The koalas are probably one of the most adorable animals on Earth, and they look like stuffed animals. They are well-known for their enormous capacity to rest as they can sleep up to twenty hours a day. The koalas consume about one kilogram of eucalyptus leaves per day, a diet that is extremely toxic to other living beings, including humans. A new study took an approach to find out how koalas can survive to this enormous intake of poisonous food by generating the whole koala genome to date.
Until now, it was thought that to support this type of food koalas had an extremely slow metabolism, which allowed them to retain food in their digestive system for an extended period.
Deciphering the koala genome
A new study, published in the journal Nature Genetics, reveals the most comprehensive koala genome to date. An international team of scientists has sequenced the 3.4 billion base pairs of koalas DNA, which has just over 26,000 genes in total.
The results show that the koala has a larger genome than that of humans and offer us new molecular clues about the characteristics of the marsupial, including the ability to feed solely on eucalyptus leaves. These mammals have two large expansions of a set of key detoxifying genes from their usual diet.
In particular, scientists have observed that koalas have genetic sequences that contain instructions for making very important proteins, belonging to the cytochrome P450. This family of enzymes, also present in the human species, helps metabolize compounds so that cells can survive.
Studying koalas DNA might help scientists save this species
According to the Koala Genome Consortium, knowing the DNA sequences that help these marsupials detoxify is important for their veterinary care.
These genes would allow them to metabolize drugs used to relieve pain and antibiotics against chlamydia, a sexually transmitted disease caused by a bacterium that affects koalas. Also, the study has also shown for the first time the genes related to the immune system of these marsupials.
Additionally, scientists have discovered that a single specimen may contain more than 100 insertions of the koala retrovirus into its genome. These infectious agents attack the marsupial defenses, similar to the action of HIV in humans. According to the authors, these findings will allow us to know which strains are more aggressive and will help the conservation of a species vulnerable to extinction.
Erin VanDyke lives on her family farm and has more than 35 years of hands-on experience with the use of livestock guard dogs for predator control. On their farm, Jan and her family use corgis as herding dogs and have raised Shetland sheep, Fainting goats, Morgan and Trakehner horses, and historic breeds of chickens and turkeys. Erin is also an active beekeeper.