[Polyploid mitoses in mink trophoblast cells].
Mitotic figures in the mink placental trophoblasts have been observed under the light microscope using actions and air-dried preparations. The tetra- and octaploid metaphase chromosome spreads were found on Giemsa-stained air-dried preparations. A high percentage (up to 80%) of abnormal metaphases, including k-mitoses as well as a portion of restitution anaphases, was revealed on sections of the placental trophoblast suggesting a possible block of mitosis at the meta- and anaphase. Therefore, it is very likely that genome multiplication in a portion of placental trophoblast cells in mink involves block of mitoses at meta- and anaphase followed by restitution. The chromosomal arrangement on metaphase spreads in part of cells showed a degree of separation of the whole di- and tetraploid chromosome sets within tetraploid and octaploid chromosome plates. Several spreads exhibited some allocycly of diploid chromosome sets inside the polyploid metaphases. It is not inconceivable that such an arrangement may reflect some autonomy of low-ploidy chromosome sets within the polyploid trophoblast cells in mink.
Zybina
E V
EV
Zybina
T G
TG
Isakova
G K
GK
Kiknadze
I I
II
D000818:Animals; D003584:Cytological Techniques; D047108:Embryonic Development; D005260:Female; D008907:Mink; D008938:Mitosis; D011123:Polyploidy; D011247:Pregnancy; D013997:Time Factors; D014327:Trophoblasts / Q000166:cytology*