scholarly journals Determination of novel members in the Drosophila melanogaster anteriorposterior patterning system using natural variation

2018 ◽  
Author(s):  
Ashley A. Jermusyk ◽  
Sarah E. Gharavi ◽  
Aslesha S. Tingare ◽  
Gregory T. Reeves

AbstractThe anterior-posterior axis of the developing Drosophila melanogaster embryo is patterned by a well-studied gene regulatory network called the Gap Gene Network. This network acts to buffer the developing pattern against noise, thereby minimizing errors in gene expression and preventing patterning defects.In this paper, we sought to discover novel regulatory regions and transcription factors acting in a subset of the Gap network using a selection of wild-caught fly lines derived from the Drosophila Genetic Reference Panel (DGRP). The fly lines in the DGRP contain subtle genomic differences due to natural variation; we quantified the differences in positioning of gene expression borders of two anterior-poster patterning genes, Krüppel (Kr) and Even-skipped in 13 of the DGRP lines. The differences in the positions of Krüppel and Even-skipped were then correlated to specific single nucleotide polymorphisms and insertions/deletions within the select fly lines. Putative enhancers containing these genomic differences were validated for their ability to produce expression using reporter constructs and analyzed for possible transcription factor binding sites. The identified transcription factors were then perturbed and the resulting Eve and Kr positioning was determined. In this way, we found medea, ultraspiracle, glial cells missing, and orthopedia effect Kr and Eve positioning in subtle ways, while knock-down of pangolin produces significant shifts in Kr and subsequent Eve expression patterns. Most importantly this study points to the existence of many additional novel members that have subtle effects on this system and the degree of complexity that is present in patterning the developing embryo.

2020 ◽  
Vol 375 (1795) ◽  
pp. 20190341 ◽  
Author(s):  
Judit Salces-Ortiz ◽  
Carlos Vargas-Chavez ◽  
Lain Guio ◽  
Gabriel E. Rech ◽  
Josefa González

Most of the genotype–phenotype analyses to date have largely centred attention on single nucleotide polymorphisms. However, transposable element (TE) insertions have arisen as a plausible addition to the study of the genotypic–phenotypic link because of to their role in genome function and evolution. In this work, we investigate the contribution of TE insertions to the regulation of gene expression in response to insecticides. We exposed four Drosophila melanogaster strains to malathion, a commonly used organophosphate insecticide. By combining information from different approaches, including RNA-seq and ATAC-seq, we found that TEs can contribute to the regulation of gene expression under insecticide exposure by rewiring cis -regulatory networks. This article is part of a discussion meeting issue ‘Crossroads between transposons and gene regulation’.


2017 ◽  
Author(s):  
Erik Clark ◽  
Andrew D. Peel

ABSTRACTLong-germ insects, such as the fruit fly Drosophila melanogaster, pattern their segments simultaneously, whereas short germ insects, such as the beetle Tribolium castaneum, pattern their segments sequentially, from anterior to posterior. While the two modes of segmentation at first appear to be very different, many details of segmentation gene expression are surprisingly similar between long-germ and short-germ species. Collectively, these observations hint that insect segmentation may involve fairly conserved patterning mechanisms, which occur within an evolutionarily malleable spatiotemporal framework. Based on genetic and comparative evidence, we now propose that, in both Drosophila and Tribolium embryos, the temporal progression of the segmentation process is regulated by a temporal sequence of Caudal, Dichaete, and Odd-paired expression. These three transcription factors are broadly expressed in segmenting tissues, providing spatiotemporal information that intersects with the information provided by periodically-expressed segmentation genes such as the pair-rule factors. However, they are deployed differently in long-germ versus short-germ insects, acting as simple timers in Drosophila, but as smooth, retracting wavefronts in Tribolium, compatible with either gap gene-based or oscillator-based generation of periodicity, respectively.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7877 ◽  
Author(s):  
Yanhua Cao ◽  
Xiongwei Zhao ◽  
Yajuan Liu ◽  
Yalong Wang ◽  
Wenmei Wu ◽  
...  

P1B-type ATPases, known as heavy metal ATPases (HMAs), play an important role in the control of cadmium (Cd) accumulation in plants. In this study, a total of 12 ZmHMA genes were identified in the maize genome and particularly classified into six clusters based on their phylogenetic relationship and motif compositions. Furthermore, the expression patterns of different ZmHMA genes varied with developmental stages, and were tissue specific under normal conditions. ZmHMA2 and ZmHMA3 genes exhibited significant up-regulation under Cd treatment. Eventually, the association analysis between 103 inbred lines and alleles in ZmHMA2 and ZmHMA3 revealed that one insertion–deletion (InDel) in the intron from ZmHMA2 was associated with leaf Cd concentration under low Cd condition at the seedling stage. Twenty polymorphisms in ZmHMA3 were significantly associated with leaf Cd concentration under various Cd levels at seedling and maturing stages. Five single nucleotide polymorphisms (SNPs) and two InDels of these significantly associated polymorphic loci from ZmHMA3 caused the amino acid substitutions and insertion or deletion events. Importantly, the proteins encoded by ZmHMA2 and ZmHMA3 genes were located in the plasma membrane. This comprehensive analysis will provide an important theoretical basis for future functional verification of ZmHMA genes to unravel the mechanisms of Cd accumulation in leaves of maize. Additionally, the favorable alleles in ZmHMA3 will lay a foundation for the marker-assisted selection of low Cd accumulation in maize.


2010 ◽  
Vol 34 (8) ◽  
pp. S75-S75
Author(s):  
Weifeng Zhu ◽  
Zhuoqi Liu ◽  
Daya Luo ◽  
Xinyao Wu ◽  
Fusheng Wan

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Erika Calvano Küchler ◽  
Agnes Schröder ◽  
Vinicius Broska Teodoro ◽  
Ute Nazet ◽  
Rafaela Scariot ◽  
...  

Abstract Background This study aimed to investigate, if different physiological concentrations of vitamin D (25(OH)D3) and single nucleotide polymorphisms in vitamin D receptor (VDR) gene have an impact on gene expression in human periodontal ligament (hPDL) fibroblasts induced by simulated orthodontic compressive strain. Methods A pool of hPDL fibroblasts was treated in absence or presence of 25(OH)D3 in 3 different concentrations (10, 40 and 60 ng/ml). In order to evaluate the role of single nucleotide polymorphisms in the VDR gene, hPDL fibroblasts from 9 patients were used and treated in absence or presence of 40 ng/ml 25(OH)D3. Each experiment was performed with and without simulated orthodontic compressive strain. Real-time PCR was used for gene expression and allelic discrimination analysis. Relative expression of dehydrocholesterol reductase (DHCR7), Sec23 homolog A, amidohydrolase domain containing 1 (AMDHD1), vitamin D 25-hydroxylase (CYP2R1), Hydroxyvitamin D-1-α hydroxylase, receptor activator of nuclear factor-κB ligand (RANKL), osteoprotegerin (OPG), cyclooxygenase-2 (COX-2) and interleukin-6 (IL6) was assessed. Three single nucleotide polymorphisms in VDR were genotyped. Parametric or non-parametric tests were used with an alpha of 5%. Results RANKL, RANKL:OPG ratio, COX-2, IL-6, DHCR7, CYP2R1 and AMDHD1 were differentially expressed during simulated orthodontic compressive strain (p < 0.05). The RANKL:OPG ratio was downregulated by all concentrations (10 ng/ml, 40 ng/ml and 60 ng/ml) of 25(OH)D3 (mean = 0.96 ± 0.68, mean = 1.61 ± 0.66 and mean = 1.86 ± 0.78, respectively) in comparison to the control (mean 2.58 ± 1.16) (p < 0.05). CYP2R1 gene expression was statistically modulated by the different 25(OH)D3 concentrations applied (p = 0.008). Samples from individuals carrying the GG genotype in rs739837 presented lower VDR mRNA expression and samples from individuals carrying the CC genotype in rs7975232 presented higher VDR mRNA expression (p < 0.05). Conclusions Simulated orthodontic compressive strain and physiological concentrations of 25(OH)D3 seem to regulate the expression of orthodontic tooth movement and vitamin-D-related genes in periodontal ligament fibroblasts in the context of orthodontic compressive strain. Our study also suggests that single nucleotide polymorphisms in the VDR gene regulate VDR expression in periodontal ligament fibroblasts in the context of orthodontic compressive strain.


2021 ◽  
Vol 49 (5) ◽  
pp. 030006052110148
Author(s):  
Xue Qiao ◽  
Xing Niu ◽  
Jiayi Liu ◽  
Lijie Chen ◽  
Yan Guo ◽  
...  

Ameloblastoma is a common odontogenic epithelial tumor that exhibits various biological behaviors, ranging from simple cystic expansion to aggressive solid masses characterized by local invasiveness, a high risk of recurrence, and even malignant transformation. We report on two cases of unusually large solid ameloblastomas. We detected epithelial–mesenchymal transition-related gene expression and HRAS gene single nucleotide polymorphisms, providing possible molecular evidence of mesenchymal morphological changes in ameloblastoma. The detailed analysis of the pathogenesis of these two cases of ameloblastoma may deepen our understanding of this rare disease and offer promising targets for future targeted therapy.


2013 ◽  
Vol 45 (16) ◽  
pp. 685-696 ◽  
Author(s):  
Attia Fatima ◽  
Dermot G. Morris

microRNAs (miRNAs) are a class of small noncoding RNA that bind to complementary sequences in the untranslated regions of multiple target mRNAs resulting in posttranscriptional regulation of gene expression. The recent discovery and expression-profiling studies of miRNAs in domestic livestock have revealed both their tissue-specific and temporal expression pattern. In addition, breed-dependent expression patterns as well as single nucleotide polymorphisms in either the miRNA or in the target mRNA binding site have revealed associations with traits of economic importance and highlight the potential use of miRNAs in future genomic selection programs.


2018 ◽  
Vol 5 (8) ◽  
pp. 180458 ◽  
Author(s):  
Eva Jiménez-Guri ◽  
Karl R. Wotton ◽  
Johannes Jaeger

Gap genes are involved in segment determination during early development of the vinegar fly Drosophila melanogaster and other dipteran insects (flies, midges and mosquitoes). They are expressed in overlapping domains along the antero-posterior (A–P) axis of the blastoderm embryo. While gap domains cover the entire length of the A–P axis in Drosophila, there is a region in the blastoderm of the moth midge Clogmia albipunctata , which lacks canonical gap gene expression. Is a non-canonical gap gene functioning in this area? Here, we characterize tarsal-less ( tal ) in C. albipunctata . The homologue of tal in the flour beetle Tribolium castaneum (called milles-pattes, mlpt ) is a bona fide gap gene. We find that Ca-tal is expressed in the region previously reported as lacking gap gene expression. Using RNA interference, we study the interaction of Ca-tal with gap genes. We show that Ca-tal is regulated by gap genes, but only has a very subtle effect on tailless (Ca-tll), while not affecting other gap genes at all. Moreover, cuticle phenotypes of Ca-tal depleted embryos do not show any gap phenotype. We conclude that Ca-tal is expressed and regulated like a gap gene, but does not function as a gap gene in C. albipunctata .


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