Green-blood pigmentation in lizards

Scientists explore DNA secrets of green-blooded lizards

This surprised the researchers, who made a decision to investigate the matter and disclose the mystery of the green blood.

Prasinohaema prehensicauda is a green-blooded lizard with high concentrations of biliverdin, or a toxic green bile pigment, found in New Guinea.

These lizards, selengkapnya Skinks (Prasinohaema), possess several unique and unusual features.

The green pigment comes from high levels of biliverdin, a "toxic waste product made during the body's normal breakdown of red blood cells", NPR reports.

A group of lizards inhabiting the island of New Guinea boasts one of the most exotic traits of any animal: green blood. We review the literature for fish species with high concentrations of plasma biliverdin and pathological biliverdin accumulation in humans; we find that Prasinohaema species have plasma biliverdin concentrations approximately 1.5-30 times greater than fish species with green blood plasma and 40 times greater than humans with green jaundice.

Christopher Austin, from the Museum of Natural Science at Louisiana State University, has been studying these reptiles extensively and seems to be fascinated with them.

"In addition to having the highest concentration of biliverdin recorded for any animal, these lizards have somehow evolved a resistance to bile pigment toxicity".

They found that green blood in these lizards likely evolved four different times, and that all of the green-blooded lizards were probably descended from a red-blooded ancestor.

"Oh, these animals are gorgeous, truly some of the most handsome and enigmatic lizards in the world, living on one of the most megadiverse islands on the planet", Austin said. The team studied the DNA of 51 species of New Guinea skinks, including six with green blood. Their results will be published on May 16 in Science Advances.

The fact that green blood emerged independently on numerous occasions suggests it may be evolutionarily beneficial, according to the researchers. As of now, however, the function of bile pigment in green-blooded lizards remains a mystery.

Previous research has demonstrated that bile pigment can act as an antioxidant, terminating free radicals.

"The green-blooded skinks of New Guinea are fascinating to me as a parasitologist because a similar liver product, bilirubin, is known to be toxic to human malaria parasites".

The reason for this, as scientists believe, may be the fact that biliverdin is helping the lizards to defend themselves against malaria and other parasitic infections for which bile is as strong a poison, as humans and other multicellular animals. This is the only species of green-blooded skink that lays eggs. The researchers say the next step is to identify the specific genes responsible for green blood.



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