Implementation of two high through-put techniques in a novel application: detecting point mutations in large EMS mutated plant populations

Background  

The establishment of mutant populations together with the strategies for targeted mutation detection has been applied successfully to a large number of organisms including many species in the plant kingdom. Considerable efforts have been invested into research on tomato as a model for berry-fruit plants. With the progress of the tomato sequencing project, reverse genetics becomes an obvious and achievable goal.     

The effects of climate variability on zooplankton and basking shark (Cetorhinus maximus) relative abundance off southwest Britain

At small spatial scales basking sharks (Cetorhinus maximus) forage selectively on zooplankton along thermal fronts, but the factors influencing broader scale patterns in their abundance and distribution remain largely unknown. Using long‐term sightings data collected off southwest Britain between 1988 and 2001, we show that the number of basking sharks recorded was highly correlated with abiotic factors, principally sea surface temperature (SST) and the lagged effect of SST in the previous month, but only very weakly to zooplankton density. This suggests that the changes in number of basking sharks recorded over large spatio‐temporal scales are more closely related to the availability of climate‐driven thermal resources than prey availability, whereas the converse is supported by previous studies at local scales. Taken together, these results imply scale‐dependent behavioural responses in basking sharks, with small‐scale foraging movements linked by broad scale responses to temperature variation.     

Isolation and pathogenicity of Australian strains of Eimeria praecox and Eimeria mitis

Objective To determine the presence of E praecox and E mitis in Australia, to isolate representative strains of these species from chickens and determine their pathogenicity.
Design Morphological, physiological and cross protection studies were undertaken to confirm the identity of Australian isolates of E praecox and E mitis.
Procedure Oocysts were isolated from a backyard flock at Jimboomba, southeastern Queensland and numbers of E praecox and E mitis enriched by passage in chickens immune to five other species of poultry Eimeria . Oocysts of mean conformation and size of the two species were purified by single oocyst passage. Two isolates that closely matched recorded parameters for E praecox and E mitis were selected and designated JP and JM respectively. The cross protection between the isolates and E acervulina was determined by infection and challenge experiments. The virulence of the two isolates was determined by comparing weight gains of groups of birds inoculated with JP isolate or JM isolate with untreated groups.
Results Isolates JP and JM most closely matched recorded parameters of E praecox and E mitis respectively. Groups of chickens, previously infected with JP and JM isolates, showed no significant protection against infection with E acervulina . In a separate trial, groups of susceptible chickens inoculated with 10⁵ oocysts of JP and JM isolates showed significantly reduced weight gains compared with untreated controls.
Conclusion Isolates JP and JM are E praecox and E mitis respectively, confirming the presence of these species in Australia. These isolates were found capable of causing significant reductions in weight gains in susceptible chickens.