Ty1 insertions in intergenic regions of the genome of Saccharomyces cerevisiae transcribed by RNA polymerase III have no detectable selective effect

The retrotransposon Ty1 of Saccharomyces cerevisiae inserts preferentially into intergenic regions in the vicinity of RNA polymerase III-transcribed genes. It has been suggested that this preference has evolved to minimize the deleterious effects of element transposition on the host genome, and thus to favor their evolutionary survival. This presupposes that such insertions have no selective effect. However, there has been no direct test of this hypothesis. Here we construct a series of strains containing single Ty1 insertions in the vicinity of tRNA genes, or in the rDNA cluster on chromosome XII, which are otherwise isogenic to strain 337, containing zero Ty1 elements. Competition experiments between 337 and the strains containing single Ty1 insertions revealed that in all cases, the Ty1 insertions have no selective effect in rich medium. These results are thus consistent with the hypothesis that the insertion site preference of Ty1 elements has evolved to minimize the deleterious effects of transposition on the host genome.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72266/1/S1567-1356_03_00199-5.pd

Rising CO2 concentrations affect settlement behaviour of larval damselfishes

Reef fish larvae actively select preferred benthic habitat, relying on olfactory, visual and acoustic cues to discriminate between microhabitats at settlement. Recent studies show exposure to elevated carbon dioxide (CO2) impairs olfactory cue recognition in larval reef fishes. However, whether this alters the behaviour of settling fish or disrupts habitat selection is unknown. Here, the effect of elevated CO2 on larval behaviour and habitat selection at settlement was tested in three species of damselfishes (family Pomacentridae) that differ in their pattern of habitat use: Pomacentrus amboinensis (a habitat generalist), Pomacentrus chrysurus (a rubble specialist) and Pomacentrus moluccensis (a live coral specialist). Settlement-stage larvae were exposed to current-day CO2 levels or CO2 concentrations that could occur by 2100 (700 and 850 ppm) based on IPCC emission scenarios. First, pair-wise choice tests were performed using a two-channel flume chamber to test olfactory discrimination between hard coral, soft coral and coral rubble habitats. The habitat selected by settling fish was then compared among treatments using a multichoice settlement experiment conducted overnight. Finally, settlement timing between treatments was compared across two lunar cycles for one of the species, P. chrysurus. Exposure to elevated CO2 disrupted the ability of larvae to discriminate between habitat odours in olfactory trials. However, this had no effect on the habitats selected at settlement when all sensory cues were available. The timing of settlement was dramatically altered by CO2 exposure, with control fish exhibiting peak settlement around the new moon, whereas fish exposed to 850 ppm CO2 displaying highest settlement rates around the full moon. These results suggest larvae can rely on other sensory information, such as visual cues, to compensate for impaired olfactory ability when selecting settlement habitat at small spatial scales. However, rising CO2 could cause larvae to settle at unfavourable times, with potential consequences for larval survival and population replenishment

Serum markers CASA and CA 15-3 in ovarian cancer: All MUC1 assays are not the same

The serum MUC1 markers CASA and CA 15-3 were compared with CA 125 in the serum of patients with ovarian cancer and in pregnant women. Used individually, CASA and CA 15-3 gave sensitivities of 54 and 56% in pre-operative ovarian carcinoma (n = 50), though these were lower than with CA 125 (84%). CASA levels were elevated in 3 women with a negative CA 125, while CA 15-3 was elevated in 2 of these women. The combined use of CA 125 with CASA or CA 15-3 led to the preclinical detection of recurrence in 4/5 patients, with mean lead times of 3.6 and 4.3 months, respectively. Of particular interest was the marked difference in reactivity observed with CASA and CA 15-3 in some patients, despite both assays utilising monoclonal antibodies (MAbs) that react with the MUC1 mucin. CA 15-3 and CASA showed a lower than expected correlation in patients with ovarian cancer (r = 0.70), with some patients having high concentrations of one mucin marker and low concentrations of another. Furthermore, different marker profiles were observed when monitoring the progress of patients with these markers. Marked differences between CA 15-3 and CASA were also observed in the serum of pregnant women (n = 10), where CASA showed marked elevation (mean 33.6 times cutpoint) and CA 15-3 did not (mean 0.88 times cutpoint). These data suggest that the specificities of the MAbs used in these assays affect the glycoform of MUC1 detected, and that it should not be assumed that all MUC1 assays will behave in the same manner

Serum mucin antigens CASA and MSA in tumors of the breast, ovary, lung, pancreas, bladder, colon, and prostate: A blind trial with 420 patients

The tumor markers CASA (cancer-associated serum antigen) and MSA (mammary serum antigen) have previously been shown to be useful in the clinical management of ovarian and breast carcinoma, respectively, but have not been assessed in other types of cancer. These assays were compared with carcinoembryonic antigen (CEA) and prostate-specific antigen (PSA) in a blind trial using sera from the Mayo Clinic-National Cancer Institute (NCI) Diagnostic Serum Bank.CASA and MSA were assessed retrospectively in a blind trial using 465 serum samples from the Mayo Clinic-NCI Diagnostic Serum Bank representing malignant and benign disease of the breast, ovary, lung, pancreas, bladder, colon, and prostate and age-matched and gender-matched healthy control donors. CASA, MSA, and PSA levels were determined using commercially available kits, and CEA values and clinical details were later provided by the Mayo Clinic.CASA and MSA showed good reproducibility in 45 duplicate samples. CASA values were significantly elevated in the serum of patients with malignant tumors of the breast (44%), ovary (58%), lung (56%), prostate (48%), and bladder (54%), but not in those with benign conditions of these organs or pancreatic or colon cancer. MSA levels were only elevated significantly in cancers of the breast (52%) and ovary (58%). CASA showed significantly better sensitivity than either CEA (20%) or MSA (25%) in the detection of lung cancer, whereas CEA showed significantly superior detection of colon cancers (78%). CASA was not as sensitive as PSA in prostate cancer (48% versus 96%), but gave superior specificity in nonmalignant conditions of the prostate (93% versus 70%), although this was not statistically significant.The commercial CASA and MSA assays are reliable and reproducible tests for these tumor markers. In addition to ovarian cancer, CASA is also elevated significantly in many patients with breast, lung, prostate, and bladder cancer and has potential clinical use in patients with these tumors. The use of the MSA assay appears restricted to breast cancer

Evaluation of a capture screening enzyme-linked immunosorbent assay for combined determination of immunoglobulin M and G antibodies produced during Dengue infection.

A commercially available enzyme-linked immunosorbent assay (ELISA) (PanBio Dengue Screening ELISA) that utilized both immunoglobulin M (IgM) and IgG capture in the same microtiter well for the diagnosis of dengue infection was evaluated. Sensitivity in primary and secondary dengue was 95%, while specificity was 94%