Sex in Relation to Chromosomes and Genes

  title={Sex in Relation to Chromosomes and Genes},
  author={Calvin B. Bridges},
  journal={The American Naturalist},
  pages={127 - 137}
  • C. Bridges
  • Published 1 March 1925
  • Biology
  • The American Naturalist
sions as readily as they do throws considerable doubt on the hypothesis that they are even primarily sex-producing. It may be a mere coincidence. They may be merely sex-indicating and after a case of sex reversal they can not even be that. The sex of the egg may be determined even before fertilization takes place. Many botanists formerly thought that a diploid number of chromosomes was the cause of sporophytic expression and a haploid number the cause of gametophytic expression, but we now know… 

Autonomy and nonautonomy of sex determination in triploid intersex mosaics of C. elegans.

The observed patterns of male and female cells in individual animals indicate that sex determination decisions can be influenced by anterior-posterior position and that sex decision can be made as late as the third larval stage of postembryonic development, suggesting that C. elegans is not entirely cell autonomous.

Chromosome Number, Polyploidy, and Sex in the Animal Kingdom

The method of disjunction of the sex genes is particularly interesting to follow in polyploids, and it has been proved that certain types of segregation are favoured compared with others (Rumex acetosa, Drosophila).

The structure and function of the sex chromosomes in man.

The development and application of new techniques for the study of human chromosomes has revealed that the genetics of sex determination in man appears to be different from any other system so far known and may still be accommodated within the limits of a balance theory.

Reversal of an ancient sex chromosome to an autosome in Drosophila

The results reveal several puzzling aspects of Drosophila dot chromosome biology to be possible remnants of its former life as a sex chromosome, such as its minor feminizing role in sex determination or its targeting by a chromosome-specific regulatory mechanism.

Polyploids and sex determination in Caenorhabditis elegans.

There exists on the C. elegans X chromosome at least three (and perhaps many more) dose-sensitive sites that act cumulatively in determining sex.

Sex Determination in Drosophila melanogaster

Current intensive research in this area should lead within the next few years to definitive knowledge at the molecular level of the cascade of differential splicing of regulatory genes, and how this hierarchy ultimately gives rise to the appropriate sex-specific patterns of structural gene expression that underlie sexual dimorphism.

Structure, function and evolution of sex-determining systems in Dipteran insects.

The results show that sex-determining cascades, in comparison to other regulatory pathways, evolve much more rapidly.

Chromosome polymorphism and sex determination in a wild population of tsetse

A natural population of Glossina palpalis palPalis (R-D) found to contain a high incidence of aneuploids, the composition of which may be used to explain the mechanism of sex determination in the genus.

XX Male : Isolation of the First Caenorhabditis elegans Sex-Determination Mutants

The first sex-determination mutants to be found in the nematode Caenorhabditis elegans (Hodgkin in which sex is also determined by an X:A ratio) were reported, marking the 25th anniversary of a paper marked by the absolute number of X chromosomes.



Variations in Datura Due to Changes in Chromosome Number

It is argued that certain of the pure lines of Datura differ slightly from others when grown in comparable pedigrees, but the fact remains that so far as sharply contrasting Mendelian characters are concerned, the jimson weed is highly stable, while the Portulaca is highly mutable.


A complete reversal of the ordinary criss-cross inheritance of recessive sex-linked characters occurs in a line of Drosophila recently obtained, and is explicable on the assumption that the two X-chromosomes of the mother are united and behave at reduction as a single body.

Untersuchungen uiber Intersexualitat

  • Zeit . f . ind . Abst . U . Verer .
  • 1920

Polyploidie und Geschlechterverteilung bei Splachnuin splhericum Schwartz

  • Flora
  • 1923