Proliferation and migration of primordial germ cells in We/We mouse embryos.
We have examined the numbers and distribution of primordial germ cells in We/We, We/+, and +/+ mouse embryos using Southern blotting to determine embryo genotypes. At early somite stages (5-7 somites: approximately 8 1/2 days post coitum [dpc]) there are 50 to 100 germ cells in embryos of all genotypes. The number of germ cells in We/+ and +/+ embryos then begins to increase: at later somite stages (17-19 somites: approximately 9 1/2 dpc) they number about 200, and by 10 1/2 dpc there are approximately 725 We/+ and 850 +/+ germ cells. During this time, however, the number of germ cells in We/We embryos remains less than 100. At 8 1/2 dpc, the distribution of germ cells in the hindgut endoderm is the same in all genotypes. By 9 1/2 dpc, 30% of We/We germ cells are found in ectopic sites (allantois and vitelline artery); germ cell distribution along the length of the hindgut appears normal, but germ cells remain confined to the floor of the gut in We/We embryos, rather than being distributed around its circumference as in the other two genotypes. By 10 1/2 days, the migration of We/We germ cells through the dorsal mesentery lags behind that of the other genotypes, and a larger proportion remains in the gut wall.
Buehr
M
M
MRC Mammalian Development Unit, University College London, England.
McLaren
A
A
Bartley
A
A
Darling
S
S
D000483:Alleles; D000818:Animals; D002452:Cell Count; D002455:Cell Division / Q000502:physiology; D002465:Cell Movement / Q000502:physiology; D004622:Embryo, Mammalian / Q000166:cytology*; D005838:Genotype; D005854:Germ Cells / Q000254:growth & development* / Q000502:physiology; D005865:Gestational Age; D051379:Mice; D008809:Mice, Inbred C3H; D008817:Mice, Mutant Strains