Meiosisina

Meiosisina is a proposed meiosis-associated protein identified in several lineages of eukaryotes. The name derives from meiosis and the common protein suffix -ina. It is described as a small, predominantly nuclear protein with predicted coiled-coil regions, suggesting a role in chromosomal processes during meiotic prophase.

Discovery and distribution: Comparative genomic analyses have revealed meiosisina-like genes in a subset of unicellular eukaryotes and plants, often located near Spo11 homologs or other meiotic genes. The protein has not been reported in all major lineages and its presence varies among species, indicating lineage- or condition-specific utility.

Structure and localization: In silico predictions point to a mainly coiled-coil architecture, with short conserved motifs of uncertain catalytic activity. Experimental data in model systems suggest meiosinina contains nuclear localization signals and associates with chromatin during meiotic entry.

Function and mechanism: Meiosisina is proposed to act during early meiotic prophase I, potentially coordinating with the Spo11-driven program of double-strand breaks or later processing steps. It is thought to function as a scaffold or adaptor that helps recruit recombination factors and stabilizes the assembly of axial elements, thereby promoting proper homolog pairing and synapsis.

Significance and status: Meiosisina serves as a model for studying the regulation of meiotic recombination in diverse eukaryotes. If validated, its activity could explain some differences in recombination landscapes across species and inspire synthetic biology approaches to modulate meiotic outcomes.

See also: meiosis, Spo11, recombination, synaptonemal complex.