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WIP proteins form a plant specific subfamily of C2H2 zinc finger (ZF) proteins. In this study, we functionally characterized the WIP domain, which consists of four ZF motifs, and discuss molecular functions for WIP proteins. Mutations in each of the ZFs lead to loss of function of the TT1/WIP1 protein in Arabiopsis thaliana. SV40 type nuclear localisation signals were detected in two of the ZFs and functionally characterized using GFP fusions as well as new mutant alleles identified by TILLING. Promoter swap experiments showed that selected WIP proteins are partially able to take over TT1 function. Activity of the AtBAN promoter, a potential TT1 target, could be increased by the addition of TT1 to the TT2-TT8-TTG1 regulatory complex.
Seasonal, host sex and age-related variations in helminth egg and coccidian oocyst counts were investigated in a naturally infected wild bushbuck (Tragelaphus scriptus) population in Queen Elizabeth National Park, western Uganda from April 2000 to February 2002. The prevalence and mean intensity quantified as the number of eggs and oocysts per gram of faeces were taken as a measure of parasite burdens. Host sex and age-related differences in prevalence values were not found but the overall prevalence of Eimeria sp. was significantly higher during the rainy season, and peak counts were recorded either during or soon after a peak rainfall. A similar trend was observed for Moniezia spp., although the results were marginally not significant. There were also no significant differences in mean intensity values, relative to host sex, age or season.
Bushbuck (Tragelaphus scriptus) often deposit faeces at specific localised defecation sites (LDS). We tested whether LDS have a function in the context of parasite avoidance. In a population of bushbuck in Queen Elizabeth National Park, Uganda, seven radio-collared individuals were observed. We recorded feeding behaviour inside and outside LDS. Furthermore, pasture contamination with gastro-intestinal tract parasites inside and outside LDS was examined. There were significant differences between the expected and the observed feeding rates inside LDS, but, contrary to our prediction, the bushbuck increased their feeding rate inside LDS. There was no significant difference in the parasite contamination of pastures inside and outside LDS. We discuss the hypothesis that LDS mainly serve a social function in bushbuck communities, whereas parasite avoidance seems to play a minor or no role
While several authors suggest that bushbuck (Tragelaphus scriptus Pallas) from tropical areas with an approximately bimodal rainfall pattern breed throughout the year, there is also a report of seasonal breeding in this species. In this study, we provide indirect evidence of seasonality in reproduction by analysing behavioural data (e.g. rates of mixed-sex sightings) in a population of bushbuck inhabiting an equatorial savannah ecosystem in western Uganda. Observation rates of mixed-sex sightings were correlated with rainfall patterns. We suggest that peaks in reproductive behaviour following the wet season may be advantageous if calves are born during the next wet season, when fresh vegetation is available.
In most mammals, females are philopatric while males disperse in order to avoid inbreeding. We investigated social structure in a solitary ungulate, the bushbuck Tragelaphus sylvaticus in Queen Elizabeth National Park, Uganda by combining behavioural and molecular data. We correlated spatial and social vicinity of individual females with a relatedness score obtained from mitochondrial DNA analysis. Presumed clan members shared the same haplotype, showed more socio-positive interactions and had a common home range. Males had a higher haplotype diversity than females. All this suggests the presence of a matrilineal structure in the study population. Moreover, we tested natal dispersal distances between male and female yearlings and used control region sequences to confirm that females remain in their natal breeding areas whereas males disperse. In microsatellite analysis, males showed a higher genetic variability than females. The impoverished genetic variability of females at both molecular marker sets is consistent with a philopatric and matrilineal structure, while the higher degree of genetic variability of males is congruent with a higher dispersal rate expected in this sex. Evidence even for male long-distance dispersal is brought about by one male carrying a haplotype of a different subspecies, previously not described to occur in this area.
Integrative studies of plant growth require spatially and temporally resolved information from high-throughput imaging systems. However, analysis and interpretation of conventional two-dimensional images is complicated by the three-dimensional nature of shoot architecture and by changes in leaf position over time, termed hyponasty. To solve this problem, Phytotyping(4D) uses a light-field camera that simultaneously provides a focus image and a depth image, which contains distance information about the object surface. Our automated pipeline segments the focus images, integrates depth information to reconstruct the three-dimensional architecture, and analyses time series to provide information about the relative expansion rate, the timing of leaf appearance, hyponastic movement, and shape for individual leaves and the whole rosette. Phytotyping(4D) was calibrated and validated using discs of known sizes, and plants tilted at various orientations. Information from this analysis was integrated into the pipeline to allow error assessment during routine operation. To illustrate the utility of Phytotyping(4D), we compare diurnal changes in Arabidopsis thaliana wild-type Col-0 and the starchless pgm mutant. Compared to Col-0, pgm showed very low relative expansion rate in the second half of the night, a transiently increased relative expansion rate at the onset of light period, and smaller hyponastic movement including delayed movement after dusk, both at the level of the rosette and individual leaves. Our study introduces light-field camera systems as a tool to accurately measure morphological and growth-related features in plants.
Significance Statement Phytotyping(4D) is a non-invasive and accurate imaging system that combines a 3D light-field camera with an automated pipeline, which provides validated measurements of growth, movement, and other morphological features at the rosette and single-leaf level. In a case study in which we investigated the link between starch and growth, we demonstrated that Phytotyping(4D) is a key step towards bridging the gap between phenotypic observations and the rich genetic and metabolic knowledge.