In 335 B.C.E., Aristotle proposed that the heat of the male partner during intercourse determined sex. At least in the case of reptiles, Aristotle was on to something. What about in other animals?
Soon after the rediscovery of Mendel's work, several scientists noted traits in their crosses seemed “coupled.” But this deviated from Mendel's principles, so how did they explain this?
Can paying attention establish a new field? Learn about Thomas Hunt Morgan, the first person to definitively link trait inheritance to a specific chromosome and his white-eyed flies.
Prenatal diagnostic testing can now determine whether a fetus carries a debilitating or fatal sex-linked mutation. But with such screening, why hasn't the disease allele frequency gone down?
Gene dosage is very important to proper control of gene expression and cellular physiology. These articles review how one X chromosome is activated in cells with two X chromosomes to ensure the proper dosage of transcripts from this chromosome.
Females (XX) carry twice as many X-linked genes on their sex chromosomes as males (XY). How do cells control gene expression to manage this potentially lethal dosage problem?
X inactivation turns off entire chromosomes, whereas imprinting turns off only specific genes. How do these processes work, and why do they often produce similar results?
