READ ME file for DRYAD data file for to accompany: Extent and variability of interstitial telomeric sequences and their effects on estimates of telomere length Authors: Foote, Christopher; Vleck, David; Vleck, Carol Contact Author: Carol Vleck Contact Author Email: cvleck@iastate.edu Data Filename: Interstitial telomeric sequence gel data Introductory information. All gel data are included that were used to calculate telomere lengths and fractional content of interstitial telomeric sequences for each species. The file contains the date each gel was run, the species and bird identify for each lane used on each gel and the optical density data for each lane. Sums of optical density and position (kb) determined from size markers were used for all calculations as described in the citation. Data from 15 gels are included. Each gel was hybridzed to a telomere probe before denaturation and the optical density and position data for each lane extracted using Image J. The same gel was stripped, denatured and relabeled with the same telomere probe. Optical density and position data were then extracted again from the denatured gel using Image J. Some lanes were not included because they contained size markers (3 run on each gel), the internal standard sample, DNA from other species or because the DNA did not fully digest. Gels were prepared and run by Christopher Foote, Analysis was done by Christopher Foote and Carol Vleck. Please contact Carol Vleck for any questions (cvleck@iastate.edu). Column Headings A. Date the gel was initiated using the international standard notation of YYYYMMD B. species code using the American Ornithologists Union code as follows: TRES Ð tree swallow, Tachycineta bicolor BARS Ð barn swallow, Hirundo rustica MANS Ð mangrove swallow, Tachycineta albilinea REVI- red-eyed vireo, Vireo olivaceus ZF Ð zebra finch, Taeniopygia guttata CHSP Ð chipping sparrow, Spizella passerina C. The bird identification number for each species. In some cases two or three gels were run with different individuals for each species. In some cases the same individual was run in more than one lane on a gel. For one tree swallow gel the same pool sample was run in every lane. D. The lane number for that individual on a given gel E. Using the nondenatured gel, the sum of the optical densities (from Image J analysis for phosphor images) multiplied by the molecular size of the DNA at that position for all positions on the gel between 1.6 and 40 kb. Approximately 440 positions for each lane were included in this summation. Units are arbitrary. F. Using the denatured gel, the sum of the optical densities (from Image J analysis for phosphor images) for all positions on the gel between 1.6 and 40 kb. Approximately 440 positions for each lane were included in this summation. Units are arbitrary. G. The calculated mean telomere length in kb using the nondenatured gel which does not include the interstitial telomeric sequences. H. The calculated mean telomere length in kb using the denatured gel which includes the interstitial telomeric sequences. The mean is lower using this method because the average interstitial telomere sequence is shorter than the average true telomere sequence. I. The G-score for each lane on some gels calculated for Column E (the non-denatured gel) calculated as mean value for that lane minus the average value for that column on the gel divided by the standard deviation for that column on that gel. J. The G-score for each lane on some gels calculated for Column F (the denatured gels) calculated as mean value for that lane minus the average value for that column on the gel divided by the standard deviation for that column on that gel.