fat-4
C. elegans
Delta(5) fatty acid desaturase fat-4
What the model saw
Gene: fat-4 Organism: Caenorhabditis elegans Known functions: Delta(5) fatty acid desaturase fat-4. acyl-CoA (8-3)-desaturase activity. oxidoreductase activity. oxidoreductase activity, acting on paired donors, with oxidation of a pair of donors resulting in the reduction of molecular oxygen to two molecules of water. stearoyl-CoA 9-desaturase activity.
View unredacted entry
Delta(5) fatty acid desaturase fat-4. acyl-CoA (8-3)-desaturase activity. oxidoreductase activity. oxidoreductase activity, acting on paired donors, with oxidation of a pair of donors resulting in the reduction of molecular oxygen to two molecules of water. stearoyl-CoA 9-desaturase activity.
Solver output
fat-4 encodes a Delta(5) fatty acid desaturase in C. elegans, responsible for introducing double bonds into fatty acyl-CoA substrates, including conversion of dihomo-γ-linolenic acid (DGLA) to arachidonic acid (AA) and related polyunsaturated fatty acid (PUFA) biosynthesis steps. Proper PUFA composition of membrane phospholipids is critical for membrane fluidity, mitochondrial function, and lipid signaling. In C. elegans, the PUFA biosynthesis pathway (involving fat-1 through fat-4 desaturases) has been linked to lifespan regulation; loss of specific desaturases alters the balance of pro- and anti-inflammatory eicosanoid-like lipid mediators and affects membrane homeostasis. Delta(5) desaturase activity specifically controls the ratio of DGLA to AA, and DGLA accumulation (as seen in fat-4 loss-of-function) has been shown to extend lifespan in some contexts, suggesting that fat-4's normal activity (consuming DGLA) may be slightly anti-longevity; however, the overall PUFA biosynthetic function of fat-4 supports membrane integrity and lipid signaling pathways that broadly promote healthy aging. The net effect of fat-4's normal desaturase function in maintaining balanced PUFA profiles is considered modestly pro-longevity through maintenance of membrane homeostasis and lipid-mediated signaling.
GenAge curators classify each gene's normal function as promoting (Pro-Longevity) or opposing (Anti-Longevity) longevity, based on synthesis across studies. Loss-of-function effects can vary from this depending on the manipulation.
Advisor judgment
The model predicted pro_longevity but the ground truth is anti_longevity. Interestingly, the model's own reasoning partially acknowledged the correct answer - it noted that "DGLA accumulation (as seen in fat-4 loss-of-function) has been shown to extend lifespan in some contexts, suggesting that fat-4's normal activity (consuming DGLA) may be slightly anti-longevity." This is actually consistent with the ground truth (fat-4 is anti-longevity, meaning its normal function reduces lifespan). However, the model then contradicted itself and concluded pro_longevity based on a hand-wavy argument about "membrane homeostasis." The model had the right mechanistic insight but drew the wrong conclusion from it. The reasoning quality is poor because the model identified the correct mechanism (fat-4 consuming DGLA is anti-longevity) but then overrode this with a generic argument to reach the wrong answer.
Raw API responses
solver
{
"reasoning": "fat-4 encodes a Delta(5) fatty acid desaturase in C. elegans, responsible for introducing double bonds into fatty acyl-CoA substrates, including conversion of dihomo-γ-linolenic acid (DGLA) to arachidonic acid (AA) and related polyunsaturated fatty acid (PUFA) biosynthesis steps. Proper PUFA composition of membrane phospholipids is critical for membrane fluidity, mitochondrial function, and lipid signaling. In C. elegans, the PUFA biosynthesis pathway (involving fat-1 through fat-4 desaturases) has been linked to lifespan regulation; loss of specific desaturases alters the balance of pro- and anti-inflammatory eicosanoid-like lipid mediators and affects membrane homeostasis. Delta(5) desaturase activity specifically controls the ratio of DGLA to AA, and DGLA accumulation (as seen in fat-4 loss-of-function) has been shown to extend lifespan in some contexts, suggesting that fat-4's normal activity (consuming DGLA) may be slightly anti-longevity; however, the overall PUFA biosynthetic function of fat-4 supports membrane integrity and lipid signaling pathways that broadly promote healthy aging. The net effect of fat-4's normal desaturase function in maintaining balanced PUFA profiles is considered modestly pro-longevity through maintenance of membrane homeostasis and lipid-mediated signaling.",
"confidence": 0.68,
"key_pathways": [
"polyunsaturated fatty acid (PUFA) biosynthesis",
"membrane lipid homeostasis",
"lipid-mediated signaling / eicosanoid-like mediators"
],
"mechanism_class": "deregulated_nutrient_sensing",
"longevity_influence": "pro_longevity"
}advisor
{
"notes": "The model predicted pro_longevity but the ground truth is anti_longevity. Interestingly, the model's own reasoning partially acknowledged the correct answer - it noted that \"DGLA accumulation (as seen in fat-4 loss-of-function) has been shown to extend lifespan in some contexts, suggesting that fat-4's normal activity (consuming DGLA) may be slightly anti-longevity.\" This is actually consistent with the ground truth (fat-4 is anti-longevity, meaning its normal function reduces lifespan). However, the model then contradicted itself and concluded pro_longevity based on a hand-wavy argument about \"membrane homeostasis.\" The model had the right mechanistic insight but drew the wrong conclusion from it. The reasoning quality is poor because the model identified the correct mechanism (fat-4 consuming DGLA is anti-longevity) but then overrode this with a generic argument to reach the wrong answer.",
"failure_mode": "confident_wrong",
"answer_correct": false,
"mechanism_correct": false,
"reasoning_quality": 2,
"ground_truth_questionable": false
}