title: [Three twinning types in mink (Mustela vison) embryogeny].
abstract: 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.
authors: G K
authors: GK
authors: Isakova
mesh_terms: D000818:Animals; D004622:Embryo, Mammalian; D008907:Mink / Q000235:genetics*; D012730:Sex Chromosomes / Q000235:genetics; D014427:Twins / Q000235:genetics