Single point mutation of a gene creates mirror-image animals in fresh water gastropod

Joint Event on 10^th International Conference on Genomics and Molecular Biology & 6^th International Conference on Integrative Biology

May 21-23, 2018 Barcelona, Spain

Reiko Kuroda

Tokyo University of Science, Japan

Keynote: J Mol Genet Med

Abstract :

Body handedness of gastropod Lymnaea stagnalis is determined by a single gene locus that functions maternally. We have previously shown that the gene dictates the cytoskeletal dynamics at the third cleavage (from the fourth to the eight-cell stage), and only the embryos of dominant chirality exhibit SD (spiral deformation) and SI (spindle inclination) at this stage. Further, we could create fertile snails of mirror-image body plan by altering the chirality of blastomeres through mechanical manipulation at this stage. In this talk, the identification of the handedness-determining gene will be discussed. Using pure dextral (DD) and sinistral (dd) strains as well as its F2 through to F10 backcrossed lines, the single handedness-determining-gene locus was mapped by genetic linkage analysis, BAC cloning and chromosome walking. We have identified the actin related diaphanous gene Lsdia1 as the candidate. There are tandemly-repeated highly-homologus genes, Lsdia1 and Lsdia2. Although the cDNA and derived amino acid sequences of the genes are very similar, we could discriminate the two genes/proteins in our molecular biology experiments. The Lsdia1 gene of the sinistral strain carries a single point mutation which causes a frameshift mutation abrogating full-length LsDia1 protein expression. In the dextral strain, it is already translated prior to oviposition. Expression of Lsdia1 (only in the dextral strain) and Lsdia2 (in both chirality) decreases after the 1-cell stage, with no asymmetric localization throughout.

Biography :

Reiko Kuroda obtained her PhD in Chemistry from the University of Tokyo, and carried out her Post-doctoral studies at King’s College London. Her research focuses on chirality, both in the field of Chemistry and Biology: chirality recognition, transfer and amplification in the solid state, development of chiroptical spectroscophotometers to enable condensed-phase measurements, and the molecular basis of snail body handedness. She has published 328 peer-reviewed papers.
Email:rkuroda@rs.tus.ac.jp