Detection of the Microtubule Cytoskeleton of the Coccidian Toxoplasma gondii and the Hemoflagellate Leishmania donovani by Monoclonal Antibodies Specific for β-Tubulin1

Seven monoclonal antibodies specific for mammalian β-tubulin demonstrate the microtubule cytoskeleton of Toxoplasma gondii and Leishmania donovani by indirect immunofluorescence microscopy. Immunoblots of T. gondii and L. donovani proteins separated by SDS polyacrylamide gel electrophoresis confirm the specificity of the monoclonal antibodies for tubulin. Differential staining of flagellar and subpellicular microtubule populations was not seen in L. donovani with these antibodies. All seven antibodies also detected the subpellicular microtubules of T. gondii, but the polar ring and conoid of this organism was not visualized by any of them. This technique provides a rapid and specific way to assess microtubular organization in whole organisms.     

Golden Eagles Aquila chrysaetos: land use and food in northeast Scotland

This paper contrasts changes in breeding numbers and breeding success of Golden Eagles Aquila chrysaetos on four areas with different land uses. On land primarily used for deer stalking but also for grouse shooting, and supporting abundant prey, the number of eagle pairs was steady in 1944-80. On deer land with fewer prey, the number of pairs declined greatly in the 1960s, when deer carrion became scarcer following increased shooting of red deer. On grouse moors incorporating deer stalking, the number of pairs declined in the 1950s due to persecution by gamekeepers, and then largely recovered as this lessened. On grouse moors with little or no stalking, the number of pairs fell after 1946 and remained low due to persecution, which has continued since then. Eagles on grouse moors bred poorly due to persecution. On deer land they were seldom persecuted by estate staff, and bred well. On an area of deer land, the mean annual number of young reared per undisturbed clutch in summer was related to the estimated weight of prey in the spring of the same year. The eagles have remained fairly pesticide-free, and bred well in 1963-65 when more contaminated birds in west Scotland bred poorly.     

Heat-resistant Bacteria in Pasteurized Whole Egg

Samples of egg melange taken from an egg packing station contained an average of 7·3 x 10⁴ organisms/ml which survived laboratory pasteurization at 65°C for 3 min. Many of the organisms surviving pasteurization were found to be coryneform bacteria related to Microbacterium lacticum which could be differentiated into several groups. The remainder were a miscellaneous collection of unidentified cocci and coccobacilli and some Bacillus spp. The coryneform bacteria were shown to be the most heat-resistant isolates with negligible loss of viability after 60 min at 65°C, At least two of the representative strains were very heat-resistant, 0·01% surviving 20 and 38 min at 80°C in phosphate buffer at pH 7·1. Growth tests showed that none of the isolates grew at 5°C after 10 d incubation but those capable of growing most rapidly at 10° and 15°C were also the most heat-resistant. Such strains had a doubling time at 15°C of between 6 and 8 h in whole egg. Freezing the coryneform bacteria in liquid whole egg at –18°C had negligible effect on viability or heat-resistance at 65°C.     

The use of water and some inorganic salt solutions to advance sugar beet seed. II. Experiments under controlled and field conditions

The effect of seed advancement on the early growth of sugar beet was determined in two experiments made under controlled conditions and eight field experiments made between 1974 and 1978. The experiments in the growth room suggested that seed advancement increased the rate of emergence and seedling dry weight over a wide range of soil moisture contents but seedling numbers were only greater under sub-optimal moisture conditions. Similarly, in most field experiments, seed advancement resulted in more rapid emergence and larger seedlings. In four field experiments, seed advancement gave up to 16% more plants, and in three experiments a significant increase in final sugar yield of up to 0–7 t h^-1 was detected. The plants were hand-singled to a uniform stand and had the crops been drilled to a stand, some yield responses would have been larger. Seed advancement did not decrease the plant stand or final yield in any experiments. Results in 1977 and 1978 provided some evidence that seed advancement may help reduce the damage caused by field mice and the number of plants which bolt and, by making emergence more rapid, be particularly beneficial on soils prone to slumping or capping. There might, however, be a slightly increased risk of frost injury if advanced seed is used for early sowings.     

ULTRASTRUCTURE AND HISTOCHEMISTRY OF THE POSTERIOR OESOPHAGUS OF NASSARIUS RETICULATUS (LINNAEUS)

The posterior oesophagus of N. reticulatus (Linnaeus) consistsof two histologically distinct regions. The epithelium of thethickened segment in the visceral haemocoel is virtually uniform.The cells are lipid-rich and can take up lipid from food. Inaddition, enzyme histochemistry indicates a capacity for theuptake of sugars and amino acids. The basal plasmalemma is elaboratelyinfolded and associated with numerous elongate mitochondria,features indicating an active ion pump. The physiological roleof this pump is unknown. (Received 26 March 1985; accepted 10 May 1985)