https://doi.org/10.5061/dryad.hqbzkh1j6

Data includes the 1) finished data table for the Cuticular hydrocarbon (CHC) analyses; 2) the raw data created by the GC-MS for the CHC analyses and 3) the raw data created from the TD-GC-MS for the Metapleural gland secretions (6890 gas chromatograph (GC) coupled to a 5975 mass selective detector (MS) by Agilent Technologies (Waldbronn, Germany). The folders for each data point contain all the information which is readable by the Softwares Chemstation or Masshunter Qualitative Analysis (Agilent Technologies).

Description of the data and file structure

The finished data table (1) contains the cleaned up datatable of the raw CHC data (2). In the datatable we identified the Hydrocarbon Compound (Compound), the type of compound (type), the Retention time the compound appears on the Gas Chromatograph in minutes (Ret Time) and the standardised Retention Index (Ret Index).

The Cuticular Hydrocarbon (CHC) Sample IDs are composed of my initials (EF: Erik Frank), the year (20: 2020) and their individual ID (1 to 60). The numbers received different treatments: 1-6 CHC profile extracted at timepoint 0 of infected ants. 7-18 CHC profile extracted after 2hours of infected ants. 19-30 CHC profile extracted after 11 hours of infected ants. 31-36: CHC profile extracted at timepoint 0 of sterile ants. 37-48 CHC profile extracted after 2hours of sterile ants. 49-61 CHC profile extracted after 11 hours of sterile ants. Infected ants refer to ants whose leg injury was exposed to Pseudomonas aeruginosa, while for sterile ants the leg injury was exposed to a sterile PBS solution. In addition we ran conditioning blanks to assure the purity of the GC-MS machine and the quality of the hexane and remove any potential contaminants. These are in the sub-folder "conditioning blanks" and named Hexane_1 to 6. Between the runs we also ran additional Hexane samples to assure the quality was maintained throughout the run. These are named "Hexane_1" and Hexane_Blank_2 to 4.

The Metapleuralgland samples are named after the species Megaponera analis from which they were taken from (M_analis), followed by the gland abbreviation (mpg) and sample number (1 to 3). Each sample contains 6 pooled metapleural glands taken from 6 individual worker ants. The sample "test after mpg" was a TD-GC-MS run containing an empty glass tube to identify contaminants or potential remnants from the sample runs.

To quantify differences in CHC profiles between infected and sterile ant workers, we placed the ants in hexane for 10 minutes to extract the CHC profile. The cuticular hydrocarbon extracts were then evaporated to a volume of approximately 100 μL and 1 μL was analyzed by using a 6890 gas chromatograph (GC) coupled to a 5975 mass selective detector (MS) by Agilent Technologies (Waldbronn, Germany). The GC was equipped with a DB-5 capillary column (0.25 mm ID × 30 m; film thickness 0.25 μm, J & W Scientific, Folsom, Ca, USA). Helium was used as a carrier gas with a constant flow of 1 mL/min. A temperature program from 60 °C to 300 °C with 5 °C/min and finally 10 min at 300 °C was employed. Mass spectra were recorded in the EI mode with an ionization voltage of 70 eV and a source temperature of 230 °C. The software ChemStation v. F.01.03.2357 (Agilent Technologies, Waldbronn, Germany) for windows was used for data acquisition. Identification of the components was accomplished by comparison of library data (NIST 17) with mass spectral data of commercially purchased standards and diagnostic ions.

The Metapleuralgland samples were placed in a glass-wool-packed thermodesorption tube and placed in the thermodesorber unit (TDU; TD100-xr, Markes, Offenbach am Main, Germany). The thermodesorption tube was heated up to 260°C for 10 min. The desorbed components were transferred to the cold trap (5 °C) to focus the analytes using N2 flow in splitless mode. The cold trap was rapidly heated up to 310 °C at a rate of 60 °C per minute, held for 5 min and connected to the GC-MS (Agilent 7890B GC and 5977 MS, Agilent Technologies, Palo Alto, USA) via a heated transfer line (300 °C). The GC was equipped with an HP-5MS UI capillary column (0.25 mm ID × 30 m; film thickness 0.25 μm, J & W Scientific, Folsom, Ca, USA). Helium was the carrier gas using 1.2874 ml/min flow. The initial GC oven temperature was 40 °C for 1 min, then raised at a rate of 5°C per min until reaching 300 °C, where it was held for 3 minutes. The transfer line temperature between GC and MS was 300 °C. The mass spectrometer was operated in electron impact (EI) ionization mode, scanning m/z from 40 to 650, at 2.4 scans per second. Chemical compounds were identified using the same protocol as for the CHCs.

Code/Software

All Data was quantified and prepared using MassHunter Qualitative Analysis (Agilent Technologies) and Excel for Mac (Version 16.79.1).