Dataset Information

The Antarctic Weddell seal genome reveals evidence of selection on cardiovascular phenotype and lipid handling.

ABSTRACT: The Weddell seal (Leptonychotes weddellii) thrives in its extreme Antarctic environment. We generated the Weddell seal genome assembly and a high-quality annotation to investigate genome-wide evolutionary pressures that underlie its phenotype and to study genes implicated in hypoxia tolerance and a lipid-based metabolism. Genome-wide analyses included gene family expansion/contraction, positive selection, and diverged sequence (acceleration) compared to other placental mammals, identifying selection in coding and non-coding sequence in five pathways that may shape cardiovascular phenotype. Lipid metabolism as well as hypoxia genes contained more accelerated regions in the Weddell seal compared to genomic background. Top-significant genes were SUMO2 and EP300; both regulate hypoxia inducible factor signaling. Liver expression of four genes with the strongest acceleration signals differ between Weddell seals and a terrestrial mammal, sheep. We also report a high-density lipoprotein-like particle in Weddell seal serum not present in other mammals, including the shallow-diving harbor seal.

SUBMITTER: Noh HJ

PROVIDER: S-EPMC8854659 | biostudies-literature | 2022 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

The Antarctic Weddell seal genome reveals evidence of selection on cardiovascular phenotype and lipid handling.

Noh Hyun Ji HJ Turner-Maier Jason J Schulberg S Anne SA Fitzgerald Michael L ML Johnson Jeremy J Allen Kaitlin N KN Hückstädt Luis A LA Batten Annabelle J AJ Alfoldi Jessica J Costa Daniel P DP Karlsson Elinor K EK Zapol Warren M WM Buys Emmanuel S ES Lindblad-Toh Kerstin K Hindle Allyson G AG

Communications biology 20220217 1

The Weddell seal (Leptonychotes weddellii) thrives in its extreme Antarctic environment. We generated the Weddell seal genome assembly and a high-quality annotation to investigate genome-wide evolutionary pressures that underlie its phenotype and to study genes implicated in hypoxia tolerance and a lipid-based metabolism. Genome-wide analyses included gene family expansion/contraction, positive selection, and diverged sequence (acceleration) compared to other placental mammals, identifying selec ...[more]

PMID: 35177770

Similar Datasets

Project description:Lactation is the most energy-demanding event in mammals' reproduction. In pinnipeds, females are the only food providers to the young and have developed numerous behavioral and physiological lactation strategies, from capital-breeding to income-breeding. Lactating females' fine-scale foraging strategy, and precise understanding of how females supplement their pup's needs as well as their own are important to understand the species' ecology and energetic balance. Polar pinnipeds, inhabiting extreme environments, are sensitive to climate change and variability, understanding their constraints and foraging strategy during lactation is therefore important. In 2019, three sonar tags were deployed on lactating Weddell seals in Terre Adélie (East Antarctica) for 7 days, to study fine-scale predator-prey interactions. Feeding activity was mostly benthic, reduced, central-placed, and spatially limited. Females spent most of their time hauled-out. A total of 331 prey capture attempts (PrCAs) were recorded using triaxial acceleration data, with 125 prey identified on echograms (5 cm, acoustic size). All PrCAs occurred on the seafloor, shallower than usual records (mean depth of 88 m, vs 280 m after their molt). We also found that they only fed in three of the five identified dive shapes, during the ascent or throughout the dive. Half of the prey were reactive to the seal's approach, either leaving the seafloor, or escaping just above the seafloor, suggesting that the seals hunt by chasing them from the seabed. Seals continuously scanned the area during the approach phase, evoking opportunistic foraging. Our results provide additional evidence that Weddell seal forage during lactation, displaying a mix of capital-breeding and income-breeding strategies during this period of physiological stress. This work sheds light on previously unexplored aspects of their foraging behavior, such as shallow water environments, targeting benthic prey, generally focusing on single prey rather than schools, and evidence of visual scanning through observed head movements.

Project description:This study investigates the spatiotemporal dynamics of Antarctic sea ice concentration (SIC) and its interactions with environmental factors from 2011 to 2023, focusing on the Weddell Sea. SIC products derived from MODIS data were assessed and compared with six widely used datasets, including AMSR2/NT2 and MWRI/NT2. Among these, MWRI/NT2 exhibited the highest consistency with MODIS-derived SIC, achieving a correlation coefficient of 0.94, the lowest bias (0.23%), and the smallest mean absolute deviation (MAD) and root mean square deviation (RMSD), making it the preferred dataset for further analysis. Seasonal trends reveal that SIC experienced the most significant decline during autumn (-10.7 ± 2.3 × 10³ km² yr⁻¹) and the smallest reduction in winter (-1.3 ± 0.5 × 10³ km² yr⁻¹). Correlation analysis identified sea surface temperature (SST), wind speed, and latent heat flux (LHF) as the primary drivers of seasonal SIC variability, with SST exhibiting strong negative correlations across all seasons (r = -0.81, p < 0.01). Spatially, SIC in the Weddell Sea displayed significant heterogeneity in its relationship with environmental factors. SST demonstrated a negative correlation with SIC, particularly in the western Weddell Sea, with lags of -3 to -5 months. LHF consistently promoted sea ice growth, with the strongest influence along the eastern Weddell Sea coast. Zonal and meridional winds exhibited both promoting and suppressing effects on SIC depending on the region and time period, reflecting complex wind-sea ice interactions. Mean sea level pressure (MSLP) showed opposing effects: suppressing SIC in the northern Weddell Sea and promoting it in the southern Weddell Sea. The use of geographically and temporally weighted regression (GTWR) allowed the quantification of the spatial and temporal heterogeneity of these factors, with LHF identified as the most influential variable (median standardized coefficient = 1.44). These findings highlight the intricate interplay between atmospheric, oceanic, and sea ice dynamics in the Weddell Sea and provide a framework for understanding the drivers of sea ice variability under changing climatic conditions.

Dataset Information

The Antarctic Weddell seal genome reveals evidence of selection on cardiovascular phenotype and lipid handling.

Publications

The Antarctic Weddell seal genome reveals evidence of selection on cardiovascular phenotype and lipid handling.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets