[Three twinning types in mink (Mustela vison) embryogeny].
The frequency of emergence of monochorial twins in the postimplantational embryogeny of the American mink and their karyotypes were studied. Monochorial pairs were found in which embryos had different karyotypes: 2n, XX and 2n, XY or 2n and 3n. This fact contradicts the notion that monochorial twins should be monozygotic and genetically identical but confirms our earlier hypothesis that a third twinning type exists in mink: monozygotic but genetically different. The mechanism of the emergence of this twinning type in mammals is discussed. It is suggested that the high (up to 4.5%) frequency of its emergence in the American mink is related to obligate embryonic diapause, causing abnormal fertilization.
Isakova
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GK
D000818:Animals; D004622:Embryo, Mammalian; D008907:Mink / Q000235:genetics*; D012730:Sex Chromosomes / Q000235:genetics; D014427:Twins / Q000235:genetics