Spo11

Spo11
National Center for Biotechnology Information, U.S. National Library of Medicine · Public domain · source
Name	Spo11
Organism	Eukaryota
Gene symbol	SPO11
Function	Catalyzes DNA double-strand breaks during meiosis

Spo11 Spo11 is a meiosis-specific protein responsible for initiating programmed DNA double-strand breaks (DSBs) that promote homologous recombination and chromosome segregation. It was characterized through genetic, biochemical, and cytological studies in model organisms and linked to fertility, genome stability, and evolutionary processes. Studies connecting Spo11 to recombination have involved multiple laboratories and institutions using organisms ranging from yeast to vertebrates.

Discovery and Nomenclature

Spo11 was identified through genetic screens and cytological analyses in the yeast laboratory of Gerald Fink-era research and subsequent molecular cloning efforts in laboratories associated with Bruce Baker, Scott Keeney, and collaborators at institutions including Cold Spring Harbor Laboratory and Howard Hughes Medical Institute. The name derives from loss-of-function phenotypes observed in screens for sporulation defects in Saccharomyces cerevisiae and historical yeast genetics studies in the era of the Yeast Genetics Conference. Early biochemical characterization referenced homology to the archaeal topoisomerase VI subunit A discovered in comparative genomics projects tied to groups at EMBL and University of Cambridge.

Molecular Structure and Mechanism

Spo11 is structurally related to the A subunit of topoisomerase VI and shares a conserved active-site tyrosine that forms a covalent phosphotyrosyl bond with DNA; structural insights were informed by crystallography and cryo-electron microscopy efforts coordinated by researchers at Max Planck Society and structural biology centers at Stanford University and Harvard University. Mechanistic models integrate data from biochemical reconstitution assays developed in the laboratories of Scott Keeney and Michael Lichten, along with mutational analyses from groups at University of California, Berkeley and Columbia University. The catalytic cycle involves a transesterification reaction mediated by acid–base residues and coordination of divalent metal ions, with topology and strand passage features reminiscent of the Topoisomerase VI complex characterized in archaeal systems.

Role in Meiosis and Double-Strand Break Formation

During prophase I of meiosis, Spo11-dependent DSBs are temporally and spatially patterned across chromosomes, a phenomenon documented in studies using cytology and next-generation sequencing from teams at Cold Spring Harbor Laboratory, University of Oxford, and Max Planck Institute for Plant Breeding Research. Spo11 collaborates with accessory proteins characterized in genetic screens from Saccharomyces cerevisiae and Schizosaccharomyces pombe research communities, including partners identified in papers from European Molecular Biology Laboratory investigators. The DSBs created by Spo11 are processed by conserved recombination machinery involving factors discovered at University of Cambridge and University of California, San Francisco, linking to crossover control mechanisms studied in classical work at The Rockefeller University.

Regulation and Temporal Control

Temporal control of Spo11 activity is coordinated with cell-cycle regulators and checkpoint kinases uncovered in studies at Massachusetts Institute of Technology, Johns Hopkins University, and Princeton University. Phosphorylation events and protein–protein interactions that modulate Spo11 loading and activity were mapped by proteomics teams at Broad Institute and signaling groups at University of Chicago. Spatial regulation, including hotspot localization and chromatin context, was illuminated by chromatin immunoprecipitation and single-molecule mapping approaches from consortia involving European Bioinformatics Institute and laboratories at University of California, San Diego.

Evolutionary Conservation and Diversity

Comparative genomics surveys across eukaryotes and archaeal homolog studies from groups at National Center for Biotechnology Information and University of Tokyo demonstrate conservation of the catalytic tyrosine and structural fold, with lineage-specific diversification reported in plants, fungi, and metazoans studied by teams at Max Planck Institute for Developmental Biology and Scripps Research. Evolutionary analyses leveraging datasets from 1000 Genomes Project-era resources and phylogenomic pipelines developed at Wellcome Sanger Institute traced orthologs and paralogs, revealing differences in accessory factors and hotspot determinants across clades.

Genetic Mutations and Phenotypic Consequences

Mutations in the SPO11 gene and orthologs produce meiotic arrest, reduced fertility, and aberrant crossover patterns, phenotypes documented in genetic studies at University of California, Davis, University of Wisconsin–Madison, and clinical genetics centers such as Mayo Clinic for human infertility investigations. Functional assays and animal models developed at National Institutes of Health and academic centers including University of Pennsylvania have linked specific amino-acid substitutions to loss of catalytic activity or altered DSB distribution, informing genotype–phenotype correlations pursued by reproductive biology consortia and translational groups at Cedars-Sinai Medical Center.

Category:Meiosis proteins