Identification of the coding region for the putidaredoxin reductase gene from the plasmid of Pseudomonas putida

The first 12 NH₂-terminal amino acids of the Pseudomonas putida putidaredoxin reductase were shown to be Met-Asn-Ala-Asn-Asp-Asn-Val-Val-Ile-Val-Gly-Thr. Comparison of these data with the DNA sequence of the BamHI-HindIII 197-base fragment derived from the PstI 2.2-kb fragment obtained from the P. putida plasmid showed that the putidaredoxin reductase gene was downstream from the cytochrome P-450 gene and the intergenic region had the 24-nucleotide sequence TAAACACATGGGAGTGCGTGCTAA. The Shine-Dalgarno sequence GGAG was detected in this region. The initiating triplet for the reductase gene was GTG, which normally codes for valine, but in the initiating codon position codes for methionine. From the amino acid sequence and X-ray data comparisons with other flavoproteins, what appears to be the AMP binding region of the FAD can be recognized in the NH₂-terminal portion of the reductase involving residues 5–35.This article was presented during the proceedings of the International Conference on Macromolecular Structure and Function, held at the National Defence Medical College, Tokorozawa, Japan, December 1985.     

New and noteworthy South American species of Agalinis (Scrophulariaceae)

Agalinis bandeirensis is a Brazilian species distinguished by linear bracts, short pedicels, and villous stamens.Agalinis ramulifera, from southern Brazil, is distinguished by many, short, leafy branches and small flowers.Agalinis linarioides subsp.rojasi, from Paraguay, is distinguished by paniculate inflorescences, short calyx lobes, and broad corollas.Gerardia bangii, G. digitalis, andG. meyeniana are recognized as species ofAgalinis and appropriate transfers are made.     

Two new species of Esterhazya (Scrophulariaceae) from Brazil

Barringer, Kerry (Department of Botany, Field Museum of Natural History, Chicago, IL 60605). Two new species of Esterhazya (Scrophulariaceae) from Brazil. Brittonia 37: 195–198. 1985.—Esterhazya petiolata is a distinctive species with ovate, petiolate leaves, spreading brances, and broadly tubular-campanulate flowers. It is known from the Serra Dourada of Goiás. Esterhazya eitenorum has narrow, lanceolate leaves, acute calyx lobes, and purple-pink flowers and is known from the planalto of Mt. Itatiaia.     

N-Acetyl-Aspartyl-Glutamate: Regional Levels in Rat Brain and the Effects of Brain Lesions as Determined by a New HPLC Method

Abstract: An isocratic HPLC method to measure endogenous N -acetyl-aspartyl-glutamate (NAAG) and N -acetyl-aspartate (NAA) is described. After removal of primary amines by passage of tissue extracts over AG-50 resin, the eluate was subject to HPLC anion-exchange analysis and eluted with phosphate buffer with absorbance monitored at 214 nm. The retention time for NAA was 5.6 min and for NAAG 11.4 min with a limit sensitivity of 0.1 nmol. The levels of NAA and NAAG were measured in 16 regions of rat brain and in heart and liver. NAAG was undetectable in heart and liver and exhibited 10-fold variation in concentration among brain regions; the highest levels were found in spinal cord. In contrast, low concentrations of NAA were detectable in heart and liver, and the regional distribution of NAA in brain varied only twofold. The regional distribution of NAA and NAAG correlated poorly. To assess the neuronal localization of these two compounds, the effects of selective brain lesions on their levels were examined. Decortication caused a 28% decrease in NAAG levels in the ipsi-lateral striatum while NAA decreased 38%. Kainate lesion of the striatum resulted in a 31% decrease in NAAG in the ipsilateral striatum, whereas NAA fell by 58%. Kainate lesion of the hippocampus resulted in significant decrements in NAAG and NAA in the hippocampus and septum. Transection of the spinal cord at midthorax resulted in a 51% decrease in NAAG levels immediately caudal and a 40% decrease immediately rostral to the lesion; however, NAA decreased only 30% in these areas. These results are consistent with a neuronal localization of NAAG in brain. Combined with the fact that NAAG interacts with a subpopulation of glutamate receptors, these results suggest that NAAG may serve as an excitatory neurotransmitter.     

Identification of the coding region for the putidaredoxin reductase gene from the plasmid of Pseudomonas putida

The first 12 NH₂-terminal amino acids of the Pseudomonas putida putidaredoxin reductase were shown to be Met-Asn-Ala-Asn-Asp-Asn-Val-Val-Ile-Val-Gly-Thr. Comparison of these data with the DNA sequence of the BamHI-HindIII 197-base fragment derived from the PstI 2.2-kb fragment obtained from the P. putida plasmid showed that the putidaredoxin reductase gene was downstream from the cytochrome P-450 gene and the intergenic region had the 24-nucleotide sequence TAAACACATGGGAGTGCGTGCTAA. The Shine-Dalgarno sequence GGAG was detected in this region. The initiating triplet for the reductase gene was GTG, which normally codes for valine, but in the initiating codon position codes for methionine. From the amino acid sequence and X-ray data comparisons with other flavoproteins, what appears to be the AMP binding region of the FAD can be recognized in the NH₂-terminal portion of the reductase involving residues 5–35.     

A new species of Daphnopsis (Thymelaeaceae) from Brazil

Daphnopsis filipedunculata, a new species from Serra dos Carajás, Pará, Brazil, is distinguished by its long, thin primary peduncles and constricted hypanthium.     

Monogamy in black vultures: genetic evidence from DNA fingerprinting

Recent research has indicated that avian mating systems maycommonly deviate from monogamy due to extrapair fertilizations(EPFs). Because the majority of avian species have long beenconsidered monogamous, accurate measurement of the frequencyof EPFs in a variety of species is important to enhance understandingof the evolution of avian mating systems. We used DNA fingerprintingto investigate the apparently monogamous mating system of blackvultures (Coragyps airaius) by assaying parentage within severalnuclear families. Monogamy is suggested in black vultures becausemated pairs exhibit long-term pair bonding and year-round association,and share incubation and nestling feeding duties equally. Thirtytwobreeders and 36 nestlings representing 16 complete nuclear familieswere tagged for individual identification and sampled for DNAanalysis using 2 restriction enzymes and 3 probes for hypervariableregions. Putative parents were assigned parentage in all cases.We empirically examined the probability of detecting EPFs bycomparing nestlings' fingerprints to those of a putative parentand another randomly chosen adult. All putative parents couldbe assigned with 95%confidence and all outside adults couldbe similarly excluded. There is therefore no evidence for successfulEPFs in this population, indicating a mating system that doesnot deviate from strict monogamy. The complex social behaviorof black vultures may eliminate the opportunity for EPFs dueto the prohibition of copulations in the presence of relatives.     

General practitioners' perceptions of the tolerability of antidepressant drugs: a comparison of selective serotonin reuptake inhibitors and tricyclic antidepressants.

OBJECTIVE: To examine inceptions and discontinuations of antidepressants in general practice. DESIGN: An observational study analysing data from an ongoing cross sectional postal survey. Every three months a representative sample of 250 doctors recorded prescribing activity for four weeks. This provided 4000 general practitioner weeks of recording per year. SETTING: A representative panel of general practitioners in England, Wales, and Scotland. SUBJECTS: Patients who began a new course of an antidepressant or had their treatment stopped or changed by the general practitioner between 1 July 1990 and 30 June 1995. MAIN OUTCOME MEASURES: Numbers of patients prescribed a new course of antidepressant; numbers discontinuing treatment; the ratio of antidepressant discontinuations to antidepressant inceptions; reasons for discontinuation; proportion of switches to another antidepressant. RESULTS: There were 13,619 inceptions and 3934 discontinuations of selective serotonin reuptake inhibitors and tricyclic antidepressants during the study. The number of newly prescribed courses of antidepressants increased by 116%, mostly due to an increase in prescribing of serotonin reuptake inhibitors. The ratio of total discontinuations to inceptions was significantly lower for serotonin reuptake inhibitors (22%) than for tricyclic antidepressants (33%). Differences persisted when controlled for age and sex of patients and severity of depression. However, there was more switching away from selective serotonin reuptake inhibitors when they failed (72%) than from tricyclic antidepressants (58%). CONCLUSIONS: Selective serotonin reuptake inhibitors are less likely than tricyclic antidepressants to be discontinued. A prospective study is needed in general practice to assess the implications of differences in discontinuation rates and switches on clinical and economic outcomes.