singlenucleus

Singlenucleus is a term used to describe a cell or organism that contains a single nucleus, a state also described as uninucleate. It is defined in contrast to multinucleate cells, which harbor two or more nuclei in a common cytoplasm, such as skeletal muscle fibers and certain fungal hyphae.

Most animal somatic cells are uninucleate, with the nucleus coordinating gene expression and cellular regulation. The nucleus houses the genome and organizes transcriptional control, RNA processing, and replication. In some tissues, nuclei may be polyploid or there may be multiple nuclei per cell, reflecting developmental or functional specialization. For example, hepatocytes commonly show binucleation or polyploidy, and skeletal muscle fibers are multinucleate. In mammals, erythrocytes mature by shedding their nucleus, becoming anucleate rather than uninucleate, a different outcome from the typical singlenucleus state.

In plants, fungi, and other protists, nuclei number per cell ranges from single to multiple, depending on species and life cycle stage. The count of nuclei is a descriptive criterion used in histology and cytology to characterize cell type, development, and pathology; deviations from the typical nucleus count can indicate differentiation status, polyploidy, or disease.

Singlenucleus thus denotes a basic cellular architecture with one nucleus, but natural variation across tissues and organisms means that uninucleate cells coexist with binucleate, multinucleate, and anucleate forms.