The evolutionary history of the amylase multigene family in Drosophila pseudoobscura

In Drosophila pseudoobscura, the amylase (Amy) multigene family is contained within a series of inversions, or gene arrangements, on the third chromosome. The Standard (ST), Santa Cruz (SC), and Tree Line (TL) inversions are central to the phylogeny of arrangements, and have clusters of other arrangements derived from them. The gene arrangements belonging to each of these three clusters have a characteristic number of Amy genes, ranging from three in ST to two in SC to one in TL. This distribution pattern can reflect a history of either duplications or deletions, although the data available in the past did not permit a decision between these alternatives. We provide unambiguous evidence that three Amy genes were present before the divergence of the ST, SC, and TL arrangements. Thus, the current status of the Amy multigene family is the result of deletions in the TL and SC arrangements, which created three new pseudogenes: TL Amy2-psi, TL Amy3-psi, and SC Amy3- psi. Analysis of pseudogene sequences revealed that, in the SC and ST arrangements, pseudogene evolution has been retarded, most likely due to the homogenization effect of gene conversion. Finally, by determining the original copy number, we have reconstructed the evolutionary history of the Amy multigene family and linked it with the evolution of the central gene arrangements.      

USE OF SENSORY EVALUATION FOR MEASURING DEODORIZING EFFECTS OF AN AIR CONDITIONER

The application of sensory methodology for measuring deodorizing effect of an air conditioner equipped with electric plasma was introduced. Deodorizing effect was measured using chemical and sensory methods at different time (0, 30 and 60 min) and mode (control, blowing and cooling) of an air conditioner. Smoke from a roll of cigarette in a closed room was used as a source of odor and the concentrations of acetic acid and ammonia were measured as odorous chemical components. As one of the sensory methods triangle test was used and as a first step to obtain deodorizing effects by triangle test, the threshold of each panelist was obtained as the log dilution ratio of odor concentration at which the difference from odorless air was detected. The odor concentration at each time and mode was calculated using the threshold of the panel and the deodorizing effect was obtained on the basis of the odor concentration. In addition to a triangle test, scaling methods such as category scaling or magnitude estimation were used to measure deodorizing effect of an air conditioner. Deodorizing effects by scaling methods were calculated based on odor intensity with time at each mode. The regression analysis was done between the efficacy of deodorizing effect by sensory test and those by acetic acid and ammonia, the R² values of the regression equations for triangle test, category scale, and magnitude estimation were 0.84, 0.72 and 0.69, respectively. Deodorizing effect by triangle test explained the decrease of acetic acid and ammonia better than those by category scaling or magnitude estimation while high cost and time consuming labor involved in triangle tests reduced the merit. The results of this study demonstrated that various sensory methods could be used to measure deodorizing effect of air conditioners and further researches on fast and reliable methods are needed to establish the official procedures.     

IgE formation in the rat following infection with Nippostrongylus brasiliensis. III. Soluble factor for the generation of IgE-bearing lymphocytes.

Normal rat bone marrow cells incubated with serum or lymph from Nippostrongylus brasiliensis (Nb)-infected rats showed an increase in the proportion of IgE-bearing cells in culture. This effect was produced in a similar fashion by cell-free supernatants (CFS) from cultures of mesenteric lymph node cells obtained from Nb-infected rats. The action of CFS on bone marrow cells appeared to be specific for the generation of IgE-bearing cells since the proportion of IgM-bearing cells in the culture did not change. The IgE-bearing cells in bone marrow cell cultures consisted of small lymphocytes, blast cells, and mast cells, and the addition of CFS to the cultures predominantly increased the number of IgE-bearing blast cells. CFS was also effective in increasing the proportion of IgE-bearing small lymphocytes in cultures of normal mesenteric lymph node cells. Removal of IgE in CFS by an anti-IgE immunosorbent did not affect the ability of CFS to generate IgE-bearing cells. The factor(s) in CFS responsible for this activity was shown to migrate with serum beta-globulins in zone electrophoresis and to possess a molecular size of between 10(4) and 2 X 10(4) m.w. The ability of CFS to generate IgE-bearing cells was diminished by treatment with the enzymes trypsin and ribonuclease A, but was unaffected by chymotrypsin.     

Cell division and sister chromatid exchanges in 45,X/46,X,i(Xq) mosaicism

Summary The kinetics of cell division and sister chromatid exchanges were studied in PHA-stimulated short-term cultivations of peripheral blood by means of the BUDR/FPG technique in controls and in five patients with 45,X/46,X,i(Xq) mosaicism. No significant differences in the length of the cell cycle were observed between 45,X/46,X,i(Xq) and control 46,XX cells. The number of SCE on late i(Xq) was only nonsignificantly elevated (0.6 per i(Xq)) against the value expected on the basis of its relative length.     

ENZYMATIC BIOSYNTHESIS OF ETHANOLAMINE- AND CHOLINE-PHOSPHOGLYCERIDES IN RETINA DURING DEVELOPMENT. EFFECT OF LIGHT STIMULATION

Choline- and ethanolamine-phosphoglycerides (CPG and EPG) are the most abundant phospholipids of retinal membranes. We have investigated some regulatory mechanisms involved in the final steps of their biosynthesis, namely those catalysed by CDP-choline 1,2 diradyl-sn-glycerol choline phosphotransferase (CPT) and CDP-ethanolamine 1,2 diradyl-sn-glycerol ethanolamine phosphotransferase (EPT). We have studied both enzymes in the retina which offers an excellent model for the investigation of the molecular basis of the effect of its physiological stimulus, the light. In chick retina. the specific activity (SA) of EPT reached a maximum at the 18th day of embryonic life and decreased thereafter. In the case of CPT, a similar peak of SA was observed at hatching. The time of maximum SA of EPT and CPT corresponded to the period during which retinal rod outer segments are formed. The apparent K_m values of EPT and CPT determined with whole retinal homogenates for CDP-bases showed different profiles. The apparent K_m of EPT decreased during embryonic life and increased thereafter whereas the apparent K_m of CPT did not change during ontogenesis. Light stimulation of calf retinal homogenates had different effects on phosphotransferase activities. In the presence of only endogenous diacylglycerol (DAG) the SA of CPT was 2-fold higher for dark-adapted retinas, whereas no differences in EPT activities were observed. After addition of exogenous DAG (4mM) to the incubation medium, light stimulation of the retina led to a 50% increase of EPT activity whereas no effect was observed for CPT. These different effects could be related to the cyclic nucleotides present in retina before and after light stimulation. In addition all the data presented in this study indicate that, as in brain, CPT and EPT in retina are two different enzymes.     

Heligmosomoides polygyrus: CD4+ but not CD8+ T cells regulate the IgE response and protective immunity in mice.

Oral inoculation of BALB/c mice with infective larvae of Heligmosomoides polygyrus resulted in chronic infection characterized by the release of parasite eggs in the feces for several months. The actual number of eggs per gram of feces was dependent on the dose of the inoculum. Serum IgE in infected mice peaked at a level of greater than 70 micrograms/ml during Weeks 3 through 6 following inoculation, and high levels of IgE (greater than 40 micrograms/ml) persisted for over 14 weeks. Protective immune responses resulted in reduced egg production and the development of markedly fewer adult worms in the small intestines following a challenge inoculation. The role of CD4+ and CD8+ T cells in these responses was examined by depletion in vivo of either T cell subpopulation with rat mAb specific for the appropriate determinants. Mice treated with anti-CD4 during a primary infection had increased EPG which was due primarily to an increase in worm fecundity (eggs produced per adult female). A challenge inoculation of mice that had been cleared of the primary infection with an anthelmintic drug induced a protective response that reduced development of new adult worms by 70-80% and their fecundity by greater than 90%. This protective response was abrogated by injection of mice with anti-CD4. Serum IgE diminished when adult worms were removed after anthelmintic treatment. A more precipitous drop in serum IgE followed successive treatments of mice with an anthelmintic and anti-CD4. In addition, the anamnestic serum IgE response to a challenge inoculation was reduced by over 80% in anti-CD4-treated mice. Anti-CD8 treatment had no appreciable effect on the immunological or parasitological parameters measured following a challenge inoculation with H. polygyrus. Thus, CD4+ T cells regulate host protective immunity, worm fecundity, and IgE levels in an H. polygyrus infection. This experimental system may be particularly suitable for analysis of chronic nematode infections of humans and livestock because of the responsiveness of the parasite in vivo to changes in host immune function.