The human SURF1 gene encoding a protein involved in cytochrome c oxidase (COX) assembly, is mutated in most patients presenting Leigh syndrome associated with COX deficiency. Proteins homologous to the human Surf1 have been identified in nine eukaryotes and six prokaryotes using database alignment tools, structure prediction and/or cDNA sequencing. Their sequence comparison revealed a remarkable Surf1 conservation during evolution and put forward at least four highly conserved domains that should be essential for Surf1 function. In Paracoccus denitrificans, the Surf1 homologue is found in the quinol oxidase operon, suggesting that Surf1 is associated with a primitive quinol oxidase which belongs to the same superfamily as cytochrome oxidase.
The identification of habitat requirements of invasive species is essential to evaluate their spread and to assess the vulnerability of recipient ecosystems. We studied the distribution and abundance of the invasive signal crayfish (Pacifastacus leniusculus) in 43 sites in northern Spain and analysed the relationships with several abiotic and biotic parameters of the aquatic ecosystems. Our results indicated that the abundance of signal crayfish was positively associated with vegetation cover and negatively associated with boulders. Also, its abundance was positively correlated with water temperature, organic matter, cations (e.g. sodium), anions (e.g. sulfates) and abundance of some native fish species (Parachondrostoma miegii and Luciobarbus graellsii). We concluded that the habitat of signal crayfish is among salmonid stretches (headwaters) with cold waters and low proportion of organic debris, and among cyprinid stretches (low waters) with warmer waters which it inhabits with another invasive crayfish, the red swamp crayfish (Procambarus clarkii). Our analysis indicated that the presence of signal crayfish is limited in the uppermost stretches by lower water temperatures and a lower proportion of organic debris. The existence of a natural environmental limiting factor in upstream reaches facilitates the conservation of aquatic ecosystems and native fauna.
Some tenebrionind beetles inhabiting the Namib desert are known for using their body to collect water droplets from wind-blown fogs. We aim to determine whether dew water collection is also possible for desert insects. For this purpose, we investigated the infra-red emissivity, and the wetting and structural properties, of the surface of the elytra of a preserved specimen of Physasterna cribripes (Tenebrionidæ) beetle, where the macro-structure appears as a series of "bumps", with "valleys" between them. Dew formation experiments were carried out in a condensation chamber. The surface properties (infra-red emissivity, wetting properties) were dominated by the wax at the elytra surface and, to a lower extent, its micro-structure. We performed scanning electron microscope on histological sections and determined the infra-red emissivity using a scanning pyrometer. The emissivity measured (0.95±0.07 between 8-14 μm) was close to the black body value. Dew formation occurred on the insect's elytra, which can be explained by these surface properties. From the surface coverage of the condensed drops it was found that dew forms primarily in the valleys between the bumps. The difference in droplet nucleation rate between bumps and valleys can be attributed to the hexagonal microstructure on the surface of the valleys, whereas the surface of the bumps is smooth. The drops can slide when they reach a critical size, and be collected at the insect's mouth.
ABSTRACT A new species of Orchesellides is described from material collected in the Valsaín forest (Segovia, Spain), and conserved in the collection of the National Museum of Natural Sciences (MNCN), CSIC, Madrid. The genus was known only from the eastern Palaearctic, Oriental, and Indo-Pacific (Hawaii) regions. This is the first reference for the genus from the western Palaearctic region, creating an interesting disjunct distribution. The value of the morphological characteristics for the identification of the species is discussed.
Two new species of Entomobrya are described from two caves of Asturias and Cantabria (north of Spain). The specimens were found in the Bonet collembolan collection at the “Museo Nacional de Ciencias Naturales” of Madrid (Spain). Entomomobrya boneti n. sp. was found in three slides containing 11, 4 and 1 specimens respectively, from the “Cueva del Castillo”, Puente el Viesgo (Santander). Entomobrya luquei n. sp. was found in a slide with 11 specimens from “Cueva de Cuetu-Lledías”, Llanes (Asturias). The species are described considering a set of 39 morphological and chaetotaxy characters. Both species appear to be troglophiles by the pigment reduction, although there are no other troglomorphic characters present. The gut content is composed of organic matter and fungus spores.