scholarly journals The Effects of Amino Acids on the Labellar Hair Chemosensory Cells of the Fly

1970 ◽  
Vol 56 (6) ◽  
pp. 768-782 ◽  
Author(s):  
Akio Shiraishi ◽  
Mastaro Kuwabara

The effects of amino acids on the labellar hair chemosensory cells were examined with two kinds of flies (the fleshfly, Boettcherisca peregrina, and the blowfly, Phormia regina). As a result of this examination, the effects of amino acids were divided into four main classes. Amino acids in class 1 did not stimulate any chemoreceptor cell. Amino acids in class 2 inhibited nonspecifically the discharges from three kinds of chemosensory cells. Amino acids in class 3 stimulated the salt receptor cell. Amino acids in class 4 stimulated the sugar receptor cell. A possibility that a fourth neuron in the labellar hair chemosensory cell might be a protein or an amino acid receptor cell was eliminated.

1973 ◽  
Vol 61 (1) ◽  
pp. 74-88 ◽  
Author(s):  
Nancy R. Goldrich

Behavioral responses to labellar stimulation with 19 L-amino acids were predicted on the basis of electrophysiological responses of largest labellar hairs. With the exceptions alanine, aspartic and glutamic acids, and valine tests of these predictions confirmed that Phormia can discriminate amino acids, and that these acids may be grouped according to their effects. Electrophysiological investigation of the four exceptions was repeated and results were consistent with the behavioral data. In particular, these acids elicited previously unreported responses from the salt receptor. The discrepancies between this and earlier studies may be explainable, in part, on methodological grounds. There was evidence for response differences among hairs of different sizes and among the largest labellar hairs themselves. The significance of amino acid discrimination for the problem of protein recognition can only be speculated upon until more complete electrophysiological and nutritional information is available.


2004 ◽  
Vol 67 (3) ◽  
pp. 589-597 ◽  
Author(s):  
Petrine Wellendorph ◽  
Kasper B. Hansen ◽  
Anders Balsgaard ◽  
Jeremy R. Greenwood ◽  
Jan Egebjerg ◽  
...  

1956 ◽  
Vol 34 (6) ◽  
pp. 527-532 ◽  
Author(s):  
Ernest Hodgson ◽  
Vernon H. Cheldelin ◽  
R. W. Newburgh

Phormia regina grown on a chemically defined diet under sterile conditions has been shown to have a specific dietary requirement for choline. The present work shows that carnitine and 2,2-dimethylaminoethanol can completely replace this in the diet whereas betaine is ineffective in this respect. Deletion of single amino acids from a mixture of 18 adequate for growth has previously shown the following 10 amino acids to be essential: arginine, histidine, leucine, lysine, phenylalanine, threonine, tryptophan, valine, proline, and isoleucine. The present work: shows by the inability of the organism to grow on these essential amino acids that this method is not adequate to detect amino acid combinations for which alternate requirements exist. By the deletion of groups of two or more amino acids it has been shown that P. regina has a dietary requirement for either methionine or cystine and for either glutamic acid or aspartic acid. Growth on the 10 essential amino acids is stimulated by yeast extract. This is apparently not due to a simple replacement of missing amino acids, since the addition of yeast creates an increased requirement for thiamine.


2001 ◽  
Vol 45 (2) ◽  
pp. 546-552 ◽  
Author(s):  
Laurent Poirel ◽  
Thierry Lambert ◽  
Salih Türkoglü ◽  
Esthel Ronco ◽  
Jean-Louis Gaillard ◽  
...  

ABSTRACT Two clonally unrelated Pseudomonas aeruginosa clinical strains, RON-1 and RON-2, were isolated in 1997 and 1998 from patients hospitalized in a suburb of Paris, France. Both isolates expressed the class B carbapenem-hydrolyzing β-lactamase VIM-2 previously identified in Marseilles in the French Riviera. In both isolates, thebla VIM-2 cassette was part of a class 1 integron that also encoded aminoglycoside-modifying enzymes. In one case, two novel aminoglycoside resistance gene cassettes,aacA29a and aacA29b, were located at the 5′ and 3′ end of the bla VIM-2 gene cassette, respectively. The aacA29a and aacA29b gene cassettes were fused upstream with a 101-bp part of the 5′ end of theqacE cassette. The deduced amino acid sequence AAC(6′)-29a protein shared 96% identity with AAC(6′)-29b but only 34% identity with the aacA7-encoded AAC(6′)-I1, the closest relative of the AAC(6′)-I family enzymes. These aminoglycoside acetyltransferases had amino acid sequences much shorter (131 amino acids) than the other AAC(6′)-I enzymes (144 to 153 amino acids). They conferred resistance to amikacin, isepamicin, kanamycin, and tobramycin but not to gentamicin, netilmicin, and sisomicin.


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