Meeting Abstract

105-4  Saturday, Jan. 7 14:30 – 14:45  DNA methylation reprogramming during development in the self-fertilizing mangrove rivulus, Kryptolebias marmoratus, and its environmental sensitivity. FELLOUS, A*; LABED-VEYDERT, T; LESCAT, L; VOISIN, A.S; LOCREL, M; EARLEY, R.L; SILVESTRE, F; Laboratory of Evolutionary and Adaptive Physiology, University of Namur, Rue de Bruxelles 61, 5000 Namur, Belgium.; Department of Biological Sciences, University of Alabama, 300 Hackberry Lane, Box 870344, Tuscaloosa, AL 35487, USA. alexandre.fellous@unamur.be

Kryptolebias marmoratus is native from the mangrove of the Gulf of Mexico. It presents great adaptive capacities and is characterized by a high level of phenotypic plasticity. In natural populations, hermaphrodites coexist with a low proportion of males (androdioecy) and it displays the unique ability for a vertebrate of self-fertilization. As a new biological model, mechanisms controlling the key transitions during its life history remain largely unknown. Among them, DNA methylation has important regulatory functions controlling gene expression, and thus the phenotype. Here, we explored the dynamic of global DNA methylation by LUMA assays. Significant differences between hermaphrodite ovotestes and male testes were observed (87.2% and 79.6%, respectively). After fertilization, a decrease in DNA methylation occurred from 27.8% in fertilized eggs to 15.8% in gastrula, immediately followed by an increase and re-establishment of the adult pattern by the stage 26 (liver formation) (70.0%). In addition, characterization of genes coding for DNA-methyltransferase enzymes (DNMT1, DNMT3A and DNMT3B) suggests evolutionary conservation of this family. Together these results provide evidence of an original reprogramming pattern of DNA methylation which, was investigated by temperature exposures. Altogether, we hypothesize that DNA methylation may have a crucial role in adaptive evolution of the rivulus.