2. Academic Validation
  3. Genome-wide analysis unveils the differentiated "external" and "internal" lectin system in the tropical sea cucumber Holothuria leucospilota

Genome-wide analysis unveils the differentiated "external" and "internal" lectin system in the tropical sea cucumber Holothuria leucospilota

  • Dev Comp Immunol. 2025 Dec:173:105527. doi: 10.1016/j.dci.2025.105527.
Xinyue Ren 1,  Zhou Qin 2,  Renhui Liu 1,  Ting Chen 2,  Tiehao Lin 3,  Xinyu Sun 1,  Jiasheng Huang 2,  Wenjie Pan 2,  Caixia Long 1,  Chunhua Ren 2,  Haipeng Qin 4,  Peiming Zheng 5,  Aifen Yan 6,  Lihong Yuan 7
Affiliations

Affiliations

  • 1 School of Life Sciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou, 510006, PR China.
  • 2 State Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China.
  • 3 Guangdong Institute for Drug Control, Guangzhou, 5106630, PR China.
  • 4 Agro-Tech Extension Center of Guangdong Province, Huizhou, 516081, PR China.
  • 5 Guangdong Jinyang Biotechnology Co., Ltd, Maoming, 525027, PR China.
  • 6 School of Medicine, Foshan University, Foshan, 528000, PR China. Electronic address: [email protected].
  • 7 School of Life Sciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou, 510006, PR China. Electronic address: [email protected].
PMID: 41274536 DOI: 10.1016/j.dci.2025.105527
Abstract

To date, the understanding of lectin-related immunity in sea cucumbers remains limited. Through a comprehensive genome-wide analysis, 133 lectin genes were identified from Holothuria leucospilota, a sea cucumber species with high ecological and economic significance in the Pacific and Indian Oceans. These lectins were classified into five subtypes, with C-type lectin being the predominant form, and the presence of SUEL-like lectin and Malectin reported here for the first time in sea cucumbers. Transcriptomic analysis across twelve tissues and sixteen developmental stages revealed ubiquitous expression of H. leucospilota lectins. A key finding was the compartmentalization of lectin systems: SUEL-like lectins expressed in the body wall constitute an "external" defense system, while C-type lectins produced by coelomocytes form an "internal" immune system. This spatial and functional specialization reflects a sophisticated immune strategy in invertebrates, enabling targeted pathogen recognition at different bodily interfaces. Furthermore, distinct immune responses to Vibrio, LPS, and poly(I:C) were observed among different lectins. We also identified an ovary-specific C-type lectin, suggesting a potential role in early embryonic development. This study not only fills a knowledge gap regarding lectin genes in sea cucumbers but also establishes a broader framework for understanding complex immune mechanisms in echinoderms.

Keywords

Holothuria leucospilota; Immune function; Lectin; Pathogenic challenge.

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