Biology subjects

Quintela, M.

Publications and source records attributed to Quintela, M..

4 recordsLinked to original sources

bioRxiv2025

Genetics in the ocean's twilight zone: Population structure of the Mueller's pearlside across its distribution range

The large estimates of mesopelagic fish biomass have fuelled harvesting interests in the relatively untouched oceans twilight zone. The Muellers pearlside, one of the most abundant species inhabiting the north Atlantic mesopelagic layer, is a candidate to such fisheries despite its enormous ecological importance and the insufficient knowledge about its population genetic structure. To shed light on the latter, 863 individuals sampled across the North Atlantic and Mediterranean were genotyped using 170 genome-wide SNPs. Analyses revealed habitat-driven differentiation in three units: Mediterranean Sea, oceanic samples, and Norwegian fjords. These groups were not completely isolated to each other as a cline of Mediterranean admixture was detected in the Eastern Atlantic facade up to 47{degrees}N in an otherwise genetically homogeneous oceanic cluster. Temperature seemed to modulate the differentiation patterns, and in the Mediterranean added to the complicated topography of the Greek Seas to shape genetic structure. In the Norwegian coastline, sills did not hamper genetic exchange among fjords ranging 200 km apart, probably due to the position of the species in the water column together with its swimming capacity. This genetic information should be combined with demographic properties to outline the management of this species prior to any eventual fishery attempt.

genetics↗

bioRxiv2024

Limited parallelism in genetic adaptation to brackish water bodies in European sprat and Atlantic herring

The European sprat is a small plankton-feeding clupeid present in the northeastern Atlantic Ocean, the Mediterranean Sea as well as in the brackish Baltic Sea and Black Sea. This species is the target of a major fishery and therefore an accurate characterization of its genetic population structure is crucial to delineate proper stock assessments that aid ensuring the fisherys sustainability. Here we present (i) a draft genome assembly, (ii) pooled whole genome sequencing of 19 population samples covering most of the species distribution range, and (iii) the design and test of a SNP-chip resource and use this to validate the population structure inferred from pooled sequencing. These approaches revealed, using the populations sampled here, three major groups of European sprat: Oceanic, Coastal and Brackish with limited differentiation within groups even over wide geographical stretches. Genetic structure is largely driven by six large putative inversions that differentiate Oceanic and Brackish sprats, while Coastal populations display intermediate frequencies. Interestingly, populations from the Baltic and the Black Seas share similar frequencies of haplotypes at these putative inversions despite their distant geographic location. The closely related clupeids European sprat and Atlantic herring both show genetic adaptation to the brackish Baltic Sea, providing an opportunity to explore the extent of genetic parallelism. This analysis revealed limited parallelism in the form of three sharp signals of selection that overlapped between the two species and contained single genes such as PRLRA, which encodes the receptor for prolactin, a freshwater-adapting hormone in euryhaline species, and THRB, a receptor for thyroid hormones, important both for metabolic regulation and the development of red cone photoreceptors.

genomics↗

bioRxiv2022

Global, regional, and cryptic population structure in a high gene-flow transatlantic fish

1Lumpfish (Cyclopterus lumpus) is a transatlantic marine fish displaying large population sizes and a high potential for dispersal and gene-flow. These features are expected to result in weak population structure. Here, we investigated population genetic structure of lumpfish throughout its natural distribution in the North Atlantic using two approaches: I) 4393 genome wide SNPs and 95 individuals from 10 locations, and II) 139 discriminatory SNPs and 1,669 individuals from 40 locations. Both approaches identified extensive population genetic structuring with a major split between the East and West Atlantic and a distinct Baltic Sea population, as well as further differentiation of lumpfish from the English Channel, Iceland, and Greenland. The targeted discriminatory loci displayed [~]2-5 times higher divergence than the genome wide approach, revealing further evidence of local population substructures. Lumpfish from Isfjorden in Svalbard were highly distinct but resembled most fish from Greenland. The Kattegat area in the Baltic transition zone, formed a previously undescribed distinct genetic group. Also, further subdivision was detected within North America, Iceland, West Greenland, Barents Sea, and Norway. Although lumpfish have considerable potential for dispersal and gene-flow, the observed high levels of population structuring throughout the Atlantic suggests that this species displays natal homing and potentially local populations with adaptive differences. This fine-scale population structure calls for consideration when defining management units for lumpfish fishing stocks and in decisions related to sourcing and moving lumpfish for farming and cleaner fish use.

evolutionary biology↗

bioRxiv2020

Loss of erythroblasts in acute myeloid leukemia causes iron redistribution with clinical implications

Acute myeloid leukemia (AML) is a heterogeneous disease with poor prognosis and limited treatment strategies. Determining the role of cell-extrinsic regulators of leukemic cells is vital to gain clinical insights into the biology of AML. Iron is a key extrinsic regulator of cancer but its systemic regulation remains poorly explored in AML. To address this question, we studied iron metabolism in AML patients at diagnosis and mechanisms involved using the syngeneic MLL-AF9-induced AML mouse model. We found that AML is a disorder with a unique iron profile not associated with inflammation or transfusion and characterized by high ferritin, low transferrin, high transferrin saturation (TSAT), and high hepcidin. The increased TSAT in particular, contrasts with observations in other cancer types and in anemia of inflammation. Using the MLL-AF9 mouse model of AML, we demonstrated that leukemic blasts take up iron and that the AML-induced loss of erythroblasts is responsible for iron redistribution and an increase in TSAT. We also show that elevated TSAT at diagnosis is independently associated with increased overall survival in AML and suggest that TSAT may be a relevant prognostic marker in AML.

cancer biology↗