A boy with the whistling face syndrome or cranio-carpotarsal dysplasia is described. He had severely limited respiratory excursions, which apparently predisposed him to atelectasis and respiratory infections following general anesthetics. A review of the natural history and variability of the syndrome is presented.
A 4.0 kb fragment from a plasmid genomic DNA library of the marine bacterium Alteromonas haloplanktis ATCC 19855 was found in the presence of Na+ to complement the dagA gene of Escherichia coli. We have completely sequenced this fragment and the position of the Na(+)-linked D-alanine glycine permease gene (dagA) on the fragment has been determined by complementation. The predicted carrier protein consists of 542 amino acid residues (M(r) 58,955). Its hydropathy profile suggests it is composed of eight transmembrane segments with a long hydrophilic region between segments six and seven. Significant similarity has been found between this Na(+)-linked permease and the Na+/proline permeases of E. coli and Salmonella typhimurium and the human and rabbit intestinal Na+/glucose cotransporters.
The nudibranch Coryphella rufibranchialis (JOHNSTON) feeds on a variety of hydroids, including Tubularia larynx ELLIS & SOLANDF.R. Experiments in which density of prey and predators were altered showed that more prey were eaten as prey density increased. However, more prey were consumed at low predator densities, presumably because of mutual interference among nudibranchs at the higher predator densities. The number of prey consumed per nudibranch was maximal with low predator densities and a ratio of 25--50 polyps per predator.CorypheUa seems to show an opportunistic feeding strategy involving solitary predators rapidly depleting hydroid colonies and moving on to new colonies.
The transport of D-alanine by Escherichia coli K-12 neither requires nor is stimulated by Na+. The transport of D-alanine by the marine bacterium Alteromonas haloplanklis 214 requires Na+ specifically. Mutants of E. coli which were unable to transport D-alanine were isolated by enrichment for D-cycloserine resistance. One of the mutants was transformed with a gene bank of A. haloplanktis chromosomal DNA. Two transformants, E. coli RMl(pPMl) and E. coli RM1(pPM2) were able to transport D-alanine by a Na+-dependent mechanism. Li' and K' were unable to replace Na+. Both transformants contained chimeric plasmids with inserts which hybridized with A. haloplanklis but not E. coli chromosomal DNA or each other. Despite the lack of homology between the inserts, Na+-dependent D-alanine transport in the two transformants could not be distinguished either by kinetic studies or by differences in the capacity of various amino acids to compete for D-alanine uptake.Alteromonas haloplanktis 214 accumulates solutes by a Na+-solute symport mechanism energized by an electrochemical potential of Na+ ions (17), while a Na+-proton antiporter maintains a downhill gradient of Na+ into the cells (16). In these respects, the organism is similar to a number of other bacteria possessing Na+-dependent transport systems (11). A. haloplanktis 214 transports D-alanine, D-serine, glycine, ax-aminoisobutyric acid, and to a lesser extent L-alanine by a pathway that requires Na+ (8). A transport system serving for the entry of D-alanine, D-serine, and glycine is also found in Escherichia coli (3,20,26), but in this organism the accumulation of these amino acids is energized by an electrochemical potential of protons (1, 15). In a previous report, MacLeod et al. (13) described the preparation of a gene bank of A. haloplanktis chromosomal DNA and showed that various biosynthetic genes in the gene bank could be expressed in E. coli. In the present study, we isolated mutants of E. coli defective for D-alanine transport and used the gene bank to obtain transformants of one of these which transport D-alanine by a Na+-dependent mechanism. This is the first report of the cloning in E. coli of genes for Na+-dependent transport from a marine bacterium. The melB gene which codes for the Na+-driven transport camer for melibiose in E. coli has been cloned (25) and sequenced (27).
MATERIALS AND METHODSBacterial strains and culture conditions. E. coli K-12 E02717 (20) (F-hisGI purF) argHI thi-l dagA3 pyrBS9 ara-13 lacY) [ been investigated previously in this laboratory (10). E. coli strains were grown in either L broth (12) or M9 minimal medium (5) further supplemented with 5 mM adenine hydrochloride, 0.6 mM arginine hydrochloride, 0.1 mM histidine, 0.05 mM thiamine hydrochloride, and 0.01 mM * Corresponding author. 825 uracil and containing either 5 g of glycerol per liter (M9-glycerol medium) or 5 g of D-alanine per liter (M9-D-alanine medium) as carbon source. Ampicillin was also included at 50 ,ug/ml in L broth and at 25 pug/ml in M9 media when the media wer...
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