Regulation of NHE, NHERF1, NKA, NKCC, IGF-1 and AQP, etc., by miRNAs under salinity in fish. Second messengers induce the transcription of DNA. miRNAs regulate gene expression and function in target genes. They regulate transcription of the target genes and protein synthesis. NHE, mean Na⁺/H⁺-exchanger; NHERF, Na⁺/H⁺ exchanger regulatory factor 1; NKCC, mean Na⁺-K⁺-2Cl- cotransporter; NKA, mean Na⁺/K⁺-ATPase; AQP, mean Aquaporin; IGF, mean insulin growth factor.

Regulation of GATA1, MyoD, PER2, GHITM, HMOX1 and HSP90 etc. by miRNAs under temperature in fish. miRNAs can negatively regulate the transcription of DNA induced by second messengers. miRNAs regulate gene expression and function in target genes. They regulate transcription of the target genes and protein synthesis. GATA1, mean GATA binding protein 1; MyoD, Myoblast determination protein; PER2, mean period circadian regulator 2; GHITM, mean growth hormone inducible transmembrane protein; HMOX1, mean heme oxygenase 1; HSP90, mean heat shock protein 90.

Regulation of CASPASE3, VEGF, SOD, HIF-1a, PFKL, HK, LDH and DDX5, etc., by miRNAs under oxygen concentration in fish. Second messengers induce the transcription of DNA. miRNAs regulate gene expression and function in target genes. They regulate transcription of the target genes and protein synthesis. VEGF, mean vascular endothelial growth factor; SOD, superoxidase dismutase; HIF-1a, mean hypoxia-inducible factor 1a; HK, mean hexokinase; LDH, mean lactate dehydrogenase; DDX5, mean DEAD-Box Helicase 5.

Role of microRNAs in the regulation of insulin and liver metabolism including the upregulation of FAS, SREBF1, ACLY and downregulation of CPT1a, CPT1b. FAS, SREBF1, ACLY, CPT1a and CPT1b, etc., are regulated by miRNAs under feed in fish. FAS, mean Fatty acid synthase; SREBF1, sterol regulatory element binding transcription factor 1; ACLY, mean ATP citrate lyase; CPT1a, mean carnitine palmitoyl-transferase 1a; CPT1b, mean carnitine palmitoyl-transferase 1B.

Regulation of BCL2, CYB561D2, GPER, NRF2, P38MAPK, SDH and CYT-C, etc., by miRNAs under environmental chemicals and sea water metal elements in fish. Second messengers induce the transcription of DNA. miRNAs regulate gene expression and function in target genes. They regulate transcription of the target genes and protein synthesis. BCL2, mean B-cell lymphoma 2; CYB561D2, Cytochrome B561 Family Member D2; GPER, mean G protein-coupled estrogen receptor; NRF2, mean nuclear factor erythroid-2-related factor 2; P38MAPK, mean p38 mitogen-activated protein kinases; SDH, mean succinate dehydrogenase; CYT-C, mean cytochrome C; cAMP, cyclic adenosine monophosphate; cGMP, cyclic guanosine monophosphate.

Standard analysis process and prospect of environment-related miRNAs in fish. (A) Data sets download, (B) search of background knowledge, (C) read alignment, (D) identification and characterization of known and novel miRNAs, (E) target prediction, (F) downstream analysis.