Sexual dimorphism of the bony labyrinth: A new age‐independent method

Currently in physical anthropology there is a need for reliable methods of sex estimation for immature individuals and highly fragmented remains. This study develops a sex estimation technique from discriminant function analysis of the bony labyrinth as it matures before puberty and can survive taphonomic conditions that would destroy most other skeletal material. The bony labyrinth contains the organs of hearing and balance. For this reason biologists and paleoanthropologists have undertaken research in this area to understand evolutionary changes in locomotion. Prior studies have found clear differences between species, but within‐species variation has not been satisfactorily investigated. 3D segmentations of the left and right labyrinths of 94 individuals from a Cretan collection were generated and measured. Mean measurements of height, width, size, and shape indices were analyzed for sexual dimorphism, bilateral asymmetry, and measurement error. Significant sexual dimorphism was detected for several measurements. For sex estimation, the single best variable was the radius of curvature of the posterior semicircular canal, which achieved 76% accuracy. Two multivariate functions increased accuracy to 84%. Although these equations are less accurate than equations for complete long bones and crania, they appear to be as accurate as or better than other techniques for sexing immature individuals and temporal bones. Am J Phys Anthropol 151:290–301, 2013. © 2013 Wiley Periodicals, Inc.     

Phytoplankton trigger the production of cryptic metabolites in the marine actinobacterium Salinispora tropica

Filamentous members of the phylum Actinobacteria are a remarkable source of natural products with pharmaceutical potential. The discovery of novel molecules from these organisms is, however, hindered because most of the biosynthetic gene clusters (BGCs) encoding these secondary metabolites are cryptic or silent and are referred to as orphan BGCs. While co-culture has proven to be a promising approach to unlock the biosynthetic potential of many microorganisms by activating the expression of these orphan BGCs, it still remains an underexplored technique. The marine actinobacterium Salinispora tropica, for instance, produces valuable compounds such as the anti-cancer molecule salinosporamide but half of its putative BGCs are still orphan. Although previous studies have used marine heterotrophs to induce orphan BGCs in Salinispora, its co-culture with marine phototrophs has yet to be investigated. Following the observation of an antimicrobial activity against a range of phytoplankton by S. tropica, we here report that the photosynthate released by photosynthetic primary producers influences its biosynthetic capacities with production of cryptic molecules and the activation of orphan BGCs. Our work, using an approach combining metabolomics and proteomics, pioneers the use of phototrophs as a promising strategy to accelerate the discovery of novel natural products from marine actinobacteria.     

The social and reproductive behavior of the eyed flounder,Bothus ocellatus,with notes on the spawning ofBothus lunatus andBothus ellipticus

Synopsis Observations of the Caribbean eyed flounder,Bothus ocellatus, were made during two field trips to Bonaire, Netherlands Antilles (January 1990, and December 1990 – January 1991) at depths from 3 to 6 meters. Data were collected by six scuba divers during 54 dives totaling 70 hours. Three mating groups were observed, each consisted of a male and 1 to 6 females. Each female had a distinct subunit within the male's territory. Courtship activity began about one hour before sunset and continued until sunset, when the male retired for the night. Both males and females retired into the sand at locations outside their daytime territory. Every day, males attempted to mate with each female individually within their territory. Spawning began with the male moving under the female who was resting on the sandy bottom. The pair then made a slow upward rise approximately 15 to 75 cm above the substrate, which culminated in a release of a cloud of gametes.Bothus lunatus andBothus ellipticus exhibited similar social organization toB. ocellatus, but differences in the spawning rise were observed. Intraspecific agonistic behavior was observed within males ofB. ocellatus andB. ellipticus.Senior author     

Metal uptake byCaryophyllaceae species from metalliferous soils in northern Greece

Plant samples collected from 17 populations of 9 taxa of the generaDianthus, Minuartia, Scleranthus, andSilene (Caryophyllaceae), growing in 14 metalliferous sites of N Greece, and surface soil samples from their growth area were analysed for Cu, Pb, Zn, Cd, Ni, Cr, Fe, Mn, Ca, Mg. Metal uptake varies considerably between the populations. A resistance mechanism excluding Cu and Pb from the aerial parts of the plants over a wide range of the soil concentrations up to a critical soil level appeared to exist, whereas Zn concentrations in plants were analogously related to those of the soil.Scleranthus perennis subsp.perennis showed the highest Cu concentration (205 µg/g), whereasMinuartia cf.bulgarica hyperaccumulated Pb (1175 µg/g). Ca concentrations in plants were in most cases much higher than those in soil, whereas the contrary was true for Mg. As a result the Ca/Mg ratio, which was in almost all cases lower than 1 in the soil, was much increased in the plants.     

Leptothoe,a new genus of marine cyanobacteria (Synechococcales) and three new species associated with sponges from the Aegean Sea

Cyanobacterial diversity associated with sponges remains underestimated, though it is of great scientific interest in order to understand the ecology and evolutionary history of the symbiotic relationships between the two groups. Of the filamentous cyanobacteria, the genus Leptolyngbya is the most frequently found in association with sponges as well as the largest and obviously polyphyletic group. In this study, five Leptolyngbya‐like sponge‐associated isolates were investigated using a combination of molecular, chemical, and morphological approach and revealed a novel marine genus herein designated Leptothoe gen. nov. In addition, three new species of Leptothoe, Le. sithoniana, Le. kymatousa, and Le. spongobia, are described based on a suite of distinct characters compared to other marine Leptolyngbyaceae species/strains. The three new species, hosted by four sponge species, showed different degrees of host specificity. Leptothoe sithoniana and Le. kymatousa hosted by the sponges Petrosia ficiformis and Chondrilla nucula, respectively, seem to be more specialized than Le. spongobia, which was hosted by the sponges Dysidea avara and Acanthella acuta. All three species contained nitrogen‐fixing genes and may contribute to the nitrogen budget of sponges. Leptothoe spongobia TAU‐MAC 1115 isolated from Acanthella acuta was shown to produce microcystin‐RR indicating that microcystin production among marine cyanobacteria could be more widespread than previously determined.     

Differential Recognition Preferences of the Three Src Homology 3 (SH3) Domains from the Adaptor CD2-associated Protein (CD2AP) and Direct Association with Ras and Rab Interactor 3 (RIN3)

CD2AP is an adaptor protein involved in membrane trafficking, with essential roles in maintaining podocyte function within the kidney glomerulus. CD2AP contains three Src homology 3 (SH3) domains that mediate multiple protein-protein interactions. However, a detailed comparison of the molecular binding preferences of each SH3 remained unexplored, as well as the discovery of novel interactors. Thus, we studied the binding properties of each SH3 domain to the known interactor Casitas B-lineage lymphoma protein (c-CBL), conducted a peptide array screen based on the recognition motif PxPxPR and identified 40 known or novel candidate binding proteins, such as RIN3, a RAB5-activating guanine nucleotide exchange factor. CD2AP SH3 domains 1 and 2 generally bound with similar characteristics and specificities, whereas the SH3-3 domain bound more weakly to most peptide ligands tested yet recognized an unusually extended sequence in ALG-2-interacting protein X (ALIX). RIN3 peptide scanning arrays revealed two CD2AP binding sites, recognized by all three SH3 domains, but SH3-3 appeared non-functional in precipitation experiments. RIN3 recruited CD2AP to RAB5a-positive early endosomes via these interaction sites. Permutation arrays and isothermal titration calorimetry data showed that the preferred binding motif is Px(P/A)xPR. Two high-resolution crystal structures (1.65 and 1.11 Å) of CD2AP SH3-1 and SH3-2 solved in complex with RIN3 epitopes 1 and 2, respectively, indicated that another extended motif is relevant in epitope 2. In conclusion, we have discovered novel interaction candidates for CD2AP and characterized subtle yet significant differences in the recognition preferences of its three SH3 domains for c-CBL, ALIX, and RIN3.     

Presence of Cicadomorpha in olive orchards of Greece with special reference to Xylella fastidiosa vectors

Insects of the infraorder Cicadomorpha cause serious economic impact on agriculture because of pathogens’ transmission. The vector-borne bacterium Xylella fastidiosa, which is associated with olive quick decline syndrome, is exclusively transmitted by insects of this infraorder and more specific by sharpshooters and spittlebugs. Efficient control practices of the insect vectors are necessary for the control of the disease in cases of outbreaks. Therefore, the knowledge of the vectors' species as well as the robust understanding of their biology and ecology is of crucial importance. In the present study, extensive sampling was conducted in 28 olive orchards of Greece during the years 2017 and 2018 aiming to investigate which species of this infraorder are present, with special interest to those which are considered as vectors of the bacterium. During the surveys, 4,350 Cicadomorpha insects were collected. Forty-two, five and one species of the families Cicadellidae, Aphrophoridae and Cercopidae, respectively, were identified. The results of the surveys revealed that the main potential vectors of X. fastidiosa in Greek olive orchards are the spittlebugs Philaenus spumarius and Neophilaenus campestris. Those species have wide distribution in Greece and are present for a long period during the year, and they inhabit both the ground vegetation and the olive trees' canopy. A representative portion of the captured spittlebugs was analysed with molecular methods, and the analysis confirmed the absence of X. fastidiosa in the tested individuals.     

Distinct Agonist Regulation of Muscarinic Acetylcholine M2-M3 Heteromers and Their Corresponding Homomers

Each subtype of the muscarinic receptor family of G protein-coupled receptors is activated by similar concentrations of the neurotransmitter acetylcholine or closely related synthetic analogs such as carbachol. However, pharmacological selectivity can be generated by the introduction of a pair of mutations to produce Receptor Activated Solely by Synthetic Ligand (RASSL) forms of muscarinic receptors. These display loss of potency for acetylcholine/carbachol alongside a concurrent gain in potency for the ligand clozapine N-oxide. Co-expression of a form of wild type human M₂ and a RASSL variant of the human M₃ receptor resulted in concurrent detection of each of M₂-M₂ and M₃-M₃ homomers alongside M₂-M₃ heteromers at the surface of stably transfected Flp-In^TM T-REx^TM 293 cells. In this setting occupancy of the receptors with a muscarinic antagonist was without detectable effect on any of the muscarinic oligomers. However, selective agonist occupancy of the M₂ receptor resulted in enhanced M₂-M₂ homomer interactions but decreased M₂-M₃ heteromer interactions. By contrast, selective activation of the M₃ RASSL receptor did not significantly alter either M₃-M₃ homomer or M₂-M₃ heteromer interactions. Selectively targeting closely related receptor oligomers may provide novel therapeutic opportunities.     

Evaluation of the Genotoxic and Antigenotoxic Effects of Chios Mastic Water by the In Vitro Micronucleus Test on Human Lymphocytes and the In Vivo Wing Somatic Test on Drosophila

Chios mastic gum, a plant-derived product obtained by the Mediterranean bush Pistacia lentiscus (L.) var. chia (Duham), has generated considerable interest because of its antimicrobial, anticancer, antioxidant and other beneficial properties. Its aqueous extract, called Chios mastic water (CMW), contains the authentic mastic scent and all the water soluble components of mastic. In the present study, the potential genotoxic activity of CMW, as well as its antigenotoxic properties against the mutagenic agent mitomycin-C (MMC), was evaluated by employing the in vitro Cytokinesis Block MicroNucleus (CBMN) assay and the in vivo Somatic Mutation And Recombination Test (SMART). In the former assay, lymphocytes were treated with 1, 2 and 5% (v/v) of CMW with or without MMC at concentrations 0.05 and 0.50 µg/ml. No significant micronucleus induction was observed by CMW, while co-treatment with MMC led to a decrease of the MMC-induced micronuclei, which ranged between 22.8 and 44.7%. For SMART, larvae were treated with 50 and 100% (v/v) CMW with or without MMC at concentrations 1.00, 2.50 and 5.00 µg/ml. It was shown that CMW alone did not modify the spontaneous frequencies of spots indicating lack of genotoxic activity. Τhe simultaneous administration of MMC with 100% CMW led to considerable alterations of the frequencies of MMC-induced wing spots with the total mutant clones showing reduction between 53.5 and 74.4%. Our data clearly show a protective role of CMW against the MMC-induced genotoxicity and further research on the beneficial properties of this product is suggested.     

c-Type Cytochrome Biogenesis Can Occur via a Natural Ccm System Lacking CcmH,CcmG, and the Heme-binding Histidine of CcmE

The Ccm cytochrome c maturation System I catalyzes covalent attachment of heme to apocytochromes c in many bacterial species and some mitochondria. A covalent, but transient, bond between heme and a conserved histidine in CcmE along with an interaction between CcmH and the apocytochrome have been previously indicated as core aspects of the Ccm system. Here, we show that in the Ccm system from Desulfovibrio desulfuricans, no CcmH is required, and the holo-CcmE covalent bond occurs via a cysteine residue. These observations call for reconsideration of the accepted models of System I-mediated c-type cytochrome biogenesis.