scholarly journals Phenotypic Analysis of the Dopa decarboxylase Gene Cluster Mutants in Drosophila melanogaster

1996 ◽  
Vol 87 (3) ◽  
pp. 175-190 ◽  
Author(s):  
T. R. F. Wright
Genetics ◽  
1995 ◽  
Vol 141 (2) ◽  
pp. 629-655 ◽  
Author(s):  
D G Stathakis ◽  
E S Pentz ◽  
M E Freeman ◽  
J Kullman ◽  
G R Hankins ◽  
...  

Abstract We report the complete molecular organization of the Dopa decarboxylase gene cluster. Mutagenesis screens recovered 77 new Df(2L)TW130 recessive lethal mutations. These new alleles combined with 263 previously isolated mutations in the cluster to define 18 essential genes. In addition, seven new deficiencies were isolated and characterized. Deficiency mapping, restriction fragment length polymorphism (RFLP) analysis and P-element-mediated germline transformation experiments determined the gene order for all 18 loci. Genomic and cDNA restriction endonuclease mapping, Northern blot analysis and DNA sequencing provided information on exact gene location, mRNA size and transcriptional direction for most of these loci. In addition, this analysis identified two transcription units that had not previously been identified by extensive mutagenesis screening. Most of the loci are contained within two dense subclusters. We discuss the effectiveness of mutagens and strategies used in our screens, the variable mutability of loci within the genome of Drosophila melanogaster, the cytological and molecular organization of the Ddc gene cluster, the validity of the one band-one gene hypothesis and a possible purpose for the clustering of genes in the Ddc region.


Genetics ◽  
1984 ◽  
Vol 106 (4) ◽  
pp. 679-694
Author(s):  
Denise Gilbert ◽  
Jay Hirsh ◽  
T R F Wright

ABSTRACT Nine lethal complementation groups flanking the Drosophila Dopa decarboxylase (Ddc) gene, have been localized within 100 kb of cloned chromosomal DNA. Six of these complementation groups are within 23 kb of DNA, and all ten complementation groups, including Ddc, lie within 78-82 kb of DNA. The potential significance of this unusually high gene density is discussed.


1995 ◽  
Vol 15 (5) ◽  
pp. 2367-2373 ◽  
Author(s):  
N Armes ◽  
M Fried

The Surf-3 gene of the unusually tight mouse Surfeit locus gene cluster has been identified as the highly conserved ribosomal protein gene L7a (rpL7a). The topography and juxtaposition of the Surfeit locus genes are conserved for the 600 million years of divergent evolution between mammals and birds. This suggests cis interaction and/or coregulation of the genes and suggests that, within this locus, gene organization plays an important role in gene expression. The further evolutionary conservation of the organization of the Surfeit locus was investigated. A cDNA encoding the Drosophila melanogaster homolog of the Surf-3/rpL7a gene was cloned, was shown to be present as a single copy, and was expressed constitutively at high levels throughout development. Genomic cosmid clones encompassing the gene and its surrounding DNA were isolated. The gene was determined to have five introns, of which two were located in the 5' untranslated region of the gene. The remaining three introns had splice sites at positions equivalent to those found in the Surf-3/rpL7a mammalian homologs. S1 analysis and 5' rapid amplification of cDNA ends both confirmed the start of transcription to occur in a polypyrimidine tract in the absence of a TATA box in the promoter. The genomic region around the Surf-3/rpL7a gene was analyzed by low-stringency hybridization with murine Surfeit gene probes, by partial sequence analysis, and by hybridization of fragments to Northern (RNA) blots. No homologs of other members of the Surfeit gene cluster were detected in close proximity to the D. melanogaster Surf-3/rpL7a gene. However, a gene which was detected directly 3' to the Surf-3/rpL7a gene was shown to encode a homolog of a mammalian serine-pyruvate aminotransferase.


1981 ◽  
Vol 1 (6) ◽  
pp. 475-485
Author(s):  
J Hirsh ◽  
N Davidson

We have isolated chromosomal deoxyribonucleic acid clones containing the Drosophila dopa decarboxylase gene. We describe an isolation procedure which can be applied to other nonabundantly expressed Drosophila genes. The dopa decarboxylase gene lies within or very near polytene chromosome band 37C1-2. The gene is interrupted by at least one intron, and the primary mode of regulation is pretranslational. At least two additional sequences hybridized by in vivo ribonucleic acid-derived probes are found within a 35-kilobase region surrounding the gene. The developmental profile of ribonucleic acid transcribed from one of these regions differs from that of the dopa decarboxylase transcript.


Science ◽  
1986 ◽  
Vol 234 (4779) ◽  
pp. 998-1002 ◽  
Author(s):  
S. Scholnick ◽  
S. Bray ◽  
B. Morgan ◽  
C. McCormick ◽  
J Hirsh

2013 ◽  
Vol 79 (6) ◽  
pp. 1923-1933 ◽  
Author(s):  
François P. Douillard ◽  
Angela Ribbera ◽  
Hanna M. Järvinen ◽  
Ravi Kant ◽  
Taija E. Pietilä ◽  
...  

ABSTRACTFourLactobacillusstrains were isolated from marketed probiotic products, includingL. rhamnosusstrains from Vifit (Friesland Campina) and Idoform (Ferrosan) andL. caseistrains from Actimel (Danone) and Yakult (Yakult Honsa Co.). Their genomes and phenotypes were characterized and compared in detail withL. caseistrain BL23 andL. rhamnosusstrain GG. Phenotypic analysis of the new isolates indicated differences in carbohydrate utilization betweenL. caseiandL. rhamnosusstrains, which could be linked to their genotypes. The two isolatedL. rhamnosusstrains had genomes that were virtually identical to that ofL. rhamnosusGG, testifying to their genomic stability and integrity in food products. TheL. caseistrains showed much greater genomic heterogeneity. Remarkably, all strains contained an intactspaCBApilus gene cluster. However, only theL. rhamnosusstrains produced mucus-binding SpaCBA pili under the conditions tested. Transcription initiation mapping demonstrated that the insertion of aniso-IS30element upstream of the pilus gene cluster inL. rhamnosusstrains but absent inL. caseistrains had constituted a functional promoter driving pilus gene expression. AllL. rhamnosusstrains triggered an NF-κB response via Toll-like receptor 2 (TLR2) in a reporter cell line, whereas theL. caseistrains did not or did so to a much lesser extent. This study demonstrates that the twoL. rhamnosusstrains isolated from probiotic products are virtually identical toL. rhamnosusGG and further highlights the differences between these andL. caseistrains widely marketed as probiotics, in terms of genome content, mucus-binding and metabolic capacities, and host signaling capabilities.


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