scholarly journals Genetic variation in the odorant receptor gene OR4 and bit habits in natural populations of Aedes aegypti from Antioquia department, Colombia

2019 ◽  
Author(s):  
Juan Sebastian Pino
Keyword(s):  
Genetic Variation ◽  
Aedes Aegypti ◽  
Odorant Receptor ◽  
Receptor Gene ◽  
Natural Populations ◽  
Low Frequency ◽  
Arrival Rate ◽  
Population Diversity ◽  
Genetic Population ◽  
Or Genes

AbstractIt has been determined factors that make humans more attractive to mosquitoes and which strategies they use to detect a potential host. Preferential differences for human/non-human hosts are related to variations in odorant receptors (OR) genes in the Aedes aegypti mosquitoes. This study use sequencing to establish the genetic variation in the odor receptor OR4 in 900 mosquitoes from different regions of Antioquia. A behavioral test using an olfactometer was also made to stablish the relationship of these variation with the attraction on different human hosts. The analysis in the attraction and OR4 variants did not show significant differences in the arrival rate among different human hosts. No significant differences in the description of OR4 variants between populations and between hosts, show that this gene is homogeneously distributed. The analysis showed a high genetic population diversity, measured as polymorphism and heterozygosity. This may be due to a few high frequency haplotypes in all the populations examined, suggesting a model of high gene flow between populations and/or selection in favor of these variants in all populations. Other low-frequency variants, many of which are population-specific, reflect the effect of genetic drift probably due to stochastic changes in the size of natural mosquito populations.

scholarly journals Bioinformatics Discovery of Putative Enhancers within Mouse Odorant Receptor Gene Clusters

2019 ◽  
Vol 44 (9) ◽  
pp. 705-720
Author(s):  
James E Farber ◽  
Robert P Lane
Keyword(s):  
Odorant Receptor ◽  
Receptor Gene ◽  
Gene Clusters ◽  
Small Subset ◽  
Histone 3 ◽  
Large Size ◽  
Dnase Hypersensitivity ◽  
Or Gene ◽  
Or Genes ◽  
Flanking Regions

Abstract Olfactory neuronal function depends on the expression and proper regulation of odorant receptor (OR) genes. Previous studies have identified 54 putative intergenic enhancers within or flanking 40 mouse OR clusters. At least 2 of these putative enhancers have been shown to regulate the expression of a small subset of proximal OR genes. In recognition of the large size of the mouse OR gene family (~1400 OR genes distributed across multiple chromosomal loci), it is likely that there remain many additional not-as-yet discovered OR enhancers. We utilized 23 of the previously identified enhancers as a training set (TS) and designed an algorithm that combines a broad range of epigenetic criteria (histone-3-lysine-4 monomethylation, histone-3-lysine-79 trimethylation, histone-3-lysine-27 acetylation, and DNase hypersensitivity) and genetic criteria (cross-species sequence conservation and transcription-factor binding site enrichment) to more broadly search OR gene clusters for additional candidates. We identified 181 new candidate enhancers located at 58 (of 68) mouse OR loci, including 25 new candidates identified by stringent search criteria whose signal strengths are not significantly different from the 23 previously characterized OR enhancers used as the TS. Additionally, we compared OR enhancer versus generic enhancer features in order to evaluate likelihoods that new enhancer candidates specifically function in OR regulation. We found that features distinguishing OR-specific function are significantly more evident for enhancer candidates located within OR clusters as compared with those in flanking regions.

scholarly journals An olfactory receptor gene underlies reproductive isolation in perfume-collecting orchid bees

2019 ◽  
Author(s):  
P. Brand ◽  
I. A. Hinojosa-Díaz ◽  
R. Ayala ◽  
M. Daigle ◽  
C. L. Yurrita Obiols ◽  
...  
Keyword(s):  
Reproductive Isolation ◽  
Odorant Receptor ◽  
Receptor Gene ◽  
Rapid Evolution ◽  
Natural Populations ◽  
Reproductive Barriers ◽  
Species Identity ◽  
Orchid Bees ◽  
Major Barrier ◽  
Genetic Mechanisms

Speciation is facilitated by the evolution of reproductive barriers that prevent or reduce hybridization among diverging lineages. However, the genetic mechanisms that control the evolution of reproductive barriers remain elusive, particularly in natural populations. We identify a gene associated with divergence in chemical courtship signaling in a pair of nascent orchid bee lineages. Male orchid bees collect perfume compounds from flowers and other sources to subsequently expose during courtship display, thereby conveying information on species identity. We show that these two lineages exhibit differentiated perfume blends and that this change is associated with the rapid evolution of a single odorant receptor gene. Our study suggests that reproductive isolation evolved through divergence of a major barrier gene involved in chemically mediated pre-mating isolation via genetic coupling.

scholarly journals Screening for Odorant Receptor Genes Expressed in Aedes Aegypti Involved in Blood-Feeding and Oviposition Behaviors

2021 ◽  
Author(s):  
Meng Ni ◽  
Teng Zhao ◽  
Hui-xin Lv ◽  
Man-jin Li ◽  
Dan Xing ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Olfactory System ◽  
Mosquito Control ◽  
Odorant Receptor ◽  
Blood Feeding ◽  
Differentially Expressed ◽  
Expression Levels ◽  
Blood Sucking ◽  
Or Genes ◽  
Reproductive Processes

Abstract Background: Aedes aegypti is one of the most important vector worldwide, and its survival and reproductive processes depend heavily on the olfactory system. In this study, the expression levels of all odorant receptor (OR) genes of Ae. aegypti were explored in different physiological periods to identify olfactory genes that may be associated with mosquito blood sucking and searching for oviposition sites.Methods: Four groups, consisting of Ae. aegypti males (M), pre-blood-feeding females (F), post-blood-feeding females (B) and post-oviposition females (O), were established. A total of 114 pairs of primer targeting all OR genes were designed based on the whole genome of Ae. aegypti. The expression of OR genes was evaluated by real-time fluorescence quantitative PCR for relative quantification and the comparison of differences between groups.Results: A total of 53 differentially expressed OR genes were identified between males and females in Ae. aegypti antennae. And 8, 5 and 13 differentially expressed OR genes were identified before versus after blood feeding, before versus after oviposition and post-blood-feeding versus post-oviposition, respectively. Meanwhile, 16 OR genes were significantly differentially expressed in multiple physiological periods of mosquitoes.Conclusions: A large number of ORs with significant intergroup differences and high expression levels were screened in this study, including OR75, OR88, OR110 and OR115 and so on. Some of these genes are reported for the first time, providing possible targets for the development of mosquito control pathways based on the olfactory system.

scholarly journals Molecular characterization of the Aedes aegypti odorant receptor gene family

2007 ◽  
Vol 0 (0) ◽  
pp. 070717083332002-??? ◽  
Author(s):  
J. Bohbot ◽  
R. J. Pitts ◽  
H.-W. Kwon ◽  
M. Rützler ◽  
H. M. Robertson ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Gene Family ◽  
Molecular Characterization ◽  
Odorant Receptor ◽  
Receptor Gene ◽  
Receptor Gene Family

scholarly journals Local parasite pressures and host genotype may modulate epigenetic diversity in a mixed-mating fish

2019 ◽  
Author(s):  
Waldir M. Berbel-Filho ◽  
Carlos Garcia de Leaniz ◽  
Paloma Morán ◽  
Jo Cable ◽  
Sergio M. Q. Lima ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Dna Methylation ◽  
Genetic Variation ◽  
Natural Populations ◽  
Mixed Mating ◽  
Host Genotype ◽  
Genetic Population ◽  
Low Genetic Diversity ◽  
Population Structuring ◽  
Epigenetic Diversity

AbstractParasite-mediated selection is one of the main drivers of genetic variation in natural populations. The persistence of asexual reproduction and self-fertilization, however, challenges the notion that low genetic variation and inbreeding compromise the host’s ability to respond to pathogens. DNA methylation represents a potential mechanism for generating additional adaptive variation under low genetic diversity. We compared genetic diversity (microsatellites and AFLPs), variation in DNA methylation (MSAFLPs), and parasite loads in three populations of Kryptolebias hermaphroditus, a unique mixed-mating (partially self-fertilising) fish, to analyse the potential adaptive value of DNA methylation in relation to genetic diversity and parasite loads. We found strong genetic population structuring, as well as differences in parasite loads and methylation levels among sampling sites and selfing lineages. Globally, the interaction between parasites and inbreeding with selfing lineages influenced DNA methylation, but parasites seemed more important in determining methylation levels at the local scale.

scholarly journals A purely bioinformatic pipeline for the prediction of mammalian odorant receptor gene enhancers

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Andrea Degl’Innocenti ◽  
Gabriella Meloni ◽  
Barbara Mazzolai ◽  
Gianni Ciofani
Keyword(s):  
Odorant Receptor ◽  
Receptor Gene ◽  
Gene Families ◽  
Or Gene ◽  
Comprehensive Classification ◽  
Genomic Clusters ◽  
Or Genes ◽  
Multiple Receptor

Abstract Background In most mammals, a vast array of genes coding for chemosensory receptors mediates olfaction. Odorant receptor (OR) genes generally constitute the largest multifamily (> 1100 intact members in the mouse). From the whole pool, each olfactory neuron expresses a single OR allele following poorly characterized mechanisms termed OR gene choice. OR genes are found in genomic aggregations known as clusters. Nearby enhancers, named elements, are crucial regulators of OR gene choice. Despite their importance, searching for new elements is burdensome. Other chemosensory receptor genes responsible for smell adhere to expression modalities resembling OR gene choice, and are arranged in genomic clusters — often with chromosomal linkage to OR genes. Still, no elements are known for them. Results Here we present an inexpensive framework aimed at predicting elements. We redefine cluster identity by focusing on multiple receptor gene families at once, and exemplify thirty — not necessarily OR-exclusive — novel candidate enhancers. Conclusions The pipeline we introduce could guide future in vivo work aimed at discovering/validating new elements. In addition, our study provides an updated and comprehensive classification of all genomic loci responsible for the transduction of olfactory signals in mammals.

scholarly journals Macrogeographic genetic variation in a human commensal: Aedes aegypti, the yellow fever mosquito

1983 ◽  
Vol 41 (3) ◽  
pp. 241-258 ◽  
Author(s):  
Graham P. Wallis ◽  
Walter J. Tabachnick ◽  
Jeffrey R. Powell
Keyword(s):  
Genetic Variation ◽  
Aedes Aegypti ◽  
Genetic Distance ◽  
East Africa ◽  
Genetic Population ◽  
South Eastern ◽  
Major Cluster ◽  
Distance Data ◽  
Multivariate Discriminant ◽  
Mexican Populations

SUMMARYGenetic variation at 11 enzyme loci in Aedes aegypti populations collected from 63 localities around the world is presented. A UPGMA tree based on genetic distance values clusters populations of sylvan A. aegypti formosus from West Africa and East Africa together, along with Asian and south-eastern U.S. populations. Domestic A. aegypti aegypti from East Africa and all other New World populations form the other major cluster. Multivariate discriminant analysis allows recognition of seven major global ‘genetic–geographic’ groups, which are consistent with the genetic distance data. Populations from the south-eastern U.S. are clearly genetically distinct from other U.S. and Mexican populations. This distinct gene pool may be indicative of reinfestation of areas where A. aegypti appears to have been absent in the recent past. Other evolutionary and epidemiological implications of the genetic population structure of Aedes aegypti are discussed.

scholarly journals Genetic Background Effects on the Expression of an Odorant Receptor Gene

2021 ◽  
Vol 15 ◽  
Author(s):  
Artur Guazzelli Leme Silva ◽  
Maira Harume Nagai ◽  
Thiago Seike Nakahara ◽  
Bettina Malnic
Keyword(s):  
Dna Methylation ◽  
Genetic Background ◽  
Odorant Receptor ◽  
Receptor Gene ◽  
Transcript Abundance ◽  
Mouse Strains ◽  
Or Gene ◽  
Genetic Background Effects ◽  
Methylation Patterns ◽  
Or Genes

There are more than 1000 odorant receptor (OR) genes in the mouse genome. Each olfactory sensory neuron expresses only one of these genes, in a monoallelic fashion. The transcript abundance of homologous OR genes vary between distinct mouse strains. Here we analyzed the expression of the OR gene Olfr17 (also named P2) in different genomic contexts. Olfr17 is expressed at higher levels in the olfactory epithelium from 129 mice than from C57BL/6 (B6) mice. However, we found that in P2-IRES-tauGFP knock-in mice, the transcript levels of the 129 Olfr17 allele are highly reduced when compared to the B6 Olfr17 allele. To address the mechanisms involved in this variation we compared the 5′ region sequence and DNA methylation patterns of the B6 and 129 Olfr17 alleles. Our results show that genetic variations in cis regulatory regions can lead to differential DNA methylation frequencies in these OR gene alleles. They also show that expression of the Olfr17 alleles is largely affected by the genetic background, and suggest that in knock-in mice, expression can be affected by epigenetic modifications in the region of the targeted locus.

scholarly journals Expansion and accelerated evolution of 9-exon odorant receptors in Polistes paper wasps

2020 ◽  
Author(s):  
Andrew W. Legan ◽  
Christopher M. Jernigan ◽  
Sara E. Miller ◽  
Matthieu F. Fuchs ◽  
Michael J. Sheehan
Keyword(s):  
Gene Family ◽  
Odorant Receptor ◽  
Receptor Gene ◽  
Gene Family Evolution ◽  
Paper Wasp ◽  
Wasp Species ◽  
Accelerated Evolution ◽  
Evolution Of Sociality ◽  
Or Gene ◽  
Or Genes

ABSTRACTIndependent origins of sociality in bees and ants are associated with independent expansions of particular odorant receptor (OR) gene subfamilies. In ants, one clade within the OR gene family, the 9-exon subfamily, has dramatically expanded. These receptors detect cuticular hydrocarbons (CHCs), key social signaling molecules in insects. It is unclear to what extent 9-exon OR subfamily expansion is associated with the independent evolution of sociality across Hymenoptera, warranting studies of taxa with independently derived social behavior. Here we describe odorant receptor gene family evolution in the northern paper wasp, Polistes fuscatus, and compare it to four additional paper wasp species spanning ~40 million years of divergence. We find 200 functional OR genes in P. fuscatus matching predictions from neuroanatomy, and more than half of these are in the 9-exon subfamily. Lineage-specific expansions of 9-exon subfamily ORs are tandemly arrayed in Polistes genomes and exhibit a breakdown in microsynteny relative to tandem arrays in other OR subfamilies. There is evidence of episodic positive diversifying selection shaping ORs in expanded subfamilies, including 9-exon, E, H, and L, but 9-exon ORs do not stand out as selectively diversified among Polistes species. Accelerated evolution has resulted in lower amino acid similarity and high dN/dS among 9-exon ORs compared to other OR subfamilies. Patterns of OR evolution within Polistes are consistent with 9-exon OR function in CHC perception by combinatorial coding, with both selection and drift contributing to interspecies differences in copy number and sequence.

Genetic Population Diversity of Aedes caspius in Southern Provinces of Iran

2018 ◽  
Vol 111 (1) ◽  
pp. 31-37 ◽  
Author(s):  
S DOOSTI ◽  
MR YAGHOOBI-ERSHADI ◽  
MM SEDAGHAT ◽  
SH MOOSA-KAZEMI ◽  
K AKBARZADEH ◽  
...  
Keyword(s):  
Population Diversity ◽  
Genetic Population ◽  
Aedes Caspius
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