New Species of Black Coral (Cnidaria: Antipatharia) from the Northern Gulf of Mexico

A new species of black coral, Antlpathes expansa (Cnldarla: Antlpatharla) from the northeastern Gulf of Mexico Is described. The species Is distinguished from other westem Atlantic flabellate species by having large, conical, tuberculate spines. A. expansa resembles the lndo-Paclflc species Antlpathes cancellata (Brook) but differs In having a non-retlculate corallum and slightly larger polyps

Mechanism and substrate specificity of telomeric protein POT1 stimulation of the Werner syndrome helicase

Loss of the RecQ helicase WRN protein causes the cancer-prone progeroid disorder Werner syndrome (WS). WS cells exhibit defects in DNA replication and telomere preservation. The telomeric single-stranded binding protein POT1 stimulates WRN helicase to unwind longer telomeric duplexes that are otherwise poorly unwound. We reasoned that stimulation might occur by POT1 recruiting and retaining WRN on telomeric substrates during unwinding and/or by POT1 loading on partially unwound ssDNA strands to prevent strand re-annealing. To test these possibilities, we used substrates with POT1-binding sequences in the single-stranded tail, duplex or both. POT1 binding to ssDNA tails did not alter WRN activity on nontelomeric duplexes or recruit WRN to telomeric ssDNA. However, POT1 bound tails inhibited WRN activity on telomeric duplexes with a single 3′-ssDNA tail, which mimic telomeric ends in the open conformation. In contrast, POT1 bound tails stimulated WRN unwinding of forked telomeric duplexes. This indicates that POT1 interaction with the ssDNA/dsDNA junction regulates WRN activity. Furthermore, POT1 did not enhance retention of WRN on telomeric forks during unwinding. Collectively, these data suggest POT1 promotes the apparent processivity of WRN helicase by maintaining partially unwound strands in a melted state, rather than preventing WRN dissociation from the substrate

Black Corals of the Flower Garden Banks National Marine Sanctuary

Black corals (Cnidaria: Anthozoa: Antipatharia) of the Flower Garden Banks National Marine Sanctuary (FGBNMS) are described. A key to the species is provided and supplemented with in situ and laboratory photos. The microscopic skeletal features of the species are illustrated from photographs taken with a scanning electron microscope. Thirteen species of black corals are found in the FGBNMS, belonging to the families Antipathidae (Antipathes furcata Gray 1857; Antipathes atlantica Gray 1857, Stichopathes luetkeni Brook 1889; Stichopathes pourtalesi Brook 1889, and Stichopathes sp.); Aphanipathidae [Aphanipathes pedata (Gray 1857), Elatopathes abietina (Pourtalès 1874), Acanthopathes thyoides (Pourtalès 1880) and Phanopathes expansa (Opresko and Cairns 1992)]; and Myriopathidae [Plumapathes pennacea (Pallas 1766), Tanacetipathes tanacetum (Pourtalès 1880), Tanacetipathes hirta (Gray 1857), and Tanacetipathes cf. thamnea (Warner 1981)]

Two new species of Dendrobrachia Brook, 1889 (Cnidaria: Octocorallia: Dendrobrachiidae) from the north-eastern Atlantic and western Mediterranean

Examination of recent benthic material collected during several cruises in the Gulf of Cadiz (NE Atlantic) and the Strait of Sicily (Mediterranean) has allowed the taxonomic reassessment of some previously identified specimens belonging to the monogeneric gorgonian family Dendrobrachiidae Brook, 1889. Dendrobrachia fallax Brook, 1889 is the type species of the single genus in this family, and was originally described from Ascension Island (South Atlantic). Subsequently, other authors reported the presence of this species in Cape Verde Islands (north-eastern Atlantic) and some Mediterranean localities (Alboran Sea and the Strait of Sicily). The study of the specimen from the Prince of Monaco collections in Cape Verde Islands, and recently collected material from the Gulf of Cadiz (north-eastern Atlantic) and in the south of Malta (Mediterranean), materials previously considered as D. fallax, allow us to recognize two undescribed species in this genus. All previous records of D. fallax from the north-eastern Atlantic and Mediterranean should be considered incorrect. Opresko and Bayer (1991) added two additional species of Dendrobrachia. Two new species are described here and compared with their congeners.Acciones Integradas Hispano-Portuguesas research program (HP-2004-0048CRUP - Acções Integradas 2005 (E82-05)Training Through Research Programme, IOC-UNESC

Validation of Image-Based Species Identifications of Black Corals (Order Antipatharia) on Mesophotic Rocks

Biodiversity, an important measure of ecosystem health, is challenging to ascertain using sampled specimens in remote deep-sea environments. As image-based identifications become a predominant method for deep-sea species characterizations, there is a need to evaluate the accuracy of species- and genus-level identifications from video and still images to provide a reliable measure of biodiversity. This study presents a validation of the ability to make accurate image-based identifications of black coral species in the northwestern Gulf of Mexico from standard-definition video collected by a remotely operated vehicle. Results indicate that the greatest number of misidentifications occurred at species-level groupings (42.2% error), whereas genus-level groupings possessed 12.0% error, and identifications to kappa groupings had no error. We recommend genus-level groupings to maintain accurate identifications while maximizing estimates of biodiversity

A New Name for the Hawaiian Antipatharian Coral Formerly Known as Antipathes dichotoma (Cnidaria: Anthozoa: Antipatharia).

v. ill. 23 cm.QuarterlyA Hawaiian species of antipatharian coral previously identified as Antipathes dichotoma Pallas, 1766, is described as Antipathes griggi Opresko, n. sp. The species forms tall, bushy colonies with elongate, upright terminal branches, often arranged uniserially. Spines are conical, mostly 0.20 to 0.26 mm tall, apically bifurcated, multilobed to jagged in appearance, and covered over most of their surface with small roundish to elongate papillae. Minute secondary spines may occur on some of the thicker branches. Polyps are 1 to 1.6 mm in transverse diameter. The species resembles A. fruticosa Gray in branching pattern, size of spines, and presence of secondary spines but differs in morphology and density of the spines (thicker, more crowded primary spines and fewer secondary spines in A. griggi). Other related species differ from A. griggi in having more widely spreading and irregularly arranged branches, no secondary spines, and either smaller spines with fewer apical lobes (A. curvata van Pesch, A. arborea Dana, and A. galapagensis Deichmann) or larger spines with the apical lobes arranged in a somewhat coronate pattern [A. spinulosa (Schultze) and A. lentipinna Brook]

Telomeric protein TRF2 protects Holliday junctions with telomeric arms from displacement by the Werner syndrome helicase

WRN protein loss causes Werner syndrome (WS), which is characterized by premature aging as well as genomic and telomeric instability. WRN prevents telomere loss, but the telomeric protein complex must regulate WRN activities to prevent aberrant telomere processing. Telomere-binding TRF2 protein inhibits telomere t-loop deletion by blocking Holliday junction (HJ) resolvase cleavage activity, but whether TRF2 also modulates HJ displacement at t-loops is unknown. In this study, we used multiplex fluorophore imaging to track the fate of individual strands of HJ substrates. We report the novel finding that TRF2 inhibits WRN helicase strand displacement of HJs with telomeric repeats in duplex arms, but unwinding of HJs with a telomeric center or lacking telomeric sequence is unaffected. These data, together with results using TRF2 fragments and TRF2 HJ binding assays, indicate that both the TRF2 B- and Myb domains are required to inhibit WRN HJ activity. We propose a novel model whereby simultaneous binding of the TRF2 B-domain to the HJ core and the Myb domain to telomeric arms promote and stabilize HJs in a stacked arm conformation that is unfavorable for unwinding. Our biochemical study provides a mechanistic basis for the cellular findings that TRF2 regulates WRN activity at telomeres

New Records of Deep-Water Cnidaria (Scleractinia & Antipatharia) from the Gulf of Mexico

Slxty·three species of azooxanthellate scleractinians and 26 species of antipatharians are recorded from the Gulf of Mexico. This report constitutes the first Inventory of Antipatharia within the geographic boundaries of the Gulf of Mexico whose southern limits are the Yucatan Straits to the south and the Florida Straits to the east. Thirteen range extensions of azooxanthellate species of the Order Scleractinia, and 28 species of the Order Antipatharia are reported. With respect to new records, we report four new records of azooxanthelate scleractinians and six new records of antipatharians from the outer continental shelf. One of the species, Slbopathes macrosplna Opresko, 1993, represents a new species In the western Atlantic region and appears related to Sibopathes gephura Van Pesch, 1914. The Gulf scleractinian fauna constitutes 54% of those known from the western Atlantic; the antipatharian fauna constitutes 93% of the western Atlantic fauna. These two groups are most diverse (55-56 species) in the regions of the Gulf adjacent to the Caribbean Sea and Atlantic Ocean (subdivisions I and VI). Diversity gradually decreases towards the western Gulf. Only six species are known from subdivision IV (east Mexico shelf and slope) and 23 species are recorded from subdivision V (Campeche Bank, Mexico)

Oxidative damage in telomeric DNA disrupts recognition by TRF1 and TRF2

The ends of linear chromosomes are capped by protein–DNA complexes termed telomeres. Telomere repeat binding factors 1 and 2 (TRF1 and TRF2) bind specifically to duplex telomeric DNA and are critical components of functional telomeres. Consequences of telomere dysfunction include genomic instability, cellular apoptosis or senescence and organismal aging. Mild oxidative stress induces increased erosion and loss of telomeric DNA in human fibroblasts. We performed binding assays to determine whether oxidative DNA damage in telomeric DNA alters the binding activity of TRF1 and TRF2 proteins. Here, we report that a single 8-oxo-guanine lesion in a defined telomeric substrate reduced the percentage of bound TRF1 and TRF2 proteins by at least 50%, compared with undamaged telomeric DNA. More dramatic effects on TRF1 and TRF2 binding were observed with multiple 8-oxo-guanine lesions in the tandem telomeric repeats. Binding was likewise disrupted when certain intermediates of base excision repair were present within the telomeric tract, namely abasic sites or single nucleotide gaps. These studies indicate that oxidative DNA damage may exert deleterious effects on telomeres by disrupting the association of telomere-maintenance proteins TRF1 and TRF2

Widest geographic distribution of a shallow and mesophotic antipatharian coral (Anthozoa: Hexacorallia): Antipathes grandis VERRILL, 1928 – confirmed by morphometric and molecular analyses

We provide the first record of the shallow and mesophotic ( 200 m depth) benthic taxa have such wide geographic distributions