DOI: 10.5061/dryad.9w0vt4brt
title: Thermal stress in lobsters affects cardiac lipidome

description: Lipids are fundamental components of many biological structures, and their
 composition is diet dependent. Differences in lipid composition can impact
 the functioning of cellular membranes and proteins, subsequently altering
 the organism’s ability to respond to environmental conditions. The
 American lobster (Homarus americanus) is an economically important
 shellfish in New England and is frequently kept in lobster impoundments
 (pounds) for prolonged periods where they are typically fed herring, which
 differs from the natural diet of wild-caught lobsters. In this study, we
 compared the lipid composition of lobster muscle, heart, and
 hepatopancreas from wild caught and from pound kept lobsters that were fed
 different diets. We performed lipidomic analysis, mitochondrial function
 tests, tested gene expression of cellular stress markers, and evaluated
 thermal stress tolerance assessing heart and ventilation rate, as well as
 hemolymph oxygenation during a fast progressive temperature challenge. We
 find a significant shift in lipid composition in pound kept lobster hearts
 together with reduced mitochondrial function, and increased gene
 transcription of cellular stress markers HSP70 and AMPK, indicating a
 worse nutritional state, compared to wild fed lobsters. The shift in the
 various parameters did not lead to a shift in thermal thresholds,
 indicating a substantial plasticity and tolerance to compensate for
 adverse diet-induced conditions. This study links mechanistically diet,
 lipid composition, mitochondrial function and thermal tolerance and
 highlights the need of a more detailed understanding of cellular processes
 to understand climate change-induced impacts on marine invertebrates.
description: Frozen tissue samples were used in mass spectrometry-based
 multiple precursor ion scan (MPIS) lipidomic analysis (Simons et al.,
 2012) at the MaineHealth Institute for Research (MHIR) Proteomics and
 Lipidomics core facility in Scarborough, Maine. Lipids were isolated using
 a modified Bligh and Dyer protocol (Bligh and Dyer, 1959; Liaw et al,
 2016; Okeoma et al., 2024) using dichloromethane and methanol. Briefly,
 around 20 mg of tissue was transferred to an Eppendorf cup with 200 µL of
 66% methanol (MeOH) (Alfa Aesar-Themo Fisher, Waltham, MA, USA) in LC-MS
 grade water (Burdick and Jackson-Honeywell, Muskegon, MI, USA) and kept on
 ice all the time. Tissues were homogenized with a pellet pestle motor
 (Kimble, Millville, NJ, USA) and then by sonication using a Branson
 Sonifier 250 (VWR Scientific, Radnor, PA, USA) for ten 30-second cycles at
 30% until the tissue was dissolved. Samples sat on ice for 10 min to allow
 for debris to settle. Supernatants were then transferred to a glass
 screw-cap tube. 66% MeOH and 0.9 mL dichloromethane (DCM) (Sigma Aldrich,
 St. Louis, MO, USA) was added to allow all samples to reach a volume of 3
 mL. Samples were then vortexed and 50-100 µL MeOH was added to allow for a
 DCM-MeOH-sample monophase. Samples were incubated at room temperature for
 30 minutes before the aqueous and organic phases were separated by the
 subsequent addition of 1 mL water and 0.9 mL DCM. All samples were
 centrifuged at 1200 rpm for 10 minutes and the lower DCM organic phase was
 removed to a new glass tube and dried under nitrogen and a partial vacuum
 using a Visiprep manifold (Supelco, Bellefonte, PA, USA). Lipid extracts
 were dissolved in lipid load solution: MeOH/DCM (50:50, v/v) containing 10
 mM ammonium acetate (NH<sub>4</sub>Ac) LC/MS grade (Fisher,
 Waltham, MA, USA) for MS analysis. Approximately 100 µL of a 4-fold
 diluted lipid extract in lipid load solution, was delivered by PAL3 System
 (LEAP Technologies, Naperville, IL, USA) into the source of a Sciex QTRAP
 4000 mass spectrometer. A PAL3-RSI (Trajan Inc.) robotic sample handling
 instrument was used to deliver lipid load solution at a rate of 0.25 mL
 min<sup>-1</sup> during all the runs. Source parameters
 included gases GS1 at 15 and GS2 at 20, curtain gas at 10, IonSpray
 voltage 5300, temperature at 150, and collision energy was 50 eV. Each
 sample was injected twice and, positive and negative polarity modes were
 acquired simultaneously in serial experiments from a single sample
 infusion. The instrument was controlled, and quality control for
 instrument performance included bovine heart extract (Avanti
 Research/Croda Inc., Alabaster, AL, USA).
description: # Lobster diet affects lipidomics and thermal tolerance
 [https://doi.org/10.5061/dryad.9w0vt4brt](https://doi.org/10.5061/dryad.9w0vt4brt) ## Description of the data and file structure Lobsters were caught off the Maine coast (wild caught) or purchased from a local lobster pound (Pound) and then kept in a flow through aquarium for about 150 days and fed typical pound diet (herring) or wild diet (mussel) leading to 4 groups: pound kept pound-fed lobsters (PKPF) wild-caught, pound-fed lobsters (WCPF) pound-kept, wild-fed (PKWF) and wild-caught, wild-fed (WCWF). Heart tissue was extracted after 150 days of differential feeding herring or mussels and analyzed by mass spectrometry-based multiple precursor ion scan (MPIS) for lipid composition. ### Files and variables #### File: Lobster_lipidome-Positive.xlsx **Description:** This dataset represents **lipidomics data** — specifically, measurements of **sphingomyelin (SM) species** detected in a series of biological or experimental samples using mass spectrometry. This dataset captures relative abundance of sphingomyelin (SM) lipids across a series of experimental samples, probably for comparing lipid profiles across different tissues, treatments, or time points. These data are typical of lipidomics or metabolomics studies and are used to assess how lipid composition varies in biological systems. **Variables** * Peak name: respective identified lipid species * group: lipid class * peak amplitude for the respective treatments WCWF, WCPF, PKPF, or PKWF - Wild caught Wild Fed, WCWF, - Wild caught pound fed, WCPF, - Pound kept Pound fed, PKPF, - Pound kept wild fed, PKWF #### File: Lobster_lipidome_Negative.xlsx **Description:** This dataset presents lipid species detection data across different biological or experimental samples. It is used for: Comparative lipidomics, Identifying lipid patterns across conditions, and quality control (via blank samples). * **Row**: An index number for each lipid species (e.g., 1, 2, 3…). * **Peak**: The name of the identified lipid molecule. **Variables** * * Peak name: respective identified lipid species * group: lipid class * peak amplitude for the respective treatments WCWF, WCPF, PKPF, or PKWF - Wild caught Wild Fed, WCWF, - Wild caught pound fed, WCPF, - Pound kept Pound fed, PKPF, - Pound kept wild fed, PKWF Together, the positive and negative ion datasets allow for comprehensive **lipidomic profiling** of lobster heart tissue under different feeding and environmental conditions. These data are instrumental in assessing how lipid composition is influenced by diet and origin, and could be used to explore physiological responses or adaptations. **Access Information** Other publicly accessible locations of the data: * n/a Data was derived from the following sources: * n/a