Page 59 - 《水产学报》2026年第04期

4 期 水 产 学 报 50 卷

Identification, evolution, expression pattern and ecological adaptation
strategies of the FABP gene family in Japanese anchovy
(Engraulis japonicus)

1,2
1*
1
WANG Ruixiang , WANG Huan , LIU Shufang , ZHUANG Zhimeng 1
(1. State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute,
Chinese Academy of Fishery Sciences, Qingdao 266071, China;
2. College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China)

Abstract: The Japanese anchovy (Engraulis japonicus), a keystone lipid-rich species in the Yellow and East China Seas eco-
systems, plays a vital role in energy flow, and its lipid metabolism mechanisms significantly influence population dynamics.
The fatty acid-binding protein (FABP) gene family is central to lipid metabolism regulation. This study aimed to systematically
identify the FABP gene family members in E. japonicus and analyze their molecular characteristics and expression profiles,
thereby providing a foundation for elucidating the molecular mechanisms of lipid metabolism and ecological adaptation in this
species. Based on the chromosome-level genome of the E. japonicus, FABP gene family members were screened using Hidden
Markov Model (HMM) and homology BLAST searches. Their phylogenetic relationships, gene structures, conserved motifs,
chromosomal locations, gene duplication events, and three-dimensional protein structures were analyzed through bioinformat-
ics approaches. Transcriptome data from different tissues (heart, liver, muscle, gonad), sexes, and body length groups were util-
ized to analyze gene expression profiles. A total of 14 FABP genes belonging to 7 subtypes (FABP1, FABP2, FABP3, FABP4,
FABP6, FABP7, FABP10a) were identified in the E. japonicus genome, unevenly distributed across 9 chromosomes. Phylogen-
etic analysis classified these genes into three distinct clades. Synteny and tandem duplication analyses revealed that FABP1
genes (FABP1.1 and FABP1.2) originated from segmental duplication, while four FABP3 genes (FABP3.1-3.4) formed a tan-
dem duplication cluster on chromosome 9. All FABP proteins possess the typical β-barrel tertiary structure, although some
FABP7 genes showed deletions of conserved motifs. Transcriptome analysis demonstrated that FABP gene expression exhib-
ited significant tissue specificity (e.g., high expression of FABP1 and FABP10a in liver), sex specificity (e.g., specific high
expression of FABP7 in testis), and certain correlations with body length. Notably, multi-copy genes (e.g., different paralogs of
FABP3 and FABP7) showed markedly divergent expression patterns across tissues, suggesting potential functional differenti-
ation. This study presents the first systematic identification and characterization of the FABP gene family in the E. japonicus.
Gene duplication events, particularly the tandem duplication of FABP3, and the subsequent expression divergence may enhance
the capacity for lipid uptake, transport, and utilization in E. japonicus, representing an adaptive molecular evolution in response
to its high-lipid diet and periodic migratory life history. These findings provide novel theoretical insights for understanding the
pivotal role of E. japonicus in energy flow within marine ecosystems at the molecular level and for the sustainable utilization of
fishery resources.

Key words: Engraulis japonicus; lipid metabolism; FABP gene family; molecular characterization; expression pattern
Corresponding author: LIU Shufang. E-mail: liusf@ysfri.ac.cn
Funding projects: National Key R&D Program of China (2024YFD2400401); National Modern Agricultural Industry Techno-
logy System (CARS-47); Central Public-interest Scientific Institution Basal Research Fund, YSFRI, CAFS (20603022024023)

https://www.china-fishery.cn 中国水产学会主办 sponsored by China Society of Fisheries
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