Biology Stack Exchange is a question and answer site for biology researchers, academics, and students. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I am not a biology student, but just want to know if GULO gene are present only in mammals or all species possess it ?

And is GULO gene active in human fetus?

share|improve this question
up vote 4 down vote accepted

GULO encodes L-gulonolactone oxidase which catalyses a step in the biosynthetic pathway to ascorbic acid (vitamin C).

I did a BLAST search at NCBI using the mouse GULO protein as probe, excluding mammals, and I saw highly significant hits in reptiles, birds, sea urchins, fungi and bacteria. I conclude that this enzyme, (or very close relatives) is ubiquitous.

Humans (and other primates; also guinea pigs and the Dalmatian coach hound) have a defective GULO gene and so require dietary ascorbate.

Since the gene is non-functional in humans it isn't expressed in the foetus.

share|improve this answer
+1 Finally I got to know why humans and guinea pigs need dietary Vitamin C. – biogirl Feb 22 '14 at 16:41

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.