The Strategy of the Genes. The genes on the differential regions of the sex chromosomes show patterns of inheritance related to sex. A recent study suggests another mechanistic role by which dosage compensation can affect patterns of gene expression on the Drosophila X chromosome.
The odds of either of these two scenarios are so low that X-linked recessive diseases are sometimes referred to as male only diseases. This is in sharp contrast to most birds wherein the W is much smaller and has many fewer genes than the Z.
Previous Topic. Another example of X-linked sex traits is hemophilia. By the early 20th century, ten of Victoria's descendents had hemophilia. Read More on This Topic.
Some inconvenient truths about sex chromosome dosage compensation and the potential role of sexual conflict. The Y chromosome is considerably shorter than the X. The Y chromosomes in tsetse flies and at least two species of Homoptera may also have B chromosome origins.
Evolution of sex chromosomes.
Empirical evidence seems to support this prediction, although we note the existence of an ascertainment bias to observing meiotic drive on sex chromosomes than on autosomes. Each parent contributes one half of each pair or 23 chromosomes to their child, 22 autosomal and 1 sex chromosome.
Jaenike J. Muller HJ.