- the third stage of prophase in meiosis, during which each chromosome pair separates into sister chromatids with some breakage and crossing over of genes.
Also pach·y·ne·ma [pak-uh-nee-muh] /ˌpæk əˈni mə/.
Origin of pachytene
< French pachytène (1900), equivalent to Greek pachý(s) thick + -tène -tene
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- the third stage of the prophase of meiosis during which the chromosomes become shorter and thicker and divide into chromatids
from Greek pakhus thick + tainia band
- The third stage of the prophase of meiosis during which the homologous chromosomes become short and thick and divide into four distinct chromatids.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.