In many animal species, a chromosomes differ between a sexes. The masculine has a Y chromosome. In some animals, however, for instance birds, it is a other approach round. In birds, a females have their possess sex chromosome, a W chromosome. For a first, researchers in Uppsala have mapped a genetic structure and expansion of a W chromosome.
Every particular of a class has a same sorts of chromosomes, with one exception. In many species, a approach a sexes differ is that males have their possess sex chromosome, a Y chromosome. This contains genes that outcome in a growth of masculine characters and reproductive organs. If there is no Y chromosome, a mammal will be a female.
In birds, however, a conditions is different. It is a females that have a singular sex chromosome – a W chromosome.
In a investigate published currently in Nature Communications, Linnea Smeds, Hans Ellegren and their colleagues uncover that, surprisingly enough, a bird’s W chromosome does not enclose genes that lead to a growth of a female.
“Sex integrity in birds and other animals with a W chromosome seems instead to count on a series of their homogeneous to a X chromosome. Two copies of it produces a male, one duplicate (plus a W chromosome) produces a female,” says Hans Ellegren.
The W chromosome seems instead to duty as some kind of aegis for females given it contains genes identical to those in a X chromosome. In sequence for certain genes to work, it is vicious that an particular has dual copies of that gene. In this way, a W chromosome can offer as a element for females who usually have one duplicate of a X chromosome.
Researchers have detected that a W chromosome changes during a slower rate than any other partial of a genetic material.
“This is since it is usually hereditary on a maternal side and fewer mutations arise in females than in males,” says Hans Ellegren.
Most mutations start during a arrangement of virus cells. Males furnish a vastly larger series of virus cells than females and so a luck that a spermatazoa contains a new turn is most larger than for an egg cell.
The W chromosome is a usually chromosome from a dungeon iota that is hereditary on a maternal side. It shares this skill with a tiny volume of DNA found in dungeon mitochondria.
Source: University of Uppsala