World Congress of Malacology Antwerp ... - Unitas Malacologica

adapted retinal mRNA showed 1.4- and 2-fold inductions of α-tubulin and S-crystallin, respectively,
when compared to dark-adapted retinas. Percent volume analysis of dark-adapted retinal protein
showed that α-tubulin and S-crystallin were 2-fold more abundant when compared to light-adapted
retinas. Coinciding with the observed differential expression are the following morphological
changes of dark- and light-adapted rhabdomeres: the number of rhabdomeric microvilli increase in
the dark, resulting in the growth of rhabdomeres; whereas, there is a decrease in the number of
rhabdomeric microvilli in the light, resulting in the diminution of the rhabdomeres. We believe that
mRNA for these cytoskeletal proteins may be stored and translated when needed in either the dark or
light. If masking and unmasking of these mRNAs does occur, then regulatory elements or sequences
should be present in the 3’UTR regions. CPEB is a 62 kDa trans-acting RNA binding protein, which
binds to the variable CPE consensus sequence, U4-5A1-3U, in 3’ UTR regions of mRNA, and is
indicated in temporal regulation of translational activation and repression. Using western blot
analysis and immunocytochemistry, we have identified the presence of CPEB in dark- and lightadapted
octopus retinas. Using 3’RACE analysis of the 3’ UTR regions of α-tubulin and S-crystallin
mRNAs, we have detected the following CPE-like sequences in the 3’ UTR of isolated 326-bp Scrystallin
A and B variants: UUUAACA, UUUUUAA, and UUUUA. The detection of CPEB and the
identification of the putative CPE-like sequences in the S-crystallin 3’ UTR suggest that CPEB may
be involved in the activation of masked S-crystallin mRNA, but not in the regulation of α-tubulin
mRNA, resulting in increased S-crystallin protein synthesis in dark-adapted octopus retinas.
Morphological and molecular characterization of the Roman snail Helix pomatia with data on
the phylogeny of the genus Helix (Pulmonata, Helicidae)
Ketmaier, Valerio 1 ; Fiorentino, Viviana 2 ; Tiedemann, Ralph 1 ; Manganelli, Giuseppe 2 ; Giusti,
Folco 2
1. Unit of Evolutionary Biology/Systematic Zoology, Institute of Biochemistry and Biology,
University of Potsdam, Karl-Liebknecht-Str. 24-25, D-14476, Potsdam, Germany,
Email: ketmaier@rz.uni-potsdam.de; tiedeman@rz.uni-potsdam.de
2. Dipartimento di Scienze Ambientali “G. Sarfatti”, Università di Siena, Via Mattioli 4, I-53100,
Siena, Italy,
Email: vivianafiorentino@unisi.it; manganelli@unisi.it; giustif@unisi.it
Diagnostic uncertainties have favoured fraudulent traffic of different edible snails which are sold
under the name of the costly Roman snail: Helix pomatia. The application of molecular markers
combined with diagnostic morphological characters is thus decisive for reliable identification of the
species in natural and non-natural conditions as well as in prepared food products. Given the
commercial value of the Roman snail and the lack of knowledge about its phylogeography, we
endeavoured to cover most of the species range with our sampling (i.e. Sweden, Denmark, Germany,
United Kingdom, France and Italy). The study is based on analysis of sequence variation at two
mitochondrial (CO1 and 16S rRNA) and two nuclear (ITS-1 and ITS-2) genes plus detailed study of
genital structure. To place the study in a wider phylogenetic context we also included four congeneric
species from European sites (H. campana, H. cincta, H. ligata and H. lucorum), plus four other
helicids (Cornu aspersum, C. mazzullii, Eobania vermiculata and Helicigona lapicida) as outgroups.
Molecular data supports the monophyly of the genus Helix and robustly clustered all Roman snail
populations included in the study. We found seven haplotypes in H. pomatia, five of them unique to
single populations and only two shared among different populations (France-NW Italy and Sweden-
Denmark, respectively). The relatively little divergence detected among haplotypes (from 1 to 6
substitutions) suggests recent northward expansion (historical and at least partly human-mediated) of
the species. The anatomical analyses are in full agreement with the above scenario. All of the Roman
snail populations showed substantial uniformity of the genital characters examined.
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