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result(s) for
"Sen, Sidharth"
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The DNA binding landscape of the maize AUXIN RESPONSE FACTOR family
2018
AUXIN RESPONSE FACTORS (ARFs) are plant-specific transcription factors (TFs) that couple perception of the hormone auxin to gene expression programs essential to all land plants. As with many large TF families, a key question is whether individual members determine developmental specificity by binding distinct target genes. We use DAP-seq to generate genome-wide in vitro TF:DNA interaction maps for fourteen maize ARFs from the evolutionarily conserved A and B clades. Comparative analysis reveal a high degree of binding site overlap for ARFs of the same clade, but largely distinct clade A and B binding. Many sites are however co-occupied by ARFs from both clades, suggesting transcriptional coordination for many genes. Among these, we investigate known QTLs and use machine learning to predict the impact of
cis
-regulatory variation. Overall, large-scale comparative analysis of ARF binding suggests that auxin response specificity may be determined by factors other than individual ARF binding site selection.
AUXIN RESPONSE FACTORS (ARFs) are a family of plant-specific transcriptional factors involved in auxin signaling. Here, the authors adapt DAP-seq technology to show the binding landscape of 14 maize ARFs and reveal class-specific binding properties and transcriptional coordination by ARFs from different classes.
Journal Article
Transcriptomics Analysis Reveals New Insights into the Roles of Notch1 Signaling on Macrophage Polarization
2019
Naïve macrophages (Mφ) polarize in response to various environmental cues to a spectrum of cells that have distinct biological functions. The extreme ends of the spectrum are classified as M1 and M2 macrophages. Previously, we demonstrated that Notch1 deficiency promotes Tgf-β2 dependent M2-polarization in a mouse model of abdominal aortic aneurysm. The present studies aimed to characterize the unique set of genes regulated by Notch1 signaling in macrophage polarization. Bone marrow derived macrophages isolated from
WT
or
Notch1
+/−
mice (n = 12) were differentiated to Mφ, M1 or M2-phenotypes by 24 h exposure to vehicle, LPS/IFN-γ or IL4/IL13 respectively and total RNA was subjected to RNA-Sequencing (n = 3). Bioinformatics analyses demonstrated that
Notch1
haploinsufficiency downregulated the expression of 262 genes at baseline level, 307 genes with LPS/IFN-γ and 254 genes with IL4/IL13 treatment. Among these, the most unique genes downregulated by
Notch1 haploinsufficiency
included
fibromodulin
(
Fmod
),
caspase-4
,
Has1
,
Col1a1
,
Alpl
and
Igf
. Pathway analysis demonstrated that extracellular matrix, macrophage polarization and osteogenesis were the major pathways affected by
Notch1
haploinsufficiency. Gain and loss-of-function studies established a strong correlation between
Notch1
haploinsufficiency and
Fmod
in regulating Tgf-β signaling. Collectively, our studies suggest that
Notch1
haploinsufficiency increases M2 polarization through these newly identified genes.
Journal Article
Zinc is a master-regulator of sperm function associated with binding, motility, and metabolic modulation during porcine sperm capacitation
2022
Sperm capacitation is a post-testicular maturation step endowing spermatozoa with fertilizing capacity within the female reproductive tract, significant for fertility, reproductive health, and contraception. Recently discovered mammalian sperm zinc signatures and their changes during sperm in vitro capacitation (IVC) warranted a more in-depth study of zinc interacting proteins (further zincoproteins). Here, we identified 1752 zincoproteins, with 102 changing significantly in abundance (P < 0.05) after IVC. These are distributed across 8 molecular functions, 16 biological processes, and 22 protein classes representing 130 pathways. Two key, paradigm-shifting observations were made: i) during sperm capacitation, molecular functions of zincoproteins are both upregulated and downregulated within several molecular function categories; and ii) Huntington’s and Parkinson’s disease pathways were the two most represented, making spermatozoon a candidate model for studying neurodegenerative diseases. These findings highlight the importance of Zn
2+
homeostasis in reproduction, offering new avenues in semen processing for human-assisted reproductive therapy, identification of somatic-reproductive comorbidities, and livestock breeding.
Zinc-interacting proteins in porcine sperm change during sperm maturation, particularly those associated with Huntington’s and Parkinson’s disease pathways.
Journal Article
De novo transcriptome assembly from the nodal root growth zone of hydrated and water-deficit stressed maize inbred line FR697
by
Zeng, Shuai
,
Fritschi, Felix B.
,
Sharp, Robert E.
in
631/114/2184
,
631/114/2785/2302
,
631/449/1659
2023
Certain cultivars of maize show increased tolerance to water deficit conditions by maintenance of root growth. To better understand the molecular mechanisms related to this adaptation, nodal root growth zone samples were collected from the reference inbred line B73 and inbred line FR697, which exhibits a relatively greater ability to maintain root elongation under water deficits. Plants were grown under various water stress levels in both field and controlled environment settings. FR697-specific RNA-Seq datasets were generated and used for a de novo transcriptome assembly to characterize any genotype-specific genetic features. The assembly was aided by an Iso-Seq library of transcripts generated from various FR697 plant tissue samples. The Necklace pipeline was used to combine a Trinity de novo assembly along with a reference guided assembly and the Viridiplantae proteome to generate an annotated consensus “SuperTranscriptome” assembly of 47,915 transcripts with a N50 of 3152 bp in length. The results were compared by Blastn to maize reference genes, a Benchmarking Universal Single-Copy Orthologs (BUSCO) genome completeness report and compared with three maize reference genomes. The resultant ‘SuperTranscriptome’ was demonstrated to be of high-quality and will serve as an important reference for analysis of the maize nodal root transcriptomic response to environmental perturbations.
Journal Article
Comparative Transcriptomics Reveal Metabolic Rather than Genetic Control of Divergent Antioxidant Metabolism in the Primary Root Elongation Zone of Water-Stressed Cotton and Maize
by
Sen, Sidharth
,
Oliver, Melvin J.
,
Sharp, Robert E.
in
Abscisic acid
,
Acclimation
,
antioxidant activity
2023
Under water stress, the primary root elongation zones of cotton and maize exhibit both conserved and divergent metabolic responses, including variations in sulfur and antioxidant metabolism. To explore the relative importance of metabolic and genetic controls of these responses for each species, and the extent to which responses are mediated by similar gene expression networks within the framework of ortholog groups, comparative transcriptomics analyses were conducted under conditions of equivalent tissue water stress. Ortholog analysis revealed that 86% of the transcriptome response to water stress was phylogenetically unrelated between cotton and maize. Elevated transcript abundances for genes involved in abscisic acid (ABA) biosynthesis and signaling, as well as key enzymes that enable osmotic adjustment, were conserved between the species. In contrast, antioxidant responses, at least with regard to glutathione metabolism and anti-oxidative enzymes, did not exhibit such a transcript abundance adaptive signature. In particular, previously characterized differential responses of the glutathione and sulfur metabolic pathways between cotton and maize were not evident in the transcriptomic responses. The findings indicate that the antioxidant response in both species results from a metabolic acclimation to water stress, and thus represents an example of water stress-related metabolic plasticity.
Journal Article
Maize nodal root growth maintenance during water deficit: metabolic acclimation and the role of increased solute deposition in osmotic adjustment
by
King-Miller, Shannon K.
,
Zeng, Shuai
,
Fritschi, Felix B.
in
Acclimation
,
Acclimatization
,
Accumulation
2025
Maize ( Zea mays L.) nodal roots are characterized by their ability to maintain elongation under water deficit conditions that inhibit the growth of other organs. Physiological and molecular mechanisms underlying this response were investigated using a divided-container root growth system to impose uniform and steady water deficit (WD) conditions around the nodal roots of maize cv. FR697. Kinematic growth analysis demonstrated that continued nodal root elongation under water deficit involves maintenance of both growth zone length and rates of cell production from the meristem. Nodal roots that maintain growth during WD exhibit increased rates of net solute deposition throughout the growth zone that enable osmotic adjustment and continued tissue expansion. These abilities differ from the maize primary root, which exhibits impairment of both cell expansion and cell production when grown under similar water deficit conditions. Integration of transcriptomic and metabolomic profiling revealed molecular signatures of nodal root growth maintenance, including central transcriptional responses and metabolic pathways related to osmolyte accumulation, hormone signaling, and ROS homeostasis. Several metabolic responses differed from previous characterization of the primary root, including taurine accumulation and proline synthesis via the saccharopine pathway. Further, our analysis showed that metabolic acclimation rather than transcriptional control dominated the water deficit response of the nodal root growth zone. The study highlights novel insights into the interplay of morphogenic and metabolic responses that regulate the remarkable ability of nodal roots to maintain elongation under water deficit conditions.
Journal Article
Phosphate Deficiency Negatively Affects Early Steps of the Symbiosis between Common Bean and Rhizobia
by
Reyero-Saavedra, María del Rocio
,
Sen, Sidharth
,
Sánchez-Correa, Maria del Socorro
in
Genomes
,
Infections
,
Informatics
2018
Phosphate (Pi) deficiency reduces nodule formation and development in different legume species including common bean. Despite significant progress in the understanding of the genetic responses underlying the adaptation of nodules to Pi deficiency, it is still unclear whether this nutritional deficiency interferes with the molecular dialogue between legumes and rhizobia. If so, what part of the molecular dialogue is impaired? In this study, we provide evidence demonstrating that Pi deficiency negatively affects critical early molecular and physiological responses that are required for a successful symbiosis between common bean and rhizobia. We demonstrated that the infection thread formation and the expression of PvNSP2, PvNIN, and PvFLOT2, which are genes controlling the nodulation process were significantly reduced in Pi-deficient common bean seedlings. In addition, whole-genome transcriptional analysis revealed that the expression of hormones-related genes is compromised in Pi-deficient seedlings inoculated with rhizobia. Moreover, we showed that regardless of the presence or absence of rhizobia, the expression of PvRIC1 and PvRIC2, two genes participating in the autoregulation of nodule numbers, was higher in Pi-deficient seedlings compared to control seedlings. The data presented in this study provides a mechanistic model to better understand how Pi deficiency impacts the early steps of the symbiosis between common bean and rhizobia.
Journal Article
An immunophenotype-coupled transcriptomic atlas of human hematopoietic progenitors
by
Hay, Stuart B.
,
Zhang, Xuan
,
Thakkar, Kairavee
in
631/1647/2017
,
631/250/232/2059
,
631/532/1542
2024
Analysis of the human hematopoietic progenitor compartment is being transformed by single-cell multimodal approaches. Cellular indexing of transcriptomes and epitopes by sequencing (CITE-seq) enables coupled surface protein and transcriptome profiling, thereby revealing genomic programs underlying progenitor states. To perform CITE-seq systematically on primary human bone marrow cells, we used titrations with 266 CITE-seq antibodies (antibody-derived tags) and machine learning to optimize a panel of 132 antibodies. Multimodal analysis resolved >80 stem, progenitor, immune, stromal and transitional cells defined by distinctive surface markers and transcriptomes. This dataset enables flow cytometry solutions for in silico-predicted cell states and identifies dozens of cell surface markers consistently detected across donors spanning race and sex. Finally, aligning annotations from this atlas, we nominate normal marrow equivalents for acute myeloid leukemia stem cell populations that differ in clinical response. This atlas serves as an advanced digital resource for hematopoietic progenitor analyses in human health and disease.
In this Resource article, the authors integrate genomic, bioinformatic and flow cytometric data from human bone marrow to provide an atlas of hematopoietic progenitor cell states in health and disease.
Journal Article
Multiomic profiling identifies predictors of survival in African American patients with acute myeloid leukemia
2024
Genomic profiles and prognostic biomarkers in patients with acute myeloid leukemia (AML) from ancestry-diverse populations are underexplored. We analyzed the exomes and transcriptomes of 100 patients with AML with genomically confirmed African ancestry (Black; Alliance) and compared their somatic mutation frequencies with those of 323 self-reported white patients with AML, 55% of whom had genomically confirmed European ancestry (white; BeatAML). Here we find that 73% of 162 gene mutations recurrent in Black patients, including a hitherto unreported
PHIP
alteration detected in 7% of patients, were found in one white patient or not detected. Black patients with myelodysplasia-related AML were younger than white patients suggesting intrinsic and/or extrinsic dysplasia-causing stressors. On multivariable analyses of Black patients,
NPM1
and
NRAS
mutations were associated with inferior disease-free and
IDH1
and
IDH2
mutations with reduced overall survival. Inflammatory profiles, cell type distributions and transcriptional profiles differed between Black and white patients with
NPM1
mutations. Incorporation of ancestry-specific risk markers into the 2022 European LeukemiaNet genetic risk stratification changed risk group assignment for one-third of Black patients and improved their outcome prediction.
Analysis of exomes and transcriptomes from 100 African American patients with acute myeloid leukemia identifies ancestry-related variation in mutation profiles and survival. Refined risk classification suggests clinical relevance of these ancestry-associated differences.
Journal Article
Adventitial macrophage accumulation impairs perivascular nerve function in mesenteric arteries with inflammatory bowel disease
2023
Inflammatory bowel disease (IBD) involves aberrant immune responses and is associated with both cardiovascular disease risk and altered intestinal blood flow. However, little is known about how IBD affects regulation of perivascular nerves that mediate blood flow. Previous work found perivascular nerve function is impaired in mesenteric arteries with IBD. The purpose of this study was to determine the mechanism of impaired perivascular nerve function.INTRODUCTIONInflammatory bowel disease (IBD) involves aberrant immune responses and is associated with both cardiovascular disease risk and altered intestinal blood flow. However, little is known about how IBD affects regulation of perivascular nerves that mediate blood flow. Previous work found perivascular nerve function is impaired in mesenteric arteries with IBD. The purpose of this study was to determine the mechanism of impaired perivascular nerve function.RNA sequencing was performed on mesenteric arteries from IL10-/- mice treated with H.hepaticus to induce disease (IBD) or left non-gavaged (Control). For all other studies, Control and IBD mice received either saline or clodronate liposome injections to study the effect of macrophage depletion. Perivascular nerve function was assessed using pressure myography and electrical field stimulation. Fluorescent immunolabeling was used to label leukocyte populations and perivascular nerves.METHODSRNA sequencing was performed on mesenteric arteries from IL10-/- mice treated with H.hepaticus to induce disease (IBD) or left non-gavaged (Control). For all other studies, Control and IBD mice received either saline or clodronate liposome injections to study the effect of macrophage depletion. Perivascular nerve function was assessed using pressure myography and electrical field stimulation. Fluorescent immunolabeling was used to label leukocyte populations and perivascular nerves.IBD was associated with increased in macrophage-associated gene expression, and immunolabeling showed accumulation of adventitial macrophages. Clodronate liposome injection eliminated adventitial macrophages, which reversed significant attenuation of sensory vasodilation, sympathetic vasoconstriction and sensory inhibition of sympathetic constriction in IBD. Acetylcholine-mediated dilation was impaired in IBD and restored after macrophage depletion, but sensory dilation remained nitric oxide independent regardless of disease and/or macrophage presence.RESULTSIBD was associated with increased in macrophage-associated gene expression, and immunolabeling showed accumulation of adventitial macrophages. Clodronate liposome injection eliminated adventitial macrophages, which reversed significant attenuation of sensory vasodilation, sympathetic vasoconstriction and sensory inhibition of sympathetic constriction in IBD. Acetylcholine-mediated dilation was impaired in IBD and restored after macrophage depletion, but sensory dilation remained nitric oxide independent regardless of disease and/or macrophage presence.Altered neuro-immune signaling between macrophages and perivascular nerves in the arterial adventitia contributes to impaired vasodilation, particularly via dilatory sensory nerves. Targeting the adventitial macrophage population may help preserve intestinal blood flow in IBD patients.CONCLUSIONAltered neuro-immune signaling between macrophages and perivascular nerves in the arterial adventitia contributes to impaired vasodilation, particularly via dilatory sensory nerves. Targeting the adventitial macrophage population may help preserve intestinal blood flow in IBD patients.
Journal Article