X- and Y-chromosomal gene expression during spermatogenesis, studied in the context of separation of X and Y spermatozoa

Mankind has been interested in S6X preselection since ancient times. Methods presumed to achieve sex preselection have already been described by Greek philosophers as far as 500 B.C. (reviewed by Betteridge, 1984). Although it took almost 2500 years since then to develop reliable and repeatable methods, sex preselection is now possible and is actually applied in both humans and livestock. It can be achieved either by sexing of early embryos or by separation of X and Y chromosome-bearing spermatozoa (X and Y spermatozoa)

Population Reports. Series I, Number 2: Periodic Abstinence. Sex Preselection--Not Yet Practical

https://hsrc.himmelfarb.gwu.edu/pop_reports/1006/thumbnail.jp

A Systematic Evaluation of Methods to Separate X- and Y- Bearing Sperm

This project was initiated to determine if was possible to enrich either X- or Y- bearing sperm, and hence to preselect the sex of a child. Two of the possible reasons why couple might want to select the sex of a child are firstly because of a family history of an X-linked recessive genetic disorder, which usually only affect sons, and secondly families who have had several children of one sex. For this study, men with three or more children of the same sex were recruited following the publication of an article in The West Australian newspaper. The percentage of X- and Y- bearing sperm within the semen samples of men with three or more children of the same sex was determined using dual colour fluorescence in situ hybridisation (FISH). The aim of the investigation was to determine if these men had an altered ratio of X- to Y- bearing sperm, which would explain why these men had a predominance of children of one sex. Comprehensive analyses were also carried out on the semen samples. The reliability of the dual colour FISH technique was established using a number of standard metaphase spreads; from male and female subjects and an individual with Klinefelters syndrome. It was determined that dual colour FISH was a suitable technique for determining the percentage of X- or Y- bearing sperm within a sample. The semen samples were processed using one of two protocols. Samples from men with three or more daughters were treated using Human serum albumin columns, with the intention of increasing the percentage of Y-bearing sperm within the final fraction. It has been suggested that this method enriches the Y- bearing sperm from a sample due to the differential motility exhibited by the X- and Y- bearing sperm, although this characteristic has not been proven. Samples from men with three or more sons were processed using 8-layer ISolate® discontinuous gradients, with, the aim of enhancing the amount of X- bearing sperm within the final fraction. This method is based on the formation of the discontinuous gradients because Percoll has not been approved for the production of sperm fractions for human insemination. It has been suggested that the X- and Y- bearing sperm can be enriched using such gradients either as a result of differences in their velocity of sedimentation or due to a greater nett negative charge on the surface of X- bearing sperm. However, neither of these theories have been validated. As it has also been proposed that the survival rate of X- bearing sperm is slightly longer than that for Y- bearing sperm, this was also investigated. In summary no statistically significant enrichment of X- or Y- bearing sperm was observed following the treatment of the semen samples with either the ISolate® discontinuous gradient or the Human serum albumin column protocols. Nor was there any enrichment in X- bearing sperm due to their suggested greater survival time

A Case of Problematic Diffusion

Sex determination techniques have diffused rapidly in India, and are being used to detect female fetuses and subsequently to abort them. This technology has spread rapidly because it imparts knowledge that is of great value within the Indian context, and because it fits in neatly with the modernization dynamic within India, which itself has enmeshed with traditional patriarchal institutions to oppress Indian women. More research needs to be done on ways to stem the adoption of problematic innovations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68396/2/10.1177_107554709401500301.pd

Gender preselection

published_or_final_versio

Proportional assessment of X and Y chromosome-bearing spermatozoa in bull and boar ejaculates using conventional and real-time PCR techniques

Considerable variation in the percentage of Y-chromosome bearing spermatozoa (%Y-CBS) between ejaculates in the same male has been reported. Collection regime has been speculated to influence the degree of variation in %Y-CBS in bull ejaculates (Chandler et al., 1998). Experiments were designed to evaluate the effects of two collection regimes on %Y-CBS. Conventional PCR combined with gel electrophoresis and image analysis was employed to determine %Y-CBS in ejaculates from two bulls collected on 7-day intervals and two bulls on 21-day intervals. Real-time PCR technology was used to quantify %Y-CBS in the same ejaculates. Boar ejaculates were also analyzed with both techniques and compared to the percent male piglets in litters resulting from the assayed ejaculates. Collection day (P\u3c0.0001) significantly affected %Y-CBS as determined by both PCR methods. Ejaculate nested within bull (P\u3c0.07) was significant in the conventional PCR study and collection frequency (P\u3c0.0001) in the realtime PCR trial. Ejaculate nested within boar was highly significant (P\u3c0.0001) for both technologies. Boar was significant (P\u3c0.002) in the conventional PCR study. Predicted %Y-CBS determined by real-time PCR was significantly correlated (0.52, P=0.004) to percent male piglets. Both PCR techniques were effective in quantifying the variation in %Y-CBS in bull and boar ejaculates. Manipulation of %Y-CBS via collection regime may prove valuable for altering the secondary sex ratio in animal agriculture

Sex Selection: Regulating Technology Enabling the Predetermination of a Child\u27s Gender

The debate over the prohibition of sex (or gender) selection (also known as preselection or predetermination ), has focused almost exclusively on the context of aborting a wrong-sex fetus after a fetal gender-identification procedure. Despite the fact that sex selection abortions represent only a small subset of sex selection procedures, attitudes toward the former are driving general policy approaches to the latter. However, the issues are analytically distinct, and only during the former infancy of the pre-conceptive (and non-abortive post-conceptive) technology for sex selection were members on both sides of the debate afforded the economy of using one logic to support views on two issues

Gendercide : a review of the missing women

The term gendercide was first coined in 1985 and refers to the deliberate extermination of persons of a particular sex. The notion and its potential consequences had been conceived as far back as 1793, when the Marquis Nicolas de Condorcet had speculated “what might be [the effect] on humankind [of] the discovery of a means of producing a male or female child according to the will of the parents [...]. Supposing that this is likely to become a common practice, [...] would it [not] lead to [changes] in the social relations of human beings, whose consequences could be harmful to the peaceable development of that indefinite perfectibility with expectations of which we have flattered humankind?”peer-reviewe

Preconception Sex Selection: Demand and Preferences in the United States

Preconception sex selection for nonmedical reasons raises important moral, legal, and social issues. The main concern is based upon the assumption that a widely available service for sex selection will lead to a socially disruptive imbalance of the sexes. For a severe sex ratio distortion to occur, however, at least two conditions have to be met. First, there must be a significant preference for children of a particular sex, and second, there must be a considerable interest in employing sex selection technology. Our objective was to ascertain such demand and preferences among the United States general population