2. Behavioral Biology TALKS - Deutsche Zoologische Gesellschaft

and Pax10 show mosaic phylogenetic distributions: Pax4 has been found so far only
in mammals and teleosts, while a careful survey of publicly available databases
revealed the presence of Pax10 only in a few non-mammalian vertebrates. Pax10 is
characterized by a paired-type homeodomain, but lacks the paired domain that is
present in all other Pax genes (Pax1-9). Despite the lack of the paired domain, a
molecular phylogenetic analysis unambiguously placed Pax10 genes within the
Pax4/6 subgroup. To tackle the question about the origin of Pax10 we established
both intra- and inter-genomic comparisons of chromosomal regions containing Pax4,
-6 and -10 in vertebrate model organisms. We found conserved synteny indicating
that the origin of Pax10 was part of a large-scale duplication event. Thus, Pax10 is
presumably the third identified member of the original gene quartet generated by
the two rounds of whole-genome duplication that occurred in the ancestral
vertebrate genome. An analysis of the expression patterns of Pax10 genes in
zebrafish, Xenopus and anole lizard using in situ hybridizations and quantitative RT-
PCR showed that Pax10 expression patterns differed between three different
vertebrate classes and revealed secondary changes in developmental roles between
the three sister genes Pax4, -6 and -10.
�21 Peter Lesny A 704 / 16:30
Transcription factors from the parasitic barnacle Sacculina carcini (Crustacea:
Rhizocephala) identified by transcriptomic analyses
Authors: Peter Lesny 1 , Andreas Vilcinskas 2 , Lars Podsiadlowski 1
Affiliations: 1 Inst. Evolutionsbiologie & Ökologie, Universität Bonn; 2 Inst.
Phytopathologie & Angew. Zoologie, Universität Giessen / Fraunhofer
Projektgruppe "Bio-ressourcen", Giessen
Rhizocephala are endoparasitic barnacles with a highly aberrant adult morphology,
predominantly parasitizing decapod crustaceans. Adults are barely recognizable as
crustaceans or even arthropods. They grow inside the host in form of a simple
branched rootlet system, built of out of two cell layers. With complete lack of
appendages, gut, brain and complex sensory organs the adult rhizocephalans rather
resemble a fungus than an arthropod. Besides molecular sequence data only the
cypris larva point to their inclusion into cirriped crustaceans. Sacculina carcini is an
abundant parasite of the shorecrab, Carcinus maenas. Its internal rootlet tissue
infiltrates and destroys the gonads and part of endocrine glands, nervous system and
other tissues. Mature parasites grow an breeding pouch out of the hosts body,
receiving male larva and subsequently breeding new larvae. We obtained mRNA
preparations from breeding pouches of S. carcini and produced a normalized cDNA
library to enhance the coverage of rare transcripts. High-throughput sequencing was
performed with the Illumina HiSeq 2000 yielding a total of 180 mio bp raw data. 5732
contigs >500 bp were assembled from that primary data, with almost 50% of these
sequences showing significant similarities to a set of all protein sequences from eight
arthropod species (six insects, tick and water flea). Here we present preliminary
comparative analyses of transcription factors with putative roles in development
identified in the transcriptomes of Sacculina and non-parasitic barnacles.
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