Sirman, A.E., Schmidt, J.E., Clark, M., Kittilson, J., Reed, W.R, Heidinger, B.J. Compensatory growth is accompanied by changes in insulin-like growth factor-1 but not markers of cellular aging in a long-lived seabird. American Naturalist. Study Abstract: Developing organisms often plastically modify growth in response to environmental circumstances, which may be adaptive, but is expected to entail long-term costs. However, the mechanisms that mediate these growth adjustments and any associated costs are less well understood. In vertebrates, one mechanism that may be important in this context is the highly conserved signaling factor insulin-like growth factor-1 (IGF-1), which is often positively related to post-natal growth and negatively related to longevity. To test this idea, we exposed captive Franklin’s gulls (Leucophaeus pipixcan) to a physiologically relevant nutritional stressor by restricting food availability during post-natal development and examined the effects on growth, IGF-1, and two potential biomarkers of cellular and organismal aging (oxidative stress, and telomeres). During food restriction, experimental chicks gained body mass more slowly and had lower IGF-1 levels than controls. Following the food restriction, experimental chicks underwent compensatory growth, which was accompanied by an increase in IGF-1 levels. Interestingly however, there were no significant effects of the experimental treatment or of variation in IGF-1 levels on oxidative stress or telomeres. These findings suggest that IGF-1 is responsive to changes in resource availability but is not associated with increased markers of cellular aging during development in this relatively long-lived species. Data S1 R script, primary dataset used in all statistical analyses, dataset used to run the PCA analysis, hatching dataset, and a dataset that includes the qPCR raw telomere values. All r code was run using R version 4.1.0. Author(s) & Roles in Data Collection and Analysis Aubrey Sirman Arrupe College at Loyola University Chicago 820 N. Michigan Avenue, Chicago, IL 60611 asirman@luc.edu Role: Collected data and wrote code for analysis Jacob Schmidt North Dakota State University, Department of Biological Sciences 1340 Bolley Drive, Fargo, ND 58102 schmidtje22@gmail.com Role: Collected data Mark Clark University of Minnesota Duluth, Swenson College of Science and Engineering 1035 Kirby Drive, 11 SSB, Duluth, MN 55812 meclark@d.umn.edu Role: Collected data and calculated growth rate values for analysis Jeff Kittilson North Dakota State University, Department of Biological Sciences 1340 Bolley Drive, Fargo, ND 58102 Jeffery.kittilson@ndsu.edu Wendy Reed University of Minnesota Duluth, Swenson College of Science and Engineering 140 Engineering Building, 1303 Ordean Court, Duluth, MN 55812 wlreed@d.umn.edu Britt Heidinger North Dakota State University, Department of Biological Sciences 1340 Bolley Drive, Fargo, ND 58102 Britt.heidinger@ndsu.edu File list (files found within DataS1.zip) Sirman_et_al_primarydataset.csv Sirman_et_al_qPCRdataset.csv Sirman_et_al_PCAdataset.csv Sirman_et_al_Hatch.csv Sirman_et_al_analysiscode.R File Descriptions In each of the following datasets, NA is used to specify missing data or blanks. Sirman_et_al_primarydataset.csv – this file was used in all statistical analyses for this manuscript. It includes all individual growth, hormone, telomere, and oxidative stress data. Variable names and descriptions for this dataset are presented below: Chick ID Unique identifier assigned to each chick ID Unique identifier assigned to each chick - this ID term is used in all analyses Collection Period Refers to the collection date for each Treatment Refers to the assigned treatment group (either Control or Experimental) Nest Assigned nest number - all chicks were divided into a rearing group and assigned a nest ID Sex Refers to the sex of each chick (either male or female) Jday Julian day Age Age in days Mass Mass in grams Hatch Date Hatch date Hatch Date Jday Hatch date in Julian day Hatch Mass Mass in grams at hatching Feeding Period Refers to the feeding periods used the growth analysis (Restriction, Realimentation, Post-realimentation) Median Absolute Growth Calculated median absolute growth rate Sampling Mass Mass in grams at the four sampling periods (day 7, 17, 27, and 40) IGF1 IGF-1 values Sampling Period Sampling period (day 7, 17,27, and 40) LnIGF1 Natural logarithm of IGF-1 values TS Telomere values (T/S ratio) LnTS Natural Logarithm of telomere values RTM Telomere values corrected for regression to the mean LnIGFd17 Natural logarithm of IGF-1 values at the day 17 sampling period. LnIGFd7 Natural logarithm of IGF-1 values at the day 7 sampling period. PCA1 Principle Component Values for Principle component 1 PC Protein Carbonyl Content OXY Antioxidant Capacity in mmol 1-1 HOCI neutralized Sirman_et_al_qPCRdataset.csv – this file contains all the raw qPCR data used to generate the telomere data in Sirman_et_alprimarydataset.csv Variable names and descriptions for this dataset are presented below: Well Name Unique identifier for individual samples, standards are not labeled and are left blank Well Type Indicates either an unknown sample or standard Threshold Indicates the threshold set on the qPCR machine Ct (dRn) tel copy number for telomere gene Ct (dRn) gap copy number for the gap gene del ct variable used to calculate telomere deldelCt variable used to calculate telomere 2power(-ddCt) variable used to calculate telomere Plate Indicates plate number Sirman_et_al_PCAdataset.csv – this dataset was used in the Principal Components Analysis. This analysis was performed in SPSS24. Variable names and descriptions for this dataset are presented below: ID Unique identifier assigned to each chick - this ID term is used in all analyses Sex Refers to the sex of each chick (either male or female) Trt Refers to the assigned treatment group (either Control or Experimental) Nest Assigned nest number - all chicks were divided into a rearing group and assigned a nest ID Age Age in days Sampling Period Mass in grams at the four sampling periods (day 7, 17, 27, and 40) Collection Period Refers to the collection date for each BM Mass in grams Wing Refers to wing chord (mm) Culmen Refers to culmen length (mm) HB Refers to head-to-bill length, a measure of growth (mm) Sirman_et_al_Hatch.csv – this dataset includes all data related to hatching in the Franklin’s gull chicks. Date Hatched Date of hatch for gull chicks Hatch (Yes or No) Refers to if the egg hatched (either yes or no) Time hatched Time of hatch Chick ID Chick ID Treatment Refers to assigned treatment after hatch (either Control or Restricted) Collection Date Refers to date of egg collection (either May 7th or May 25th) Hatch Mass (g) Mass at hatch in grams Sirman_et_al_analysiscode.R – this R script includes all the code used to run the statistical analysis. PCA Analysis The PCA analysis was not performed in R, instead it was performed in SPSS28. Instructions to run the PCA in SPSS28 can be found below. Load the Sirman_et_al_PCAdataset.csv into SPSS28 and define the structural variables (head to bill, wing chord, and culmen length) as scale variables. You will have to remove the NAs from the dataset to do this. The PCA can be performed in SPSS using the Dimension Reduction function found under the ‘Analyze’ tab. Select ‘dimension reduction’ then ‘factor analysis’. Then select your variables of interest for the PCA analysis. Click on the ‘Descriptives’ tab and select ‘Initial solution’ under Statistics, then ‘coefficients, ‘KMO and Bartlett’s test’, ‘reproduced’, ‘anti-image’ under the Correlation matrix section. For the ‘Extraction’ tab, keep all the defaults, but also add the scree plot in the Display section. For the ‘Rotation’ tab select the Varimax option in the Method section and also select the ‘loading plots’ in the Display section. Then, click the ‘Scores’ button and select the ‘Save as variables’ option and keep the Regression option selected. Lastly, select the ‘Options’ button, select the ‘sorted by size’ and ‘suppress small coefficients’ option. Change the absolute value to ‘0.3’. Click continue and then ‘ok’ to generate the output.