title: Transcriptomic Analysis of Compromise Between Air-Breathing and Nutrient Uptake of Posterior Intestine in Loach (Misgurnus anguillicaudatus), an Air-Breathing Fish.
abstract: Dojo loach (Misgurnus anguillicaudatus) is an air-breathing fish species by using its posterior intestine to breathe on water surface. So far, the molecular mechanism about accessory air-breathing in fish is seldom addressed. Five cDNA libraries were constructed here for loach posterior intestines form T01 (the initial stage group), T02 (mid-stage of normal group), T03 (end stage of normal group), T04 (mid-stage of air-breathing inhibited group), and T05 (the end stage of air-breathing inhibited group) and subjected to perform RNA-seq to compare their transcriptomic profilings. A total of 92,962 unigenes were assembled, while 37,905 (40.77 %) unigenes were successfully annotated. 2298, 1091, and 3275 differentially expressed genes (fn1, ACE, EGFR, Pxdn, SDF, HIF, VEGF, SLC2A1, SLC5A8 etc.) were observed in T04/T02, T05/T03, and T05/T04, respectively. Expression levels of many genes associated with air-breathing and nutrient uptake varied significantly between normal and intestinal air-breathing inhibited group. Intraepithelial capillaries in posterior intestines of loaches from T05 were broken, while red blood cells were enriched at the surface of intestinal epithelial lining with 241 ± 39 cells per millimeter. There were periodic acid-schiff (PAS)-positive epithelial mucous cells in posterior intestines from both normal and air-breathing inhibited groups. Results obtained here suggested an overlap of air-breathing and nutrient uptake function of posterior intestine in loach. Intestinal air-breathing inhibition in loach would influence the posterior intestine's nutrient uptake ability and endothelial capillary structure stability. This study will contribute to our understanding on the molecular regulatory mechanisms of intestinal air-breathing in loach.
authors.affiliation: College of Fisheries, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education/Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, 437000, Hubei, People's Republic of China.
authors.forename: Songqian
authors.initials: S
authors.lastname: Huang
authors.affiliation: College of Fisheries, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education/Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, 437000, Hubei, People's Republic of China. caoxiaojuan@mail.hzau.edu.cn.|Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Hubei, People's Republic of China. caoxiaojuan@mail.hzau.edu.cn.|Hubei Provincial Engineering Laboratory for Pond Aquaculture, Hubei, People's Republic of China. caoxiaojuan@mail.hzau.edu.cn.
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Cao
authors.affiliation: College of Fisheries, Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education/Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, 437000, Hubei, People's Republic of China.
authors.forename: Xianchang
authors.initials: X
authors.lastname: Tian
mesh_terms: D000388:Air; D000818:Animals; D002452:Cell Count; D003531:Cypriniformes / Q000235:genetics* / Q000502:physiology; D004435:Eating / Q000502:physiology; D004912:Erythrocytes / Q000166:cytology / Q000502:physiology; D029941:Fish Proteins / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D015723:Gene Library; D063990:Gene Ontology; D007408:Intestinal Absorption / Q000502:physiology*; D007422:Intestines / Q000098:blood supply / Q000502:physiology*; D058977:Molecular Sequence Annotation; D012119:Respiration / Q000235:genetics*; D017423:Sequence Analysis, RNA; D059467:Transcriptome
chemical_list: D029941:Fish Proteins
keywords: Air-breathing; High-throughput sequencing; Misgurnus anguillicaudatus; Nutrient uptake; Posterior intestine