Potato Expressed Sequence Tag Generation and Analysis using Standard and Unique cDNA Libraries

To help develop an understanding of the genes that govern the developmental characteristics of the potato (Solanum tuberosum), as well as the genes associated with responses to specified pathogens and storage conditions, The Canadian Potato Genome Project (CPGP) carried out 5′ end sequencing of regular, normalized and full-length cDNA libraries of the Shepody potato cultivar, generating over 66,600 expressed sequence tags (ESTs). Libraries sequenced represented tuber developmental stages, pathogen-challenged tubers, as well as leaf, floral developmental stages, suspension cultured cells and roots. All libraries analysed to date have contributed unique sequences, with the normalized libraries high on the list. In addition, a low molecular weight library has enhanced the 3′ ends of our sequence assemblies. Using the combined assembly dataset, unique tuber developmental, cold storage and pathogen-challenged sequences have been identified. A comparison of the ESTs specific to the pathogen-challenged tuber and foliar libraries revealed minimal overlap between these libraries. Mixed assemblies using over 189,000 potato EST sequences from CPGP and The Institute for Genomics Research (TIGR) has revealed common sequences, as well as CPGP- and TIGR-unique sequences. Electronic Supplementary Material Electronic Supplementary material is available for this article at and accessible for authorised users.     

Social economics of childhood glucocorticoid stress response and health

This study examines socioeconomic conditions, psychosocial stress, and health among 264 infants, children, adolescents, and young adults aged 2 months to 18 years residing in a rural Caribbean village. Fieldwork was conducted over a 9 year period (1988–1996). Research methods and techniques include salivary cortisol radioimmunoassay (N = 22,438), systematic behavioral observations, psychological questionnaires, health evaluations, medical records, informal interviews, and participant observation. Analyses of data indicate complex relations among socioeconomic conditions, stress, and health. Household income, land ownership, parental education, and other socioeconomic measures are weakly associated with child illness. There is no evidence that apparent material benefits of high socioeconomic status—such as improved housing, diet, work loads, and access to private healthcare—have important direct effects on child health in this population. However, social relationships, especially family environment, may have important effects on childhood psychosocial stress and illness. Abnormal glucocorticoid response profiles, diminished immunity, and frequent illness are associated with unstable mating relationships of parents/caretakers and household composition. We suggest that family relationships and concomitant stress and immunosuppression are important intermediary links between socioeconomic conditions and child health. Am J Phys Anthropol 102:33–53, 1997. © 1997 Wiley-Liss, Inc.     

Tyrosine-specific MAPK phosphatases and the control of ERK signaling in PC12 cells

Background

Spatio-temporal control of extracellular signal-regulated kinase (ERK) activity, a critical determinant of the cell's response to growth factors, requires timely dephosphorylation of its regulatory tyrosine and/or threonine residue by MAPK phosphatases. We studied the physiological role of kinase interaction motif (KIM)-containing protein tyrosine phosphatases (PTPs) in the control of EGF- and NGF-induced ERK activity in neuroendocrine PC12 cells.

Results

We found a single KIM-containing PTP to be endogenously expressed in rat PC12 cells: the transmembrane PTPRR isoform termed PCPTP1. Protein knock-down of PCPTP1, or fourfold overexpression of its mouse orthologue, PTPBR7, left EGF- and NGF-induced ERK1/2 activity in PC12 cells unaltered. Ectopic expression of cytosolic PTPRR isoforms, however, resulted in reduced EGF-induced ERK1/2 activity, an effect that was dependent on the phosphatase activity and the KIM-domain of these PTPs.

Conclusion

The finding that robust changes in tyrosine-specific MAPK phosphatase expression levels have minor effects on temporal ERK1/2 activity control in PC12 cells suggests that dual-specificity MAPK phosphatases may act as major regulators of growth factor-induced ERK1/2 signaling in these cells.     

myc Boxes, Which Are Conserved in myc Family Proteins, Are Signals for Protein Degradation via the Proteasome

Cellular levels of the rapidly degraded c-myc protein play an important role in determining the proliferation status of cells. Increased levels of c-myc are frequently associated with rapidly proliferating tumor cells. We show here that myc boxes I and II, found in the N termini of all members of the myc protein family, function to direct the degradation of the c-myc protein. Both myc boxes I and II contain sufficient information to independently direct the degradation of otherwise stably expressed proteins to which they are fused. At least part of the myc box-directed degradation occurs via the proteasome. The mechanism of myc box-directed degradation appears to be conserved between yeast and mammalian cells. Our results suggest that the myc boxes may play an important role in regulating the level and activity of the c-myc protein.     

Biological control of Indianmeal moth (Lepidoptera: Pyralidae) on finished stored products using egg and larval parasitoids

Biological control using hymenopteran parasitoids presents an attractive alternative to insecticides for reducing infestations and damage from the Indianmeal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae), in retail and warehouse environments. We examined the potential for using combinations of the egg parasitoid Trichogramma deion Riley (Hymenoptera: Trichogrammatidae), and the larval parasitoid Habrobracon hebetor (Say) (Hymenoptera: Braconidae) for preventing infestations of P. interpunctella in coarse-ground cornmeal as well as the influence of packaging on parasitoid effectiveness. Treatments included one or both parasitoids and either cornmeal infested with P. interpunctella eggs or eggs deposited on the surface of plastic bags containing cornmeal. H. hebetor had a significant impact on the number of live P. interpunctella, suppressing populations by approximately 71% in both unbagged and bagged cornmeal. In contrast, T. deion did not suppress P. interpunctella in unbagged cornmeal. However, when released on bagged cornmeal, T. deion significantly increased the level of pest suppression (87%) over bagging alone (15%). When H. hebetor was added to bagged cornmeal, there was a significant reduction of live P. interpunctella compared with the control (70.6%), with a further reduction observed when T. deion was added (96.7%). These findings suggest that, in most situations, a combined release of both T. deion and H. hebetor would have the greatest impact; because even though packaging may protect most of the stored products, there are usually areas in the storage landscape where poor sanitation is present.     

Thrombolytic Therapy in Haemolytic-Uraemic Syndrome

The treatment of five children with the haemolytic-uraemic syndrome using streptokinase is described to illustrate the difficulties and limitations of thrombolytic therapy in this disease. This experience is germane to the design of multicentre clinical trials.A multivariate analysis relating clinical outcome to the data obtained at the time of admission was also carried out for 31 children with the disease treated in four centres. The results suggest that this technique may help to identify those patients likely to have a fatal outcome. An expanded form of this type of analysis should be incorporated in future clinical trials.     

A laser-based method for measuring thermal nociception of cattle

We describe a method for measuring nociception in cattle using a CO(2) laser aimed at the caudal aspect of the metatarsi. In Experiment 1, infrared thermography showed that calves responded by lifting their legs when skin temperatures reached 45-55 degrees C. In Experiment 2a, the validity of the method was tested by comparing the response latencies of 14 calves to two power settings (2.25 W vs. 4.5 W) with each setting being applied six times. We found that both leg-lift latencies and tail-flick latencies were lower at the higher power setting, and the calves were more likely to respond by kicking than by simply moving the leg. The standard deviations between and within calves were smaller at the higher power setting, and the large within-calf variation means that at least three tests were required to obtain reliable measures that could differentiate between calves. In Experiment 2b, application of the laser at a range of power settings (2.0, 3.0, 4.0, 4.5, 5.0 and 5.5 W) on 16 calves showed that response latencies decreased as power increased up to 4.5 W, after which no further change occurred. In Experiment 3, the repeatability of the method was evaluated on nine measures with the high power setting (4.5 W). The coefficient of variation associated with repetition of the measures was 36%. In general, we found little change in response latencies with repeated use of the laser, except that responses on the second test tended to be shorter. Experiment 4 showed that ambient temperatures between 16 degrees C and 27 degrees C did not affect response latencies, but these were longer at temperatures of 7 degrees C. We suggest that the method is a useful way of measuring cattle's sensitivity to nociception as the animals need not be restrained and the distance to the animal need not be closely controlled. However, to obtain accurate, valid and reliable measures it is necessary to use a high power setting (4.5 W) and take at least three consecutive measures of the response latency.