scholarly journals Chemosensory Characteristics of Two Semanotus bifasciatus Populations

Forests ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 655 ◽  
Author(s):  
Zhang ◽  
Shen ◽  
Zhang ◽  
Wang ◽  
Kong ◽  
...  

Semanotus bifasciatus (Motschulsky) (Cerambycidae: Coleoptera) is a major forest borer in China, and attractants provide a promising method for the control of this pest. Exploration of the chemosensory mechanisms of S. bifasciatus is important for the development of efficient attractants for this pest. However, little information is available about the olfactory mechanisms of S. bifasciatus. Previous research has indicated that the trapping effects of the same attractant are different between Beijing and Shandong populations of S. bifasciatus. To explore the reasons for this, next-generation sequencing was performed to analyze the antennal transcriptome of both sexes of the two S. bifasciatus populations, and the olfactory-related genes were identified. Furthermore, the expression levels and single nucleotide polymorphisms (SNPs) of the olfactory-related genes between the two populations were compared. We found that the expression levels of odorant binding proteins (OBPs), odorant receptors (ORs), and sensory neuron membrane proteins (SNMPs) in male S. bifasciatus of the Beijing population were obviously lower than those in the Shandong population, and most of the conserved SNPs in OBPs and ORs of the two populations showed more diversity in the Beijing population. Our work provides a foundation for future research of the molecular olfactory mechanisms and pest management of S. bifasciatus, as well as other longhorn beetles.

Insects ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 397
Author(s):  
Gabriel I. Ballesteros ◽  
Daniela A. Sepúlveda ◽  
Christian C. Figueroa

Generalist parasitoids of aphids, such as the wasp Aphidius ervi, display significant differences in terms of host preference and host acceptance, depending on the host on which they developed (natal host), which is preferred over a non-natal host, a trait known as host fidelity. This trait allows females to quickly find hosts in heterogeneous environments, a process mediated by chemosensory/olfactory mechanisms, as parasitoids rely on olfaction and chemical cues during host selection. Thus, it is expected that proteins participating in chemosensory recognition, such as odorant-binding proteins (OBPs) and odorant receptors (ORs) would play a key role in host preference. In this study, we addressed the effect of parasitoid reciprocal host switching between two aphid hosts (Sitobion avenae and Acyrthosiphon pisum) on the expression patterns of chemosensory genes in the wasp A. ervi. First, by using a transcriptomic approach based on RNAseq of A. ervi females reared on S. avenae and A. pisum, we were able to annotate a total of 91 transcripts related to chemoperception. We also performed an in-silico expression analysis and found three OBPs and five ORs displaying different expression levels. Then, by using qRT-PCR amplification, we found significant differences in the expression levels of these eight genes when the parasitoids were reciprocally transplanted from S. avenae onto A. pisum and vice versa. This suggests that the expression levels of genes coding for odorant receptors and odorant-binding proteins would be regulated by the specific plant–aphid host complex where the parasitoids develop (maternal previous experience) and that chemosensory genes coding for olfactory mechanisms would play a crucial role on host preference and host acceptance, ultimately leading to the establishment of host fidelity in A. ervi parasitoids.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Chao Ma ◽  
Chenchen Zhao ◽  
Shaowei Cui ◽  
Yan Zhang ◽  
Guangmei Chen ◽  
...  

Abstract Antennal olfaction plays a key role in insect survival, which mediates important behaviors like host search, mate choice, and oviposition site selection. As an oligophagous insect, olfaction is extremely important for Ophraella communa to locate host plants. However, information on the olfactory genes has been lacking in O. communa. Using next generation sequencing, we assembled the antennal transcriptome of O. communa and first reported the major chemosensory genes necessary for olfaction in this species. In this study, a total 105 candidate chemosensory genes were identified in O. communa antennae, including 25 odorant-binding proteins (OBPs), 11 chemosensory proteins (CSPs), four sensory neuron membrane proteins (SNMPs), 30 odorant receptors (ORs), 18 ionotropic receptors (IRs), and 17 gustatory receptors (GRs). We also identified full-length sequences of the highly conserved ORco and IR8a/25a family in O. communa. In addition, the expression profile of 15 ORs and four OBPs were validated by quantitative real-time polymerase chain reaction (qPCR). We found that OcomOR2/4/19 and OcomOBP19/20 had a biased expression in male antennae, and OcomOR8 had a biased expression in the female antennae. This large number of chemosensory genes handled by homology analysis and qPCR results will provide the first insights into molecular basis for the olfactory systems of O. communa as well as advance our understanding of olfactory mechanisms in Coleoptera.


2017 ◽  
Author(s):  
Claire Marchal ◽  
Takayo Sasaki ◽  
Daniel Vera ◽  
Korey Wilson ◽  
Jiao Sima ◽  
...  

ABSTRACTCycling cells duplicate their DNA content during S phase, following a defined program called replication timing (RT). Early and late replicating regions differ in terms of mutation rates, transcriptional activity, chromatin marks and sub-nuclear position. Moreover, RT is regulated during development and is altered in disease. Exploring mechanisms linking RT to other cellular processes in normal and diseased cells will be facilitated by rapid and robust methods with which to measure RT genome wide. Here, we describe a rapid, robust and relatively inexpensive protocol to analyze genome-wide RT by next-generation sequencing (NGS). This protocol yields highly reproducible results across laboratories and platforms. We also provide computational pipelines for analysis, parsing phased genomes using single nucleotide polymorphisms (SNP) for analyzing RT allelic asynchrony, and for direct comparison to Repli-chip data obtained by analyzing nascent DNA by microarrays.


BMC Genomics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Hao Yuan ◽  
Huihui Chang ◽  
Lina Zhao ◽  
Chao Yang ◽  
Yuan Huang

Abstract Background The sophisticated insect olfactory system plays an important role in recognizing external odors and enabling insects to adapt to environment. Foraging, host seeking, mating, ovipositing and other forms of chemical communication are based on olfaction, which requires the participation of multiple olfactory genes. The exclusive evolutionary trend of the olfactory system in Orthoptera insects is an excellent model for studying olfactory evolution, but limited olfaction research is available for these species. The olfactory-related genes of Ceracris nigricornis Walker (Orthoptera: Acrididae), a severe pest of bamboos, have not yet been reported. Results We sequenced and analyzed the transcriptomes from different tissues of C. nigricornis and obtained 223.76 Gb clean data that were assembled into 43,603 unigenes with an N50 length of 2235 bp. Among the transcripts, 66.79% of unigenes were annotated. Based on annotation and tBLASTn results, 112 candidate olfactory-related genes were identified for the first time, including 20 odorant-binding proteins (OBPs), 10 chemosensory-binding proteins (CSPs), 71 odorant receptors (ORs), eight ionotropic receptors (IRs) and three sensory neuron membrane proteins (SNMPs). The fragments per kilobase per million mapped fragments (FPKM) values showed that most olfactory-related differentially expressed genes (DEGs) were enriched in the antennae, and these results were confirmed by detecting the expression of olfactory-related genes with quantitative real-time PCR (qRT-PCR). Among these antennae-enriched genes, some were sex-biased, indicating their different roles in the olfactory system of C. nigricornis. Conclusions This study provides the first comprehensive list and expression profiles of olfactory-related genes in C. nigricornis and a foundation for functional studies of these olfactory-related genes at the molecular level.


2021 ◽  
Vol 12 ◽  
Author(s):  
Minqiang Tang ◽  
Juanling Li ◽  
Xu Hu ◽  
Lu Sun ◽  
MMU Helal ◽  
...  

The marked increase in plant genomic data has provided valuable resources for investigating the dynamic evolution of duplicate genes in polyploidy. Brassica napus is an ideal model species for investigating polyploid genome evolution. The present study comprehensively analyzed DNA and RNA variation of two representative B. napus inbredlines, Zhongshuang11 and Zhongyou821, and we investigated gene expression levels of An and Cn subgenomes in multiple tissues of the two lines. The distribution of transmitted single nucleotide polymorphisms (SNPs) was significantly different in two subgenomes of B. napus. Gene expression levels were significantly negatively correlated with number of variations in replication and transcription of the corresponding genes, but were positively correlated with the ratios of transmitted SNPs from DNA to RNA. We found a higher density of SNP variation in An than that in Cn during DNA replication and more SNPs were transmitted to RNA during transcription, which may contribute to An expression dominance. These activities resulted in asymmetrical gene expression in polyploid B. napus. The SNPs transmitted from DNA to RNA could be an important complement feature in comparative genomics, and they may play important roles in asymmetrical genome evolution in polyploidy.


Author(s):  
Collet Dandara ◽  
Patience T. Basvi ◽  
Tashinga E. Bapiro ◽  
Jane Sayi ◽  
Julia A. Hasler

AbstractCytochrome P450 1A2 (CYP1A2) is an important member of the cytochrome P450 superfamily of enzymes because of its involvement in the metabolism of some carcinogens and therapeutically important drugs. As a result, factors affecting the activity of the enzyme are the focus of considerable research effort as they may have important pharmacological or toxicological implications. CYP1A2 has been shown to exhibit a genetic polymorphism with most of the data, however, coming from studies in Caucasian and Oriental populations. In this study therefore, we investigated the frequencies of two point mutations, –163C > A and 63C > G, in two Bantu African populations. A total of 214 healthy subjects were recruited from Zimbabwe (n = 143) and Tanzania (n = 71). The two single nucleotide polymorphisms were detected using polymerase chain reaction-restriction fragment length polymorphism analysis. The frequency of –163A was 57% (95% confidence interval (CI), 54%, 60%) and 49% (95% CI, 45%, 53%) among Zimbabweans and Tanzanians, respectively, but the difference between the two populations was not statistically significant (p = 0.123). The base change 63C > G was not found in any of the subjects from the two populations. We report here a high frequency of –163C > A base change and an absence of the 63C > G change in the two African populations.


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