Abstract Background Metazoan multicellularity is rooted in mechanisms of cell adhesion, signaling, and differentiation that first evolved in the progenitors of metazoans. To reconstruct the genome composition of metazoan ancestors, we sequenced the genome and transcriptome of the choanoflagellate Salpingoeca rosetta, a close relative of metazoans that forms rosette-shaped colonies of cells. Results A comparison of the 55 Mb S. rosetta genome with genomes from diverse opisthokonts suggests that the origin of metazoans was preceded by a period of dynamic gene gain and loss. The S. rosetta genome encodes homologs of cell adhesion, neuropeptide, and glycosphingolipid metabolism genes previously found only in metazoans and expands the repertoire of genes inferred to have been present in the progenitors of metazoans and choanoflagellates. Transcriptome analysis revealed that all four S. rosetta septins are upregulated in colonies relative to single cells, suggesting that these conserved cytokinesis proteins may regulate incomplete cytokinesis during colony development. Furthermore, genes shared exclusively by metazoans and choanoflagellates were disproportionately upregulated in colonies and the single cells from which they develop. Conclusions The S. rosetta genome sequence refines the catalog of metazoan-specific genes while also extending the evolutionary history of certain gene families that are central to metazoan biology. Transcriptome data suggest that conserved cytokinesis genes, including septins, may contribute to S. rosetta colony formation and indicate that the initiation of colony development may preferentially draw upon genes shared with metazoans, while later stages of colony maturation are likely regulated by genes unique to S. rosetta.

The American Psychiatric Association Resource Document for Catatonia was prepared by the Catatonia Work Group of the Council on Consultation-Liaison Psychiatry, with the goal of supporting psychiatrists, trainees, and other mental healthcare workers and to provide a useful framework for understanding catatonia. In 2023, the American Psychiatric Association Council on Consultation-Liaison Psychiatry convened a work group to develop a resource document on Catatonia. A draft of this document was reviewed by the Council in December 2024, and a revised version was approved by this Council in January 2025. The accepted version was subsequently reviewed by the American Psychiatric Association Council on Women's Mental Health, Council on Geriatric Psychiatry, Council on Research, Council on Quality Care, Committee on Practice Guidelines, and Committee on Ethics in December 2024. The final version was approved by the Joint Reference Committee on March 12, 2025, and posted to the American Psychological Association website. In this resource document, we review the history of the catatonia and its epidemiology including prevalence and risk factors. We review the common evaluation methods including rating scales, diagnostic criteria, and clinical evaluation of medical causes of catatonia and its complications, with a focus on the physical examination, laboratory studies, neuroimaging, and electroencephalography. We review the differential diagnosis of catatonia across the medical and psychiatric context of care including abulia/akinetic mutism, delirium, major neurocognitive disorders, locked-in syndrome, late-stage Parkinsons disease, stiff-person syndrome, akathisia, mania, malignant catatonia/neuroleptic malignant syndrome, autoimmune encephalitis, and serotonin syndrome. In this resource document, we additionally review the pathophysiology of catatonia and highlight common interventions and treatment recommendations, with a focus on benzodiazepines and electroconvulsive therapy. We additionally highlight considerations in specific populations including pediatrics, the medically complex, pregnancy and postpartum period, and dementia. We conclude the document with a review of ethical and legal considerations and provide some suggestions for educational resources.