• Cellular division resulting in the formation of gametes.
  • Consists of two nuclear divisions.
  • Results in one gamete each containing 1N chromosomes,
  • Leptotene - pairing of diploid chromosomes
  • Zygotene - transitory pairing stage
  • Pachytene - genetic exchange between chromosomes
  • Diplotene - resting stage at which oocytes arrest in primordial follicles.
  • Diakinesis or germinal vesicle stage - meiosis resumes in the Graffian follicle. Caused by the LH from the anterior pituitary.
Metaphase I
  • bivalents arranged on microtubules. Cell divides to contain 2 1N chromosomes.
  • Anaphase - bivalents move to opposite poles. Dog, fox and horse ovulate this structure.
Metaphase II and polar body extrusion
  • a 1N chromosome is expelled (the polar body) to leave the cell 1 1N chromosome in the secondary oocyte.
  • this is the ovulated structure in most species.

contributed by Bruce E Eilts on 22-June-2000
modified by
Eric Huey

contributed by Bruce E Eilts on 25 September 2012


To  Main



Send an email to ask a question that has not been adequately covered.