New Hamsters!

We just received a new strain of Siberian dwarf hamsters. They are an inbred line from Bruce Goldman at UMASS Amherst. They are reported to change color reliably and, as they are a different collection from the stocks that we've been using so far, they should be genetically distinct from ours to some degree.

I'm hoping to use them to assay imprinting within P. sungorus if they are different enough. Of the projects that I've done so far, the main shortcoming is that I do not know which genes are imprinted in hamsters and which are not. I have to guess based on the genes that are imprinted in house mice, deer mice, and humans. This is a problem because we know that different species imprint different genes. For example, deer mice do not imprint Mash2 while house mice do. Of the genes I surveyed in our original strains of dwarf hamster, there were three that appeared to not be imprinted, but that may instead be due to imprinting breaking down in both reciprocal hybrids. Using this new strain of P. sungorus I should be able to determine which genes are actually imprinted within that species.

This will of course depend on whether there are an appreciable number of nucleotide differences between the two strains. In order to determine whether an allele is imprinted, I have to find at least one diagnostic SNP within the expressed region. If these two strains are very closely related, they may not have such diagnostic SNPs. However, I think that they likely will as between P. campbelli and P. sungorus there are 3-6 diagnostic sites per kilobase and those two are relatively recently diverged. The standing polymorphism within one species should be less, but likely still high enough for there to be at least 1 SNP in each exon. I am assuming that these two independent collections will have sampled different subsets of the standing species-level polymorphism and so will have enough differences to answer my question.