Benchmarking Literature Retrieval for a Model Organism: A Dictyostelium Case Study
Authors: Yun Wang, Gad Shaulsky, Tomaž Curk, Blaž Zupan
Organizations: University of Ljubljana, Faculty of Computer and Information Science, Večna pot 113, 1000 Ljubljana, Slovenia · Department of Molecular and Human Genetics, Baylor College of Medicine, Baylor Plaza, Houston, TX 77030, USA
Biological literature retrieval systems are often developed and evaluated using broad biomedical corpora and general-purpose search tasks. However, many curated knowledge bases operate in narrower model-organism domains, where the literature is sparse and terminology is organism-specific. We introduce a retrieval benchmark from dictyBase for Dictyostelium, a model organism in cell and developmental biology. The benchmark consists of curator-generated biological queries linked to PubMed-indexed articles, together with structured gene annotations. Using this benchmark, we study three factors in niche biological retrieval: cross-encoder reranking, gene-aware query expansion, and abstract-only versus full-text retrieval. We report that reranking and gene-aware query expansion improve retrieval selectively: reranking is most useful when the model is well suited to biological evidence matching, whereas curated annotations help clarify compact biological queries by reducing vocabulary mismatch. Full-text chunks substantially improve retrieval when abstracts omit supporting evidence, increasing both candidate recall and top-rank performance, although these cases are harder than queries supported by abstracts. Data and code are publicly available at https://github.com/fulaibaowang/dictycite, and the benchmark dataset is additionally archived on Zenodo.
Figures & tables
Figure 1: Construction of a retrieval instance from a dictyBase gene page. (A) The source page for gene pkaC ( http://dictybase.org/gene/DDB_G0283907 ) contains structured gene annotations and curator-generated notes with inline citations. (B) A curator-generated claim is extracted as the query, and its inline citation is mapped to a PubMed-indexed article used as the cited relevance judgment. Auxiliary fields are used in later experiments: gene annotations support gene-aware query expansion, and the LLM-assisted evidence label supports the full-text analysis by marking whether the cited abstract is sufficient for the claim or whether full-text evidence may be needed.
Figure 2: Two-stage retrieval and reranking pipeline. Stage 1 builds a recall-oriented candidate pool by fusing BM25 and dense retrieval with RRF. Stage 2 reranks the fused candidates with a cross-encoder and combines the reranker order with the original retrieval-fusion order through a second RRF step to produce the final ranking.
System
Description
Model size
MRR@10
Δ vs. BM25
BM25
Lexical baseline
–
0.593
–
BM25+Dense
Lexical+dense RRF
–
0.568
−2.6 [ −4.1 , −1.0 ]
MiniLM-L12
Lightweight MS MARCO CE
33M
0.541
−5.2 [ −7.0 , −3.4 ]
BGE-m3
Strong multilingual CE
0.6B
0.605
+1.2 [ −0.5 , +2.8 ]
MedCPT
PubMed-trained biomedical CE
∼ 110M
0.650
+5.7 [ +4.2 , +7.2 ]
BGE-Gemma
LLM-based CE reranker
3B
0.707
+11.4 [ +9.8 , +13.0 ]
Table 1: Ranker comparison on the full dataset (1,656 queries). Model size denotes the approximate number of parameters for neural rerankers; “–” indicates systems without a neural reranker. MRR@10 is the mean reciprocal rank at cutoff 10, where higher values indicate better top-rank performance. Δ vs. BM25 reports the difference in MRR@10 from the BM25 baseline in percentage points; positive values indicate improvement over BM25, and brackets show 95% paired-bootstrap confidence intervals.
Figure 3: Effect of gene-aware query expansion. Three query variants are compared: the original query (the curator claim), the claim plus gene synonyms, and the claim plus both gene synonyms and product descriptions. (a) BM25 Recall@K, (b) dense Recall@K, and (c) mean MRR@K after BGE-m3 reranking, each plotted against the cutoff rank K on the x-axis. (d) Change in MRR@10 (y-axis, in MRR@10 units) relative to the original-query baseline for BGE-m3, MedCPT, and BGE-Gemma; the two bars per reranker are the two expansion variants, and positive values indicate that expansion improved the final ranking. Paired-bootstrap confidence intervals for the MRR@10 deltas are reported in Table S1 .
Figure 4: Retrieval and reranking by abstract-evidence level on the has-PDF subset. The upper row shows first-stage Recall@K from BM25+Dense RRF retrieval. The lower row shows post-rerank MRR@K using BGE-m3. Columns correspond to abstract supports detail (n=707), abstract supports core (n=585), and abstract insufficient (n=350). Solid lines show the abstract-only baseline; dashed lines show the corpus augmented with full-text chunks.
Figure S1: Per-query reranking effect relative to BM25. Δ MRR@10 is computed as reranker minus BM25 and grouped as hurt, helped, or near tie using thresholds of ±0.025 . Similar aggregate scores mask different query-level behavior: MiniLM-L12 is mostly harmful, BGE-m3 is balanced, and MedCPT and BGE-Gemma shift more queries toward positive deltas.
Reranker
Original
+ Synonyms
+ Synonyms and products
BGE-m3
0.576
0.623 ( +4.7 , [ +2.6 , +6.8 ])
0.622 ( +4.6 , [ +2.2 , +7.1 ])
MedCPT
0.624
0.682 ( +5.8 , [ +3.7 , +7.9 ])
0.673 ( +5.0 , [ +2.7 , +7.2 ])
BGE-Gemma
0.694
0.703 ( +0.9 , [ −0.5 , +2.3 ]) †
0.701 ( +0.7 , [ −0.6 , +2.1 ]) †
Table S1: Effect of gene-aware query expansion on the query-expansion subset. Each cell reports MRR@10. For expanded-query variants, parentheses report the paired-bootstrap difference from the original-query baseline for the same reranker, in percentage points, with 95% confidence intervals.
has-PDF subset
full dataset
R@1000
MRR@10
R@1000
MRR@10
Evidence level
n
Abs
+Chk
Abs
+Chk
n
Abs
+Chk
Abs
+Chk
Abstract supports detail
707
0.993
0.997
0.802
0.843
816
0.993
0.997
0.803
0.829
Abstract supports core
585
0.986
0.998
0.505
0.636
654
0.982
0.992
0.503
0.608
Abstract insufficient
350
0.784
0.972
0.161
0.385
387
0.788
0.949
0.164
0.357
Table S2: First-stage Recall@1000 and post-rerank MRR@10 (BGE-m3) by abstract-evidence level, shown for the has-PDF subset (Fig. 4 ) and for the full 1,656-query dataset with partial full-text coverage. Full-dataset gains are diluted because some cited PMIDs lack chunked-corpus coverage, but the qualitative pattern is unchanged.
Graduate Program in Bioinformatics, The University of British Columbia · Centre for Molecular Medicine and Therapeutics, BC Children’s Hospital Research Institute · Department of Medical Genetics, The University of British Columbia +1