We studied reciprocal hybrids of Mus musculus musculus and M. m. domesticus. These two subspecies of house mouse were found to differ in their social behaviour, the former being less aggressive than the latter. The paternal effect on aggression (observed repeatedly in laboratory mice) was not found. However, F2 generation mice were less aggressive than those from the F1 generation, and the maternal effect was also significant in a homogenous test set.
The attractiveness hypothesis predicts that females should bias the sex ratio of their offspring towards sons when mated to attractive males. Females of many socially monogamous bird species commonly engage in extra-pair fertilizations (EPFs). Assuming that extra-pair males are more attractive to females than their social partners, and that sons inherit superior traits from their fathers, extra-pair young should be more likely males. According to the maternal condition hypothesis male-biased sex ratio in offspring should be also associated with better female body condition. We evaluated these ideas in the scarlet rosefinch (Carpodacus erythrinus), socially monogamous songbird with moderate level of extra-pair fertilizations. Contrary to the attractiveness hypothesis we have found no significant effect of paternity (within-pair or extra-pair) on the sex of individual offspring. Furthermore, data did not suggest that females mated to males with more elaborated plumage colour were more likely to produce sons. However, consistently with the maternal condition hypothesis, high-quality females produced more sons than daughters. Our results indicate that scarlet rosefinch females may not be able to manipulate the primary sex ratio of their offspring in relation to the attractiveness of their mate, but they may adjust it according to their own condition.
Genetic variation among populations of commensal house mice was studied across the territories of the Czech and Slovak Republics and in some adjacent areas of Germany. We used six diagnostic allozyme loci (Es-2, Gpd-1, Idh-1, Mpi, Np, Sod-1) and the following molecular markers: B1 insertion in the Btk gene (X chromosome), Zfy2 18-bp deletion (Y chromosome), BamH I restriction site in the mt-Nd1 gene (mtDNA) and Hba-4ps 16-bp insertion (diagnosing the presence of t haplotypes). In total, 544 individuals taken from 49 localities were examined. Almost the entire territories of the Czech Republic and Slovakia were found to be occupied by Mus musculus, the only exception being the westernmost parts of the Czech Republic, where M. musculus meets the range of M. domesticus and forms a narrow belt of hybrid populations. Despite this, domesticus-type alleles of some allozyme markers (notably Es-2) were also found at sites well within the range of M. musculus, either tens or hundreds of kilometres behind the hybrid zone. This provides evidence of either: (1) introgression of some markers into the species’ genome due to free gene flow through the zone, or (2) human-mediated long-distance migrations, or (3) incomplete lineage sorting. Conversely, variants of molecular markers typical for M. domesticus in Btk, Zfy2 and mt-Nd1were only found in the westernmost populations studied. t haplotypes were quite frequent in some populations, irrespective of whether M. domesticus, M. musculus or their hybrids, yet no t/t homozygotes were found. The mean frequency of t/+ heterozygotes found within the study populations was 13%.
The purpose of this Summer School, which took place in Liblice 1 to 7 September 2008, was to introduce the students and post-docs to updated procedures used in the analyses of molecular data-sets applied to problem-solving in conservation genetics. This was done by bringing together geneticists statisticians and empirical conservation geneticists who presented theoretical lectures and led practical computer work. and Josef Bryja, Pavel Munclinger.