THE SPREAD OF BEET YELLOWS AND BEET MOSAIC VIRUSES IN THE SUGAR-BEET ROOT CROP I. FIELD OBSERVATIONS ON THE VIRUS DISEASES OF SUGAR BEET AND THEIR VECTORS MYZUS PERSICAE SULZ. AND APHIS FABAE KOCH

A survey of aphids and virus diseases of sugar-beet root crops in eastern England was made between 1940 and 1948. Prior to 1943 the observations were made on fertilizer experiments; from 1943 onwards they were made on commercial fields selected for position in relation to beet and mangold seed crops. The incidence of beet yellows increased with increasing numbers of Myzus persicae , but not of Aphis fabae. The relation with M. persicae was sufficiently close to suggest that it is the most important, possibly the only important, vector of beet yellows virus. Beet mosaic virus also increased with increasing numbers of M. persicae , but the relation was not close enough to exclude the possibility of other vectors.
Numbers of A. fabae on sugar beet were slightly, but consistently, depressed by the use of salt as a fertilizer. Other fertilizers had variable effects. Neither aphids nor virus are likely to be greatly affected by fertilizers.
Beet yellows is most prevalent in areas where seed crops are grown, but within these areas nearness to individual seed crops did not appear to increase its incidence. M. persicae were more numerous on sugar beet in seed-crop areas than elsewhere, and this alone might account for the prevalence of yellows. Beet mosaic virus is more closely associated with seed crops than is beet yellows. It is most prevalent near to seed crops within the seed-crop areas.     

SEPALLATA3: the 'glue' for MADS box transcription factor complex formation

Background  

Plant MADS box proteins play important roles in a plethora of developmental processes. In order to regulate specific sets of target genes, MADS box proteins dimerize and are thought to assemble into multimeric complexes. In this study a large-scale yeast three-hybrid screen is utilized to provide insight into the higher-order complex formation capacity of the Arabidopsis MADS box family. SEPALLATA3 (SEP3) has been shown to mediate complex formation and, therefore, special attention is paid to this factor in this study.     

Global transcriptional response of pig brain and lung to natural infection by Pseudorabies virus

Background  

Pseudorabies virus (PRV) is an alphaherpesviruses whose native host is pig. PRV infection mainly causes signs of central nervous system disorder in young pigs, and respiratory system diseases in the adult.     

Large-scale redistribution of maximum fisheries catch potential in the global ocean under climate change

Previous projection of climate change impacts on global food supply focuses solely on production from terrestrial biomes, ignoring the large contribution of animal protein from marine capture fisheries. Here, we project changes in global catch potential for 1066 species of exploited marine fish and invertebrates from 2005 to 2055 under climate change scenarios. We show that climate change may lead to large-scale redistribution of global catch potential, with an average of 30–70% increase in high-latitude regions and a drop of up to 40% in the tropics. Moreover, maximum catch potential declines considerably in the southward margins of semienclosed seas while it increases in poleward tips of continental shelf margins. Such changes are most apparent in the Pacific Ocean. Among the 20 most important fishing Exclusive Economic Zone (EEZ) regions in terms of their total landings, EEZ regions with the highest increase in catch potential by 2055 include Norway, Greenland, the United States (Alaska) and Russia (Asia). On the contrary, EEZ regions with the biggest loss in maximum catch potential include Indonesia, the United States (excluding Alaska and Hawaii), Chile and China. Many highly impacted regions, particularly those in the tropics, are socioeconomically vulnerable to these changes. Thus, our results indicate the need to develop adaptation policy that could minimize climate change impacts through fisheries. The study also provides information that may be useful to evaluate fisheries management options under climate change.     

Assessing deer densities and impacts at the appropriate level for management: a review of methodologies for use beyond the site scale

• 1 Population density alone is unlikely to be a good predictor of the impacts of deer on their environment. The assessment of management requirements should therefore be based on assessment of deer impacts, alongside estimates of density.
• 2 Both density and impacts need to be monitored at a landscape scale, and there is a need to develop appropriate methodologies that allow managers to consider the current and likely future impact of deer.
• 3 The relevant scale for assessment (and management) varies both with deer species and context of impact, but should always encompass at least the estimated biological range of the population of deer present in an area. Some impacts (e.g. deer–vehicle collisions, and risks of disease transmission) may need to be assessed at a wider regional level.
• 4 In this review we consider various approaches available for assessing: absolute or relative animal abundance; impacts of ungulates on agriculture, forestry, amenity woodlands and other conservation sites; impacts on public safety (e.g. through road traffic accidents) and on humans or livestock through potential spread of disease.
• 5 In each case the advantages and disadvantages of a variety of methods are considered, before recommendations are made for methodologies which are sufficiently accurate, sufficiently robust and sufficiently practical to be favoured in a management context.
• 6 To address impacts at the landscape scale requires management policies that integrate information on both positive and negative impacts of deer in order to ensure appropriate and holistic management. We present a decision‐support framework suitable for use within the UK, using inputs from a variety of possible impact types to assist managers and forewarn of situations where current management may need to be modified.

     

Case Study: Polycystic Livers in a Transgenic Mouse Line

Three mice (2 male, 1 female; age, 5 to 16 mo) from a mouse line transgenic for keratin 14 (K14)-driven LacZ expression and on an outbred Crl:CD1(ICR) background, were identified as having distended abdomens and livers that were diffusely enlarged by numerous cysts (diameter, 0.1 to 2.0 cm). Histopathology revealed hepatic cysts lined by biliary type epithelium and mild chronic inflammation, and confirmed the absence of parasites. Among 21 related mice, 5 additional affected mice were identified via laparotomy. Breeding of these 5 mice (after 5 mo of age) did not result in any offspring; the K14 mice with polycystic livers failed to reproduce. Affected male mice had degenerative testicular lesions, and their sperm was immotile. Nonpolycystic K14 control male mice bred well, had no testicular lesions, and had appropriate sperm motility. Genetic analysis did not identify an association of this phenotype with the transgene or insertion site.Abbreviations: K14, keratin 14 promoter; LacZ, bacterial β-galactosidase LacZ reporter; Lsamp, mouse limbic system-associated membrane proteinPolycystic disease is a multiorgan disorder and is the most common genetic life-threatening disease in people, affecting more than 600,000 Americans.¹⁶ Cystic liver disease in people typically is associated with polycystic kidney disease^22,36 but can exist in its absence. Currently, 2 autosomal dominant genes (PRKCSH and SEC63P) that cause a human polycystic liver disease condition without renal involvement have been identified.^4-6,13Numerous rodent models of polycystic kidneys with concurrent polycystic liver exist.^8,34,39,40 However, effective models of polycystic liver without polycystic kidneys would be useful to address clinical and mechanistic issues of polycystic liver not associated with polycystic kidneys.^6,31Here we report multiple cases of a spontaneous polycystic liver phenotype without a kidney phenotype in a transgenic mouse line. We also describe the effect of the transgene on disease expression and our attempts to develop this stock as an animal model.     

COMPARISON OF TWO BARLEY YELLOW-DWARF VIRUSES IN GLASSHOUSE AND FIELD EXPERIMENTS

Comparisons were made of the host ranges, interactions in infected plants, and effects on yields of cereals of two isolates of barley yellow-dwarf virus, one avirulent, RV, obtained from Rothamsted farm (Watson & Mulligan, 1956) and the other virulent, KV, obtained from Kent. They resembled each other and the American yellow-dwarf viruses in their ability to infect wild grasses but differences were found when the infection tests were made using inbred lines of the same grass species. KV infected one variety each of rice, rye and maize, and caused symptoms in each.
When plants were first infected with RV and later, when symptoms had fully developed, with KV, they suffered the same loss of yield from KV as did plants infected for the same length of time with KV alone. Therefore plants infected with RV were not protected against infection with KV. Similarly, aphids ( Rhopalosiphum padi L.), fed first on sources of RV and then on KV, transmitted mainly KV so there was no evidence of protection in the insect vectors.
Effects on yield of cereals were related to the time of appearance and intensity of symptoms. The effect of RV was not only less than that of KV but was also more variable.