Genome of the rainbow trout (Oncorhynchus mykiss) encodes two distinct muscle regulatory factors with homology to MyoD

Previously we identified a trout myogenic factor related to MyoD. We now present a cDNA encoding a novel trout myogenic factor (TMyoD2) expressed in embryonic muscle. Nucleotide analysis and amino acid comparison showed that this cDNA encodes a MyoD-like protein of 275 amino acids that is distinct but related to TMyoD with 78% identity over the entire length. The protein sequence conservation between TMyoD2 and TMyoD was calculated to be 90% within the basic/ helix-loop-helix domain that is involved in DNA binding and heterooligomerisation. At the nucleotide level, comparison of TMyoD with TMyoD2 reveals that the translated regions are flanked by highly divergent 3′ and 5′ ends. The substantial differences observed at translated and especially untranslated regions strongly suggest that TMyoD and TMyoD2 mRNA originate from different loci. The TMyoD and TMyoD2 mRNA are likely transcribed from two distinct genes which were duplicated during the tetraploïdization of the salmonid genome.     

Prenatal immunization for the protection of infants against whooping cough

Summary Prenatal immunization against whooping cough could, in theory at least, save the lives of infants. With this in view the present report outlines the results obtained when a group of mothers were immunized with whooping cough vaccine during pregnancy. The immunization procedures followed resulted in low agglutination titres in the mother and subsequently in the infant. As a result, it was necessary to arrange a different schedule of immunizations.     

Macromolecular binding equilibria in the lac repressor system: studies using high-pressure fluorescence spectroscopy

High hydrostatic pressure coupled with fluorescence polarization has been used to investigate protein subunit interactions and protein-operator association in lac repressor labeled with a long-lived fluorescent probe. On the basis of observation of a concentration-dependent sigmoidal decrease in the dansyl fluorescence polarization, we conclude that application of high hydrostatic pressure results in dissociation of the lac repressor tetramer. The 2-fold decrease in the rotational relaxation time and the high-pressure plateau are consistent with a tetramer to dimer transition. The volume change for tetramer dissociation to dimer is -82 +/- 5 mL/mol. The dissociation constant calculated from the data taken at 4.5 degrees C is 4.3 +/- 1.3 nM. The tetramer dissociation constant increases by a factor of 3 when the temperature is raised from 4.5 to 21 degrees C. A very small effect of inducer binding on the subunit dissociation is observed at 4.5 degrees C; the Kd increases from 4.5 to 7.1 nM. At 21 degrees C, however, inducer binding stabilizes the tetramer by approximately 0.8 kcal/mol. Pressure-induced monomer formation is indicated by the curves obtained upon raising the pH to 9.2. The addition of IPTG shifts the pressure transition to only slightly higher pressures at this pH, indicating that the stabilization of the tetramer by inducer is not as marked as that observed at pH 7.1. From the decrease in the polarization of the dansyl repressor-operator complexes, we also conclude that the application of pressure results their dissociation and that the volume change is large in absolute value (approximately 200 mL/mol). The lac repressor-operator complex is more readily dissociated upon the application of pressure than the tetramer alone, indicating that operator binding destabilizes the lac repressor tetramer.     

Activites proteolytiques et anti-trypsine des graines de Vigna unguiculata: Repartition et interaction

Data are given on distribution of caseolytic, BAPA-asic and anti-trypsin activities in albumins and globulins from embryos and cotyledons of Vigna seeds. Embryos are found to be richer in proteolytic enzymes than cotyledons. Trapping of anti-trypsin inhibitors solely enhances the albumin's caseolytic activities. Globulins do not show any BAPA-asic activity. The globulinic anti-trypsin inhibitors are similar on polyacrylamid gels (four fractions) whether the cotyledons or axes are used. The albuminic ones show one fraction more.