Ivimey-Cook ER, Sales K, Carlsson H, Immler S, Chapman T, Maklakov AA (2021) Transgenerational fitness effects of lifespan extension by dietary restriction in Caenorhabditis elegans. Proc R Soc B, https://doi.org/10.1098/rspb.2021.0701

So, intergenerational effects (F1) improve fitness in the same intermittentfasting environment at the cost to fitness in the control environment – makes sense in every way and nice to see such clear result. Adaptive parental effects that come at a cost.

Transgenerational effects – they affect both lifespan and fitness up to F3! But – they reduce fitness of great-grandoffspring, not only that, they remove lifespan extension effect that is normally conferred byintermittentfasting!

In short, transgenerational (F3) effects of dietary restriction via intermittentfasting do occur but sometimes it would be better without them! Intergenerational effects are good when parents correctly guess offspring environment, otherwise not so much.

Transgenerational and intergenerational trade-offs is something to consider when studying their evolution.

Lind MI, Carlsson H, Duxbury EML, Ivimey-Cook E, Maklakov AA (2021) Cost-free lifespan extension via optimisation of gene expression in adulthood aligns with the developmental theory of ageing. Proc R Soc B, 288: 20201728

There were two ‘ageing’ symposia + a life-history symposium + a non-genetic effects symposium at ESEB 2019 – a lot of interesting and relevant talks.

Laura Travers presented a poster on the effect of autophagy on survival and fitness under dietary restriction, testing recent evolutionary theory of DR.

Here is the link to a session at Life-History symposium where I gave an invited talk on the role of non-energy-based trade-offs in ageing, highlighting the possibility that age-specificity of gene expression is not sufficiently optimised in adulthood and contributes to ageing. This presentation was followed by Irja Ratikainen’s invited talk who used C. remanei nematodes to test some of her models of the evolution of lifespan in variable environments in collaboration with Martin Lind’s lab in Uppsala and our lab. Finally, Ed Ivimey-Cook talked about our dietary restriction experiment in C. elegans that spans several generations later in the same session:

https://www.rajulive.fi/streams/session2-tuesday-morning

Next day, Liz Duxbury talked about the preliminary results of her mutation accumulation experiment testing how down-regulation of daf-2 expression in adulthood affects mutation rates:

https://www.rajulive.fi/streams/session6-wednesday-afternoon/

Reduced expression of the insulin/insulin-like nutrient-sensing signalling (IIS) pathway gene daf-2 in adult Caenorhabditis elegans nematode worms increases longevity without affecting fecundity, but the effect of parental lifespan extension on adult offspring is largely unknown. We found that reduced IIS signalling in parental generation increases offspring fitness. We used RNA interference (RNAi) to silence daf-2 expression in sexually mature C. elegans hermaphrodites from three different genotypes: N2 wildtype, as well as ppw-1 and rrf-1 mutants that are deficient for RNAi in germline and soma, respectively. Long-lived daf-2 RNAi parents showed normal fecundity as self-fertilizing hermaphrodites and improved late-life reproduction when mated to males. Remarkably, the offspring of daf-2 RNAi parents produced more progeny and had higher Darwinian fitness across all three genotypes. Thus, reduced IIS signalling in adulthood improves offspring quality supporting the emerging view that suboptimally high levels of nutrient-sensing signalling in late-life lie at the heart of ageing.

https://www.biorxiv.org/content/early/2018/08/31/405019

Ed joins our lab from October 1st as BBSRC-funded postdoc on the project that deals with transgenerational effects of dietary restriction on ageing and Darwinian fitness.

Ed has a general interest in ageing, maternal effects, and quantitative genetics. In particular, he is interested in understanding how biological processes and life-history trade-offs contribute to the vast observed diversity in trait ageing trajectories. For his PhD, he used experimental and widescale comparative analyses to investigate the detrimental effects of increasing maternal age manifested on offspring traits.

David Murray joins our lab as ERC-funded Research Technician on a collaborative project with Simone Immler’s group to work on ageing and reproduction in zebrafish.

David has a long-standing interest in aquatic ecosystems and, after finishing his PhD in Glasgow,  worked in Vienna and Berlin, and, most recently, at UEA in Matt Gage’s lab. He has broad interests in sustainable aquaculture, conservation biology and phenotypic plasticity.

Elizabeth joined our lab in July 2018 as ERC-funded postdoc. She is working on the relationship between ageing and germline mutation rate.

Previously, Elizabeth worked on sex-specific life history effects of dietary manipulation, and the evolution and genetics of virus resistance in natural populations of fruit fly species.

Laura Travers joined our lab as 3-year ERC-funded senior postdoctoral research associate to work on transgenerational effects of parental lifespan extension.

Laura has a broad interest in ageing, sexual selection, and evolutionary genetics. In particular, she is interested in understanding how trade-offs between life history traits such as reproduction and lifespan drive evolutionary change.

Happy to announce that our BBSRC proposal with Co-Is Tracey Chapman (UEA BIO), Simone Immler (UEA BIO) and David Thybert (EI and UEA BIO) was approved and this means more research on the trans-generational consequences of parental lifespan extension!

We will be advertising positions for a postdoc and a research assistant (technician) soon!

Martyna became a true expert in life-history trade-offs – both professionally and personally: