Genome-wide identification and skin expression of immunoglobulin superfamily in discus fish (Symphysodon aequifasciatus) reveal common genes associated with vertebrate lactation

Xin Liu; Xiang-Fei Ding; Bin Wen; Teng-Fei Ma; Qin-Wang; Zhong-Jun Li; Yan-Shen Zhang; Jian-Zhong Gao; Zai-Zhong Chen

doi:10.1016/j.gene.2023.147260

Genome-wide identification and skin expression of immunoglobulin superfamily in discus fish (Symphysodon aequifasciatus) reveal common genes associated with vertebrate lactation

Gene. 2023 Apr 30:862:147260. doi: 10.1016/j.gene.2023.147260. Epub 2023 Feb 10.

Authors

Xin Liu¹, Xiang-Fei Ding¹, Bin Wen², Teng-Fei Ma¹, Qin-Wang¹, Zhong-Jun Li¹, Yan-Shen Zhang¹, Jian-Zhong Gao³, Zai-Zhong Chen⁴

Affiliations

¹ Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai 201306, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China; Shanghai Engineering Research Center of Aquaculture, Shanghai Ocean University, Shanghai 201306, China.
² Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai 201306, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China; Shanghai Engineering Research Center of Aquaculture, Shanghai Ocean University, Shanghai 201306, China; National Demonstration Centre for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China. Electronic address: bwen@shou.edu.cn.
³ Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai 201306, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China; Shanghai Engineering Research Center of Aquaculture, Shanghai Ocean University, Shanghai 201306, China; National Demonstration Centre for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China.
⁴ Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai 201306, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China; Shanghai Engineering Research Center of Aquaculture, Shanghai Ocean University, Shanghai 201306, China; National Demonstration Centre for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China. Electronic address: chenzz@shou.edu.cn.

PMID: 36775217
DOI: 10.1016/j.gene.2023.147260

Abstract

Discus Symphysodon spp. employs an unusual parental care behavior where fry feed on parental skin mucus after hatching. Studies on discus immunoglobulin superfamily (IgSF) especially during parental care are scarce. Here, a total of 518 IgSF members were identified based on discus genome and clustered into 12 groups, unevenly distributing on 30 linkage groups. A total of 92 pairs of tandem duplication and 40 pairs of segmental duplication that underwent purifying selection were identified. IgSF genes expressed differentially in discus skin during different care stages and between male and female parents. Specifically, the transcription of btn1a1, similar with mammalian lactation, increased after spawning, reached a peak when fry started biting on parents' skin mucus, and then decreased. The expression of btn2a1 and other immune members, e.g., nect4, fcl5 and cd22, were up-regulated when fry stopped biting on mucus. These results suggest the expression differentiation of IgSF genes in skin of discus fish during parental care.

Keywords: Discus fish; Immunoglobulin; Parental care; Skin.

MeSH terms

Animals
Cichlids* / genetics
Female
Immunoglobulins / metabolism
Lactation
Male
Mammals
Skin* / metabolism
Vertebrates

Substances

Immunoglobulins