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Record W630515564

Molecular and seasonal basis for freeze resistance in wolffish species (Anarhichas lupus, A. minor and their hybrids)

2012· dissertation· en· W630515564 on OpenAlexaboutno aff
Mariève Desjardins

Bibliographic record

VenueMemorial University Research Repository (Memorial University) · 2012
Typedissertation
Languageen
FieldEnvironmental Science
TopicPhysiological and biochemical adaptations
Canadian institutionsnot available
Fundersnot available
KeywordsBiologyGene duplicationAntifreeze proteinGeneGene poolGene flowZoologyGeneticsGenetic variationGenetic diversity
DOInot available

Abstract

fetched live from OpenAlex

During winter, the coastal waters of Newfoundland can be considered a "freeze risk ecozone" for teleost fishes. The benthic Atlantic (Anarhichas lupus - AW) and spotted wolffish (A. minor - SW) reside at opposite ends of this ecozone, with the AW facing the greatest risk because of its shallower niche. To resist freezing, AW secretes five times the level of plasma antifreeze protein (AFP) activity than does SW. -- The main basis for this difference in plasma AFP levels is gene dosage, as AW has approximately three times more AFP genes than SW. Perhaps as a result, AFP transcript levels in liver (the primary source of circulating AFP's) are several times higher in AW. One explanation for these gene and transcript dosage differences is the presence of tandemly arrayed AFP gene repeats in AW that make up two-thirds of its AFP gene pool. Such repeats are not present in SW. AW and SW diverged from a common ancestor at a time when the ebb and flow of northern glaciations would have resulted in the emergence of "freeze risk ecozones". The duplication/amplification of AFP genes in a subpopulation of ancestral wolffish would have facilitated the exploitation of this high risk habitat, resulting in the divergence and evolution of modem day AW and SW species. -- Investigations on artificially produced AW/SW hybrids showed that all the AFP genes of SW are likely shared with AW, which supports recent gene amplification as an impetus for speciation. The high dynamism of the AW AFP locus (through high variability in dosage and organisation) was best visualized in the single haplotype inherited by the hybrids. Their intermediate levels of plasma AFPs make these fish unfit for survival within the shallowest part of the "freeze risk ecozone". -- While the total levels of AFP gene transcripts varied little from winter to summer in both species (especially in the liver), differential expression of members of the two subfamilies of type III AFPs, the SP- and QAE-type genes (appellation based on the ion-exchange Sephadex resins to which each type of isoform binds), was observed. While the expression of the QAE-type transcripts was ubiquitous (both temporally and spatially), that of the SP-type genes seemed to show some level of tissue specificity, which highlights the complex evolutionary history of these genes.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: Bench or experimental
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.002
Threshold uncertainty score0.003

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0010.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.021
GPT teacher head0.224
Teacher spread0.203 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designBench or experimental
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations0
Published2012
Admission routes1
Has abstractyes

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