Search results for "Maternal effects"
showing 7 items of 17 documents
Sex-specific transgenerational effects of early developmental conditions in a passerine.
2007
Most studies dealing with the trade-off between offspring number and quality have overlooked the long-term consequences for the progeny. High investment in offspring number usually results in an increased competition among nest mates. The deterioration of the early developmental conditions, due to this increased competition, can impair individual quality over the long term, and subsequently affect survival and lifetime fecundity. Moreover, the consequences of the allocation rule to offspring number vs. quality can extend across generations and give raise to grandparental effects. These transgenerational trade-offs have been explored rarely. In the present study, we manipulated the breeding …
Evolutionary ecology of the trans-generational immune priming in an insect
2012
Trans-generational immune priming (TGIP) is defined as the plastic enhancement of offspring's immunocompetence following an immune challenge of the females of the parental generation. In vertebrates, this phenomenon is well described, and is achieved by the maternal transfer of antibodies. In invertebrates however, it has only recently been described. Since invertebrates do not possess antibodies, the mechanism of this transmission remains unknown. If the offspring is exposed to the maternal infection, an elevated immunocompetence can help it cope better with it. Nonetheless, apart from this benefit, several cues indicate that the TGIP bears some fitness costs for individuals. The evolution…
Variation in egg size and offspring phenotype among and within seven Arctic charr morphs.
2022
Maternal effects have the potential to alter early developmental processes of offspring and contribute to adaptive diversification. Egg size is a major contributor to offspring phenotype, which can influence developmental trajectories and potential resource use. However, to what extent intraspecific variation in egg size facilitates evolution of resource polymorphism is poorly understood. We studied multiple resource morphs of Icelandic Arctic charr, ranging from an anadromous morph—with a phenotype similar to the proposed ancestral phenotype—to sympatric morphs that vary in their degree of phenotypic divergence from the ancestral anadromous morph. We characterized variation in egg size and…
Maternal antibody transmission and breeding densities in the Black-headed Gull Larus ridibundus
2004
1. The offspring of avian species, especially those of colonial breeders, are exposed to a number of pathogens immediately after birth. The chick's immune system is, at that early stage still immature and inefficient. As a consequence, diseases can have a strong impact on chick survival.2. The ability of mothers to transmit passive immunity in terms of antibodies of their own acquired immunity to their chicks is probably an essential pathway to enhance the chick survival. Since the production of antibodies is costly, females are expected to adjust the transmission of passive immunity to the local disease environment.3. We found that in Black-headed Gulls (Larus ridibundus L.) yolk antibody …
The role of maternal effects in host-parasite interactions: examination of the development of the immune defense in a colonial seabird, the black-leg…
2004
One of the main aims of evolutionary biology is to understand the mechanisms responsible for the phenotypic variation on which natural selection can act. Maternal effects occur when a mother's phenotype or her environment influence her offspring's phenotype. Despite the importance of such effects for the ecology of host-parasite interactions, their role has been relatively neglected to date. In this thesis, we examined how mothers influence the immune defense of their young in an environment that varies in space and time. This work has primarily focused on a colonial seabird, the black-legged kittiwake (Rissa tridactyla). Using this model, we have first shown that specific maternal antibodi…
Population divergence in maternal investment and embryo energy use and allocation suggests adaptive responses to cool climates
2023
1. The thermal sensitivity of early life stages can play a fundamental role in constraining species distributions. For egg-laying ectotherms, cool temperatures often extend development time and exacerbate developmental energy cost. Despite these costs, egg laying is still observed at high latitudes and altitudes. How embryos overcome the developmental constraints posed by cool climates is crucial knowledge for explaining the persistence of oviparous species in such environments and for understanding thermal adaptation more broadly. 2. Here, we studied maternal investment and embryo energy use and allocation in wall lizards spanning altitudinal regions, as potential mechanisms that enable su…
Prenatal thyroid hormones accelerate postnatal growth and telomere shortening in wild great tits
2021
AbstractEarly-life environment is known to affect later-life health and disease, which could be mediated by the early-life programming of telomere length, a key hallmark of ageing. According to thefetal programming of telomere biology hypothesis, variation in prenatal exposure to hormones is likely to influence telomere length. Yet the contribution of key metabolic hormones,i.e. thyroid hormones (THs), has been largely ignored. We recently showed that in contrast to predictions, exposure to elevated prenatal THs increased postnatal telomere length in wild collared flycatchers, but the generality of such effect, its underlying proximate mechanisms and consequences on survival have not been i…