Appraisal of a Hypothesis on Embryo Fusion and Individuation
Publication Details
O'Keeffe, F.,
&
Mendz, G. L.
(2026).
Appraisal of a Hypothesis on Embryo Fusion and Individuation.
Biology, 15 (10).
Abstract
Aim: Human beings comprising two genetically different types of cells are known as tetragametic individuals. This trait is thought to arise from the fusion of two embryos. This investigation into the hypothesised fusion potential of two embryos was conducted to appraise whether embryo fusion is a correct explanation for tetragametic chimerism and an appropriate basis for legislation governing human embryo experimentation. Materials: The reported hypotheses to explain embryo fusion. Fifty documented instances of human beings comprising two genetically different types of cells scattered throughout the body. Data from studies of sesquizygotic twins with key information describing embryos with two genetically different types of cells. Methods: The development of the embryo fusion hypotheses was examined. The correctness of three hypotheses of embryo fusion was appraised. Multiple reports of tetragametic human beings were reviewed. In each case, the maternal component of the genetically different cells was analysed to ascertain the presence of identical or dissimilar contributions to the embryo genome and thus establish whether one or more oocytes were fertilised. An investigation of sesquizygotic twinning was employed to assess the possibility of dispermic fertilisation generating tetragametic individuals. Results and Conclusions: The embryo fusion hypotheses have not been demonstrated, and their analyses suggest that they propose highly unlikely/impossible biological events. Individuals with identical maternal contributions incorrectly were assumed to originate from the fusion of embryos. Sesquizygosis is a plausible mechanism by which a human embryo comprised of two genetically different types of cells could be generated.
Keywords
embryo fusion, human embryo experimentation, tetragametic individuals, individuation, sesquizygosis
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