Fatty acid profile of yolk and embryo brain tissue in lesser black-backed and herring gulls

Overview

This dataset contains fatty acid profile of egg yolks and embryo brain tissues of herring gull (Larus argentatus) and lesser black-backed gull (Larus fuscus) collected along the Belgian coast between 2022 and 2024.  The dataset includes concentrations of saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), and polyunsaturated fatty acids (PUFAs), including omega-3 and omega-6 fatty acids, and their totals.

Brief method

For each clutch (N = 259), the three eggs were ranked from first-laid to last-laid (A to C, respectively) based on egg dimensions and volume. Fatty acid analyses were performed on yolks (N = 310) and on embryo brain tissues (N = 136).

Yolk samples were obtained by sterile extraction of egg contents, while embryonic brain samples were collected through dissection of late-stage embryos. Fatty acids were converted to fatty acid methyl esters (FAMEs) by direct transesterification and analyzed using gas chromatography with flame ionization detection (GC-FID). Fatty acid peaks were identified using certified methyl ester standards and quantified using C19:0 as an internal standard. All samples were analyzed in duplicate.

Rationale

The dataset was generated to assess to what extent the PUFA profile measured in the yolk of one egg per clutch could be a reliable proxy for the yolk and brain PUFA profile of its sibling. This proxy could be a promising lead to investigate pre-natal (maternal) effects of fatty acid on brain and cognitive development of chicks (Gémard et al., submitted; Knoch et al., in prep).

Funding

This study was funded by the Methusalem Project 01M00221 (Ghent University; https://www.ugent.be/en/research/funding/bof/methusalem), an ERC Consolidator Grant (European Union’s Horizon 2020 research and innovation programme, grant agreement no. 769595),  a FWO (Flemish Research Foundation) PhD Fellowship grant (No. 11P3G24N), and a FWO (Flemish Research Foundation) PhD Fellowship grant (No. 11F0823N, 11F0825N).

Variable description

The dataset comprises 10 variables:

• species – Gull species: HG (herring gull), LBBG (lesser black-backed gull), or UNK (unknown).
• clutchLocation – Nest location where the eggs were collected: BL (Blankenberge), BR (Bredene), DH (De Haan), DP (De Panne), KN (Knokke), KS (Koksijde), OO (Oostende), ZB (Zeebrugge), or ZW (Zwin).
• clutchID – Unique clutch identifier (259 unique values).
• eggID – Unique egg identifier consisting of the clutch ID and egg rank (A, B, or C)(420 unique values)
• eggRank – Laying order of the egg: A (first-laid), B (second-laid), or C (last-laid).
• yearCollected – Year of egg collection (2022, 2023, or 2024).
• matrix – Biological matrix in which fatty acids were measured: yolk or brain.
• fattyAcid – Fatty acid measured. "Sum" represents the total concentration of all quantified fatty acids.
• unit – Unit in which fatty acid concentrations were measured.
• meanMeasurement – Fatty acid concentration calculated as the mean of the two analytical replicates.