Integrative testis transcriptome analysis reveals differentially expressed miRNAs and their mRNA targets during early puberty in Atlantic salmon

• Main Authors: Skaftnesmo, Kai Ove, Edvardsen, Rolf B, Furmanek, Tomasz, Crespo, D., Andersson, E., Kleppe, Lene, Taranger, G.L., Bogerd, J., Schulz, R.W., Wargelius, Anna
• Other Authors: Sub Developmental Biology, Institute for Marine and Atmospheric Research, Developmental Biology
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2017
• Subjects: Aquaculture; Integrative analysis; MiRNA; Salmo salar; apelin; messenger RNA; microRNA; microRNA 101; microRNA 125b; microRNA 135a; microRNA 137; microRNA 145; microRNA 181a; microRNA 18a; microRNA 190a; microRNA 202; microRNA 20a; microRNA 216a; microRNA 217; microRNA 2184; microRNA 222; microRNA 222a; microRNA 25; microRNA 26b; microRNA 30c; microRNA 724; microRNA 92b; microRNA new194; microRNA new271; microRNA new289; progesterone; sonic hedgehog protein; unclassified drug; unindexed drug; Wnt protein; animal cell; animal experiment; animal tissue; article; cell cycle; cell proliferation; developmental stage; gene cluster; gene control; gene expression; genetic association study; male; nonhuman; precocious puberty; Atlantic salmon
• Online Access: https://dspace.library.uu.nl/handle/1874/359011

Background: Our understanding of the molecular mechanisms implementing pubertal maturation of the testis in vertebrates is incomplete. This topic is relevant in Atlantic salmon aquaculture, since precocious male puberty negatively impacts animal welfare and growth. We hypothesize that certain miRNAs modulate mRNAs relevant for the initiation of puberty. To explore which miRNAs regulate mRNAs during initiation of puberty in salmon, we performed an integrated transcriptome analysis (miRNA and mRNA-seq) of salmon testis at three stages of development: an immature, long-term quiescent stage, a prepubertal stage just before, and a pubertal stage just after the onset of single cell proliferation activity in the testis. Results: Differentially expressed miRNAs clustered into 5 distinct expression profiles related to the immature, prepubertal and pubertal salmon testis. Potential mRNA targets of these miRNAs were predicted with miRmap and filtered for mRNAs displaying negatively correlated expression patterns. In summary, this analysis revealed miRNAs previously known to be regulated in immature vertebrate testis (miR-101, miR-137, miR-92b, miR-18a, miR-20a), but also miRNAs first reported here as regulated in the testis (miR-new289, miR-30c, miR-724, miR-26b, miR-new271, miR-217, miR-216a, miR-135a, miR-new194 and the novel predicted n268). By KEGG enrichment analysis, progesterone signaling and cell cycle pathway genes were found regulated by these differentially expressed miRNAs. During the transition into puberty we found differential expression of miRNAs previously associated (let7a/b/c), or newly associated (miR-15c, miR-2184, miR-145 and the novel predicted n7a and b) with this stage. KEGG enrichment analysis revealed that mRNAs of the Wnt, Hedgehog and Apelin signaling pathways were potential regulated targets during the transition into puberty. Likewise, several regulated miRNAs in the pubertal stage had earlier been associated (miR-20a, miR-25, miR-181a, miR-202, let7c/d/a, miR-125b, miR-222a/b, miR-190a) or ...