Response due to 0 somatic antigen ofShigella dysenteriae in rabbits

Zusammenfassung Hochgereinigtes Antigen vonShigella dysenteriae bewirkte eine signifikante Temperatursteigerung in Kaninchen.     

FKF1 is essential for photoperiodic-specific light signalling in Arabidopsis

Adaptation to seasonal change is a crucial component of an organism's survival strategy. To monitor seasonal variation, organisms have developed the capacity to measure day length (photoperiodism). Day-length assessment involves the photoperiodic control of flowering in Arabidopsis thaliana, whereby the coincidence of light and high expression of CONSTANS (CO) induces the expression of FLOWERING LOCUS T (FT), leading to flowering in long-day conditions. Although controlling CO expression is clearly a key step in day-length discrimination, the mechanism that generates day-length-dependent CO expression remains unknown. Here we show that the clock-controlled FLAVIN-BINDING, KELCH REPEAT, F-BOX (FKF1) protein has an essential role in generating the diurnal CO peak and that this function is dependent on light. We show that a recombinant FKF1 LIGHT, OXYGEN OR VOLTAGE (LOV) domain binds the chromophore flavin mononucleotide and undergoes light-induced photochemistry, indicating that FKF1 may function as a photoperiodic blue-light receptor. It is likely that the circadian control of FKF1 expression and the light regulation of FKF1 function coincide to control the daytime CO waveform precisely, which in turn is crucial for day-length discrimination by Arabidopsis.     

Biochemical changes of muscle proteins in goldfish (Carassius auratus) during thermal acclimatization

Zusammenfassung Kälteadaptierte Goldfische (Carassius auratus) bauen mehr Leuzin in Muskelproteine ein, wobei die Steigerung in verschiedenen Muskeleiweissfraktionen gleich ist. Aus kälteadaptierten Goldfischmuskeln ist mehr Myosin und sarkoplasmisches Eiweiss extrahierbar.     

Mutation of protein kinase A causes heterochronic development of Dictyostelium.

In heterochronic mutants the relative timing of developmental events is altered compared with the wild type. This generally results in a disordered embryo, though heterochronic mutations may also be an important source of evolutionary variation. In the rapidly developing (rde) mutants of Dictyostelium, stalk and spore cells differentiate before morphogenesis is complete. We have traced the lesion in one class of these mutants to the regulatory subunit of cyclic AMP-dependent protein kinase (pk-A). Inactivation of this protein results in the unrestrained activity of the catalytic subunit, so prematurely triggering terminal cell differentiation.     

A 41, XYY mouse

Summary Cytogenetic analyses of bone marrow and meiotic cells in an apparently normal male mouse clearly revealed the presence of an extra Y chromosome leading to 2n=41, XYY. During meiosis the sex chromosomes formed all possible types of combinations (XYY, XY/Y, YY/X and X/Y/Y). Compared to 40, XY normal mice, the sperm count was significantly less, but the incidence of sperm head abnormality was at the normal level.Acknowledgment. The authors are grateful to Prof. G. K. Manna, Department of Zoology, Kalyani University, for his valuable comments and Prof. M. C. Dash, School of Life Sciences, Sambalpur University for providing necessary facilities. Thankful acknowledgment to CSIR, India for a SRF awarded to RNK.     

The crystal structure of murrayazoline (Mahanimbidine,curryangin)

Riassunto La struttura del murrayazoline, un'alcoloide carbazole, é stata confermata per via cristallografica con i raggi X.