The specific immune response of offspring was stronger in 2014 than in 2013 (1.370.11 and0.170.12 [log (mOD min1)], respectively) and depended on nestling status (Table2). knowledge about how prenatal immune-mediated maternal effects interact with various postnatal rearing conditions to affect offspring development and phenotype in wild LSD1-C76 bird population remains elusive. Here we experimentally studied the interactive effects of pre-laying maternal immunization with a bacterial antigen (lipopolysaccharide) and post-hatching rearing conditions, altered by brood size manipulation, on offspring growth and humoral immunity of wild great tits (Parus major). == Results == We found that maternal immunization and brood size manipulation interactively affected the growth and specific humoral immune response of avian offspring. Among nestlings reared in enlarged broods, only those that Rabbit polyclonal to LPGAT1 originated from immunized mothers grew better and were heavier at fledging stage compared to those that originated from non-immunized mothers. In contrast, no such effects were observed among nestlings reared in non-manipulated (control) broods. Moreover, offspring of immunized females had a stronger humoral immune response to lipopolysaccharide during postnatal development than offspring of non-immunized females, but only when the nestling was reared in control broods. == Conclusions == This study demonstrates that offspring development and their ability to cope with pathogens after hatching are driven LSD1-C76 by mutual influences of pathogen-induced prenatal maternal effects and post-hatching rearing conditions. Our findings suggest that immune-mediated maternal effects may have context-dependent influences on offspring growth and immune function, related to the postnatal environmental conditions experienced by the progeny. LSD1-C76 == Electronic supplementary material == The online version of this article (10.1186/s12983-018-0272-y) contains supplementary material, which is available to authorized users. Keywords:Brood size manipulation, Food availability, Great tit, Humoral immune response, LPS, Maternal antibodies,Parus major, Prenatal maternal effects == Background == Early life environmental conditions play a key role in determining an individuals phenotype, with consequences for fitness [1,2]. Mothers, to a large extent, provide the primary environment experienced by their offspring both before and after birth/hatching. Indeed, females have the potential to create and adjust the prenatal environment and thus affect developmental trajectories of their progeny [3]. Such prenatal maternal effects (MatEs) not only influence embryo growth and development (e.g. [4]), but most importantly, determine morphology, physiology and behaviour of offspring during their postnatal life (e.g. [3,5,6]). However, the prenatal environment provided by a mother is usually, at least to some extent, under the influence of the environmental conditions experienced by her before and during breeding. As a result, mothers can transfer some information about the local environment they experience to the next generation (e.g. [7,8]). Such environmentally-induced MatEs have been suggested to be a form of adaptation to a heterogeneous but predictable environment, by which females can prepare their progeny for postnatal conditions, to enhance fitness [3,9]. However, the fitness benefits of prenatal MatEs are primarily expected when the female and her offspring experience the same environmental conditions [2,9]. Prenatal transfer of antibodies (Abs) from a mother to her progeny is a good example of a MatE by which a female may shape offspring resistance to pathogens and parasites [1012]. Maternal antibodies (MatAbs) are a primary form of protection against pathogens for neonates, since the lack of a mature and efficient immune system makes them especially prone to infections [13,14]. Therefore, Ab-mediated MatEs may benefit offspring by helping them to cope with pathogens and parasites and ultimately increase their survival prospects (e.g. [10,1517]). However, females can only provide this protection to offspring against pathogenic antigens to which they have been previously LSD1-C76 uncovered (e.g. [18]). Moreover, there is evidence that maternally-derived Abs affect the development of a neonates immune system, which has consequences for immune function in both the short- and long-term (e.g. [12]). On the one hand, MatAbs may primary an offsprings own immunity and thereby induce a stronger LSD1-C76 humoral immune response to pathogenic antigens encountered.