DOI: 10.5061/dryad.z08kprr8k
title: Dietary Restriction Improves Fitness of Aging Parents But Reduces Fitness of Their Offspring in Nematodes

description: Abstract Dietary restriction (DR) is a well-established intervention to
 extend lifespan across taxa. Recent studies suggest that DR-driven
 lifespan extension can be cost-free, calling into question a central
 tenant of the evolutionary theory of aging. Nevertheless, boosting
 parental longevity can reduce offspring fitness. Such intergenerational
 trade-offs are often ignored but can account for the “missing costs” of
 longevity. Here, we use the nematode Caenorhabditis remanei to test for
 effects of DR by fasting on fitness of females and their offspring.
 Females deprived of food for 6 days indeed had increased fecundity,
 survival, and stress resistance after re-exposure to food compared with
 their counterparts with constant food access. However, offspring of DR
 mothers had reduced early and lifetime fecundity, slower growth rate, and
 smaller body size at sexual maturity. These findings support the direct
 trade-off between investment in soma and gametes challenging the
 hypothesis that increased somatic maintenance and impaired reproduction
 can be decoupled.
description: For methods on data collection, please see Mautz et al.
 (2019) Dietary restriction improves fitness of ageing parents but reduces
 fitness of their offspring in nematodes. <em>The Journals of
 Gerontology: Series A </em>(<em>in press</em>). 10.1093/gerona/glz276 
description: FILE: female_reproduction_lifespan_data.csv  
         <strong> Variable           
 description</strong>            
 line                  row number in dataset            
 treatment       AL = ad libitum, constant access to food; TF = temporary
 fasting, no food first 6 days after sexual maturity
             individual        number of individual by
 treatment             gen                  Generation
 marker. F0 for treatment/control females. F1 for offspring of
 treatment/control females            
 D0                    Date of birth            
 trtIDgen           unique identifier for each individual.
 Treatment-Identification number - Generation
             plate                plate number
             day                  day of reproduction
             date                 date of reproduction
             alr                    Age at last reproduction.
 ‘date’ column with last non-zero value for ‘larvae’ column minus “D0’
 column.             lifespan           Length of
 life.             larvae              Number of larvae
 produced for that respective plate/day            
 matcensor       Maternal censoring for lifespan analysis. For females that
 were still producing eggs on death date.  
   FILE: female_heat-shock_data.csv
 <strong>       
  </strong><strong> Variable         
 description</strong>            
 treatment       AL = ad libitum, constant access to food; TF = temporary
 fasting, no food first 6 days after sexual maturity
             plate                plate number. Each plate had 10
 females             hour                 time at which
 knock down was assessed. Knock-down was assessed every hour for 7
 hours.             a                      Freely moving
 or normal movement after being prodded gently by scorer
             b                      Abnormal, non-sinusoidal
 movement or not freely moving (i.e. only anterior portion of body moving)
 after being prodded gently by scorer            
 c                      not moving even after being stimulated by scorer,
 but with buccal pump moving or completely non-response
                                     NB: categories b, c were
 combined in analysis.            
 FILE: offspring_reproduction_lifespan_data.csv
             <strong> Variable         
  description</strong>            
 line                  row number in dataset            
 treatment        AL = ad libitum, constant access to food; TF = temporary
 fasting, no food first 6 days after sexual maturity
             individual        number of individual by
 treatment             gen                  Generation
 marker. F0 for treatment/control females. F1 for offspring of
 treatment/control females            
 D0                    Date of birth            
 plate                plate number            
 day                  day of reproduction            
 colldate           date that plate of larvae was collected
             alr                    Age at last reproduction.
 ‘colldate’ column with last non-zero value for ‘larvae’ column minus “D0’
 column.             lifespan           Length of life.
 max(collate) - D0             larvae              Total
 count of larvae on the plate            
 matcensor       Maternal censoring for lifespan analysis. For females that
 were still producing eggs on death date.  
 FILE: offspring_development_size_data.csv    
       <strong> Variable           
 description</strong>            
 treatment        AL = ad libitum, constant access to food; TF = temporary
 fasting, no food first 6 days after sexual maturity
             plate                plate number
             female                       
 date1               date which eggs were laid     
             time1              time at which plates were
 generated (plates were generated in two blocks).
             comb1             combination of date1 and time1 to
 calculate development time            
 comb2             combination of date2 and time2 to calculate development
 time             date2               date at which
 individuals becamesexually mature            
 time2              time at which individual became sexually
 mature             pic                   reference
 number for picture of that individual            
 size                  measurement of size (in mm sq).
   FILE:
 offspring_heat-shock_data.csv        
   <strong> Variable           
 description</strong>            
 treatment       AL = ad libitum, constant access to food; TF = temporary
 fasting, no food first 6 days after sexual maturity
             f0_plate          plate on which the test worm
 developed             f1_plate          plate on which
 worm was placed for heat shock treatment (worms from development plates
 were randomized across treatment plates)            
 time                Hour at which knock down was assessed. Knock-down was
 assessed every hour for 7 hours.            
 a                      Freely moving or normal movement after being
 prodded gently by scorer            
 b                      Abnormal, non-sinusoidal movement or not freely
 moving (i.e. only anterior portion of body moving) after being prodded
 gently by scorer             c                      not
 moving even after being stimulated by scorer, but with buccal pump moving
 or completely non-response
                                     NB: categories b, c were
 combined in analysis.   FILE:
 Temporary fasting nematodes data analysis.Rmd
             NB: R code used to analyze above data files