis of chromatin binding sites of meiotic specific proteins genome-wide in mouse spermatocytes. However, further progress is still highly dependent on the reliable isolation of sufficient quantities of spermatocytes at specific stages of prophase I. Here, we describe a combination of methodologies adapted for rapid and reliable isolation of synchronized fixed mouse spermatocytes. We show that chromatin isolated from these cells can be used to study chromatin binding sites by ChIP-seq. High quality data we obtained from INO80 ChIP-seq in zygotene cells was used for functional analysis of chromatin binding sites.

systems biology↗

bioRxiv2019

CHD4-NURD controls spermatogonia survival and differentiation

Testis development and sustained germ cell production in adults rely on the establishment and maintenance of spermatogonia stem cells and their proper differentiation into spermatocytes. Chromatin remodeling complexes regulate critical processes during gamete development by restricting or promoting accessibility of DNA repair and gene expression machineries to the chromatin. Here, we investigated the role of CHD4 and CHD3 catalytic subunits of the NURD complex during spermatogenesis. Germ cell-specific deletion of Chd4 early in gametogenesis, but not Chd3, resulted in arrested early gamete development due to failed cell survival of neonate undifferentiated spermatogonia stem cell population. Candidate assessment revealed that CHD4 controls expression of Dmrt1 and its downstream target Plzf, both described as prominent regulators of spermatogonia stem cell maintenance. Our results show the requirement of CHD4 in mammalian gametogenesis pointing to functions in gene expression early in the process.

developmental biology↗