scholarly journals Ultraconserved non-coding DNA within insect phyla

2019 ◽  
Author(s):  
Thomas Brody ◽  
Amar Yavatkar ◽  
Alexander Kuzin ◽  
Ward F. Odenwald

Abstract Background Presence of ultra-conserved sequence elements in vertebrate enhancers suggest that transcription factor regulatory interactions are shared across phylogenetically diverse species. To date evidence for similarly conserved elements among evolutionarily distant insects such as flies, mosquitos, ants and bees, has been elusive. This study has taken advantage of the availability of the assembled genomic sequence of these insects to explore the presence of ultraconserved sequence elements in these phylogenetic groups.Results To investigate the integrity of fly regulatory sequences across ~100 million years of evolutionary divergence from the fruitfly Drosophila melanogaster , we compared Drosophila non-coding sequences to those of Ceratitis capitata , the Mediterranean fruit fly and Musca domestica , the domestic housefly. Using various alignment techniques, Blastn, Clustal, Blat, EvoPrinter and Needle, we show that many of the conserved sequence blocks (CSBs) that constitute Drosophila cis -regulatory DNA, recognized by EvoPrinter alignment protocols, are also conserved in Ceratitis and Musca . We term the sequence elements shared among these species ultraconserved CSBs (uCSBs). The position of the uCSBs with respect to flanking genes is also conserved. Blastn alignments also detect putative cis -regulatory sequences shared among evolutionarily distant mosquitos Anopheles gambiae and Culex pipiens and Aedes aegypti. We have also identified conserved sequences shared among bee species. Side by side comparison of bee and ant EvoPrints identify uCSBs shared between the two taxa, as well as more poorly conserved CSBs in either one or the other taxon but not in both.Conclusions The results suggest that CSBs represent the point of interaction of multiple trans-regulators whose functions and interactions are conserved across divergent genera. Analysis of uCSBs in dipterans, mosquitos and bees will lead to a greater understanding of their evolutionary origin and the function of their conserved non-coding sequences.

2019 ◽  
Author(s):  
Thomas Brody ◽  
Amar Yavatkar ◽  
Alexander Kuzin ◽  
Ward F. Odenwald

AbstractPresence of ultra-conserved sequence elements in vertebrate enhancers suggest that transcription factor regulatory interactions are shared across phylogenetically diverse species. To date evidence for similarly conserved elements among evolutionarily distant insects such as flies, mosquitos, ants and bees, has been elusive. This study has taken advantage of the availability of the assembled genomic sequence of these insects to explore the presence of ultraconserved sequence elements in these phylogenetic groups. To investigate the integrity of fly regulatory sequences across ~100 million years of evolutionary divergence from the fruitfly Drosophila melanogaster, we compared Drosophila non-coding sequences to those of Ceratitis capitata, the Mediterranean fruit fly and Musca domestica, the domestic housefly. Using various alignment techniques, Blastn, Clustal, Blat, EvoPrinter and Needle, we show that many of the conserved sequence blocks (CSBs) that constitute Drosophila cis-regulatory DNA, recognized by EvoPrinter alignment protocols, are also conserved in Ceratitis and Musca. We term the sequence elements shared among these species ultraconserved CSBs (uCSBs). The position of the uCSBs with respect to flanking genes is also conserved. The results suggest that CSBs represent the point of interaction of multiple trans-regulators whose functions and interactions are conserved across divergent genera. Blastn alignments also detect putative cis-regulatory sequences shared among evolutionarily distant mosquitos Anopheles gambiae and Culex pipiens and Aedes aegypti. We have also identified conserved sequences shared among bee species. Side by side comparison of bee and ant EvoPrints identify uCSBs shared between the two taxa, as well as more poorly conserved CSBs in either one or the other taxon but not in both. Analysis of uCSBs in dipterans, mosquitos and bees will lead to a greater understanding of their evolutionary origin and the function of their conserved sequences.


2020 ◽  
Vol 10 (9) ◽  
pp. 3015-3024 ◽  
Author(s):  
Thomas Brody ◽  
Amarendra Yavatkar ◽  
Alexander Kuzin ◽  
Ward F Odenwald

Abstract This study has taken advantage of the availability of the assembled genomic sequence of flies, mosquitos, ants and bees to explore the presence of ultraconserved sequence elements in these phylogenetic groups. We compared non-coding sequences found within and flanking Drosophila developmental genes to homologous sequences in Ceratitis capitata and Musca domestica. Many of the conserved sequence blocks (CSBs) that constitute Drosophila cis-regulatory DNA, recognized by EvoPrinter alignment protocols, are also conserved in Ceratitis and Musca. Also conserved is the position but not necessarily the orientation of many of these ultraconserved CSBs (uCSBs) with respect to flanking genes. Using the mosquito EvoPrint algorithm, we have also identified uCSBs shared among distantly related mosquito species. Side by side comparison of bee and ant EvoPrints of selected developmental genes identify uCSBs shared between these two Hymenoptera, as well as less conserved CSBs in either one or the other taxon but not in both. Analysis of uCSBs in these dipterans and Hymenoptera will lead to a greater understanding of their evolutionary origin and function of their conserved non-coding sequences and aid in discovery of core elements of enhancers. This study applies the phylogenetic footprinting program EvoPrinter to detection of ultraconserved non-coding sequence elements in Diptera, including flies and mosquitos, and Hymenoptera, including ants and bees. EvoPrinter outputs an interspecies comparison as a single sequence in terms of the input reference sequence. Ultraconserved sequences flanking known developmental genes were detected in Ceratitis and Musca when compared with Drosophila species, in Aedes and Culex when compared with Anopheles, and between ants and bees. Our methods are useful in detecting and understanding the core evolutionarily hardened sequences required for gene regulation.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ami Shah ◽  
Madison Ratkowski ◽  
Alessandro Rosa ◽  
Paul Feinstein ◽  
Thomas Bozza

AbstractOlfactory sensory neurons express a large family of odorant receptors (ORs) and a small family of trace amine-associated receptors (TAARs). While both families are subject to so-called singular expression (expression of one allele of one gene), the mechanisms underlying TAAR gene choice remain obscure. Here, we report the identification of two conserved sequence elements in the mouse TAAR cluster (T-elements) that are required for TAAR gene expression. We observed that cell-type-specific expression of a TAAR-derived transgene required either T-element. Moreover, deleting either element reduced or abolished expression of a subset of TAAR genes, while deleting both elements abolished olfactory expression of all TAARs in cis with the mutation. The T-elements exhibit several features of known OR enhancers but also contain highly conserved, unique sequence motifs. Our data demonstrate that TAAR gene expression requires two cooperative cis-acting enhancers and suggest that ORs and TAARs share similar mechanisms of singular expression.


Microbiology ◽  
2006 ◽  
Vol 152 (9) ◽  
pp. 2515-2528 ◽  
Author(s):  
M. Sofia Ciampi

Rho-dependent transcription terminators participate in sophisticated genetic regulatory mechanisms, in both bacteria and phages; they occur in regulatory regions preceding the coding sequences of genes and within coding sequences, as well as at the end of transcriptional units, to prevent readthrough transcription. Most Rho-dependent terminators have been found in enteric bacteria, but they also occur in Gram-positive bacteria and may be widespread among bacteria. Rho-dependent termination requires both cis-acting elements, on the mRNA, and trans-acting factors. The only cis-acting element common to Rho-dependent terminators is richness in rC residues. Additional sequence elements have been observed at different Rho termination sites. These ‘auxiliary elements' may assist in the termination process; they differ among terminators, their occurrence possibly depending on the function and sequence context of the terminator. Specific nucleotides required for termination have also been identified at Rho sites. Rho is the main factor required for termination; it is a ring-shaped hexameric protein with ATPase and helicase activities. NusG, NusA and NusB are additional factors participating in the termination process. Rho-dependent termination occurs by binding of Rho to ribosome-free mRNA, C-rich sites being good candidates for binding. Rho's ATPase is activated by Rho–mRNA binding, and provides the energy for Rho translocation along the mRNA; translocation requires sliding of the message into the central hole of the hexamer. When a polymerase pause site is encountered, the actual termination occurs, and the transcript is released by Rho's helicase activity. Many aspects of this process are still being studied. The isolation of mutants suppressing termination, site-directed mutagenesis of cis-acting elements in Rho-dependent termination, and biochemistry, are and will be contributing to unravelling the still undefined aspects of the Rho termination machinery. Analysis of the more sophisticated regulatory mechanisms relying on Rho-dependent termination may be crucial in identifying new essential elements for termination.


2019 ◽  
Author(s):  
Juan C. Villada ◽  
Maria F. Duran ◽  
Patrick K. H. Lee

Understanding the interplay between genotype and phenotype is a fundamental goal of functional genomics. Methane oxidation is a microbial phenotype with global-scale significance as part of the carbon biogeochemical cycle, and is a sink for greenhouse gas. Microorganisms that oxidize methane (methanotrophs) are taxonomically diverse and widespread around the globe. Recent reports have suggested that type Ia methanotrophs are the most prevalent methane-oxidizing bacteria in different environments. In methanotrophic bacteria, complete methane oxidation is encoded in four operons (pmoCAB, mmoXYZBCD, mxaFI, andxoxF), but how evolution has shaped these genes to execute methane oxidation remains poorly understood. Here, we used a genomic meta-analysis to investigate the coding sequences that encode methane oxidation. By analyzing isolate and metagenome-assembled genomes from phylogenetically and geographically diverse sources, we detected an anomalous nucleotide composition bias in the coding sequences of particulate methane monooxygenase genes (pmoCAB) from type Ia methanotrophs around the globe. We found that this was a highly conserved sequence that optimizes codon usage in order to maximize translation efficiency and accuracy, while minimizing the synthesis cost of transcripts and proteins. We show that among the seven types of methanotrophs, only type Ia methanotrophs possess a unique coding sequence of thepmoCABoperon that is under positive selection for optimal resource allocation and efficient synthesis of transcripts and proteins in environmental counter gradients with high oxygen and low methane concentrations. This adaptive trait possibly enables type Ia methanotrophs to respond robustly to fluctuating methane availability and explains their global prevalence.


2001 ◽  
Vol 2 (4) ◽  
pp. 226-235 ◽  
Author(s):  
Amanda Cottage ◽  
Yvonne J. K. Edwards ◽  
Greg Elgar

As a result of genome, EST and cDNA sequencing projects, there are huge numbers of predicted and/or partially characterised protein sequences compared with a relatively small number of proteins with experimentally determined function and structure. Thus, there is a considerable attention focused on the accurate prediction of gene function and structure from sequence by using bioinformatics. In the course of our analysis of genomic sequence fromFugu rubripes, we identified a novel gene,SAND, with significant sequence identity to hypothetical proteins predicted inSaccharomyces cerevisiae, Schizosaccharomyces pombe, Caenorhabditis elegans, aDrosophila melanogastergene, and mouse and human cDNAs. Here we identify a furtherSANDhomologue in human andArabidopsis thalianaby use of standard computational tools. We describe the genomic organisation ofSANDin these evolutionarily divergent species and identify sequence homologues from EST database searches confirming the expression of SAND in over 20 different eukaryotes. We confirm the expression of two different SAND paralogues in mammals and determine expression of one SAND in other vertebrates and eukaryotes. Furthermore, we predict structural properties of SAND, and characterise conserved sequence motifs in this protein family.


2002 ◽  
Vol 79 (2) ◽  
pp. 111-118 ◽  
Author(s):  
K. NAGA MOHAN ◽  
PARAMITA RAY ◽  
H. SHARAT CHANDRA

The co-occurrence of three chromosome-wide phenomena – imprinting, facultative heterochromatization and diffuse centromere – in the mealybug Planococcus lilacinus makes investigation of the genomics of this species an attractive prospect. In order to estimate the complexity of the genome of this species, 300 random stretches of its DNA, constituting ∼0·1% of the genome, were sequenced. Coding sequences appear to constitute ∼53·5%, repeat sequences ∼44·5% and non-coding single-copy sequences ∼2% of the genome. The proportion of repetitive sequences in the mealybug is higher than that in the fruit fly Drosophila melanogaster (∼30%). The mealybug genome (∼220 Mb) is about 1·3 times the size of the fly genome (∼165 Mb) and its GC content (∼35%) less than that of the fly genome (∼40%). The relative abundance of various dinucleotides, as analysed by the method of Gentles and Karlin, shows that the dinucleotide signatures of the two species are moderately similar and that in the mealybug there is neither over-representation nor under-representation of any dinucleotide.


mBio ◽  
2019 ◽  
Vol 10 (2) ◽  
Author(s):  
W. Ryan Will ◽  
Peter Brzovic ◽  
Isolde Le Trong ◽  
Ronald E. Stenkamp ◽  
Matthew B. Lawrenz ◽  
...  

ABSTRACTGene duplication and subsequent evolutionary divergence have allowed conserved proteins to develop unique roles. The MarR family of transcription factors (TFs) has undergone extensive duplication and diversification in bacteria, where they act as environmentally responsive repressors of genes encoding efflux pumps that confer resistance to xenobiotics, including many antimicrobial agents. We have performed structural, functional, and genetic analyses of representative members of the SlyA/RovA lineage of MarR TFs, which retain some ancestral functions, including repression of their own expression and that of divergently transcribed multidrug efflux pumps, as well as allosteric inhibition by aromatic carboxylate compounds. However, SlyA and RovA have acquired the ability to countersilence horizontally acquired genes, which has greatly facilitated the evolution ofEnterobacteriaceaeby horizontal gene transfer. SlyA/RovA TFs in different species have independently evolved novel regulatory circuits to provide the enhanced levels of expression required for their new role. Moreover, in contrast to MarR, SlyA is not responsive to copper. These observations demonstrate the ability of TFs to acquire new functions as a result of evolutionary divergence of bothcis-regulatory sequences and intransinteractions with modulatory ligands.IMPORTANCEBacteria primarily evolve via horizontal gene transfer, acquiring new traits such as virulence and antibiotic resistance in single transfer events. However, newly acquired genes must be integrated into existing regulatory networks to allow appropriate expression in new hosts. This is accommodated in part by the opposing mechanisms of xenogeneic silencing and countersilencing. An understanding of these mechanisms is necessary to understand the relationship between gene regulation and bacterial evolution. Here we examine the functional evolution of an important lineage of countersilencers belonging to the ancient MarR family of classical transcriptional repressors. We show that although members of the SlyA lineage retain some ancestral features associated with the MarR family, theircis-regulatory sequences have evolved significantly to support their new function. Understanding the mechanistic requirements for countersilencing is critical to understanding the pathoadaptation of emerging pathogens and also has practical applications in synthetic biology.


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