Data from: Formin is associated with left-right asymmetry in the pond snail and the frog

While components of the pathway that establishes left-right asymmetry have been identified in diverse animals, from vertebrates to flies, it is striking that the genes involved in the first symmetry-breaking step remain wholly unknown in the most obviously chiral animals, the gastropod snails. Previously, research on snails was used to show that left-right signaling of Nodal, downstream of symmetry breaking, may be an ancestral feature of the Bilateria. Here, we report that a disabling mutation in one copy of a tandemly duplicated, diaphanous-related formin is perfectly associated with symmetry breaking in the pond snail. This is supported by the observation that an anti-formin drug treatment converts dextral snail embryos to a sinistral phenocopy, and in frogs, drug inhibition or overexpression by microinjection of formin has a chirality-randomizing effect in early (pre-cilia) embryos. Contrary to expectations based on existing models, we discovered asymmetric gene expression in 2- and 4-cell snail embryos, preceding morphological asymmetry. As the formin-actin filament has been shown to be part of an asymmetry-breaking switch in vitro, together these results are consistent with the view that animals with diverse body plans may derive their asymmetries from the same intracellular chiral elements.

Usage Note:
Alignment of formin intron sequences from Euhadra species
Data relates to Figure S2d.
Euhadra_formin_intron_sequence.fas
Alignment of formin intron sequences from Partula species
Data relates to Figure S2e
Partula_formin_intron_sequences.fas
Alignment of FH2 domain sequences
Data relates to Figure S2a. Original alignment kindly provided by Dimitra Chalkia (see Chalkia et al 2008). New accessions were then added manually.
FH2_animals.fas
Alignment of gastropod FH2 domain sequences
Data relates to Figure S2b
gastropods_fh2_domain_aligned.fas
Alignment of formin gene sequences from Lymnaea stagnalis
Contains sequences of Ldia1 and Ldia2, derived from dextral and sinistral haplotypes
Ldia_aligned.fas
Predicted gene sequences for candidate genes
Sequences for sinistral and dextral-derived haplotypes
Lfry_Ltud_Lprcp_Lmfsd.fas
Concatenated alignment of 28S and 18S sequences
Concatenated alignment of 28S (1-3712) and 18S sequences (3716-5448). Data relates to Figure S2c and Figure 1.
LSU_SSU.fas
Table S1
Table S1 from the paper in Excel format
qPCR raw data
The data in this files relates to Figure 1, Figure S2a and text in the Supplementary Information. Further detail within the file.
qPCR_raw_data_relates_to_Fig1_FigS2a.xlsx
Assembly of BACs
Assembly of the BAC sequences with SPAdes assembler, removing the low coverage scaffolds.
BAC_assembly.fasta.gz
Genome assembly of Lymnaea stagnalis
The genome of Lymnaea stagnalis assembled with SOAPdenovo using PE and MP libraries.
gLs.scaffolds.fa.gz

Davison, Angus; McDowell, Gary S.; Holden, Jennifer M. et al. (2017). Data from: Formin is associated with left-right asymmetry in the pond snail and the frog [Dataset]. Dryad. https://doi.org/10.5061/dryad.r4342