The origin of human triploidy: an integration of qualitative and quantitative evidence

Ra, Beatty

doi:10.1111/j.1469-1809.1978.tb01897.x

Cited by 34 publications

(18 citation statements)

References 57 publications

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“…The relative importance of digynic and diandric triploidy var ies depending on the species being studied. In man, it was thought that 60% of triploids were digynic and 40% were diandric in origin (Niebuhr, 1974;Beatty, 1978), but a more recent review by Surli (1987) suggests that probably nearer to 85% of human triploids are diandric and only 15% are digynic in origin. In the mouse, a different situation is found, since digynic triploidy is more com monly encountered (Vickers, 1967, 1969a, b: Wroblewska.…”

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confidence: 99%

Analysis of the sex-chromosome constitution of digynic triploid mouse embryos

Speirs¹,

Kaufman²

1989

Cytogenet Genome Res

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LT/Sv strain mice regularly ovulate up to 50% of their eggs as primary oocytes, which are fertilisable and give rise to digynic triploid embryos. A similar number of eggs are ovulated as secondary oocytes and, following fertilisation, give rise to normal diploid embryos. Pregnant LT/Sv females were autopsied at about midday on day 10 of gestation, when normal diploid embryos would be expected to possess between 25 and 30 pairs of somites. While a few of the triploid embryos either consisted of disorganised embryonic masses or were resorbing, most were at readily recognisable embryonic stages. Just over half of the embryos recovered were “unturned,” while the remainder had “turned” and possessed between 15 and 25 pairs of somites. The triploids were usually readily recognised, owing to their small size and because they often displayed neural tube and cardiac defects. All of the embryos recovered were analysed cytogenetically by G-banding to establish their ploidy and sex-chromosome constitution. The XY:XX sex ratio of the 105 diploid embryos recovered, all of which had “turned,” was 1.06:1 while the overall XXY: XXX sex ratio of the 120 triploids was 1:1. Analysis of only the developmentally most advanced triploid embryos (i.e., the 49 that had “turned”) revealed that the XXY: XXX sex ratio in this group was 1.13:1, which was not significantly different from the expected ratio of 1:1. The crown-rump lengths of the XY and XX “turned” embryos were almost identical, as were those of the XXY and XXX “turned” embryos, although the triploids were significantly smaller than the diploids. No obvious effect of sex-chromosome constitution on developmental potential was therefore observed in this study in relation to either the digynic triploid or the control diploid embryos.

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confidence: 99%

Analysis of the sex-chromosome constitution of digynic triploid mouse embryos

Speirs¹,

Kaufman²

1989

Cytogenet Genome Res

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“…In man, a maximum likelihood analysis indicated that XXX and 1 1 7 had viabilities of comparable magnitude (Beatty, 1978). In the rabbit, the M-marker segregations showed that nearly all triploidy after 8 h delayed insemination was digynic.…”

Section: (V) the Relative Viability Of XXX And Xx Y Triploidsmentioning

confidence: 96%

“…The rarity of XYY is also a feature of human triploids (cf. Beatty, 1978). There have been arguments in human material that assumed delayed fertilization of' overripe' oocytes leads to diandric triploidy mediated by dispermy (Schindler & Mikamo, 1970).…”

Section: (Iii) Properties Of the M-markermentioning

confidence: 97%

“…The 12 XXX and 24 XXY were in a proportion deviating significantly from the digynic expectation of 50:50 at the time of fertilization (Shaver & Carr (1967,1969 report 3 XXX, 7 XXY after 6-9 h delay). This suggests a higher relative viability of XXY, but a detailed quantitative check on the lines of Beatty (1978) cannot be made until more data are available.…”

Section: (V) the Relative Viability Of XXX And Xx Y Triploidsmentioning

confidence: 97%

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Digynic triploidy in rabbit blastocysts after delayed insemination

Beatty

Coulter

1978

Genet. Res.

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The origin of triploid (3N) 5j-day blastocysts in rabbits is inferred from the segregation of sex chromosomes and of an autosomal M-marker whose properties are described. 39 triploids and no tetraploids were scored among 1454 chromosomally scored blastocysts. A delay of 8 h between an ovulatory injection and subsequent insemination raised the estimated normal incidence of 0-59 % triploid blastocysts to 3-13 %. The increase is ascribed primarily to digyny (17 blastocysts), and to diandry probably mediated by dispermy (1 blastocyst). The triploid components of the two 2N/3N mosaics and the one 3N/6N were digynic. Neither superovulation nor insemination of excessive numbers of spermatozoa could be shown to give rise to triploid embryos. The diandric triploid was XYY, the first of this constitution apparently reported in the rabbit. There was some evidence that XX Y triploid blastocysts up to 5^-day gestation are more viable than XXX. In the 2N/3N mosaics each component had been entered by one spermatozoon, and the diploid component could not have been merely a contamination by diploid maternal somatic cells. In 2N/4N, 2N/4N/8N and 3N/6N mosaics, each polyploid component showed an exact doubling of the marker chromosome constitution of a component of lower ploidy; their origin is ascribed to doubling or redoubling of chromosome number in isolated embryonic cells. With earlier data included, 49-08 (+ S.B. 1-96) % of 652 diploid blastocysts were 1 7 . 460 non-experimental weaned rabbits were all diploid.

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“…In most mammals, dispermic fertilization is usually prevented by a combination of the fertilized egg's blocks to polyspermy and low sperm number in the fallopian tube. However, >1% of clinically recognized natural human conceptions [111,112] and 5-10% of those from in IVF [113] result in triploid embryos, the majority from dispermic fertilization [114][115][116].…”

Section: Eggs: Clinical Importance Of the Block To Polyspermymentioning

confidence: 99%

Secretory Mechanisms and Ca2+ Signaling in Gametes: Similarities to Regulated Neuroendocrine Secretion in Somatic Cells and Involvement in Emerging Pathologies

Ducibella

Matson

2007

Endocr Pathol

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Recent studies demonstrate that regulated secretion in probably all mammalian cells, from gonadotropes to gametes, utilizes similar signaling systems, intracellular Ca(2+) regulation, Ca(2+)-dependent proteins, cytoskeletal participation, and SNARE-mediated fusion. Thus, highly specialized cells, like sperm and eggs, should no longer be considered to have evolved a cell-type specific secretory mechanism. In gametes, Ca(2+)-dependent proteins and enzymes transduce elevations of intracellular Ca(2+) into secretory events, i.e., exocytosis of the acrosome in sperm and cortical granules in the egg. Just as secretory deficiencies have clinical consequences in endocrine and exocrine cells, failure of secretion of cortical granules or the acrosome can result in failure of normal fertilization or fertilization followed by abnormal development. With the advent of human in vitro fertilization, such gamete pathologies have been recently identified and have led to new clinical procedures to achieve normal fertilization and pregnancies. A better understanding of the common Ca(2+)-dependent secretory pathways in both gametes and somatic cells should be beneficial to investigating mis-regulation in either cell type.

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The origin of human triploidy: an integration of qualitative and quantitative evidence

Cited by 34 publications

References 57 publications

Analysis of the sex-chromosome constitution of digynic triploid mouse embryos

Analysis of the sex-chromosome constitution of digynic triploid mouse embryos

Digynic triploidy in rabbit blastocysts after delayed insemination

Secretory Mechanisms and Ca2+ Signaling in Gametes: Similarities to Regulated Neuroendocrine Secretion in Somatic Cells and Involvement in Emerging Pathologies

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