Search results for "Maternal"
showing 10 items of 488 documents
Offspring reverse transcriptome responses to maternal deprivation when reared with pathogens in an insect with facultative family life
2020
Offspring of species with facultative family life are able to live with and without parents (i.e. to adjust to extreme changes in their social environment). While these adjustments are well understood on a phenotypic level, their genetic underpinnings remain surprisingly understudied. Investigating gene expression changes in response to parental absence may elucidate the genetic constraints driving evolutionary transitions between solitary and family life. Here, we manipulated maternal presence to observe gene expression changes in the fat body of juvenile European earwigs, an insect with facultative family life. Because parents typically protect offspring against pathogens, expression chan…
Hantavirus infections in fluctuating host populations: the role of maternal antibodies.
2010
Infected females may transfer maternal antibodies (MatAbs) to their offspring, which may then be transiently protected against infections the mother has encountered. However, the role of maternal protection in infectious disease dynamics in wildlife has largely been neglected. Here, we investigate the effects of Puumala hantavirus (PUUV)-specific MatAbs on PUUV dynamics, using 7 years' data from a cyclic bank vole population in Finland. For the first time to our knowledge, we partition seropositivity data from a natural population into separate dynamic patterns for MatAbs and infection. The likelihood of young of the year carrying PUUV-specific MatAbs during the breeding season correlated p…
Advantage of rare infanticide strategies in an invasion experiment of behavioural polymorphism
2012
Killing conspecific infants (infanticide) is among the most puzzling phenomena in nature. Stable polymorphism in such behaviour could be maintained by negative frequency-dependent selection (benefit of rare types). However, it is currently unknown whether there is genetic polymorphism in infanticidal behaviour or whether infanticide may have any fitness advantages when rare. Here we show genetic polymorphism in non-parental infanticide. Our novel invasion experiment confirms negative frequency-dependent selection in wild bank vole populations, where resource benefits allow an infanticidal strategy to invade a population of non-infanticidal individuals. The results show that infanticidal beh…
Relationship between maternal transfer of immunity and mother fecundity in an insect.
2012
Trans-generational immune priming (TGIP) corresponds to the plastic adjustment of offspring immunity as a result of maternal immune experience. TGIP is expected to improve mother's fitness by improving offspring individual performance in an environment where parasitism becomes more prevalent. However, it was recently demonstrated that maternal transfer of immunity to the offspring is costly for immune-challenged female insects. Thus, these females might not provide immune protection to all their offspring because of the inherent cost of other fitness-related traits. Females are therefore expected to adjust their investment to individual offspring immune protection in ways that maximize the…
Crocodile egg sounds signal hatching time.
2008
Summary Crocodilians are known to vocalize within the egg shortly before hatching [1,2]. Although a possible function of these calls — inducing hatching in siblings and stimulating the adult female to open the nest — has already been suggested, it has never been experimentally tested [1–5]. Here, we present the first experimental evidence that pre-hatching calls of Nile crocodile ( Crocodylus niloticus ) juveniles are informative acoustic signals which indeed target both siblings and mother.
Short-term benefits, but transgenerational costs of maternal loss in an insect with facultative maternal care
2015
A lack of parental care is generally assumed to entail substantial fitness costs for offspring that ultimately select for the maintenance of family life across generations. However, it is unknown whether these costs arise when parental care is facultative, thus questioning their fundamental importance in the early evolution of family life. Here, we investigated the short-term, long-term and transgenerational effects of maternal loss in the European earwig Forficula auricularia , an insect with facultative post-hatching maternal care. We showed that maternal loss did not influence the developmental time and survival rate of juveniles, but surprisingly yielded adults of larger body and force…
Trans-generational immune priming is constrained by the maternal immune response in an insect.
2012
5 pages; International audience; Immune-challenged vertebrate and invertebrate females can transfer immunity to their off spring. Th is trans-generational immune priming (TGIP) is benefi cial for the off spring if the maternal infection risk persists across generations. However, because immunity is costly, fi tness consequences of TGIP have been found in primed off spring. Furthermore, transferring immunity to off spring may be costly for immune-challenged females who are also carrying the costs of their immune response. A negative relationship between levels of immunity between mothers and off spring might therefore be expected. Consistent with this hypothesis, we show that in the insect, …
Intergenerational fitness effects of the early life environment in a wild rodent.
2019
The early life environment can have profound, long-lasting effects on an individual's fitness. For example, early life quality might (a) positively associate with fitness (a silver spoon effect), (b) stimulate a predictive adaptive response (by adjusting the phenotype to the quality of the environment to maximize fitness) or (c) be obscured by subsequent plasticity. Potentially, the effects of the early life environment can persist beyond one generation, though the intergenerational plasticity on fitness traits of a subsequent generation is unclear. To study both intra- and intergenerational effects of the early life environment, we exposed a first generation of bank voles to two early life…
Do phase-dependent life history traits in cyclic voles persist in a common environment?
2019
Phenotype and life history traits of an individual are a product of environmental conditions and the genome. Environment can be current or past, which complicates the distinction between environmental and heritable effects on the phenotype in wild animals. We studied genome–environment interactions on phenotype and life history traits by transplanting bank voles (Myodes glareolus) from northern and southern populations, originating from low or high population cycle phases, to common garden conditions in large outdoor enclosures. The first experiment focused on the persistence of body traits in autumn-captured overwintering populations. The second experiment focused on population growth and …
Is maternal thyroid hormone deposition subject to a trade-off between self and egg because of iodine?
2021
ABSTRACT Maternal hormones constitute a key signalling pathway for mothers to shape offspring phenotype and fitness. Thyroid hormones (THs; triiodothyronine, T3; and thyroxine, T4) are metabolic hormones known to play crucial roles in embryonic development and survival in all vertebrates. During early developmental stages, embryos exclusively rely on exposure to maternal THs, and maternal hypothyroidism can cause severe embryonic maldevelopment. The TH molecule includes iodine, an element that cannot be synthesised by the organism. Therefore, TH production may become costly when environmental iodine availability is low. This may yield a trade-off for breeding females between allocating the …