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Stock M.,Leibniz Institute of Freshwater Ecology and Inland Fisheries | Grifoni G.,University of Lausanne | Armor N.,Biotechnology Institute of Monastir | Armor N.,CNRS Center of Evolutionary and Functional Ecology | And 3 more authors.
Zoologischer Anzeiger | Year: 2015

In contrast to oceanic, continental islands are expected to show less diversification and endemism and thus phylogeographic signatures of multiple colonization events from adjacent continents due to episodic connections by sea level changes. In order to test this situation for the herpetofauna of Sicily, we here focus on three amphibian and four reptile species-groups and investigate their phylogeographic relationships across the Sicily and Messina straits, where Plio-Pleistocene marine transgressions shortened the distances between (or connected) Sicily, North Africa and/or the Italian (Apennine) Peninsula. Using a multi-species, multi-marker phylogeographic approach (mitochondrial cytochrome b; 16S rDNA, nuclear intron of tropomyosin), we apply Bayesian and Maximum Likelihood phylogenetic methods and haplotype networks to examine the phylogenies, and to estimate divergence times from molecular data using the program BEAST. We recognize three colonization patterns: (i) Plio-Pleistocene colonization of Sicily from North Africa for the skinks Chalcides chalcides (1.8. Mya) and Chalcides ocellatus (0.61. My), (ii) Pleistocene colonization from the Italian Peninsula for the anurans Pelophylax spp. (0.81. Mya) and Bufo bufo (late Pleistocene), and (iii) recent (late Pleistocene to Holocene), natural or man-mediated out-of-Africa dispersal for the anuran Discoglossus pictus and out-of-Africa human introduction for the gekkonid lizards Tarentola mauritanica and Hemidactylus turcicus. The Sicilian herpetofauna shows phylogeographic signatures as typical of continental islands, with limited diversification and endemism. Colonization by terrestrial amphibians and reptiles from adjacent continents appears shaped by interactions of the active geo-marine history along with species' ecology and human intervention, including a widely neglected faunal contribution from Africa. On some small islands and in Tunisia, we found isolated local populations significant for conservation. Our results underline how only multispecies approaches involving ecologically diverse taxa are able to reveal the complexity of faunal contributions to large continental islands like Sicily. © 2015.


Amor N.,Biotechnology Institute of Monastir | Velo-Anton G.,Cornell University | Velo-Anton G.,Campus Universitario | Farjallah S.,Biotechnology Institute of Monastir | Said K.,Biotechnology Institute of Monastir
African Zoology | Year: 2010

The intraspecific variation of mitochondrial cytochrome b sequence was analysed for two widely distributed Tunisian anuran species, Discoglossus pictus and Pelophylax saharicus. We observed low genetic variation within both species (D. p. auritus 0.6% uncorrected genetic distances, P. saharicus 0.2%) and the absence of genetic structure within both species in the studied region. There is no correspondence between previously described morphotypes of P. saharicus in Tunisia and our genetic data. Our results show a lack of phylogeographic structure in both species despite their fragmented distribution across Tunisia.


Sarra F.,Biotechnology Institute of Monastir | Nabil A.,Biotechnology Institute of Monastir | Nabil A.,University of Tunis | Rached G.,Biotechnology Institute of Monastir | Khaled S.,Biotechnology Institute of Monastir
Annales Zoologici | Year: 2013

Morphometric and karyological variations were analysed within the Moorish gecko Tarentola mauritanica sensu lato from Tunisia, and compared with already published data. The results show high levels of interspecific variability, indicative of the existence of two distinct lineages: the larger one T. fascicularis, widespread in the south, nearly identical to specimens from Libya and Egypt and the other one, T. m. mauritanica, confined to the northern and central regions, belonging to the common "European" and "North African" morphotype. The observed morphological variation appears to be related to microevolutionary events (phylogenetic variation) derived from a speciation event between the two taxa. We observed that these two lineages also differed in karyotype, such as the shape of some chromosomes and position of NORs. This study highlights the importance of Tunisia as a transition area between eastern and western lineages of Moorish gecko. However, additional genetic studies seem to be essential to infer evolutionary relationships among T. mauritanica populations' across North Africa. © Fundacja Natura optima dux.


Picariello O.,University of Naples Federico II | Odierna G.,University of Naples Federico II | Petraccioli A.,University of Naples Federico II | Amor N.,Biotechnology Institute of Monastir | And 2 more authors.
Italian Journal of Zoology | Year: 2012

Two new high repetitive DNAs were isolated from Discoglossus pictus genomic DNA digested with StuI. Sequence analysis of clones indicated two types of repetitive units 143-148 bp and 170-177 bp long, respectively. Southern blot analyses show ladders of bands indicating that both repetitive units are organized in long tandem arrays and belong to two different satellite DNAs that were named Dp-sat2 and Dp-sat3. A similar ladder of bands was also produced when genomic DNA was digested with ClaI in the case of Dp-sat2, or with ScaI in the case of Dp-sat3. Quantitative dot-blot analyses indicate that Dp-sat2 and Dp-sat3 account for about 2.6% and 2.2%, respectively, of the D. pictus genome. Considering that D. pictus has a genomic DNA content of 10.5 pg/N, our data indicate that Dp-sat2 and Dp-sat3 repetitive units are present in about 2.3×106 and 1.6×106 copies per diploid genome, respectively. Dp-sat2 and Dp-sat3 probes produced the same patterns of hybrid bands in Southern blots and the same genomic content in dot-blots in all the other Discoglossus species, except D. montalentii which showed a different band pattern and genomic content. The chromosomal distribution of the two StuI satellites shows some similarities: both Dp-sat2 and Dp-sat3 probes mainly labelled the pericentromeric regions of the large chromosome pairs 1-5 and 7. Moreover, probes from both satellite DNAs also produced faint fluorescent mini-spots along almost all chromosome pairs. These data suggest that both satellite DNAs have two types of organization, one in long arrays localized in pericentromeric positions, and the other in short arrays dispersed in the genome. © 2012 Copyright 2012 Unione Zoologica Italiana.


Nabil A.,Biotechnology Institute of Monastir | Sarra F.,Biotechnology Institute of Monastir | Slim B.-Y.,Annaba University | Merella P.,University of Sassari | Khaled S.,Biotechnology Institute of Monastir
Pakistan Journal of Zoology | Year: 2011

This study describes patterns of geographic variation in morphometric characters of the African green toad Bufo boulengeri, from Tunisia (11 populations). Body size differences of 89 specimens were analysed with univariate statistics, and body proportions with multivariate methods. Among-groups differences in morphometric characters included both size and shape. Southern populations were found to have larger body size than northern ones, and there was an association between climatic factors and morphological characters. The observed clinal variation in both body size and weight may result from phenotypic plasticity correlated with local environmental factors. Copyright 2011 Zoological Society of Pakistan.


Nabil A.,Biotechnology Institute of Monastir | Sarra F.,Biotechnology Institute of Monastir | Paolo M.,University of Sassari | Slim B.-Y.,Annaba University | Khaled S.,Biotechnology Institute of Monastir
Annales Zoologici | Year: 2010

The water frog Pelophylax saharicus is the most widespread anuran in North Africa and thus subjected to widely differing environmental conditions in different parts of its distribution range. In this paper we examined genetic structure of species 15 populations across Tunisia and eastern Algeria. We evaluated a potential role of mountain ranges as significant barriers to gene flow, using a partial sequences of the mitochondrial cytochrome oxidase I gene (COI). Twenty haplotypes were recorded in a total sample of 38 individuals, whereas, an overall low genetic variation of 0.4% was observed. AMOVA revealed no significant genetic structuring related to the 4 groups across the studied area. Unimodal mismatch distributions and significantly negative values of Fu's Fs and Tajima's D statistics support a recent expansion of populations from a smaller founder population as the most plausible explanation of the observed significant deviations from neutrality in the North-East African green frog populations. © Fundacja Natura optima dux.


Liouane K.,Biotechnology Institute of Monastir | Saidana D.,Biotechnology Institute of Monastir | Edziri H.,Biotechnology Institute of Monastir | Ammar S.,Biotechnology Institute of Monastir | And 4 more authors.
Medicinal Chemistry Research | Year: 2010

The chemical composition of chloroformic, ethyl acetate, butanolic, and methanolic extracts isolated from the fungus Gliocladium sp. using different solvents of increasing polarity was analyzed by GC-FID and GC-MS. Furthermore, the antimicrobial activity of extracts was tested against five Gram-positive and Gramnegative bacteria and four pathogenic fungi. The tested extracts exhibited an interesting antibacterial activity against all bacteria tested, even against Gramnegative bacteria presenting frequently a higher resistance and against all fungi except Candida albicans. ©Birkhäuser Boston 2009.


Nabil A.,Biotechnology Institute of Monastir | Sarra F.,Biotechnology Institute of Monastir | Slim B.-Y.,Annaba University | Khaled S.,Biotechnology Institute of Monastir
Annales Zoologici | Year: 2010

To assess karyological and morphometric diversity within Discoglossus pictus Otth 1837, morphometric and cytogenetic analyses were carried out on five populations from the northern Tunisia and Algeria. A total of eight morphometric adult traits were evaluated, tadpole oral disc structure was described and chromosome patterns were assessed by means of conventional staining and banding methods (C-, Ag-NOR and CMA3 banding). Karyological data indicated the same chromosome and chromatin characters among the five populations. We observed also the same oral disk structure (LTRF: ) in all studied Discoglossus tadpoles. However, we found significant differences in morphometric parameters of the specimens from these localities. Discriminant Function Analysis (DFA) of morphometric variables correctly classified 88% of individuals to their original localities. The pattern of morphometric variation does not match the genetic observation, which suggests that body shape differences result from the phenotypic plasticity correlated with local climatic factors. © Fundacja Natura optima dux.


PubMed | Biotechnology Institute of Monastir
Type: Journal Article | Journal: Cytogenetic and genome research | Year: 2010

A new highly abundant satellite DNA from Discoglossus pictus (Dp-sat1) was isolated and characterized. The repetitive unit (0.51 kb) has 2 HindIII sites and only one SpeI site: digestion of genomic DNA with HindIII produces 3 fragments: HA (0.17 kb), HB (0.34 kb), and HC = HA + HB (0.51 kb), while digestion with SpeI produces the whole repetitive unit (0.51 kb) that contains both HindIII sites. Sequence analysis of cloned repeats indicates an average A + T content of 71%, with many A- and T-runs. Southern blot analysis shows an arrangement of multiple bands of the 0.51 kb monomer in SpeI-digested DNA, while HindIII-digested DNA shows a ladder composed of all the possible combinations of the 3 digested fragments. Quantitative dot-blot indicates that Dp-sat1 accounts for about 6% of the D. pictus genome: this value represents about 1.5 x 10(6) copies of repetitive units per nucleus. This satellite DNA is also a major repetitive DNA in 4 other Discoglossus species, in which the repetitive unit presents the same size and restriction sites except in D. montalentii where it contains a unique HindIII site. This satellite DNA was absent in all the other tested archaeo- and neo-bratrachian species, as well as non-amphibian species. Fluorescent in situ hybridization (FISH) analysis shows that Dp-sat1 is localized only in peri- and/or para-centromeric areas of the 7 small chromosome pairs, while no labeling was observed in the 7 large chromosome pairs. Remarkably, Dp-sat1 heterochromatin is found only at one pole of the nucleus, suggesting that during interphase all 7 small chromosome pairs are located in the same nuclear region.

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