We revealed new deep-water species and cryptic speciation within freshwater sponges of the endemic family Lubomirskiidae (Porifera; Demospongiae; Spongillina) based on molecular and spicule morphology analyses of ITS and CO1 mtDNA. Lubomirskiidae contains a group of closely related species which are a dominant component of the benthos in Lake Baikal, the world's deepest and most ancient lake. S...

Although the trichomes (spicules) of a pod of cowhage (Mucuna pruriens) are known to evoke a histamine-independent itch that is mediated by a cysteine protease, little is known of the itch and accompanying nociceptive sensations evoked by a single spicule and the enhanced itch and pain that can occur in the surrounding skin. The tip of a single spicule applied to the forearm of 45 subjects typi...

In the sea urchin embryo, primary mesenchyme cells (PMCs) are committed early in development to direct skeletogenesis, provided that a permissive signal is conveyed from adjacent ectoderm cells. We showed that inhibition of extracellular matrix (ECM)-ectoderm cells interaction, by monoclonal antibodies (mAb) to Pl-nectin, causes an impairment of skeletogenesis and reduced expression of Pl-SM30,...

A new species of Paracooperia Travassos, 1935 was found in small numbers in the small intestines of 36 out of 68 nyala Tragelaphus angasi Gray 1849 in the Mkuzi, Ndumu and Umfolozi Game Reserves, Natal. The worms, for which the name Paracooperia horaki is proposed, can be differentiated from the closely related Paracooperia devossi Boomker & Kingsley, 1984 by the absence of ridges on 1 of the b...

A new dermal filarioid nematode, collected from Cervus nippon nippon (sika deer) on Kyushu Island, Japan, showed close affinities between the genera Cutifilaria and Mansonella (Onchocercidae: Onchocercinae): no buccal capsule, esophagus reduced to a thin fibrous tube, and female tail with four lappets. We propose Cutifilaria as a subgenus of Mansonella. Cutifilaria was distinguished from the fi...

During Caenorhabditis elegans male spicule development, four pairs of precursor cells respond to multiple positional cues and establish a pattern of fates that correlates with relative anterior-posterior cell position. One of the extracellular cues is provided by the F and U cells, which promote anterior fates. We show that the genes in the lin-3/let-23 signalling pathway required for hermaphro...

The earliest evidence for animal life comes from the fossil record of 24-isopropylcholestane, a sterane found in Cryogenian deposits, and whose precursors are found in modern demosponges, but not choanoflagellates, calcareans, hexactinellids, or eumetazoans. However, many modern demosponges are also characterized by the presence of siliceous spicules, and there are no convincing demosponge spic...

We present an analytical model for the damping of Alfvén waves in the partially ionized chromosphere. The damping is due to collisions between ions and neutrals. The ionneutral collision frequency in this environment is such that the ion and neutral populations are almost perfectly collisionally coupled, leading the Alfvén wave to behave as if it acts on the whole plasma (i.e. including neutral...

Iron, as inorganic ion or as oxide, is widely used by biological systems in a myriad of biological functions (e.g., enzymatic, gene activation and/or regulation). In particular, marine organisms containing silica structures--diatoms and sponges--grow preferentially in the presence of iron. Using primary sponge cell culture from S. domuncula-primmorphs--as an in vitro model to study the Demospon...

Trichospirura aethiopica n. sp. is described from unidentified tubular structures (pancreatic ducts?) near the stomach of the murid Malacomys longipes Milne-Edwards, 1877 in Gabon. The extremely long and narrow buccal capsule, posterior position of the vulva, unequal spicules and absence of caudal alae readily identified the specimens as belonging to Trichospirura Smith & Chitwood, 1967, but a ...