27 research outputs found
Where are you from, stranger? The enigmatic biogeography of North African pond turtles (Emys orbicularis) .
Abstract The European pond turtle (Emys orbicularis) is a
Nearctic element in the African fauna and thought to have
invaded North Africa from the Iberian Peninsula. All North
African populations are currently identified with the subspecies
E. o. occidentalis. However, a nearly range-wide sampling in
North Africa used for analyses of mitochondrial and microsatellite
DNA provides evidence that only Moroccan populations
belong to this taxon, while eastern Algerian and Tunisian pond
turtles represent an undescribed distinct subspecies. These two
taxa are most closely related to E. o. galloitalica with a native
distribution along the Mediterranean coast of northern Spain
through southern France to western and southern Italy. This
group is sister to a clade comprising several mitochondrial lineages
and subspecies of E. orbicularis from Central and Eastern
Europe plus Asia, and the successive sisters are E. o. hellenica
and E. trinacris. Our results suggest that E. orbicularis has been
present in North Africa longer than on the Iberian Peninsula and
that after an initial invasion of North Africa by pond turtles from
an unknown European source region, there was a phase of
diversification in North Africa, followed by a later re-invasion
of Europe by one of the African lineages. The differentiation of
pond turtles in North Africa parallels a general phylogeographic
paradigm in amphibians and reptiles, with deeply divergent
lineages in the western and eastern Maghreb. Acknowledging
their genetic similarity, we propose to synonymize the previously
recognized Iberian subspecies E. o. fritzjuergenobsti with E. o.
occidentalis sensu stricto. The seriously imperiled Moroccan
populations of E. o. occidentalis represent two Management
Units different in mitochondrial haplotypes and microsatellite
markers. The conservation status of eastern Algerian pond turtles
is unclear, while Tunisian populations are endangered.
Considering that Algerian and Tunisian pond turtles represent
an endemic taxon, their situation throughout the historical range
should be surveyed to establish a basis for conservation
measures
Characterisation and expression analysis of the Atlantic halibut (Hippoglossus hippoglossus L.) cytokines: IL-1β, IL-6, IL-11, IL-12β and IFNγ
Genes encoding the five Atlantic halibut (Hippoglossus hippoglossus L.) cytokines; interleukin (IL)-1β, IL-6, IL-11b, IL-12βc, and interferon (IFN) γ, were cloned and characterised at a molecular level. The genomic organisation of the halibut cytokine genes was similar to that seen in mammals and/or other fish species. Several mRNA instability motifs were found within the 3′-untranslated region (UTR) of all cytokine cDNA sequences. The putative cytokine protein sequences showed a low sequence identity with the corresponding homologues in mammals, avian and other fish species. Nevertheless, important structural features were presumably conserved such as the presence, or absence in the case of IL-1β, of a signal peptide, secondary structure and family signature motifs. The relative expression pattern of the cytokine genes was analyzed in several halibut organs, revealing a constitutive expression in both lymphoid and non-lymphoid organs. Interestingly, the gills showed a relatively high expression of IL-1β, IL-12βc and IFNγ. The real time RT-PCR data also showed that the mRNA level of IL-1β, IL-6, IL-12βc and IFNγ was high in the thymus, while IL-11b was relatively highly expressed in the posterior kidney and posterior gut. Moreover, the halibut brain showed a relatively high level of IL-6 transcripts. Anterior kidney leucocytes in vitro stimulated with imiquimod showed a significant increase in mRNA level of the five halibut cytokine genes. The sequence and characterisation data presented here will be useful for further investigation of both innate and adaptive immune responses in halibut, and be helpful in the design of vaccines for the control of various infectious diseases