05). Pups from SM/J mothers had milk in their stomachs as soon as the first day of life, which was not observed in pups delivered by LG/J dams, which only presented milk from the second day forward (ϕ= 0.57, P < 0.001). SM/J females groomed their pups and retrieved them after nest disturbance more frequently than LG/J mothers on first day after birth (ϕ= 0.43, P < 0.01). The survival rate for animals

born to SM/J mothers was 72% while only 35% of the pups born to LG/J dams were viable after one week (P < 0.01). Figure 2 Maternal attributes of SM/J and LG/J mice inbred females. (a) Maternal performance: prepartum nest indicates the percentage of females with good quality, prepartum nests; postpartum Inhibitors,research,lifescience,medical nest indicates Inhibitors,research,lifescience,medical the percentage of females with good quality, postpartum ... In the FS test, LG/J females spent more time in an immobile or floating position than SM/J female mice (P < 0.01). In the EPM test, LG/J females spent less time and made fewer forays into the open arms of the apparatus when compared to SM/J mothers (P < 0.05 for both parameters). LG/J females also had a lower absolute frequency of entries into

either of the arms (P < 0.05). We found a correlation between pup retrieval behavior and immobility in the FS test (–0.53; P < 0.05). The performance in the EPM test was also correlated with pup retrieval (0.70 Inhibitors,research,lifescience,medical for time and 0.62 for entries in the open arms; P < 0.01 for both). Sequencing of candidate genes and Peg3 sequence variations Oxt, FosB, Inhibitors,research,lifescience,medical and Peg3 sequences in SM/J and LG/J mice showed high similarity to sequences from other Mus musculus strains in the Mouse Genome Database (MGB–NIH). Oxt showed no sequence variation between SM/J and LG/J. When we compared FosB gene sequences, we found only a G insertion in intron 1 in LG/J, but not in the SM/J strains. However, when

we compared the Peg3 sequence between SM/J and LG/J mouse strains, we found several relevant differences. The LG/J Peg3 sequence has four replacement Inhibitors,research,lifescience,medical substitutions, one on exon 8, T11062G (Leu>Arg), and the others on exon 9, namely G13744A (Asp>Asn), A13808G (Asp>Gly), and A13813G (Lys>Glu). There was also a silent substitution, T13806C (His) and a 30-bp (10 aa) tandem repeat in the coding region of Peg3. The LG/J strain showed five copies of this repeat, no but only three copies were observed in the SM/J strain (13852Δ13912) (Fig. 3). Figure 3 Sequencing and genotype variations in Peg3. (a) Representation of the nine exons of the Peg3 mouse gene. Positions of the Peg3 sequence variations in SM/J and LG/J strains are shown in the expansions. * SAR302503 ic50 represents a non-silent variation, # represents … Peg3 gene variation in F2 dams is correlated with offspring survival We investigated whether the Peg3 tandem repeat occurring three times in SM/J and five times in LG/J was associated with maternal failure based on offspring survival.