2001), anxiety (Marazziti et al. 2007), and emotional expression (Tops et al. 2007). The oxytocin peptide also acts directly on maternal care (Richard et

al. 1991). The release of oxytocin during delivery triggers maternal behavior in rodents (Pedersen et al. 1982). Oxytocin-deficient female mice fail to provide milk to offspring (Nishimori et al. 1996; Young et al. 1996), although they display otherwise normal maternal behaviors. Oxytocin may also have a role in motivating Inhibitors,research,lifescience,medical the mother to retrieve her pups (Pedersen et al. 2006), and deficits in this hormone can lead to deficient offspring care (Collins et al. 2004). The FosB gene belongs to the fos gene family known as immediate early genes (Herschman 1991; Yen et al. 1991) and is induced rapidly in specific brain regions in response to various stimuli. This induction is temporary and returns rapidly to basal levels after being triggered (Nestler et al. 1999). FosB has been associated with addictive Inhibitors,research,lifescience,medical behavior (Hiroi et al. 1997), response to hormones (Lin et al. 2003), and social behaviors, including pair bonding (Curtis and Wang 2003) and maternal care (Brown et al. 1996). In fact, FosB was the first gene described in mice to be related to maternal care (Brown et al. 1996). FosB

knockout females Inhibitors,research,lifescience,medical fail to retrieve their pups and do not crouch over the nest. Peg3 encodes a zinc-finger protein (Kuroiwa et al. 1996) and is highly expressed in brain regions crucial for maternal behavior, including the medial preoptic area of the hypothalamus, the medial amygdala, the bed nucleus of the stria terminalis, the hippocampus, and olfactory bulb (Li Inhibitors,research,lifescience,medical et al. 1999). Peg3 is a paternally expressed imprinted gene that promotes cell survival, in contrast to p53-mediated apoptosis (Relaix et al. 1998, 2000). Peg3 affects body temperature regulation, feeding behavior, and obesity in mice (Curley et al. 2005), and its disruption can lead to aberrant maternal behavior. Peg3-deficient mice are viable but are smaller than wild type, and females do not build nests, fail to retrieve pups, and have lactation problems, Inhibitors,research,lifescience,medical resulting in the death

of their progeny (Li et al. 1999). We found the same maternal behavior abnormalities reported for Oxt-, FosB-, and Peg3-deficient females (Brown et al. 1996; Nishimori et al. 1996; Young et al. 1996; Li et al. 1999) to be segregated in the intercross of LG/J and SM/J inbred mouse strains (Peripato et al. 2002). Because we have previously identified Carfilzomib these genes as positional candidates for main effect QTLs, we here investigate an association between maternal selleck catalog behaviors in SM/J and LG/J postpartum females and two www.selleckchem.com/products/Paclitaxel(Taxol).html properties of these candidate genes, DNA sequence variation and hypothalamic mRNA expression. We also tested for an effect of the Peg3 gene in/del variant on maternal care in F2 females derived from a LG/J and SM/J intercross. Materials and Methods Animals Breeding pairs of the SM/J and LG/J inbred strains (see Hrbek et al.