Date: December
4, 2019
Source:
Lund University
Researchers in Sweden and the UK have
discovered the largest known avian sex chromosome. The giant chromosome was
created when four chromosomes fused together into one, and has been found in
two species of lark.
"This was an unexpected discovery, as
birds are generally considered to have very stable genetic material with
well-preserved chromosomes," explains Bengt Hansson, professor at Lund
University in Sweden.
In a new study, the researchers charted the
genome of several species of lark, a songbird family in which all members have
unusually large sex chromosomes. The record-size chromosome is found in both
the Eurasian skylark, a species that is common in Europe, Asia and North
Africa, and the Raso lark, a species only found on the small island of Raso in
Cape Verde.
According to the Lund biologists Bengt
Hansson and Hanna Sigeman, who led the study, the four chromosomes have fused
together in stages. The oldest fusion happened 25 million years ago and the
most recent six million years ago. The four chromosomes that have formed the
larks' sex chromosome have also all developed at some time into sex chromosomes
in other vertebrates.
"The genetic material in the larks' sex
chromosome has also been used to form sex chromosomes in mammals, fish, frogs,
lizards and turtles. This indicates that certain parts of the genome have a
greater tendency to develop into sex chromosomes than others," says Bengt
Hansson.
No comments:
Post a Comment