Cross fostering in mice: Behavioral and physiological carry-over effects in adulthood

Dipartimento di Biologia Evolutiva e Funzionale, Università di Parma, Parma, Italy.
Genes Brain and Behavior (Impact Factor: 3.66). 05/2004; 3(2):115-22. DOI: 10.1111/j.1601-183X.2003.00059.x
Source: PubMed


Cross fostering is a widely used laboratory practice. However, relatively few studies have directly investigated the carry-over effects of this procedure in adult animals. The aim of the present study is to investigate the late effects of cross fostering (CF) at birth (in litters composed of no siblings) on adult mice. When adults, cross-fostered male and female mice were examined for intrasex aggression, and levels of emotionality, exploration and anxiety. In addition, body weight was monitored, several internal organs were weighed and plasma corticosterone levels were measured. When compared to controls, body weight of CF male and female mice was increased, at least after early puberty. CF males showed smaller preputial glands, while basal corticosterone level was not affected by cross fostering. In the free-exploratory test, CF males, but not females, showed a behavioral profile suggestive of lower anxiety. These effects in adulthood cannot be ascribed to differences in the maternal care received, which was not affected by cross fostering. In conclusion, cross fostering at birth induced a number of behavioral and physiological alterations in mice, particularly in males. These findings should be carefully evaluated when applying cross fostering procedure to laboratory animals.

Download full-text


Available from: Laura Gioiosa,
48 Reads
  • Source
    • "To analyze if the postulated effect is more pronounced in one of the sexes as described by e.g. Bartolomucci et al. [36], we investigated males as well as females in a test battery assessing locomotion, exploration , anxiety, social competence and depression-like behaviour. Furthermore we were interested in stress-physiological changes, i.e. changes in corticosterone. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Currently, the mouse represents the preferred model organism among mammals used for animal studies. Due to a great availability of mutant strains it represents a standard method to analyze in vivo the effects of targeted gene manipulations. While this - at least in theory - represents a valuable tool to elucidate the pathophysiology of certain human diseases, there are several caveats which need to be considered working with animals. In our study we aimed at elucidating, how a widely established breeding strategy, i.e. the use of "foster mothers" to save the survival of compromised mouse pups for ongoing experiments, per se, affects the emotional phenotype of the fostered offspring. Since it is a popular method to use outbred strains like NMRI to do this job, we sought to evaluate the potential effects of such an artificial postnatal condition and compare either offspring nurtured by their biological mothers or two different strains of foster mothers. Hence we analysed changes in maternal care and later on the emotional behaviour of male and female C57BL/6 mice reared by (i) their biological C57BL/6 mothers, (ii) C57BL/6 foster mothers and (iii) NMRI foster mothers in a behavioural test battery. In addition we assessed corticosterone levels as indicator for stress-physiological changes. Besides clear differences in maternal behaviour, our study indicates an altered emotional state (i.e. differences in anxiety and depressive-like features) in mice reared by different "categories" of mothers, which emphasizes the importance to embed such perinatal conditions in the evaluation of animal-deriving data.
    Behavioural Brain Research 08/2014; 274. DOI:10.1016/j.bbr.2014.08.021 · 3.03 Impact Factor
    • "However, the environment experienced during early development may have significant long-term effects (Monaghan 2008), which is often linked to the nutritional conditions. In fact, there is at least evidence for long-lasting physiological and behavioral effects of cross-fostering in mice (Bartolomucci et al. 2004). The latter may result from social learning (Bandura 1977). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Early family life is characterized by a close interaction between parents and their offspring. This needs to be disentangled when studying the ontogeny and evolution of a given behavior-e.g. via cross-fostering. But cross-fostering may change the expression of parent and offspring behaviors as they may respond to the novel environment. Furthermore, parent and offspring traits are potentially co-adjusted and cross-fostering may, therefore, introduce a costly mismatch. To study such consequences of cross-fostering, we created an experimental group (EG) of broods raised by foster parents from day 3 onwards and a control group of broods raised by their biological parents throughout. We tested offspring begging intensity in all broods and the provisioning of the EG-parents only, both on day 3 just before cross-fostering and then again on day 5. Costs were estimated in terms of growth and survival (offspring costs) and mass of a second clutch (parental costs). Offspring begging intensity varied with age, but this change was neither affected by cross-fostering per se nor by small-scale differences in parental provisioning between biological and foster parents. Similarly, the change in parental provisioning with offspring age among the EG-parents was not affected by the difference in begging between biological and foster nestlings. This lack in behavioral plasticity in response to cross-fostering did not entail costs to neither of the parties. Our results suggest a rather predetermined pattern of behavioral expression, which may be shaped by limits and costs to plasticity and/or an (apparent) lack of costs of a behavioral mismatch.
    Behavioral Ecology and Sociobiology 06/2014; 68:1019-1028. DOI:10.1007/s00265-014-1714-y · 2.35 Impact Factor
  • Source
    • "For example, between-strain fostering alters anxiety behaviors [51], autoimmune disease [52], and body weight [48]. Importantly, within-strain fostering also influences anxiety, juvenile social behaviors [22], [53], [54], and body weight [47], [55]. Taken together with the data shown here, we propose that fostering itself alters the maternal environment and mediates permanent changes in offspring phenotypes. "
    [Show abstract] [Hide abstract]
    ABSTRACT: It is well known that genes and environment interact to produce behavioral phenotypes. One environmental factor with long-term effects on gene transcription and behavior is maternal care. A classic paradigm for examining maternal care and genetic interactions is to foster pups of one genetic strain to dams of a different strain ("between-strain fostering"). In addition, fostering to a dam of the same strain ("within-strain fostering") is used to reduce indirect effects, via behavioral changes in the dams, of gestation treatments on offspring. Using within-and between-strain fostering we examined the contributions of genetics/prenatal environment, maternal care, and the effects of fostering per se, on adult aggressive behavior in two inbred mouse strains, C57BL/6J (B6) and DBA/2J (DBA). We hypothesized that males reared by dams of the more aggressive DBA strain would attack intruders faster than those reared by B6 dams. Surprisingly, we found that both methods of fostering enhanced aggressive behavior, but only in B6 mice. Since all the B6 offspring are genetically identical, we asked if maternal behavior of B6 dams was affected by the relatedness of their pups. In fact, B6 dams caring for foster B6 pups displayed significantly reduced maternal behaviors. Finally, we measured vasopressin and corticotrophin releasing hormone mRNA in the amygdalae of adult B6 males reared by foster or biological dams. Both genes correlated with aggressive behavior in within-strain fostered B6 mice, but not in mice reared by their biological dams. In sum, we have demonstrated in inbred laboratory mice, that dams behave differently when rearing their own newborn pups versus pups from another dam of the same strain. These differences in maternal care affect aggression in the male offspring and transcription of Avp and Crh in the brain. It is likely that rearing by foster dams has additional effects and implications for other species.
    PLoS ONE 09/2013; 8(9):e75037. DOI:10.1371/journal.pone.0075037 · 3.23 Impact Factor
Show more