Differential expression within a family of novel wound-induced genes in potato

Summary Wounding in higher plants leads to an increased synthesis of specific messenger RNAs. A cDNA clone complementary to a wound-induced message from potato tubers was used to isolate a lambda clone from a genomic library of Salanum tuberosum var. Maris Piper. DNA sequence analysis has shown that this single genomic clone contains two novel wound-induced genes, called win1 and win2, organised in close tandem array. The coding sequences of these two genes are highly homologous and are interrupted by a single intron. However, the sequences of the introns and flanking regions have diverged widely. Win1 and win2 encode cysteine-rich proteins of 200 and 211 amino-acids, respectively, which show striking homologies to several chitin-binding proteins. Southern analysis of genomic DNA has shown that win1 and win2 are members of a small multi-gene family which is estimated to have a minimum of five members per haploid genome of Maris Piper and appears to be conserved within the Solanaceae. We have shown by Northern analysis and S1 mapping that the two genes exhibit differential organ-specific expression after the wounding of a potato plant.     

T cells in murine lupus: propagation and regulation of disease

MRL/Mp-lpr/lpr mice develop a spontaneous lupus syndrome, including hypergammaglobulinemia, autoantibodies, glomerulonephritis, and lymphadenopathy. To investigate the role of lymphocyte subsets in the pathogenesis of disease, lupus-prone MRL mice deficient in T cells, T cells, or both were generated. Mice deficient in T cells developed a partially penetrant lupus syndrome, characterized by lymphadenopathy, elevated levels of class-switched immunoglobulins, an increased incidence of antinuclear antibodies, and immune deposits in kidneys which progressed to renal insufficiency over time. In comparison to wild type animals, T cell-deficient animals developed an accelerated and exacerbated disease phenotype, characterized by accelerated hypergammaglobulinemia and enhanced autoantibody production and mortality. Repertoire analysis of these latter animals identified polyclonal expansion (V) of CD4+B220-cells. Mice lacking both and T cells failed to generate class-switched autoantibodies and immune complex renal disease. First, these findings demonstrate that murine lupus in the setting of Fas-deficiency does not absolutely require the presence of T cells, and they also suggest that a significant basis for MRL/lpr disease, including renal disease, involves T cell-independent, T cell dependent, polyreactive B cell autoimmunity, upon which T cell-dependent mechanisms aggravate specific autoimmune responses. Second, these data indicate that T cells partake in the regulation of systemic autoimmunity, presumably via their effects on CD4+B220-T cells that provide B cell help. Finally, these results demonstrate that MRL/lpr B cells, despite their intrinsic abnormalities, cannot per se cause tissue injury without T cell help.Abbreviations snRNPs small nuclear ribonucleoprotein particles     

Localization of sequences regulating ancestral and acquired sites of esterase6 activity in Drosophila melanogaster

We have broadly defined the DNA regions regulating esterase6 activity in several life stages and tissue types of D. melanogaster using P- element-mediated transformation of constructs that contain the esterase6 coding region and deletions or substitutions in 5' or 3' flanking DNA. Hemolymph is a conserved ancestral site of EST6 activity in Drosophila and the primary sequences regulating its activity lie between -171 and -25 bp relative to the translation initiation site: deletion of these sequences decrease activity approximately 20-fold. Hemolymph activity is also modulated by four other DNA regions, three of which lie 5' and one of which lies 3' of the coding region. Of these, two have positive and two have negative effects, each of approximately twofold. Esterase6 activity is present also in two male reproductive tract tissues; the ejaculatory bulb, which is another ancestral activity site, and the ejaculatory duct, which is a recently acquired site within the melanogaster species subgroup. Activities in these tissues are at least in part independently regulated: activity in the ejaculatory bulb is conferred by sequences between -273 and -172 bp (threefold decrease when deleted), while activity in the ejaculatory duct is conferred by more distal sequences between -844 and -614 bp (fourfold decrease when deleted). The reproductive tract activity is further modulated by two additional DNA regions, one in 5' DNA (-613 to -284 bp; threefold decrease when deleted) and the other in 3' DNA (+1860 to +2731 bp; threefold decrease when deleted) that probably overlaps the adjacent esteraseP gene. Collating these data with previous studies suggests that expression of EST6 in the ancestral sites is mainly regulated by conserved proximal sequences while more variable distal sequences regulate expression in the acquired ejaculatory duct site.      

Risk of breast cancer in relation to the interval since last full term pregnancy.

OBJECTIVE--To examine whether the risk of breast cancer is increased by a recent term pregnancy. DESIGN--Population based case-control study. SETTING--Eight areas in the United States. SUBJECTS--Cases were 2279 multiparous women residents of the eight areas aged 25-49 who were diagnosed as having breast cancer during 1980-2. Controls were 2357 multiparous women selected from the same areas by random digit dialing. MAIN OUTCOME MEASURE--Relative risk of developing breast cancer according to the time interval since last full term pregnancy. RESULTS--The distribution of intervals since the last term pregnancy was similar in cases and controls. Adjusted for age, parity, and age at first term pregnancy, the odds ratios observed for categories of years since the last full term pregnancy were: 0-2 years, odds ratio 1.16 (95% confidence interval 0.84 to 1.59); 3-6 years, odds ratio 1.21 (0.95 to 1.54); 7-9 years, odds ratio 1.04 (0.84 to 1.38); > or = 10 years, odds ratio 1.00 (reference). CONCLUSIONS--Among multiparous women aged 25-49 years there was no association between the risk of breast cancer and the time interval since the last full term pregnancy.     

Changes in Sympathetic Nerve Terminals in the Heart of Cold-Exposed Rats

Abstract: Changes in sympathetic nerve terminals of the heart after varying periods of exposure of rats to 4°C were investigated. Two indices were used for changes in the number of noradrenaline storage vesicles, i.e., vesicular dopamine β-hydroxylase (DBH) activity and noradrenaline storage capacity. The latter was obtained after uptake of [³H]noradrenaline; endogenous content, uptake of exogenous noradrenaline, and degree of saturation of the vesicles were calculated using the specific activity of the [³H]noradrenaline. As a measure of tyrosine hydroxylase activity, whole ventricular noradrenaline, dopamine, and dihydroxyphenylacetic acid content were used. After 4 h of cold exposure there was an increase in vesicular endogenous noradrenaline content, uptake, storage capacity, and DBH activity as well as a large increase in whole ventricular dopamine. After 6 h in the cold, vesicular endogenous noradrenaline content, storage capacity, and DBH activity were decreased. The results suggest that during cold exposure there is an initial increase followed by a decrease in the number of functional vesicles in the nerve terminal, which could explain the fluctuations in the rate of noradrenaline release.     

The Computerized Laboratory Notebook concept for genetic toxicology experimentation and testing

We describe a microcomputer system utilizing the Computerized Laboratory Notebook (CLN) concept developed in our laboratory for the purpose of automating the Battery of Leukocyte Tests (BLT). The BLT was designed to evaluate blood specimens for toxic, immunotoxic, and genotoxic effects after in vivo exposure to putative mutagens. A system was developed with the advantages of low cost, limited spatial requirements, ease of use for personnel inexperienced with computers, and applicability to specific testing yet flexibility for experimentation. This system eliminates cumbersome record keeping and repetitive analysis inherent in genetic toxicology bioassays. Statistical analysis of the vast quantity of data produced by the BLT would not be feasible without a central database. Our central database is maintained by an integrated package which we have adapted to develop the CLN. The clonal assay of lymphocyte mutagenesis (CALM) section of the CLN is demonstrated. PC-Slaves expand the microcomputer to multiple workstations so that our computerized notebook can be used next to a hood while other work is done in an office and instrument room simultaneously. Communication with peripheral instruments is an indispensable part of many laboratory operations, and we present a representative program, written to acquire and analyze CALM data, for communicating with both a liquid scintillation counter and an ELISA plate reader. In conclusion we discuss how our computer system could easily be adapted to the needs of other laboratories.     

Intraspecific diversity in the fungal speciesChaunopycnis alba: Implications for microbial screening programs

Intraspecific variation among 84 isolates of the anamorphic fungusChaunopycnis alba from 26 different geographical locations was analyzed by investigating optimal growth temperatures, differences in the production of secondary metabolites and presence or absence of the cyclosporin synthetase gene. The genetic diversity was assessed using random amplified polymorphic DNA (RAPD). Analysis of these data showed high genetic, metabolic and physiological diversity within this species. Isolates from the Antarctic represented the most homogeneous group withinC. alba and together with isolates from the Arctic these polar strains differed from alpine, temperate and tropical strains by low optimal growth temperatures and by low production of secondary metabolites. Isolates from tropical climes were characterized by high optimal growth temperatures and by the production of comparatively diverse metabolite spectra. Most of the isolates that were similar in the combination of their physiological and metabolic characters were also genetically related. Isolates from different geographical origins did not show many similarities, with the exception of the cyclosporin A-producing isolates, and large diversity could be observed even within a single habitat. This leads us to the suggestion that for pharmaceutical screening programs samples should be collected from a diversity of different geographical and climatic locations. For the selection of strains for screening the RAPD assay seems to be the most powerful tool. It reflected the highest intraspecific diversity and the results corresponded well with the other characteristics.