Synapsi

Synapsi is a term that may appear in different linguistic contexts, but in English it is not the standard form of a major biological concept. The standard terms are synapsis (singular) and synapses (neuronal junctions). In some languages or technical texts, synapsi may be encountered as a plural or variant spelling; in English, however, synapsis refers to the meiotic process, while synapse refers to a neuronal connection.

In biology, synapsis describes the intimate pairing of homologous chromosomes during prophase I of meiosis. This pairing aligns homologous segments to enable genetic recombination and proper chromosome segregation in the next meiotic divisions. Synapsis begins in the leptotene to zygotene stages and is completed by pachytene, when homologs are held together along their length by protein structures.

The process is facilitated by the synaptonemal complex, a protein framework that stabilizes the pairing of homologous chromosomes. Double-strand breaks initiated by dedicated nucleases promote crossing-over, yielding chiasmata that become visible as recombination events mature. Proper synapsis and recombination ensure genetic diversity and reduce mis-segregation of chromosomes, which can lead to aneuploidies.

In neuroscience, the related term synapse denotes the junction through which neurons communicate with each other or with effector cells. The plural “synapses” is standard in English; some languages use different spellings that may resemble “synapsi.”

See also: synaptonemal complex, homologous recombination, meiosis, synapse.