X-Autosome translocations: Cytogenetic characteristics and their consequences

Mattei, Marie-Genevı̀eve; Mattéi, Jean-François; Aymé, Ségolène; Giraud, F

doi:10.1007/bf00276593

Cited by 146 publications

(95 citation statements)

References 75 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Such homology likely generates a physical association between the sex vesicle or "XY body" (64,65) and the short arm of chromosome 15; physical association likely also occurs during metaphase (66). Sequence homology between repetitive DNA in chromosome 15 (and the other acrocentric chromosomes: 13, 14, 21, and 22) and in the X chromosome may also help generate a physical association (67); this may cause the excess of translocations involving the X chromosome and chromosomes 15, 21, and 22 (68). Entanglement may underlie the susceptibility of chromosome 15 to karyotypic abnormalities (69).…”

Section: Discussionmentioning

confidence: 99%

The human sex ratio from conception to birth

Orzack

Stubblefield

Akmaev³

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

235

170

View full text Add to dashboard Cite

We describe the trajectory of the human sex ratio from conception to birth by analyzing data from (i) 3-to 6-d-old embryos, (ii) induced abortions, (iii) chorionic villus sampling, (iv) amniocentesis, and (v) fetal deaths and live births. Our dataset is the most comprehensive and largest ever assembled to estimate the sex ratio at conception and the sex ratio trajectory and is the first, to our knowledge, to include all of these types of data. Our estimate of the sex ratio at conception is 0.5 (proportion male), which contradicts the common claim that the sex ratio at conception is malebiased. The sex ratio among abnormal embryos is male-biased, and the sex ratio among normal embryos is female-biased. These biases are associated with the abnormal/normal state of the sex chromosomes and of chromosomes 15 and 17. The sex ratio may decrease in the first week or so after conception (due to excess male mortality); it then increases for at least 10-15 wk (due to excess female mortality), levels off after ∼20 wk, and declines slowly from 28 to 35 wk (due to excess male mortality). Total female mortality during pregnancy exceeds total male mortality. The unbiased sex ratio at conception, the increase in the sex ratio during the first trimester, and total mortality during pregnancy being greater for females are fundamental insights into early human development.he sex ratio at conception in humans is unknown, despite hundreds of years of speculation and research. Investigations of the sex ratio date back at least as far as Graunt (1) who described a net excess of male births (2). By the late 1800s, it was clear that more males than females die during later pregnancy (3). Beyond these facts, the demographic and genetic dynamics of the sex ratio from conception to birth are poorly resolved.The claim that the conception or primary sex ratio (PSR) is more male-biased than the birth sex ratio appears often in textbooks (4, 5) and in the scientific literature (e.g., refs. 6-11), usually with little or no description of evidence. Estimates of the PSR in these studies are typically 0.56 (proportion males) or greater. Many fewer researchers have claimed that the PSR is unbiased or slightly male-biased (12-16). A handful of researchers has claimed or implied that the PSR is female-biased (17-19) or claimed that the PSR cannot be estimated due to lack of appropriate data and/or methodological problems (20)(21)(22).Previous estimates of the PSR have no meaningful basis in data from the time of conception (or within at least a month of it). At best, the PSR has been estimated via backward extrapolation from data on induced or spontaneous abortions, fetal deaths, or live births; most of the non-live-birth data stems from the second or third trimester of pregnancy. In addition, even if one ignores the fallibility of extrapolation, biased estimates of the PSR based on spontaneous abortions and fetal deaths have usually been regarded as arising from unbiased samples of a population of embryos or fetuses having a biased PSR. The alternativ...

show abstract

Section: Discussionmentioning

confidence: 99%

The human sex ratio from conception to birth

Orzack

Stubblefield

Akmaev³

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

235

170

View full text Add to dashboard Cite

show abstract

“…In Gallus domesticus also, cytological evidence suggests that ZW gonosomes undergo non-homologous pairing in Z-autosome translocations (Solari et al, 1988 (Gustavsson et al, 1989). In that case as well as in the present translocation, the male was sterile, which is a common phenomenon in this type of translocation in man and mouse (reviewed by Mattei et al, 1982;Searle, 1982). According to Lifschytz and Lindsley (1972), the inactivation of the X chromosome is essential for normal spermatogenesis, which means that autosomal material translocated to the X chromosome interferes with X chromosome inactivation.…”

mentioning

confidence: 54%

Synaptonemal complex analysis of an X-autosome translocation-carrier in the domestic pig

Villagomez¹,

Świtoński²,

Singh³

et al. 1991

Genet Sel Evol

View full text Add to dashboard Cite

“…At least at the cytological level, X inactivation can spread over quite long distances, into autosomal material, in both murine and human X;autosome translocations (e.g., see Disteche et al 1979;Mattei et al 1982;Keitges and Palmer 1986). In addition, ectopic copies of the mouse Xist gene can lead to inactivation of at least some autosomal loci (Lee and Jaenisch 1997).…”

Section: Discussionmentioning

confidence: 99%

“…Thus, the phenomenon of X-inactivation progression has been linked cytologically to the timing of DNA synthesis. Using this difference in the timing of DNA synthesis, late-replication banding analyses of X;autosome translocations in both mouse and human have revealed that translocated autosomal material becomes later replicating compared with its intact autosomal counterpart and thus appears more like the adjacent inactive X chromosome (Eicher 1970;Disteche et al 1979;Mattei et al 1982;Keitges and Palmer 1986). Additionally, latereplication studies have suggested that the spreading of inactivation into autosomal sequences may be incomplete and discontinuous (Disteche et al 1984;Keitges and Palmer 1986;Schanz and Steinbach 1989).…”

Section: Introductionmentioning

confidence: 99%

The Spreading of X Inactivation into Autosomal Material of an X;autosome Translocation: Evidence for a Difference between Autosomal and X‐Chromosomal DNA

1998

Am. J Hum. Genet.

View full text Add to dashboard Cite

SummaryX inactivation involves initiation, propagation, and maintenance of genetic inactivation. Studies of replication timing in X;autosome translocations have suggested that X inactivation may spread into adjacent autosomal DNA. To examine the inactivation of autosomal material at the molecular level, we assessed the transcriptional activity of X-linked and autosomal loci spanning an inactive translocation in a phenotypically normal female with a karyotype of 46,X,der(X)t(X;4)(q22;q24). Since 4q duplications usually manifest dysmorphic features and severe growth and mental retardation, the normal phenotype of this individual suggested the spreading of X inactivation throughout the autosomal material. Consistent with this model, reverse transcription-PCR analysis of 20 transcribed sequences spanning 4q24-qter revealed that three known genes and 11 expressed sequence tags (ESTs) were not expressed in a somatic-cell hybrid that carries the translocation chromosome. However, three ESTs and three known genes were expressed from the t(X;4) chromosome and thus "escaped" X inactivation. This direct assay of expression demonstrated that the spreading of inactivation from the adjoining X chromosome was incomplete and noncontiguous. These findings are broadly consistent with the existence of genes known to escape inactivation on normal inactive X chromosomes. However, the fact that a high proportion (30%) of tested autosomal genes escaped inactivation may indicate that autosomal material lacks X chromosome-specific features that are associated with the spreading and/or maintenance of inactivation.

show abstract

X-Autosome translocations: Cytogenetic characteristics and their consequences

Cited by 146 publications

References 75 publications

The human sex ratio from conception to birth

The human sex ratio from conception to birth

Synaptonemal complex analysis of an X-autosome translocation-carrier in the domestic pig

The Spreading of X Inactivation into Autosomal Material of an X;autosome Translocation: Evidence for a Difference between Autosomal and X‐Chromosomal DNA

Contact Info

Product

Resources

About