DOI: 10.5061/dryad.v15dv427b
title: Data from: No evidence that life history strategies shape within-body mosaics of ageing

description: Tissues across the body may age at different rates, which creates
 within-body mosaic ageing. Life history strategies shape ageing patterns
 at the inter- and intra-specific level, but the impact of life history
 strategies on mosaic ageing patterns within individuals remains unknown.
 Reproductive tissues in individuals selected to prioritise reproduction
 may age faster than somatic tissues because of increased ‘wear and tear’.
 Alternatively, individuals that prioritise reproduction may specially
 protect reproductive tissues at the expense of somatic tissues to allow
 for increased reproductive function. Here, we used Japanese quail
 (Coturnix japonica) artificially selected for increased vs. reduced
 reproductive investment (egg size) to test how reproductive strategies
 modulate within-body variation in ageing patterns, by measuring telomere
 length as an ageing biomarker in blood, spleen and reproductive tissue
 (oviduct and testis). We did not find evidence that reproductive strategy
 shaped within-body mosaics of ageing: patterns of telomere length in
 somatic and reproductive tissues were similar in individuals selected for
 high and low reproductive investment, respectively, and strong positive
 correlations in telomere length across tissues were observed. Our results
 suggest that life history strategy does not affect tissue-specific ageing
 rate. Alternately, ‘wear and tear’ and ‘special protection’ mechanisms
 might act simultaneously and cancel each other out, resulting in similar
 telomere lengths across tissues. 
description: Individuals used in this study originated from a captive
 population of Japanese quail (<em>Coturnix japonica</em>)
 artificially selected for high (H-line) or low (L-line) maternal egg
 investment (two replicates each). In brief, in the first generation,
 females in the top and bottom 25% of egg size distribution (relative to
 body size) were selected for breeding for the replicated H-lines and
 L-lines, respectively. In subsequent generations, females within the top
 or bottom 50% were selected for breeding for the replicated H-line and
 L-line, respectively. Matings between relatives were prevented throughout
 the experiment. After four generations, H-line females laid eggs that were
 more than 1 SD bigger than egg of L-line females, while they did not
 differ in the number of eggs laid. So, H-line females invested overall
 more into reproduction. Blood, spleen and reproductive tissues were
 collected from females and males of this population and telomere lengths
 by TRF method were quantified.
description: # Data from: No evidence that life history strategies shape within-body
 mosaics of ageing
 [https://doi.org/10.5061/dryad.v15dv427b](https://doi.org/10.5061/dryad.v15dv427b) ## Description of the data and file structure This README file was generated on 25-02-2025 by Ana Angela Romero Haro GENERAL INFORMATION Title of Dataset: Data from: **No evidence that life history strategies shape within-body mosaics of ageing** Principal investigator: Name: Ana Angela Romero Haro Institution: National Museum of Natural Sciences (Madrid, Spain) Email: [ana.romero@mncn.csic.es](mailto:ana.romero@mncn.csic.es) This dataset contains the data and code required to replicate analyses in Romero-Haro et al. (in review), testing the hypothesis that mosaic ageing is affected by the life-history of individuals. ### Files and variables #### File: TL-tissues.csv **Description:** Dataset of the work, including the necessary information to replicate the results ##### Variables * ID: Identity of individuals * tissue: Kind of tissue (Blood, spleen, oviduct, testis) * tissuerep: Kind of tissue (blood, spleen, reprod) * tissuerep2: Kind of tissue (Blood, Spleen, Reproductive tissue) * Gel: Laboratory gel where the sample was run * TLkb: Average telomere length in Kb * line: Selection line of the individual according to the intensity of the reproductive investment (High/Low) * sex: Male/Female * age: Age of the individual in days * replicate: Replicate number. There are two replicates per line ## Code/software R Code to replicate the statistical analyses of the work. There are five sections: * Transformation of variables in factors - Main model: including the main model, pairwise posthoc comparisons, and checking model assumptions * Main model + age: supplementary model: similar to the main model but including age as an additional explanatory variable. - Code for figure 1 * Code for figure 2