Intergenerational Effects of Early Life Starvation on Life-History, Consumption, and Transcriptome of a Holometabolous Insect

Abstract

Intergenerational effects, also known as parental effects in which the offspring phenotype is influenced by the parental phenotype, can occur in response to parental early life food-limitation and adult reproductive environment. However, little is known about how these parental life stage-specific environments interact with each other and with the offspring environment to influence offspring phenotypes, particularly in organisms that realize distinct niches across ontogeny. We examined the effects of parental early life starvation and adult reproductive environment on offspring traits under matching or mismatching offspring early life starvation conditions using the insect Athalia rosae (turnip sawfly). The parental early life starvation treatment had context-dependent intergenerational effects on life-history and consumption traits of offspring larvae, partly in interaction with offspring conditions (intragenerational effects) and sex, while there was no significant effect of parental adult reproductive environment. In addition, parental starvation led to differential expression of only few genes, while offspring larval starvation caused a pronounced differential gene expression and modulation of multiple pathways. Our findings reveal that parental starvation leads to intergenerational effects on offspring life-history traits, consumption patterns as well as gene expression, although the effects are less pronounced than those of offspring starvation.

Chemical defense acquired via pharmacophagy can lead to herd protection in a sawfly

“…However, it is less clear if such chemical defense can be intraspecifically transmitted and whether presence of chemically defended individuals can confer protection onto undefended conspecifics. In some species, such defensive chemicals can be taken up independently of the nutrient-delivering food source, as in the case of our study organism, A. rosae, that takes up clerodanoids (and potentially also other chemicals) pharmacophagously from A. reptans plants and likely metabolized them (Paul et al, 2021b).…”

“…Moreover, such defensive chemicals acquired by the female from the male can also be incorporated into the offspring (Eisner et al, 2002;Camarano et al, 2009;Sternberg et al, 2015) providing it with benefits. Evidence for such benefits of parental clerodanoid access to offspring in A. rosae is currently lacking (Paul et al, 2021b).…”

“…Alternatively, organisms can specifically take up defensive chemicals independently of nutritional requirements, e.g. via pharmacophagy (Boppré, 1984;Nishida, 2014;Paul et al, 2021b). For example, adults of some danaine butterfly species actively incorporate defensive chemicals like pyrrolizidine alkaloids from sources such as dried plant parts (Lawson et al, 2021;Tea et al, 2021).…”

“…While effects of clerodanoids on mating behavior have been shown previously (Amano et al, 1999;Paul & Müller, 2021), empirical evidence for other functions such as in defense against predation is scarce and indirect (Nishida & Fukami, 1990). In the laboratory, the cultures are usually maintained without A. reptans leaves, suggesting that clerodanoid access is not essential for the sawflies' survival (Paul et al, 2021b(Paul et al, , 2021aPaul & Müller, 2021). Moreover, there is evidence for associated costs of clerodanoid uptake in A. rosae, such that adults with clerodanoid access exhibit a reduced lifespan (Zanchi et al, 2021).…”