The transgenerational effects of maternal low-protein diet during lactation on offspring

Environmental factors such as diet and lifestyle can influence the health of both mothers and offspring.However,its transgenerational transmission and underlying mechanisms remain largely unknown.Here,using a maternal lactation-period low-protein diet(LPD)mouse model,we show that maternal LPD during lactation causes decreased survival and stunted growth,significantly reduces ovulation and litter size,and alters the gut microbiome in the female LPD-F1 offspring.The transcriptome of LPD-F1 metaphase II(MII)oocytes shows that differentially expressed genes are enriched in female pregnancy and multiple metabolic processes.Moreover,maternal LPD causes early stunted growth and impairs metabolic health,which is transmitted over two generations.The methylome alteration of LPD-F1 oocytes can be partly transmitted to the F2 oocytes.Together,our results reveal that LPD during lactation transgenerationally affects offspring health,probably via oocyte epigenetic changes.

Offspring diet supersedes the transgenerational effects of parental diet in a specialist herbivore Neolema abbreviata under manipulated foliar nitrogen variability

Diet quality influences organismal fitness within and across generations.For herbivorous insects,the transgenerational effecets of diet remain relatively underexplored.Usinga3×3×2 factorial experiment,we evaluated how N enrichment in parental diets of Neolemd abbreviata(Larcordaire)(C oleoptera:Chrysomelidae),a biological control agent for Tradescantia fluminensis Vell.(Commelinaceae),may influence life history and performance of Fi and F2 offspring under reciprocal experiments.We found limited transgenerational effects of foliar nitrogen variability among life-history traits in both larvae and adults.Larval weight gain and mortality were responsive to parental diet contrary to feeding damage,pupal weight and duration taken to pupate.There were significant parental diet x test interactions in larval feeding damage,weight gain,pupal weight and time to pupation.Generally,offspring from parents under high N plants performed better even under low N test plants.Adult traits including oviposition selection,feeding weight and longevity did not respond to the efects of parental diet nor its interaction with test diet as was the case in the larval stage.However,the main efects of test diet were more important in determining adult performance in both generations suggesting limited sensitivity to parental diet in the adult stage.Our results show conflicting responses to parental diet between larvae and adults ofthe same generation among an insec species with both actively feeding larual and adult life stagee These tranegeneratinonal efferte,or lack thereof,may have implications on the field performance of N.abbrevita under heterogencous nutritional landscapes.

Arbuscular mycorrhizae status of host plant affects offspring’s phenotype and transcriptome expression in a low-phosphorus environment

Although the effects of arbuscular mycorrhizal fungi(AMF)on host plants have been well documented,whether the effects of AMF on parental generations affect offspring performance is not fully clear.We conducted a common garden experiment to determine whether AMF status of host plants(Medicago truncatula)affects phenotype and transcriptome expression of their offspring.Seeds from four type parental treatments(low-phosphorus(P)soil without AMF,low-P soil with AMF,high-P soil without AMF and high-P soil with AMF)were grown under low-P(LPS)and normal-P soil(OHS)conditions.The fowering pattern of LP offspring was similar to their parents,such that plants with AMF fowered earlier than those without AMF under OHS condition but were opposite under LPS condition.The transcriptome differential analysis showed that some differential transcripts(45 for parental plants growing under low-P condition and 3 for parental plants growing under high-P condition)expression patterns between offspring were comparable,and that only affected by parental AMF status regardless of the P environment that offspring was grown.Others(146 for parental plants growing under low-P condition and 2 for parental plants growing under high-P condition),however,were affected both by the parental AMF status and the offspring P environment.In addition,the number of differential transcripts between offspring whose parental plants grew under high-P condition was far less than under low-P condition.These results indicate that AMF may not only affect the current generation of host plants but also affect the offspring especially when their parents have experienced a stressful environment.

Fitness costs of reflex bleeding in the ladybird beetle Harmonia axyridis: the role of parental effects

Reflex bleeding is an important antipredator defense mechanism in Coccinellidae.We examined the costs of reflex bleeding in larval and adult stages of the ladybird beetle Harmonia axyridis on offspring fitness and reproductive performance through the comparisons between bled and control larvae,reciprocal crosses of bled/control beetles,and early and late clutch phenotypes.Beetles bled during their larval stage spent a longer time in development and weighed less than controls.Egg fertility was reduced for crosses where either one or both parents had been bled during the larval or adult stage.Offspring crosses that included a parent bled during the larval stage suffered fitness costs in development and female body mass,while those bled during the adult stage suffered no transgenerational costs.Males that suffered bleeding during their larval stage accelerated progeny development of nonbled females in early clutches,suggesting a positive transgenerational effect of larval bleeding,while males that did not suffer bleeding accelerated progeny development of bled females in later clutches.As the underlying effects of bleeding on females'offspring in the early clutches were diminished in the late ones,suggesting another transgenerational effect.The strengths of maternal and paternal effects on progeny development of parents bled at the larval stage were higher in earlier clutches.This study suggests that H.axyridis adults are less affected than larvae by the frequent use of the defensive secretions in their stressful habitats.

Genetic and Epigenetic Effects of Plant-Pathogen Interactions： An Evolutionary Perspective

Recent reports suggest that exposure to stress is capable of influencing the frequency and pattern of inherited changes in various parts of the genome. In this review, we will discuss the influence of viral pathogens on somatic and meiotic genome stability of Nicotiana tabacum and Arabidopsis thaliana. Plants infected with a compatible pathogen generate a systemic recombination signal that precedes the spread of pathogens and results in changes in the somatic and meiotic recombination frequency. The progeny of infected plants exhibit changes in global and locusspecific DNA methylation patterns, genomic rearrangements at transgenic reporter loci and resistance gene-like-loci, and even tolerance to pathogen infection and abiotic stress. Here, we will discuss the contribution of environmental stresses to genome evolution and will focus on the role of heritable epigenetic changes in response to pathogen infection.