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NIMA protein kinase is a major regulator of progression into mitosis in Aspergillus nidulans. Dominant negative forms of NIMA protein prevent entrance into mitosis in HeLa cells, suggesting that mammals have a similar pathway. We have reported previously the isolation of a murine NIMA-related kinase, designated Nek1, and more recently several additional NIMA-related human kinases have been cloned. The existence of several mammalian NIMA-related genes raises the questions of whether the di erent mammalian members have redundant, overlapping or distinct functions, and whether these functions are related to the role of NIMA in controlling mitosis. To address these questions we have studied the expression patterns of the di erent murine nek genes. To this end, we isolated a murine nek2 cDNA and compared its patterns of expression, during both gametogenesis and embryogenesis, to those of nek1. Both genes were highly expressed in developing germ cells, albeit in distinct patterns. In both females and males, nek1 is expressed much earlier than nek2, suggesting only limited ability for functional redundancy. Surprisingly, a striking speci®city of nek1 expression was found: high levels of nek1 RNA were observed in distinct regions of the nervous system, most notably in neurons of the peripheral ganglia. These patterns suggest that the di erent mammalian NIMA-related kinases participate in di erent phases of the meiotic process and may also have functions other than cell cycle control.

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Despite Pseudomonas aeruginosa antibiotic resistance, erythromycin (ERM, a macrolide) at subinhibitory concentration (sub-MIC) reduces its pathogenicity. We assessed ERM effects on P. aeruginosa in cultures containing choline (Ch) without and with 1% ethanol (Et) addition. Ch, as an osmoprotectant, increases the following virulence factors (VIFs): lectins (haemagglutination); proteases (casein and elastin lysis); haemolytic phospholipase C (PLC-H; haemolysis); pyocyanin (pigment o.d.) and autoinducers (violacein bioassay). Ethanol also increases lectins, proteases, pyocyanin, autoinducers and rhamnolipid (RHAL; haemolysis) formation, but reduces Ch-induced PLC and protease (elastase) activities. ERM has been shown to totally suppress the Et-induced VIFs, whereas partially reducing the Ch-induced ones. Unexpectedly, ERM combination with 1% Et dramatically annuls the Ch-induced factors. Et contribution might be attributed to its effect on cell membrane, displaying synergism with ERM, whereas antagonizing Ch osmoprotective potential and shifting gene expression. This information is worth further molecular investigation and clinical consideration for skin infection therapy.

The pattern of directed riboxin biosynthesis by Bucillus subtilis was studied in dependence on the cultivation conditions using the material-energy balance method (MEB).By means of comparative evaluation of experimental and theoretical values of physiological indices received from the MEB equations, we determined the key fermentation periods where it was necessary to change both aeration and mixing regimes. During the period of controled biosynthesis characteristics of self-regulation of the process have been observed, as expressed by periodical increases and decreases of glucose consumption rate and respiration intensity. The latter was inversely correlated to the velocity of riboxin synthesis and corresponded directly to changes of growth rate.