Coccidian Parasites of Intertidal Fishes from Wales: Systematics, Development, and Cytochemistry

SYNOPSIS. Examination of littoral fish Blennius pholis and Cottus bubalis caught at Aberystwyth and Porth Cwyfan, Wales. U.K., revealed 2 species of coccidia.
Eimeria dingleyi sp. n. Oocysts spherical (16.1–19.2) to subspherical (13.9–14.2 × 18.8–20.0) μm, with thin walls; sporulation outside the host to produce ellipsoid sporocysts; endogenous phases in epithelial cells throughout intestine; 26 of 58 B. pholis infected.
Eimeria variabilis (Thélohan) Reichenow. Oocysts spherical (11.9–14.6) to subspherical (9.2–10.9 × 13.9–14.3) μm; sporulation in lining of pyloric ceca and rectum; previously unrecorded schizonts and gametocytes present; 21 of 25 C. bubalis infected.
Electron microscopy revealed that the oocyst wall of E. variabilis consists of a thin membrane whereas the sporocyst wall is thick and 3-layered. Typical oocyst wall-forming bodies were absent from the macrogamete. Cytochemical tests on the endogenous stages of E. dingleyi and E. variabilis indicated that in general they resembled other coccidia in their chemical constitution.     

Molecular Techniques in the Assessment of Botanical Diversity

A variety of different molecular techniques can be used forthe study of botanical diversity. Restriction fragment lengthpolymorphism (RFLP), arbitrary primed DNA, amplified fragmentlength polymorphism (AFLP), variable number of tandem repeats(VNTR), sequence-tagged simple sequence repeats (SSRs) and polymerasechain reaction (PCR) sequencing are briefly reviewed here. Thesetechniques differ in the way that they resolve genetic differences,in the type of data that they generate and in the taxonomiclevels at which they may be most appropriately applied. It isimperative to understand the different ways in which the datafrom the different molecular techniques can be utilized beforeembarking upon a programme of applying them to any particulardiversity study. Biodiversity; RFLP; RAPD; AFLP; VNTR; SSR; molecular data; fingerprinting; genetic distances; phylogeny; conservation     

A bryozoan buildup from the Lower Carboniferous of North Wales

A carbonate buildup dominated by trepostome Bryozoa is described from Dinantian (Asbian) strata near Llandudno in North Wales. A three-phase ecological succession is recognised within the buildup: (i) a basal diverse community with fenestrate, ramose, encrusting trepostome and cystoporate bryozoans in a mud rich wackestone; (ii) a bulk facies, dominated by encrusting and foliaceous, trepostome bryozoans in a fine packstone, and (iii) a thin capping phase, dominated by unilaminar, encrusting trepostome bryozoans in a slightly coarser lithology, including skeletal debris derived from the mound top and possible flanking beds. The buildup probably had topographic relief and developed in a shallow marine environment. The internal tripartite zonation reflects the growth of the structure into a shallower, higher energy regime, with the capping beds being deposited just below wave base. The buildup developed to the north of St. George's Land, on a carbonate shelf edge bordering the deeper basinal facies of the Irish Sea Basin. Dinantian, Asbian, buildup, trepostome Bryozoa, Foraminifera, corals, calcareous algae, Carboniferous, North Wales .     

Use of conductance measurements to detect growth of Clostridium botulinum in a selective medium

Growth of Clostridium botulinum in a selective medium (SBM) was monitored using conductance measurements. The correlation of log ₁₀ counts of spores and vegetative cells with detection times was highly significant ( r = 0.96, 0.97; P < 0.001). Log₁₀ counts of Cl. botulinum growing in pasteurized pork slurries also showed a clear linear relationship with detection times ( r = 0.77) but the confidence limits (± log₁₀ 2.3) of the regression line were too wide to estimate numbers of Cl. botulinum. For growth studies of Cl. botulinum in pork slurries detection times were useful in determining whether or not a visually unspoiled sample contained growing cells. Knowledge that a sample contained growing cells allowed a count to be made within 24 h, whereas 48 h would elapse before results from a traditional plate count were available.     

Bacterial rhamnolipids are novel MAMPs conferring resistance to Botrytis cinerea in grapevine

Rhamnolipids produced by the bacteria Pseudomonas aeruginosa are known as very efficient biosurfactant molecules. They are used for a wide range of industrial applications, especially in food, cosmetics and pharmaceutical formulations as well as in bioremediation of pollutants. In this paper, the role of rhamnolipids as novel molecules triggering defence responses and protection against the fungus Botrytis cinerea in grapevine is presented. The effect of rhamnolipids was assessed in grapevine using cell suspension cultures and vitro-plantlets. Ca²⁺ influx, mitogen-activated protein kinase activation and reactive oxygen species production form part of early signalling events leading from perception of rhamnolipids to the induction of plant defences that include expression of a wide range of defence genes and a hypersensitive response (HR)-like response. In addition, rhamnolipids potentiated defence responses induced by the chitosan elicitor and by the culture filtrate of B. cinerea . We also demonstrated that rhamnolipids have direct antifungal properties by inhibiting spore germination and mycelium growth of B. cinerea . Ultimately, rhamnolipids efficiently protected grapevine against the fungus. We propose that rhamnolipids are acting as microbe-associated molecular patterns (MAMPs) in grapevine and that the combination of rhamnolipid effects could participate in grapevine protection against grey mould disease.     

Genetic and morphological differentiation patterns between sister species: the case of Onthophagus taurus and Onthophagus illyricus (Coleoptera, Scarabaeidae)

The present study investigated the morphological and genetic differentiation pattern between two sympatric dung beetle sister species, Onthophagus taurus and Onthophagus illyricus . The geometric morphometric approach coupled with the use of molecular markers allowed examination of the nature of interspecific relationships and an outline of the evolutionary and geographical processes that might have led to interspecific differentiation and the present-day partial sympatric and syntopic pattern of distribution. Geometric morphometrics failed to discrimininate the two species on the ground of external morphological traits, but revealed interspecific differences when the shape of the primary sexual traits was taken into account. The use of two different molecular markers (cytochrome oxidase subunit I gene and amplified fragment-length polymorphism) demonstrates that the two species are genetically well differentiated, forming two distinguishable lineages probably diverged during the Pliocene by allopatric speciation. No evidence of past or recent introgression and no support for hybridization were found, suggesting that sympatry was established subsequently, when speciation was accomplished. Both molecular markers and genital shape indicate that phenotypically intermediate individuals, despite their ambiguous appearance, are members of O. illyricus species rather than hybrids.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 89 , 197–211.     

Isolation and characterization of six microsatellites in the Mexican beaded lizard Heloderma horridum

Six polymorphic microsatellite loci were isolated and characterized in the threatened Mexican beaded lizard, Heloderma horridum. The number of alleles per locus ranged from three to 12, with observed heterozygosity estimates ranging from 0.00 to 0.77, and expected heterozygosity estimates ranging from 0.00 to 0.73. These microsatellites will provide a valuable tool for the investigation of the genetic variation and structure of both wild and captive H. horridum populations.     

Histological Aspects of Root Formation in Petioles of Detached Leaves of Pereskia grandifolia (Cactaceae): Natural Conditions and Effects of GA3 and Dark

Adventitious roots arise naturally on petioles of Pereskia grandifoliaHaw. held in light. At about the 12th day after the beginningof the experiment, the root primordia arise in a callus tissuedeveloped from the basal portion of the petiole. Associatedwith the development of the callus, noticeable structural changesoccur in the originating organ. Petioles maintained in darkalso form callus; however, they die in a few days. On the otherhand, petioles treated with GA,, maintained in light, developcallus and survive; but they do not give rise to roots. Someaspects are discussed, such as: the kind of origin observedfor the roots, and the possible physiological basis for theirformation, as wdl as for the inhibition of their appearance Pereskia grandifolia, adventitious root formation, gibberelljc acid, petiole structure, rooting     

Evaluation of a monoclonal antibody-based immunoassay for detecting type B Clostridium botulinum toxin produced in pure culture and an inoculated model cured meat system

A monoclonal antibody-based amplified ELISA method for detecting Clostridium botulinum type B toxin was evaluated for its ability to detect the toxin in the supernatant fluid of pure cultures and after growth from Cl. botulinum spores inoculated into pork slurries. Slurries containing NaCl (1.5–4.5%w/v) and polyphosphate (0.3%w/v) were either unheated or heated 80°C/5 min followed by 70°C/2 h before incubation at 15°, 20° or 27°C. Presence of specific toxin was confirmed by mouse bioassay and results were compared with those of the amplified ELISA method. A total of 48 strains, consisting of 38 Cl. botulinum and 10 Cl. sporogenes (putrefactive anaerobes), and 140 slurry samples were tested. Cultures of eight out of nine strains of type B Cl. botulinum and 73 of 101 slurry samples containing type B toxin were positive by ELISA; the remaining 28 slurry samples contained type B toxin at levels below or close to the detection limit (20 LD₅₀/ml) of the type B ELISA. No falsepositive reactions occurred with Cl. botulinum types A, C, D, E or F, or with the 10 strains of Cl. sporogenes. Toxin produced by one strain of Cl. botulinum type B (NCTC 3807) was not detected by this single monoclonal antibody-based amplified ELISA. With a mixture of two monoclonal antibodies, however, the toxin from NCTC 3807 could be detected without reducing the sensitivity of the ELISA.