State of the Art of Asian Seabass Lates calcarifer Larviculture

Innovative techniques opened new perspectives in the larviculture of the Asian seabass in the 1980s. Induced spawning maximized egg production while sperm preservation reduced the problem of male brood-stock supply. Studies of biometric characteristics of the fish larvae resulted in improved feeding strategies with live food. This in turn permitted a more rational use of expensive Artemia nauplii. Nutritional enhancement of the highly unsaturated fatty acid (HUFA) composition of the live food resulted in significant improvement of survival and physiological condition of the larvae at metamorphosis. A salinity stress test enabled the evaluation of the larvae's physiological status and estimation of their HUFA-requirements during the hatchery and pre-nursery phase.     

Spatial coordination of spindle assembly by chromosome-mediated signaling gradients

During cell division, chromosomes are distributed to daughter cells by the mitotic spindle. This system requires spatial cues to reproducibly self-organize. We report that such cues are provided by chromosome-mediated interaction gradients between the small guanosine triphosphatase (GTPase) Ran and importin-beta. This produces activity gradients that determine the spatial distribution of microtubule nucleation and stabilization around chromosomes and that are essential for the self-organization of microtubules into a bipolar spindle.     

Relationship between age and tibial plateau angle in dogs with cranial cruciate rupture

The pathogenesis of cranial cruciate ligament (CCL) rupture remains controversial, and its relationship to tibial plateau angle is unknown. In this study, the tibial plateau angle was measured in 200 large-breed dogs diagnosed with CCL rupture. Correlation analyses were performed to determine whether the age at the time of CCL rupture and the tibial plateau angle were related. While these two values were inversely correlated, the relationship was not strong enough to explain the frequency of CCL rupture in young, large-breed dogs. There was no statistically significant correlation between age at the time of CCL rupture and tibial plateau angle.     

Identification of Ehrlichia ruminantium (Gardel strain) IFN-gamma inducing proteins after vaccination with a killed vaccine

IFN-γ is considered as a key factor in protection against heartwater of ruminants, caused by the obligate intracellular bacterium Ehrlichia ruminantium. In this study, a better definition of the molecular masses of IFN-γ inducing proteins of the Gardel strain of E. ruminantium was obtained by the use of continuous flow electrophoresis (CFE) and sensitized polyclonal lymphocytes. Out of 15 E. ruminantium CFE fractions tested within the 14–39 kDa region, eight were commonly reacted to by all goats. Interestingly, half of these fractions fall within the 23–29 kDa region, shown previously to contain polymorphic B-cell epitopes. Thus, the results suggest that this region also contains T-cell epitopes potentially involved in protection. Also, several proteins were found to be more immunogenic than the serologically immunodominant MAP1 protein. Finally, high activity within the 15–19 kDa region was observed, which confirms previous work done with CD4+ T-cell lines obtained from cattle immunized with a South African strain of E. ruminantium. The proteins falling within the molecular weight ranges defined in this study may have potential as vaccine antigens.     

Feline dental resorptive lesions in the 13th to 14th centuries

The Schild excavation (1971-1975) unearthed 1871 feline bones from at least 181 cats from the town market in medieval Schleswig-Gottorf. Seven of the 189 mandibles and one of the 126 skulls were investigated using a combination of macroscopic, radiographic, and histologic examinations as well as Knoop hardness measurements. The preliminary results of examinations of three mandibles and one skull are presented and reveal that feline dental resorptive lesions were present in cats that lived in a settlement period dating from the 13th and 14th centuries in former Schleswig, Germany.     

Isolation and Characterization of a Novel Arabidopsis thaliana Mutant Unable to Develop Wilt Symptoms After Inoculation with a Virulent Strain of Ralstonia solanacearum

ABSTRACT To characterize host genes required for a compatible interaction, we identified a novel recessive Arabidopsis thaliana mutant, nws1 (no wilt symptoms), that failed to develop wilt symptoms in response to virulent strains of the phytopathogenic bacterium, Ralstonia solanacearum. The absence of wilting in nws1 plants was not correlated with a cell death phenotype or a constitutive expression of salicylic acid-, jasmonic acid- or ethylene-associated genes. In addition, this mutation, which conferred a symptomless phenotype in response to all the R. solanacearum strains tested, was highly specific to this pathogen, because nws1 responses to other plant pathogens, including oomycetes, nematodes, viruses, and other bacteria, were identical to those of wild-type Col-5 plants. Finally, the lack of disease development was shown to be different than RRS1-R-mediated resistance. The identification of mutants such as nws1, that are unable to develop disease, should lead to the isolation of target host factors required for pathogen growth or fitness, or of factors modified by the invading microorganism to avoid or inactivate plant defense mechanisms, and should bring a better understanding of bacterial wilt diseases.     

Plantlet regeneration from root callus of different Prunus species

Caulogenesis was obtained in vitro on the calli of Prunus sp., P. dawyckensis, P. canescens and hybrid P. incisa x serrula. These calli were formed on the roots of plantlets derived from meristem culture on a medium containing 6-benzylaminopurine (BAP) (10^?3 g/l) and gibberellic acid (GA₃) (10^?4 g/l). The first buds appeared after a month. After transfer of the calli on the same medium, the caulogenesis continued. The degree of regenation varied according to the species.     

Serologic monitoring of a broiler breeder flock previously affected by inclusion body hepatitis and testing of the progeny for vertical transmission of fowl adenoviruses

The increasing number of clinical cases of inclusion body hepatitis (IBH) associated with fowl adenoviruses (FAdVs) is a growing concern in different parts of the world, including Canada. After an outbreak of IBH in a 10-d-old pullet broiler breeder flock, we serologically monitored the flock from 8 to 46 wk of age, using the agar gel precipitation test (AGPT) offered by diagnostic laboratories and an FAdV group-specific enzyme-linked immunosorbemt assay (ELISA) developed earlier. In addition, we tested 1-d-old progeny for possible vertical transmission of FAdV when the breeder flock approached the peak of egg production by performing virus isolation and polymerase chain reaction (PCR) procedures on target organs. As in previous studies comparing the 2 tests, ELISA was more sensitive than AGPT. With ELISA, a few birds had weakly positive results at 8 wk of age, and all the birds had strongly positive results from 12 wk of age until the end of the study. This group-specific ELISA is therefore a sensitive and practical way to monitor FAdV antibodies in commercial flocks. None of the 1-d-old chicks tested were positive by PCR, nor was FAdV isolated from the same tissues, indicating an absence of transmission of infectious virus to the progeny. The lack of virus production and transmission could be due to the presence of high antibody titers in the layers.