Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2017
Erindi/veggspjald / Talk/poster V60
Höfundar / Authors: Kalina H. Kapralova (1), Sigríður Rut Franzdóttir (1), Valerie Maier (1), Arnar Palsson (1), Sigurður S. Snorrason (1) and Zophonías O. Jónsson (1)
Starfsvettvangur / Affiliations: 1. University of Iceland
Kynnir / Presenter: Kalina H. Kapralova
The Arctic charr morphs in Thingvallavatn constitute an extreme example of local phenotypic diversity. Four morphs have been described in the lake: two limnetic; planktivorous (PL) and piscivorous (PI) charr, with pointed snout and evenly protruding jaws, and two benthic; small (SB) and large benthivorous (LB) charr, with blunt snout and short lower jaw. These morphs also differ extensively in life history characteristics (size and age at maturity) and embryology. Micro-RNAs (miRNAs) play an important role in animal development. These small non-coding RNAs are involved in post-transcriptional regulation of gene expression. Sequences of many miRNAs are highly conserved, yet they often exhibit temporal and spatial heterogeneity in expression among species and have been proposed as an important reservoir for adaptive evolution and divergence. Small RNA-sequencing analysis of four developmental time points in two contrasting Arctic charr morphologies (SB from Thingvallavatn and a charr from the Holar aquaculture program with a limnetic like morphology) showed that 53 known and 19 novel miRNAs have significantly different levels of expression. From these, miR-199a was selected for further studies. Whole month insitu hybridization of miR-199a showed that it is expressed in the upper, lower jaw and the gill arches of developing embryos of all four Thingvallavatn morphs. To gain a better understanding of the developmental processeses this miRNA is involved in, which genes it interacts with and regulate, several genes including the transcription factor Ets2 were identified as targets for miR-199a. We have started functional analysis, where miR-199a is inhibited in 1-cell zebrafish embryos. Craniofacial phenotypes of the injected and not injected embryos were compared using geometric morphometrics. Our preliminary data indicates that inhibiting of miR-199a during zebrafish development leads to the shortening of the lower jaw and widening of the head, mimicking the benthic morph phenotype.