Estimates of the genetic parameters and repeatability of behavioural traits of sheep in an arena test

Over three years, seven hundred and sixty two 14-month-old Bluefaced Leicester crossbred ewe lambs were individually exposed to a 6-min arena test designed to evaluate the behaviour of sheep exposed to a situation of conflicting motivations (to seek flock mates versus avoid a motionless human). The behaviours measured included vocalisation (latency and number of bleats), locomotion (number of squares entered, number of entries to the area close to the observer) and proximity (time spent near to or distant from the observer and time in the centre of the arena). In the first year, 190 lambs were measured three times at ages between 8 and 14 months. Changes in mean levels of behaviour that were consistent with habituation were observed during these repeated tests. The repeatability of traits for vocalisation (0.58–0.71) tended to be higher than for locomotion (0.38–0.40) and for proximity to the human (0.17–0.60) with evidence of an increase in the repeatability of proximity traits between the second and third tests. There were no significant effects of litter size at birth or rearing type on behaviour and only small effects of farm of origin and breed of dam of the lamb (Scottish Blackface and Hardy Speckled Face). Heritability estimates were: latency to bleat (0.13), number of bleats (0.39), number of squares entered (0.29), time spent distant from the observer (0.13), time in the centre of the arena (0.02), time spent near to the observer (0.22) and number of entries to the area near to the observer (0.21). Phenotypic, genetic and environmental correlations were generally of similar magnitude, and indicated a moderate relationship between traits for vocalisation and locomotion, with no significant associations between traits for vocalisation and proximity to the observer. Test behaviours were not significantly correlated to yearling weight. These results demonstrate the existence of considerable genetic variation in behaviour among sheep and indicate that behavioural measures of vocalisation and proximity to the human are genetically and environmentally uncorrelated and may represent independent measures of emotional state.     

Expression and purification of a convenient Ca-calmodulin-dependent protein kinase II GST-fusion substrate

Abundant and convenient protein substrates are extremely useful tools for studying protein kinases. However, few such substrates exist for alpha-Ca(2+)-calmodulin-dependent protein kinase II (CaMKII) and those that are available are generally small and expensive peptides that are cumbersome to use. The GST-fusion expression system was used to express a 10 amino acid substrate of CaMKII PLRRTLSVAA in bacteria. Using glutathione-agarose affinity chromatography, we obtained milligram quantities of the highly purified recombinant GST-fusion protein. The GST-fusion protein was tested for its efficacy and specificity as a substrate for CaMKII in phosphorylation assays using recombinant enzyme and radiolabeled [gamma-32P]ATP. The reaction products of these phosphorylation assays were resolved by electrophoresis in SDS-polyacrylamide gels and quantified by phosphoimage analysis. It was found that compared to a phosphorylation-null substrate, GST-PLRRTLAVAA, in which the phosphorylated target serine residue was mutated to an alanine, the GST-PLRRTLSVAA substrate was phosphorylated by CaMKII with an apparent K(m) of 18 microM, indicating that the latter is a highly effective substrate for this enzyme.     

Evaluation of Restoration Techniques for the Succulent Karoo, South Africa

Abstract Possible constraints on the passive recovery of bare areas in the Karoo, a semiarid region in South Africa, include inadequate supply of seed, availability of suitable microsites for plant establishment, altered soil properties, and the truncation of key soil biotic processes. Here we investigate the possibility of initiating the restoration of bare areas by soil surface treatments with gypsum (CaSO₄) and/or organic mulch. We also apply an exogenous seed source to test the hypothesis that seed availability limits autogenic recovery. Both gypsum and mulch improved rain water infiltration, gypsum more so than mulch, and both treatments resulted in significantly higher numbers of reseeded seedlings compared with controls. Gypsum also improved the survival of the cohorts of seedlings of the larger seeded Tripteris sinuata. Tripteris showed the highest number of seedlings (maximum count of 150 seedlings/1,000 viable seeds sown) and surviving plants of the three reseeded species, which included two small‐seeded species, Ruschia spinosa and Chaetobromus dregeanus. Throughout the study period significantly higher plant volumes of naturally seeded annuals and perennials were recorded in the gypsum and/or mulch treatments compared with the controls. Germination and emergence of reseeded and naturally seeded plants appears to be determined by the availability of cool season (autumn to spring ) soil moisture, whereas follow‐up rainfall during this time is important for plant survival. Mulching of bare areas in the Succulent Karoo has the potential to re‐create vegetated areas that will further capture and conserve water, soil, and nutrients. Gypsum also showed positive results but might not be a cost‐effective option because of transport costs to these remote arid areas.     

A revision and key to the genera of Afrotropical Mantispidae (Neuropterida, Neuroptera), with the description of a new genus

The Afrotropical Mantispidae genera have previously been neglected and are poorly known. The genera are revised and redescribed. A new genus Afromantispa Snyman and Ohl is described with Afromantispa tenellacomb. n.as type species. Perlamantispa (Handschin, 1960) is synonymised with Sagittalata Handschin, 1959. The new combinations within the genus include Sagittalata austroafricacomb. n., Sagittalata bequaerticomb. n., Sagittalata dorsaliscomb. n., Sagittalata girardicomb. n., Sagittalata nubilacomb. n.,Sagittalata perlacomb. n.,Sagittalata pusillacomb. n., Sagittalata similatacomb. n., Sagittalata royicomb. n., Sagittalata tinctacomb. n. andSagittalata vasseicomb. n. An illustrated key to the genera Afromantispagen. n., Sagittalata Handschin, 1959, Mantispa Illiger, 1798, Cercomantispa Handschin, 1959, Rectinerva Handschin, 1959, Nampista Navás, 1914, and Pseudoclimaciella Handschin, 1960 is provided. The wing venation of Mantispidae is redescribed. Similarities between the genera are discussed. Subsequent studies will focus on revising the taxonomic status of species, which are not dealt with in this study.     

Monitoring of fluorescence during DNA melting as a method for discrimination and detection of PCR products in variety identification

DNA melting curves of genotype-specific PCR fragments were used to differentiate between species and amongst varieties of cereals. Melting curves were generated by ramping the temperature of PCR fragments through their dissociation temperature in the presence of a double-stranded DNA binding dye. Genotypes were discriminated by differences in the position and shape of the melting curve which is a function of the fragment's sequence, length and GC content. Amplification of 5S ribosomal RNA genes generated species-specific fragments for six of the major cereal crops. Of the 15 possible pairwise comparisons, 13 distinctions could be reliably made using melting curve position data. Wheat varieties were identified by the melting profiles of PCR products generated using microsatellite primers. DNA melting curve analysis was conveniently coupled with capillary-PCR using a LightCycler instrument to provide a rapid method of genotyping in cereals.     

Prednisolone enhances aminopeptidase turnover in adult rat small intestine

In adult male rats, fed prednisolone (0.75 mg/kg/day) for 7 days, brush border aminopeptidase activity was increased (P < 0.001) by 106% compared to pair-fed controls. [¹⁴C]Tyrosine was injected intraperitoneally 16 h and [³H]tyrosine 6 h before death. The ³H/¹⁴C ratio was 1.79 ± 0.21 (S.D.) in purified microvillus membranes from treated rats compared to 1.30 ± 0.16 (P < 0.01) in controls. Polyacrylamide gel electrophoresis of brush border membranes under denaturing conditions showed that the increased double-isotope ratio in membranes from treated rats was mainly in the high molecular weight protein subunits (> 80 kDa) Detergent-solubilized aminopeptidase was purified after in vivo labeling by protein A-Sepharose-antiaminopeptidase affinity chromatography. The ³H/¹⁴C ratio in aminopeptidase was 2.42 ± 0.15 (P < 0.05) in treated rats compared to 1.63 ± 0.13 in controls. Over the experimental period steady-state isotope reutilization and protein labeling was demonstrated and there was no isotope metabolism. Total microvillus membrane lipid content was unaffected by prednisolone. We conclude that prednisolone increases brush border aminopeptidase activity by increasing enzyme turnover. Other high molecular weight brush border proteins were similarly affected.