asynapsis


Also found in: Dictionary, Medical.

asynapsis

[‚ā·si′nap·səs]
(cell and molecular biology)
Absence of pairing of homologous chromosomes during meiosis.
References in periodicals archive ?
The total percentage of nuclei with asynapsis varied from 0.
The present study confirmed the observation on asynapsis done in our previous study (1), in which we showed that asynapsis was a general phenomenon during meiosis.
Frequencies of synaptonemal complex (SC) abnormalities in pachytene nuclei from controls Number Thin Asynapsis Fragmented SC Patients pachytene SC A B C D 1 160 1 0 7 7 4 2 148 6 2 1 15 4 3 159 0 4 0 17 5 4 162 2 2 0 6 3 5 184 1 8 0 9 0 6 153 1 1 0 6 0 7 172 7 0 1 6 7 8 182 5 2 0 15 3 9 174 1 5 0 13 3 10 169 3 2 0 18 1 Mean % 1.
From the animal kingdom, evidence exists for the occurrence of different degrees of asynapsis among chromosome pairs in grasshoppers (Rees, 1957; John & Naylor, 1961), and Hewitt and John (1965) suggested some degree of autonomous control of each bivalent in grasshoppers.
In meiotic mutants asynapsis was restricted to the Aegilops chromosomes, whereas the Secale chromosomes paired normally.