scholarly journals Cis-regulatory elements of the cholinergic gene locus in the silkworm Bombyx mori

2021 ◽  
Author(s):  
Kota Banzai ◽  
Susumu Izumi

ABSTRACTGenes of choline acetyltransferase (ChAT) and vesicular acetylcholine transporter (VAChT) are encoded in the same gene locus, called the cholinergic gene locus. They are essential in cholinergic neurons to maintain their functional phenotype. The genomic structure of the cholinergic gene locus is conserved among invertebrates to mammals. However, it is still inconclusive how cholinergic genes express only in cholinergic neurons in insects. In this study, we analyzed the upstream sequence of cholinergic gene locus in the silkworm Bombyx mori to identify specific cis-regulatory regions. We found multiple enhancer regions that are localized within 1 kb upstream of the cholinergic gene locus. The combination of promoter assays using small deletions and bioinformatic analysis among insect species illuminates two conserved sequences in the cis-regulatory region: TGACGTA and CCAAT, which are known as the cAMP response element and CAAT box, respectively. We found that dibutyryl-cAMP, an analog of cAMP, influences the expression of ChAT. Tissue-specific expression analysis of transcriptional factors showed potential candidates that control the cholinergic gene locus expression. Our investigation provides new insight into the regulation mechanism of cholinergic neuron-specific gene machinery in this lepidopteran insect.

Blood ◽  
2001 ◽  
Vol 98 (3) ◽  
pp. 610-617 ◽  
Author(s):  
Chunyan Zhang ◽  
Michael A. Thornton ◽  
M. Anna Kowalska ◽  
Bruce S. Sachis ◽  
Michael Feldman ◽  
...  

Abstract The genes for the related human (h) chemokines, PBP (platelet basic protein) and PF4 (platelet factor 4), are within 5.3 kilobases (kb) of each other and form a megakaryocyte-specific gene locus. The hypothesis was considered that the PBP and PF4 genes share a common distal regulatory region(s) that leads to their high-level megakaryocyte-specific expression in vivo. This study examined PBP and PF4 expression in transgenic mice using 4 distinct humanPBP/PF4 gene locus constructs. These studies showed that within the region studied there was sufficient information to regulate tissue-specific expression of both hPBP and hPF4. Indeed this region contained sufficient DNA information to lead to expression levels of PBP and PF4 comparable to the homologous mouse genes in a position-independent, copy number–dependent fashion. These studies also indicated that the DNA domains that led to this expression were distinct for the 2 genes; hPBP expression is regulated by a region that is 1.5 to 4.4 kb upstream of that gene. Expression of hPF4 is regulated by a region that is either intergenic between the 2 genes or immediately downstream of the hPF4 gene. Comparison of the available human and mouse sequences shows conserved flanking region domains containing potential megakaryocyte-related transcriptional factor DNA-binding sites. Further analysis of these regulatory regions may identify enhancer domains involved in megakaryopoiesis that may be useful in the selective expression of other genes in megakaryocytes and platelets as a strategy for regulating hemostasis, thrombosis, and inflammation.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yanshan Zhong ◽  
Xiaodan Lu ◽  
Zhiwei Deng ◽  
Ziqing Lu ◽  
Minghui Fu

Abstract Background Glutamine synthetase (GS) acts as a key enzyme in plant nitrogen (N) metabolism. It is important to understand the regulation of GS expression in plant. Promoters can initiate the transcription of its downstream gene. Eichhornia crassipes is a most prominent aquatic invasive plant, which has negative effects on environment and economic development. It also can be used in the bioremediation of pollutants present in water and the production of feeding and energy fuel. So identification and characterization of GS promoter in E. crassipes can help to elucidate its regulation mechanism of GS expression and further to control its N metabolism. Results A 1232 bp genomic fragment upstream of EcGS1b sequence from E. crassipes (EcGS1b-P) has been cloned, analyzed and functionally characterized. TSSP-TCM software and PlantCARE analysis showed a TATA-box core element, a CAAT-box, root specific expression element, light regulation elements including chs-CMA1a, Box I, and Sp1 and other cis-acting elements in the sequence. Three 5′-deletion fragments of EcGS1b upstream sequence with 400 bp, 600 bp and 900 bp length and the 1232 bp fragment were used to drive the expression of β-glucuronidase (GUS) in tobacco. The quantitative test revealed that GUS activity decreased with the decreasing of the promoter length, which indicated that there were no negative regulated elements in the EcGS1-P. The GUS expressions of EcGS1b-P in roots were significantly higher than those in leaves and stems, indicating EcGS1b-P to be a root-preferential promoter. Real-time Quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR) analysis of EcGS1b gene also showed higher expression in the roots of E.crassipes than in stems and leaves. Conclusions EcGS1b-P is a root-preferential promoter sequence. It can specifically drive the transcription of its downstream gene in root. This study will help to elucidate the regulatory mechanisms of EcGS1b tissue-specific expression and further study its other regulatory mechanisms in order to utilize E.crassipes in remediation of eutrophic water and control its overgrowth from the point of nutrient metabolism.


1992 ◽  
Vol 12 (12) ◽  
pp. 5768-5777
Author(s):  
B Durand ◽  
J Drevet ◽  
P Couble

The gene encoding the silk protein P25 is expressed in the posterior silk gland of Bombyx mori with strict territorial and developmental specificities. The cis-acting regulatory elements previously located within the 441-bp 5' proximal sequence of the gene were examined for protein-binding capacities. We identified two factors, BMFA and SGFB, that lead to prominent band shifts and the target sites for which are included in a region homologous to the fibroin gene enhancer sequence. Analysis of the tissue-specific incidence of both factors showed that BMFA is ubiquitous, whereas SGFB is restricted to the silk gland cells. However, SGFB was found in both posterior and middle silk gland cells and therefore likely directs organ-specific, but not territory-specific, expression. Developmental studies throughout the fourth larval molt, at which the P25 gene status changes from derepressed to repressed, revealed that BMFA is reversibly modified at the transition from intermolt to molt. Indeed, the preexisting BMFA is replaced by a structurally related factor, BMFA', during the 2 h following head capsule apolysis. The exact temporal coincidence of this conversion with the onset of gene repression suggests that BMFA' is involved in transcription inactivation and likely results from a transduction process initiated by the hormonal change at molting.


2020 ◽  
Author(s):  
Nil Aygün ◽  
Angela L. Elwell ◽  
Dan Liang ◽  
Michael J. Lafferty ◽  
Kerry E. Cheek ◽  
...  

SummaryInterpretation of the function of non-coding risk loci for neuropsychiatric disorders and brain-relevant traits via gene expression and alternative splicing is mainly performed in bulk post-mortem adult tissue. However, genetic risk loci are enriched in regulatory elements of cells present during neocortical differentiation, and regulatory effects of risk variants may be masked by heterogeneity in bulk tissue. Here, we map e/sQTLs and allele specific expression in primary human neural progenitors (n=85) and their sorted neuronal progeny (n=74). Using colocalization and TWAS, we uncover cell-type specific regulatory mechanisms underlying risk for these traits.


2021 ◽  
Vol 30 (1) ◽  
pp. 95-103
Author(s):  
Mohammad Shamimul Alam ◽  
Israt Jahan ◽  
Sadniman Rahman ◽  
Hawa Jahan ◽  
Kaniz Fatema

Tilapia is a hardy fish which can survive in water bodies polluted with heavy metals. Metal resistance is conferred by higher expression of metallothionein gene (mt) in many organisms. Level, time and tissue-specificity of gene expression is regulated through transcription factor binding sites (TFBS) which may be present in the upstream, downstream, or even in the introns of a gene. So, as a candidate regulatory region, the 5’upstream sequence of mt gene in three tilapia species, Oreochromis aureus, O. niloticus and O. mossambicus was studied. The targeted region was PCR-amplified and then sequenced using a pair of custom-designed primer. A total of only 2.7% variation was found in the sequenced genomic region among the three species. Metal-related TFBS were predicted from these sequences. A total of twenty eight TFBS were found in O. aureus and twenty nine in O. mossambicus and O. niloticus. The number of metalrelated TFBS predicted in the targeted sequence was significantly higher compared to that found in randomly selected other genomic regions of same size from O. niloticus genome. Thus, the results suggest the presence of putative regulatory elements in the targeted upstream region which might have important role in the regulation of mt gene function. Dhaka Univ. J. Biol. Sci. 30(1): 95-103, 2021 (January)


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Taotao Sheng ◽  
Shamaine Wei Ting Ho ◽  
Wen Fong Ooi ◽  
Chang Xu ◽  
Manjie Xing ◽  
...  

Abstract Background Enhancers are distal cis-regulatory elements required for cell-specific gene expression and cell fate determination. In cancer, enhancer variation has been proposed as a major cause of inter-patient heterogeneity—however, most predicted enhancer regions remain to be functionally tested. Methods We analyzed 132 epigenomic histone modification profiles of 18 primary gastric cancer (GC) samples, 18 normal gastric tissues, and 28 GC cell lines using Nano-ChIP-seq technology. We applied Capture-based Self-Transcribing Active Regulatory Region sequencing (CapSTARR-seq) to assess functional enhancer activity. An Activity-by-contact (ABC) model was employed to explore the effects of histone acetylation and CapSTARR-seq levels on enhancer-promoter interactions. Results We report a comprehensive catalog of 75,730 recurrent predicted enhancers, the majority of which are GC-associated in vivo (> 50,000) and associated with lower somatic mutation rates inferred by whole-genome sequencing. Applying CapSTARR-seq to the enhancer catalog, we observed significant correlations between CapSTARR-seq functional activity and H3K27ac/H3K4me1 levels. Super-enhancer regions exhibited increased CapSTARR-seq signals compared to regular enhancers, even when decoupled from native chromatin contexture. We show that combining histone modification and CapSTARR-seq functional enhancer data improves the prediction of enhancer-promoter interactions and pinpointing of germline single nucleotide polymorphisms (SNPs), somatic copy number alterations (SCNAs), and trans-acting TFs involved in GC expression. We identified cancer-relevant genes (ING1, ARL4C) whose expression between patients is influenced by enhancer differences in genomic copy number and germline SNPs, and HNF4α as a master trans-acting factor associated with GC enhancer heterogeneity. Conclusions Our results indicate that combining histone modification and functional assay data may provide a more accurate metric to assess enhancer activity than either platform individually, providing insights into the relative contribution of genetic (cis) and regulatory (trans) mechanisms to GC enhancer functional heterogeneity.


2020 ◽  
Vol 36 (1) ◽  
Author(s):  
Hyun Jung Chin ◽  
So-young Lee ◽  
Daekee Lee

Abstract Genetically engineered mouse models through gene deletion are useful tools for analyzing gene function. To delete a gene in a certain tissue temporally, tissue-specific and tamoxifen-inducible Cre transgenic mice are generally used. Here, we generated transgenic mouse with cardiac-specific expression of Cre recombinase fused to a mutant estrogen ligand-binding domain (ERT2) on both N-terminal and C-terminal under the regulatory region of human vasoactive intestinal peptide receptor 2 (VIPR2) intron and Hsp68 promoter (VIPR2-ERT2CreERT2). In VIPR2-ERT2CreERT2 transgenic mice, mRNA for Cre gene was highly expressed in the heart. To further reveal heart-specific Cre expression, VIPR2-ERT2CreERT2 mice mated with ROSA26-lacZ reporter mice were examined by X-gal staining. Results of X-gal staining revealed that Cre-dependent recombination occurred only in the heart after treatment with tamoxifen. Taken together, these results demonstrate that VIPR2-ERT2CreERT2 transgenic mouse is a useful model to unveil a specific gene function in the heart.


1996 ◽  
Vol 16 (6) ◽  
pp. 2777-2786 ◽  
Author(s):  
V Gailus-Durner ◽  
J Xie ◽  
C Chintamaneni ◽  
A K Vershon

The meiosis-specific gene HOP1, which encodes a component of the synaptonemal complex, is controlled through two regulatory elements, UASH and URS1H. Sites similar to URS1H have been identified in the promoter region of virtually every early meiosis-specific gene, as well as in many promoters of nonmeiotic genes, and it has been shown that the proteins that bind to this site function to regulate meiotic and nonmeiotic transcription. Sites similar to the UASH site have been found in a number of meiotic and nonmeiotic genes as well. Since it has been shown that UASH functions as an activator site in vegetative haploid cells, it seemed likely that the factors binding to this site regulate both meiotic and nonmeiotic transcription. We purified the factor binding to the UASH element of the HOP1 promoter. Sequence analysis identified the protein as Abf1 (autonomously replicating sequence-binding factor 1), a multifunctional protein involved in DNA replication, silencing, and transcriptional regulation. We show by mutational analysis of the UASH site, that positions outside of the proposed UASH consensus sequence (TNTGN[A/T]GT) are required for DNA binding in vitro and transcriptional activation in vivo. A new UASH consensus sequence derived from this mutational analysis closely matches a consensus Abf1 binding site. We also show that an Abf1 site from a nonmeiotic gene can replace the function of the UASH site in the HOP1 promoter. Taken together, these results show that Abf1 functions to regulate meiotic gene expression.


2012 ◽  
Vol 35 (3) ◽  
pp. 455-462 ◽  
Author(s):  
Reema Khurana ◽  
Hitesh Kathuria ◽  
Arnab Mukhopadhyay ◽  
Sanjay Kapoor ◽  
Akhilesh K. Tyagi

1992 ◽  
Vol 12 (8) ◽  
pp. 3653-3662
Author(s):  
P Lowings ◽  
U Yavuzer ◽  
C R Goding

Melanocytes are specialized cells residing in the hair follicles, the eye, and the basal layer of the human epidermis whose primary function is the production of the pigment melanin, giving rise to skin, hair, and eye color. Melanogenesis, a process unique to melanocytes that involves the processing of tyrosine by a number of melanocyte-specific enzymes, including tyrosinase and tyrosinase-related protein 1 (TRP-1), occurs only after differentiation from the melanocyte precursor, the melanoblast. In humans, melanogenesis is inducible by UV irradiation, with melanin being transferred from the melanocyte in the epidermis to the surrounding keratinocytes as protection from UV-induced damage. Excessive exposure to UV, however, is the primary cause of malignant melanoma, an increasingly common and highly aggressive disease. As an initial approach to understanding the regulation of melanocyte differentiation and melanocyte-specific transcription, we have isolated the gene encoding TRP-1 and examined the cis- and trans-acting factors required for cell-type-specific expression. We find that the TRP-1 promoter comprises both positive and negative regulatory elements which confer efficient expression in a TRP-1-expressing, pigmented melanoma cell line but not in NIH 3T3 or JEG3 cells and that a minimal promoter extending between -44 and +107 is sufficient for cell-type-specific expression. Assays for DNA-protein interactions coupled with extensive mutagenesis identified three factors, whose binding correlated with the function of two positive and one negative regulatory element. One of these factors, termed M-box-binding factor 1, binds to an 11-bp motif, the M box, which acts as a positive regulatory element both in TRP-1-expressing and -nonexpressing cell lines, despite being entirely conserved between the melanocyte-specific tyrosinase and TRP-1 promoters. The possible mechanisms underlying melanocyte-specific gene expression are discussed.


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