Understanding the role of germline maintenance and repair for somatic ageing

IMMLER_U21DTP

Increased longevity and healthy ageing are a long-standing dream of humanity, but they come at a cost. Trade-offs between growth, somatic maintenance and reproduction are thought to be at the heart of organismal ageing, yet the very nature of potential trade-offs and underlying mechanisms remain elusive. In fact, findings of increased lifespan without a reduction in fecundity seem to defeat the idea of a trade-off altogether. We recently suggested that the trade-offs are likely to be more hidden and involve the mechanisms responsible for the maintenance of the soma and the germline. Under this scenario, an increase in longevity may reduce germline repair and maintenance.

A recent study from our lab has shown that experimental germline ablation results in improved somatic regeneration in male zebrafish supporting the “costly germ line hypothesis”. These exciting novel findings point to a fascinating possibility of a germline-mediated trade-off between somatic growth and maintenance versus germline maintenance. The interaction between the germ line and the soma ultimately affects lifespan but we currently do not understand the underlying mechanisms of germline-soma signalling.

The aim of this project is to elucidate the mechanisms of the trade-off between the germline maintenance and the soma, which will provide fundamental insights into the physiology of lifespan and ageing. The student will employ some of the latest experimental and sequencing approaches, i.e. using knockdown and knockout methods combined with experimental manipulation, to assess the impacts on biological ageing and gene expression in germline and soma. Recently developed protocols and setups are at the student’s disposal and different steps will be implemented by visiting the relevant labs.

This is a highly collaborative PhD project between three groups (Immler: evolutionary genetics, Maklakov: ageing, Chandra: molecular biology) to combine gene manipulation, sequencing and experimental procedures for the study of the biology of ageing.

References:

Chen, H-y, Jolly, C, Bublys, K, Marcu, D, Immler, S. 2020. Trade-off between somatic and germline repair in a vertebrate supports the “expensive germ line” hypothesis. Proc Nat Acad Sci USA117: 233-238

Alavioon, G, Cabrera Garcia, A, LeChatelier, M, Maklakov, AA & Immler, S. 2019. Selection for longer-lived sperm within ejaculate reduces reproductive ageing in offspring. Evolution Letters 3: 198-206

Maklakov, AA & Immler, S. 2016. The expensive germline and the evolution of ageing. Curr Biol 26: R577-86.