Amplified Fragment Length Polymorphism (AFLP) Reveals Species-Specific Markers in the Daphnia Galeata–HyalinaSpecies Complex

Daphnia often occur in species complexes that consist of two or more co-occurring species and their hybrids. Hybrid individuals are often capable of sexual reproduction and so backcrossing with introgression occurs. To better understand hybridization and backcrossing frequency, we sought to develop PCR-based, species-specific markers in the Daphnia galeata–hyalina species complex using amplified fragment length polymorphism (AFLP). This technique produces large numbers of reproducible markers for assessing diversity across the nuclear genome and provides several advantages over mtDNA and microsatellite approaches. We examined 28 clones of D. galeata, D. hyalina, and their hybrids isolated from Lake Constance on the Swiss-German border. Using a single AFLP primer combination we found five potential species-specific markers, defined as bands that occurred in >80% of one parental species and <20% of the other. Two bands appeared to be co-dominant and were present (homozygous) in D. galeata, absent in D. hyalina, and heterozygous in the hybrid. We conclude AFLP could provide enough PCR-based, species-specific markers to identify species, hybrids, and backcrosses from even small amounts of tissue (i.e. resting eggs).     

Amphinema modernisme, a new Pandeid (Cnidaria: Anthomedusae) from the Southern Ocean

A new species of pandeid anthomedusa, Amphinema modernisme, is described from a single and complete specimen collected by a mid-water sediment trap placed at 500 m depth in open waters, over a 1066-m bottom in the Drake Passage near the South Shetland Islands. This new Amphinema is characterized by an egg-shaped apical chamber, partitioned by four narrow sacciform centrifugal prolongations of the radial canals, perradial gonads and cellular strands linking the radial canals to the exumbrella. Its morphological features are compared with those of the eight other species of the genus Amphinema and a new diagnosis for this genus is presented. Accepted: 19 July 1999     

A new Antarctic association: the case of the hydroid Sarsia medelae (new sp.) associated with gorgonians

Sarsia medelae sp. nov. is described and illustrated from material collected in the Weddell Sea during the R/V Polarstern cruises ANT XVII/3 (April 2000) and in the Ross Sea during the R/V Italica cruise XIX (March 2004). The specimens have always been observed in association with several gorgonians of genera Thouarella sp., Primnoisis sp., and Notisis sp. The polyps of Sarsia medelae are considered as mesobiont of the gorgonian host with a non-parasitic relationship. It is the first time that this kind of association, which is so far only known from the Indian and Pacific Ocean, is reported in the Southern Ocean. This finding is discussed in the framework of the hypothesis that a part of Antarctic fauna has its origin in species dating back to before the Cretaceous period, because this kind of association between a hydroid and a gorgonian host being only known in the actual Antarctic shelf and in regions belonging to the previous Thethys areas.An erratum to this article can be found at     

USP15 stabilizes TGF-β receptor I and promotes oncogenesis through the activation of TGF-β signaling in glioblastoma

In advanced cancer, including glioblastoma, the transforming growth factor β (TGF-β) pathway acts as an oncogenic factor and is considered to be a therapeutic target. Using a functional RNAi screen, we identified the deubiquitinating enzyme ubiquitin-specific peptidase 15 (USP15) as a key component of the TGF-β signaling pathway. USP15 binds to the SMAD7-SMAD specific E3 ubiquitin protein ligase 2 (SMURF2) complex and deubiquitinates and stabilizes type I TGF-β receptor (TβR-I), leading to an enhanced TGF-β signal. High expression of USP15 correlates with high TGF-β activity, and the USP15 gene is found amplified in glioblastoma, breast and ovarian cancer. USP15 amplification confers poor prognosis in individuals with glioblastoma. Downregulation or inhibition of USP15 in a patient-derived orthotopic mouse model of glioblastoma decreases TGF-β activity. Moreover, depletion of USP15 decreases the oncogenic capacity of patient-derived glioma-initiating cells due to the repression of TGF-β signaling. Our results show that USP15 regulates the TGF-β pathway and is a key factor in glioblastoma pathogenesis.     

Settlement and early survival of red coral on artificial substrates in different geographic areas: some clues for demography and restoration

The red coral Corallium rubrum (L 1758) is a long-lived, slow-growing gorgonian, endemic to Mediterranean rocky bottoms. Because of its high economic value, red coral has long been harvested, and most populations have been depleted. In the present study, 54 marble tiles were placed in June 2003 within red coral populations over 3 different geographic areas (Calafuria–Livorno and Elba MPA in Italy and Medes Islets MPA, in Spain), on vertical cliffs between 25 and 35 m. In each area 2 different sites were randomly selected. Tiles were subsequently sampled photographically. Between July and August 2003 red coral recruits settled on tiles in all the geographic areas and sites, exhibiting wide variability in their density. On the basis of a 2-factors nested ANOVA a significant variability between different sites at a few hundred metres distance occurred, indicating high variations in the recruitment process within the same red coral population. Mortality, measured in June 2004, widely varied between different geographic areas.     

Clinical Patterns and Treatment Outcome in Patients with Melancholic,Atypical and Non-Melancholic Depressions

Objective

To assess sociodemographic, clinical and treatment factors as well as depression outcome in a large representative clinical sample of psychiatric depressive outpatients and to determine if melancholic and atypical depression can be differentiated from residual non-melancholic depressive conditions.

Subjects/Materials and Method

A prospective, naturalistic, multicentre, nationwide epidemiological study of 1455 depressive outpatients was undertaken. Severity of depressive symptoms was assessed by the Hamilton Depression Rating Scale (HDRS) and the Self Rated Inventory of Depressive Symptomatology (IDS-SR₃₀). IDS-SR₃₀ defines melancholic and atypical depression according to DSM-IV criteria. Assessments were carried out after 6–8 weeks of antidepressant treatment and after 14–20 weeks of continuation treatment.

Results

Melancholic patients (16.2%) were more severely depressed, had more depressive episodes and shorter episode duration than atypical (24.7%) and non-melancholic patients. Atypical depressive patients showed higher rates of co-morbid anxiety disorders and substance abuse. Melancholic patients showed lower rates of remission.

Conclusion

Our study supports a different clinical pattern and treatment outcome for melancholic and atypical depression subtypes.     

Morphological features of the gorgonian Paramuricea macrospina on the continental shelf and shelf edge (Menorca Channel,Western Mediterranean Sea)

Morphological variability in gorgonians is frequent and commonly associated with habitat variability, often resulting in segregated morphotypes. Paramuricea macrospina is an endemic Mediterranean gorgonian species found on rocky bottoms between 40 and 160?m depth and has recently been reported as one of the most abundant species in continental shelf and shelf edge environments. Three different chromatic forms of P. macrospina were observed in the Menorca Channel: a yellow form and a light purple form occurring on maërl beds of the continental shelf, and a dark purple form occurring on rocky substrates of the shelf edge. The objective of the present work is to verify if these P. macrospina forms may represent distinct taxonomic units by analysing differences in colony morphology and sclerite size and shape of the three chromatic forms. No significant differences were found in colony shape, suggesting that environmental variability between the continental shelf and the shelf edge is not influential enough to significantly alter colony morphology. Significant differences in sclerite size and shape were found amongst all forms, suggesting that sclerites may be influenced by environmental conditions. However, the co-occurrence of the yellow and light purple forms side by side on the continental shelf may indicate a certain degree of genetic differentiation.     

Quantitative study of a hippuritid rudist lithosome in a Santonian carbonate platform in the southern Central Pyrenees

The Santonian carbonate platform deposits of the Sant Corneli anticline in the southern Central Pyrenees contain distinctive lenticular to tabular lithosomes formed by congregations of slender hippuritid rudists. Here we make a quantitative study of one of the lithosomes in the Sant Pere de Vilanoveta Member, in the northern side of Sant Corneli. It is exposed over some 4 km, along a WNW–ESE section, and shows a remarkably persistent thickness up to a maximum of 5.15 m, though for the most part it is less than 3 m thick. In the lithosome, hippuritid shells are mostly preserved inclined about 30°–60° from the perpendicular with respect to bedding. The majority of inclined shells lean towards the southwestern to southeastern quadrants, the inferred principal downstream direction. Hippuritids are loosely clustered and supported in a fine bioclastic matrix. Percentage cover of hippuritids ranges from 19.8% at the base to 31.9% in the middle and top of the lithosome. The preliminary data on numerical densities (number of individuals per unit area) of hippuritids show some clustering around values of about 290–750 individuals per m². The inclined orientation of hippuritid shells seems original and the result of active growth by the animals. The high numerical density of hippuritids at the base of the lithosome may indicate that the hippuritid congregation grew rapidly. The congregation appears to have reached an optimal level of density by the middle of the lithosome and to have maintained it through time during the development of the rudist congregation. The lithosome lacks relief and has no evidence of any rigid framework.