Chromosome painting analysis of early oogenesis in human trisomy 18.
We have used chromosome 18-specific painting probes to analyze early stages of oogenesis in two human trisomy 18 fetuses. At leptotene, a diffuse, nonlinear chromosomal fluorescence was detected as one (27%), two (42%), or three (31%) signals in 534 cells. The variation in size of these signals implies the possibility of associations between homologs prior to zygotene. At pachytene, about 75% (339/453) of the cells had a trivalent configuration, and almost half of these cells exhibited almost complete triple synapses. Approximately 24% of the pachytene cells demonstrated a bivalent:univalent configuration, and 1% exhibited complete asynapsis. Our data imply that triple synapses may be a regular feature of meiosis involving multivalents.
Cheng
E Y
EY
Department of Obstetrics and Gynecology, University of Washington, Seattle, USA.
Chen
Y J
YJ
Gartler
S M
SM
D000028:Abortion, Induced; D002874:Chromosome Mapping; D002887:Chromosomes, Human, Pair 18; D005260:Female; D005333:Fetus; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D009865:Oocytes / Q000166:cytology*; D009866:Oogenesis; D010053:Ovary / Q000166:cytology / Q000196:embryology*; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D014314:Trisomy