Isolation and characterization of polymorphic microsatellite loci in the razor clam Ensis siliqua

Five polymorphic microsatellite loci in the razor clam Ensis siliqua are described. A collection consisting of 34 individuals from Finisterre, Spain, was analysed. Loci were isolated from the sequences of intersimple sequence repeat (ISSR) markers. Detailed analysis of 42 ISSR markers led to the design of 16 primer pairs. Five of these yielded consistent and polymorphic products. The number of alleles ranged from five to 23 per locus with the observed heterozygosity ranging from 0.46 to 0.94. Linkage equilibrium was observed in all loci and three of them showed significant deviations from Hardy–Weinberg equilibrium.     

Two new taxa and a new combination for Stipa (Gramineae: Stipeae) in Tunisia

Two new taxa in Stipa L. Sect. Leiostipa Dumort., S. alba and S. letournexii ssp. ignea , are described from southern Tunisia (northern Africa). In addition, the S. letournexii complex is reviewed and a new combination, S. letournexii ssp. tunetana (H.Scholz) F.M. Vázquez, is presented.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 439–444.     

Location and Catalytic Characteristics of a Multipotent Bacterial Polyphenol Oxidase

The melanogenic marine bacterium Marinomonas mediterranea contains a multipotent polyphenol oxidase (PPO) able to oxidize substrates characteristic for tyrosinase and laccase. Thus, this enzyme shows tyrosine hydroxylase activity and it catalyzes the oxidation of a wide variety of o-diphenol as well as o-methoxy-activated phenols. The study of its sensitivity to different inhibitors also revealed intermediate features between laccase and tyrosinase. It is similar to tyrosinases in its sensitivity to tropolone, but it resembles laccases in its resistance to cinnamic acid and phenylthiourea, and in its sensitivity to fluoride anion. This enzyme is mostly membrane-bound and can be solubilized either by non-ionic detergent or lipase treatments of the membrane. The expression of this enzymatic activity is growth-phase regulated, reaching a maximum in the stationary phase of bacterial growth, but l -tyrosine, Cu(II) ions, or 2,5-xylidine do not induce it. This enzyme can be separated from a second PPO form by gel permeation chromatography. The second PPO is located in the soluble fraction and shows a sodium dodecyl sulfate (SDS)-activated action on the characteristic substrates for tyrosinase, l -tyrosine, and l -dopa, but it does not show activity towards laccase-specific substrates. The involvement of the multipotent PPO in melanogenesis and its relationship with the SDS-activated form and with the alternative functions proposed for multicopper oxidases in other microorganisms are discussed.     

The Amphibian Melanization Inhibiting Factor (MIF) Blocks the α-MSH Effect on Mouse Malignant Melanocytes

We have found that a melanization inhibitory factor (MIF) extracted from the ventral skin of Rana forreri has a slight inhibitory effect on the activity levels of tyrosinase and dopachrome tautomerase in B16/F10 and Cloudman S-91 murine melanoma cell lines. Furthermore, this factor appears to block the effects of α-MSH on these enzymatic activities. However, MIF treatment does not affect the melanogenic action of theophylline on the same cells, suggesting that MIF acts proximal to MSH-mediated cAMP formation, possibly by interaction with the MSH receptor. In this way, we show that this amphibian factor has biological activity on mammalian melanocytes. This suggests the existence of mammalian counterparts of amphibian MIF in the mouse integument that might regulate epidermal melanocytes. These peptides might be related to the agouti protein, as they share similar mechanisms of action. The interaction of different peptides with the MSH receptor would be a complex but general mechanism responsible for many mammalian coat color variants.     

Análisis de la distribución geográfica de los anomuros (Crustacea: Decapoda) del Golfo de California,México

The anomuran crabs are important from the biogeographic perspective because of their benthonic behavior in their adult state. For this reason, the present work summarizes the different studies developed to date on these crustaceans within the Gulf of California and reinforces the separation of the zone from others in the Province of Cortéz, or Cortesiana. The Gulf of California is inhibited by seventy-eight species of anomurans, belonging to seven families and twenty-eight genera. The best represented family regarding the number of genera (eleven), species (forty-five) and endemic species (eleven) is the Porcellanidae, followed by the Diogenidae with eight genera, fifteen species and four endemic species. The Gulf of California species are distributed in three large zoogeographical groups in the Eastern Pacific, the main one being the Panamic with an intrusion to the Gulf of 69.23% of the species reported. A second important group is that of the endemic species of the Gulf, with 24.35% of the existing species. The boreal species group with intrusion to the Gulf is present with 6.41%. Within the Californian Gulf, ten different zoogeographical groups are found, which demonstrate the great complexity of anomuran distribution, a product of the evolutionary history of this interior sea.     

Molecular phylogeny of the subgenus Holothuria (Selenkothuria) Deichmann, 1958 (Holothuroidea: Aspidochirotida)

The subgenus Selenkothuria comprises 12 species of tropical shallow water sea cucumbers that share morphological features, such as rods in the body wall and tube feet, modified tentacles for suspension feeding, and cryptic colours. The taxonomic status of this taxon has been controversial, but currently it is accepted as a subgenus of the genus Holothuria. Phylogenetic analyses of mitochondrial genes [cytochrome c oxidase subunit 1 (COI), 16S RNA] of ten species of Selenkothuria and related subgenera showed the polyphyly of this subgenus; monophyly was rejected by a likelihood ratio test. A geographical split divides the species of this subgenus into three different groups: one Indo‐West‐Pacific (IWP) group and two American groups. The IWP group is more closely related to Holothuria (Semperothuria) cinerascens and to other subgenera such as Roweothuria, Holothuria, and Vaneyothuria, whereas the two American groups are more closely related to each other and to some species of the subgenus Halodeima. These results suggest multiple parallel originations and diversification of ossicle morphology within the subgenus Selenkothuria. The current scheme of subgenera for the genus Holothuria is not supported, suggesting the need for a new classification. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 165 , 109–120.     

Ketoconazole Inhibits the Growth and Development of Ichthyophonus sp. (Mesomycetozoa) In Vitro

ABSTRACT. We determined the in vitro effect of the azol-derivative antifungal ketoconazole (KZ) on the morphology, growth, and development of teleost fish parasite Ichthyophonus sp. The KZ was delivered to culture medium using liposomes (L) or a lipid emulsion (E) at five different doses (i.e. 5, 50, 100, 200, and 400 μg/ml) for both L and E formulations. Controls consisted of Eagle's minimum essential medium (MEM) supplemented with 10% foetal bovine serum (MEM-10) alone (C-MEM) or containing amounts of L or E equivalent to those used in the KZ100 and KZ400 treatments (i.e. 100L, 400L, 100E, and 400E, respectively). Morphological alterations, such as a decrease in the number of dividing spores and nuclei, and condensation or even destruction of the cytoplasm, were observed using light and electron microscopy in the MEM-cultured organisms receiving KZ formulations, especially with KZ400L preparations, at both 7- and 14-d postinoculation. The KZ treatments also demonstrated a statistically significant inhibition of Ichthyophonus growth in MEM. These treatments also had an inhibitory effect on subsequent Ichthyophonus germination in Earle's fish saline agar (EFSA) medium, which was more evident for L formulations when the organism was treated for 7 d and for E formulations at 14 d. Our results endorse the potential use of KZ for the treatment for ichthyophonosis and provide support to proceed to in vivo assays.