Table 1

Unusual bile salt profiles in reptiles and mammals

Bile salt pattern

Examples

Comment


5α ('allo') bile acids

Lizards, especially Iguania

5α bile acids are generally rare in vertebrates


1α-Hydroxylation

Spotted cuscus (Phalanger maculatus)

Unusual hydroxylation leads to highly hydrophilic bile acids in this species.


1β-Hydroxylation

Feather-tailed glider (Acrobates pygmaeus)

Unusual hydroxylation site


6α-Hydroxylation

Suidae

Lesser Malay chevrotain (Tragulus javanicus)

Unusual hydroxylation site. Hyocholic acid is only detected in Suidae and the chevrotain.


6β-Hydroxylation

Muridae

Unusual hydroxylation site


7-Oxo bile acids

Queensland koala (Phascolarctos adjustus)

Unusual bile salt modification


15α-Hydroxylation

Common wombat (Vombatus ursinus)

Not seen in other mammals but found in birds


16α-Hydroxylation

Snakes

Hydroxylation at 16α is common in snakes (Boidae, Cylindrophiidae, Pythonidae, Uropeltidae) and birds but not seen in mammals.


Ursodeoxycholic acid (at > 5%)

Ursidae

Caviomorph rodents

Ursodeoxycholic acid is seen in other mammals but only as a small percentage of the bile salt pool.


Δ22 Bile acids

Agouti (Dasyprocta punctata)

Mountain paca (Cuniculus taczonowskii)

Pacharana (Dinomys branickii)

Some snakes

This unusual bile acid side-chain modification is seen in a small number of mammals and is also found in some snakes in Colubridae.


22-Hydroxylated C27 bile acids

Turtles

This type of bile salt is unique to turtles.


23R-Hydroxylation

Pinnipeds

Some snakes

23R-Hydroxylation of bile acids is common to Pinnipeds but is not seen in other Carnivora.


100% Bile alcohols

Paenungulates, rhinoceroses

Profile also seen in lobe-finned fish, jawless fish, some teleost fish, and some amphibians.


Hagey et al. BMC Evolutionary Biology 2010 10:133   doi:10.1186/1471-2148-10-133

Open Data