Chargaff difference analysis of the bithorax complex of Drosophila melanogaster

1998 ◽  
Vol 76 (1) ◽  
pp. 129-137 ◽  
Author(s):  
Kha D Dang ◽  
Previn B Dutt ◽  
Donald R Forsdyke

Much of the fruit fly genome is compact ("Escherichia coli mode"), indicating a genome-wide selection pressure against DNA with little adaptive function. However, in the bithorax complex (BX-C) homeodomain genes are widely dispersed with large introns ("mammalian mode"). Chargaff difference analysis of compact bacterial and viral genomes has shown that most mRNAs have the potential to form stem-loop structures with purine-rich loops. Thus, for many taxa if transcription is to the right, the top (mRNA synonymous) DNA strand has purine-rich loop potential, and if transcription is to the left, the top (template) strand has pyrimidine-rich loop potential. The best indicator bases for transcription direction are A and T for AT-rich genomes, and C and G for CG-rich genomes. Consistent with this, Chargaff difference analysis of BX-C genes and several non-BX-C genes shows that, whatever the mode, mRNAs have the potential to form stem-loop structures with A-rich loops. We confirm that many potential open reading frames in the BX-C are unlikely to be functional. Conversely, we suggest that a few unassigned open reading frames may actually be functional. Since apparent organization in the mammalian mode cannot be explained in terms of unacknowledged open reading frames, yet the fruit fly genome is under pressure to be compact, it is likely that many BX-C functions do not involve the encoding of proteins.Key words: base ratios, base clusters, Chargaff's second parity rule, open reading frames, transcription direction, stem-loops.

2015 ◽  
Vol 59 (8) ◽  
pp. 4577-4583 ◽  
Author(s):  
Elena Gómez-Sanz ◽  
Sybille Schwendener ◽  
Andreas Thomann ◽  
Stefanie Gobeli Brawand ◽  
Vincent Perreten

ABSTRACTA methicillin-resistantmecB-positiveMacrococcus caseolyticus(strain KM45013) was isolated from the nares of a dog with rhinitis. It contained a novel 39-kb transposon-defective completemecB-carrying staphylococcal cassette chromosomemecelement (SCCmecKM45013). SCCmecKM45013contained 49 coding sequences (CDSs), was integrated at the 3′ end of the chromosomalorfXgene, and was delimited at both ends by imperfect direct repeats functioning as integration site sequences (ISSs). SCCmecKM45013presented two discontinuous regions of homology (SCCmeccoverage of 35%) to the chromosomal and transposon Tn6045-associated SCCmec-like element ofM. caseolyticusJCSC7096: (i) themecgene complex (98.8% identity) and (ii) theccr-carrying segment (91.8% identity). Themecgene complex, located at the right junction of the cassette, also carried the β-lactamase geneblaZm(mecRm-mecIm-mecB-blaZm). SCCmecKM45013contained two cassette chromosome recombinase genes,ccrAm2andccrBm2, which shared 94.3% and 96.6% DNA identity with those of the SCCmec-like element of JCSC7096 but shared less than 52% DNA identity with the staphylococcalccrABandccrCgenes. Three distinct extrachromosomal circularized elements (the entire SCCmecKM45013, ΨSCCmecKM45013lacking theccrgenes, and SCCKM45013lackingmecB) flanked by one ISS copy, as well as the chromosomal regions remaining after excision, were detected. An unconventional circularized structure carrying themecBgene complex was associated with two extensive direct repeat regions, which enclosed two open reading frames (ORFs) (ORF46 and ORF51) flanking the chromosomalmecB-carrying gene complex. This study revealedM. caseolyticusas a potential disease-associated bacterium in dogs and also unveiled an SCCmecelement carryingmecBnot associated with Tn6045in the genusMacrococcus.


2019 ◽  
Vol 8 (32) ◽  
Author(s):  
Yen-Te Liao ◽  
Yujie Zhang ◽  
Alexandra Salvador ◽  
Vivian C. H. Wu

Escherichia phage vB_EcoM-Sa45lw, a new member of the T4-like phages, was isolated from surface water in a produce-growing area. The phage, containing double-stranded DNA with a genome size of 167,353 bp and 282 predicted open reading frames (ORFs), is able to infect generic Escherichia coli and Shiga toxin-producing E. coli O45 and O157 strains.


Yeast ◽  
1998 ◽  
Vol 14 (6) ◽  
pp. 587-591 ◽  
Author(s):  
M. L. Agostoni Carbone ◽  
G. Lucchini ◽  
P. Melchioretto ◽  
V. Nardese ◽  
M. Vanoni ◽  
...  

2020 ◽  
Author(s):  
Sebastien A. Choteau ◽  
Audrey Wagner ◽  
Philippe Pierre ◽  
Lionel Spinelli ◽  
Christine Brun

ABSTRACTThe development of high-throughput technologies revealed the existence of non-canonical short open reading frames (sORFs) on most eukaryotic RNAs. They are ubiquitous genetic elements highly conserved across species and suspected to be involved in numerous cellular processes. MetamORF (http://metamorf.hb.univ-amu.fr/) aims to provide a repository of unique sORFs identified in the human and mouse genomes with both experimental and computational approaches. By gathering publicly available sORF data, normalizing it and summarizing redundant information, we were able to identify a total of 1,162,675 unique sORFs. Despite the usual characterization of ORFs as short, upstream or downstream, there is currently no clear consensus regarding the definition of these categories. Thus, the data has been reprocessed using a normalized nomenclature. MetamORF enables new analyses at loci, gene, transcript and ORF levels, that should offer the possibility to address new questions regarding sORF functions in the future. The repository is available through an user-friendly web interface, allowing easy browsing, visualization, filtering over multiple criteria and export possibilities. sORFs could be searched starting from a gene, a transcript, an ORF ID, or looking in a genome area. The database content has also been made available through track hubs at UCSC Genome Browser.


2020 ◽  
Vol 9 (22) ◽  
Author(s):  
Anastasia V. Popova ◽  
Mikhail M. Shneider ◽  
Yulia V. Mikhailova ◽  
Andrey A. Shelenkov ◽  
Dmitry A. Shagin ◽  
...  

ABSTRACT Acinetobacter myovirus BS46 was isolated from sewage by J. S. Soothill in 1991. We have sequenced the genome of BS46 and found it to be almost unique. BS46 contains double-stranded DNA with a genome size of 94,068 bp and 176 predicted open reading frames. The gene encoding the tailspike that presumably possesses depolymerase activity toward the capsular polysaccharides of the bacterial host was identified.


2005 ◽  
Vol 86 (7) ◽  
pp. 2019-2027 ◽  
Author(s):  
Frédérick Le Goff ◽  
Isabelle Méderlé-Mangeot ◽  
André Jestin ◽  
Patrick Langlois

In this study, the in vivo effect of the 3·6 kbp deletion of the three open reading frames (ORF) 9, 10 and 11 found at the right end of the CELO genome was examined. Groups of chickens were inoculated oronasally with 105–107 p.f.u. per animal of wild-type virus and two recombinant CELO strains (rCELO) expressing luciferase and secreted alkaline phosphatase (SEAP). The tissue biodistribution, assessed by PCR, was similar for both wild-type and recombinant viruses. The infectious viral particle titre was determined by a p.f.u. counting method and the antibody responses to the CELO vector and the SEAP antigen were evaluated by ELISA. Infectious particle titres in tissues from chickens inoculated with the wild-type CELO virus increased up to 6 days post-inoculation, and declined until 11 days while titres in organs from chickens inoculated with the rCELO strain were low and only detectable at 4 days post-inoculation. Moreover, although anti-CELO antibody levels were three times lower in sera from chickens inoculated with rCELO, antibodies directed to the heterologous SEAP antigen were detected. Based on these results, no differences in tropism were observed, but the level of production of viral particles and the humoral responses appeared to decrease. Viruses replicate less efficiently with a deletion performed at the right end of the CELO genome. Nevertheless, the presence of antibodies directed to heterologous antigens makes the CELO virus an advantageous candidate for avian vaccination.


2004 ◽  
Vol 382 (3) ◽  
pp. 867-875 ◽  
Author(s):  
Astrid BRUCKMANN ◽  
H. Yde STEENSMA ◽  
M. Joost TEIXEIRA de MATTOS ◽  
G. Paul H. van HEUSDEN

14-3-3 proteins form a family of highly conserved eukaryotic proteins involved in a wide variety of cellular processes, including signalling, apoptosis, cell-cycle control and transcriptional regulation. More than 150 binding partners have been found for these proteins. The yeast Saccharomyces cerevisiae has two genes encoding 14-3-3 proteins, BMH1 and BMH2. A bmh1 bmh2 double mutant is unviable in most laboratory strains. Previously, we constructed a temperature-sensitive bmh2 mutant and showed that mutations in RTG3 and SIN4, both encoding transcriptional regulators, can suppress the temperature-sensitive phenotype of this mutant, suggesting an inhibitory role of the 14-3-3 proteins in Rtg3-dependent transcription [van Heusden and Steensma (2001) Yeast 18, 1479–1491]. In the present paper, we report a genome-wide transcription analysis of a temperature-sensitive bmh2 mutant. Steady-state mRNA levels of 60 open reading frames were increased more than 2.0-fold in the bmh2 mutant, whereas those of 78 open reading frames were decreased more than 2.0-fold. In agreement with our genetic experiments, six genes known to be regulated by Rtg3 showed elevated mRNA levels in the mutant. In addition, several genes with other cellular functions, including those involved in gluconeogenesis, ergosterol biosynthesis and stress response, had altered mRNA levels in the mutant. Our data show that the yeast 14-3-3 proteins negatively regulate Rtg3-dependent transcription, stimulate the transcription of genes involved in ergosterol metabolism and in stress response and are involved in transcription regulation of multiple other genes.


2018 ◽  
Vol 6 (21) ◽  
Author(s):  
Casey Jang ◽  
Nancy Kalaj ◽  
Brian Hwang ◽  
Lorelei Hughes ◽  
Connie Yang ◽  
...  

ABSTRACT JangDynasty is a bacteriophage that infects Mycobacterium smegmatis mc2155. It has a genome length of 70,883 bp, with 124 predicted open reading frames (ORFs), 42 of which have known functions. JangDynasty belongs to cluster O, and like other cluster O phages, it is a siphovirus with a prolate capsid.


2015 ◽  
Vol 3 (6) ◽  
Author(s):  
F. Wu ◽  
Z. Zheng ◽  
X. Deng ◽  
Y. Cen ◽  
G. Liang ◽  
...  

The draft genome sequence of “ Candidatus Liberibacter asiaticus” strain YCPsy from an Asian citrus psyllid ( Diaphorina citri ) in Guangdong, China, is reported here. The YCPsy strain has a genome size of 1,233,647 bp, 36.5% G+C content, 1,171 open reading frames (ORFs), and 53 RNAs.


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