Fragile X syndrome is caused by a mutated gene on the X chromosome. Affected individuals have developmental delays, variable levels of mental retardation, and behavioral and emotional problems. They may also have characteristic physical traits. Males...

The XY sex-determination system is the sex-determination system found in humans, most other mammals, some insects (Drosophila) and some plants (Ginkgo). In the XY sex-determination system, females have two of the same kind of sex chromosome (XX), and...

INTRODUCTION Sex determination is a process that leads to the physical separation of male and female gamete-producing structures to different individuals of a species. Even though sexually reproducing species have only three possible options-to relegate the two sexes to separate individuals, to keep...

ABSTRACT The tiger pufferfish (fugu), Takifugu rubripes, is a model fish that has had its genome entirely sequenced. By performing genomewide linkage analyses, we show that the sex of fugu is determined by a single chromosomal region on linkage group 19 in an...

Sex determination is decided by the 23rd pair of chromosomes commonly known as the sex chromosomes.