The PGSC has two additional stocks available we want to bring to our readers attention. Both are within the P. maniculatus/ P. polionotus group, for which we now have a full genetic map and nascent genome sequences (see this blog entry). The first is the previously mentioned P. polionotus leucocephalus-subgriseus intercross stock, termed LP: Please consider using them if you need P. polionotus animals!
The LP stock has additional uses apart from its obvious importance for the study of coat-color/pattern differences within this species – see these recent papers 1, 2, 3. First, the LP stock is more fecund than the parental stocks from which it was derived, making it a better choice for reproductive studies involving P. polionotus. The greater number of polymorphisms also makes it a better choice for studying allele-specific gene expression (e.g. genomic imprinting, X-chromosome inactivation).
We have found that the LS stock behaves the same way in crosses with BW in terms of growth and developmental phenotypes, and genomic imprinting profiles. See this paper (Wiley et al. 2008); many of the P. polionotus females we used were LP.
We also showed the LS stock is equivalent to PO in terms of glucose tolerance (challenge) tests and effects of stress on those thereon- see this paper (Oriel et al 2008). This test is among the key indicators of diabetes. The subject is fasted, then given a large dose of glucose. Blood sugar levels rise, and then go back to normal (failure of blood sugar levels to drop is indicative of diabetes). Interestingly, the (calmer) PO and LS animals were much better at this than BW animals, and this appeared to be due to a stress response. In other words, the species differences in regulating blood sugar seem to be due to that fact that P. polionotus can buffer stressful situations (fasting & handling in this case) than P. maniculatus.
Going through the data for that paper, I did find that LS males reacted slightly differently than PO males to an insulin tolerance test. In this test, insulin is administered so that blood sugar levels initially drop and then return to normal. Note (from the attached figure) that the stats don’t quite support this difference as being significant, however. Again, if you’re interested in P. polionotus for monogamy or other studies, please consider the LP stock. If you need rapid breeding, we particularly recommend them!