Biology subjects

Marques, A.

Publications and source records attributed to Marques, A..

At least 37 records · Page 2Linked to original sources

bioRxiv2025

Impaired trap closure in the counting-deficient Venus flytrap mutant DYSCALCULIA is caused by cell wall biomechanics

Living in nutrient-poor environments, the carnivorous Venus flytrap Dionaea muscipula captures animal prey to compensate for this deficiency. Stimulation of trigger hairs located on the inner trap surface elicits an action potential (AP). While two consecutive APs result in fast trap closure in wildtype (WT) plants, sustained AP generation by the insect struggling to escape the trap leads to jasmonic acid (JA) biosynthesis, formation of the digestive "stomach", and release of enzymes needed to decompose the victim. The Dionaea muscipula DYSCALCULIA (DYSC) mutant is able to fire touch-induced APs, but unlike WT plants, it does not snap-close its traps after two consecutive APs. Moreover, DYSC plants fail to properly initiate the JA pathway in response to mechanostimulation and even wounding, a well-known JA-dependent process conserved among plants. As demonstrated in previous studies, this DYSC mutant defect is associated with impaired decoding of mechanostimulation (i.e. touch) -induced Ca2+ signals. External JA application to the trap, however, restores slow trap closure and digestive gland function in DYSC, while rapid trap closure is JA-independent and cannot be rescued by exogenous JA application. Higher frequency mechanostimulation and thus more APs, however, revealed that DYSC is still able to close its traps, albeit much slower than WT plants. To reveal the molecular underpinnings of DYSCs delayed trap movement, we generated a chromosome-scale Dionaea genome assembly and profiled gene expression. The refined transcriptomic analysis uncovered widespread misregulation of cell wall-related genes in DYSC, implicating altered cell wall plasticity in the sluggish mutant. Cell indentation studies by atomic force microscopy revealed a strictly localized and strikingly enhanced stiffening of the cell wall for DYSC that may hinder rapid trap closure and snap buckling. Together, these genomic, transcriptomic, and biophysical data identify cell wall elasticity as a key constraint on voltage and Ca2+ dependent trap kinetics. This finding documents the interrelationship between mechanosensing and Ca2+ signaling in the ultrafast capture organ of the Venus flytrap.

plant biology↗

bioRxiv2024

Attention and working memory investigated through the P300 component in children practicing Karate at different stages of biological maturation

AimTo investigate attention and working memory, comparing children practice Karate and non-Karate practitioners at different stages of biological maturation through the amplitude and latency of the P300 component during the execution of a Go/No-Go paradigm. Material and MethodsThe P300 was analyzed for Fz, Cz, and Pz electrodes in 80 participants separated in two groups: an Karate practitioners group comprising Karate practitioners and comprising non-Karate practitioners. Each group was further subdivided according to the biological maturation range defined by Peak Height Velocity. In addition, the participants performed a Go/No-Go paradigm to measure amplitude and latency. ResultsThe EEG analysis showed Ffr electrodes Pz and Cz, an interaction was found between group and Peak Height Velocity for the amplitude variable (respectively: F = 45.858; d = 0.38; p < 0.001 / F = 10.411; d = 0.17; p = 0.004). For the Fz electrode, a main effect was found between group and Peak Height Velocity (respectively: F = 40.330; d = 0.34; p = 0.010 / F = 36.730; d = 0.30; p = 0.012) for the variable amplitude and latency. main effect between group and Peak Height Velocity (respectively: F = 7.719; d = 0.14; p = 0.012 / F = 38.370; d = 0.31; p = 0.010). ConclusionsIn general, it is possible to conclude that participants in the Karate practitioners group exhibited electrocortical measures corresponding to greater efficiency in decision-making and attention processes, motor planning, working memory, attention allocation, motor execution, and greater attentional engagement. It was also demonstrated that, despite the children being at very close chronological ages, their biological maturation differed.

neuroscience↗

bioRxiv2024

Direct and indirect regulation of β- glucocerebrosidase by the transcription factors USF2 and ONECUT2

Mutations in the GBA gene, which encodes the lysosomal enzyme {beta}-glucocerebrosidase (GCase), are the most prevalent genetic susceptibility factor for Parkinsons disease (PD). However, only approximately 20% of carriers develop the disease, suggesting the presence of genetic modifiers influencing the risk of developing PD in the presence of GBA mutations. Here we screened 1,634 human transcription factors (TFs) for their effect on GCase activity in cell lysates of the human glioblastoma line LN-229, into which we introduced the pathogenic GBA L444P variant via adenine base editing. Using a novel arrayed CRISPR activation library, we uncovered 11 TFs as regulators of GCase activity. Among these, activation of MITF and TFEC increased lysosomal GCase activity in live cells, while activation of ONECUT2 and USF2 decreased it. Conversely, ablating USF2 increased GBA mRNA and led to enhanced levels of GCase protein and activity. While MITF, TFEC, and USF2 affected GBA transcription, ONECUT2 was found to control GCase trafficking by modulating the guanine exchange factors PLEKHG4 and PLEKHG4B. Hence, our study provides a systematic approach to identifying modulators of GCase activity, expands the transcriptional landscape of GBA regulation, and deepens our understanding of the mechanisms involved in influencing GCase activity.

molecular biology↗

bioRxiv2024

Repeat-based holocentromeres of the woodrush Luzula sylvatica reveal new insights into the evolutionary transition from mono- to holocentricity

Although the centromere is restricted to a single region of the chromosome in most studied eukaryotes, members of the rush family (Juncaceae) harbor either monocentric (Juncus) or holocentric (Luzula) chromosomes. This provides an opportunity to study the evolutionary mechanisms involved in the transition to holocentricity. Here by combining chromosome-scale genome assembly, epigenetic analyses, immuno-FISH, and super-resolution microscopy, we report the occurrence of repeat-based holocentromeres in L. sylvatica. We found an irregular distribution of genes, centromeric units, and most repeats along the chromosomes. We determined the centromere function predominantly associated with two satellite DNA repeats, Lusy1 and Lusy2 of 124- and 174-bp monomer length, respectively, while CENH3 also binds satellite-free gene-poor regions. Comparative repeat analysis revealed that Lusy1 is present in most Luzula species, suggesting a conserved centromere role of this repeat. Synteny between L. sylvatica (n = 6) and J. effusus (n = 21) genomes further evidenced a chromosome number reduction in Luzula derived from multiple chromosome fusions of ancestral J. effusus-like chromosomes. We propose that the transition to holocentricity in Luzula involves: (i) fusion of small chromosomes resembling Juncus-like centromeres; (ii) expansion of atypical centromeric units; and (iii) colonization of satellite DNA for centromere stabilization.

genomics↗

bioRxiv2023

KNL1 and NDC80 represent new universal markers for the detection of functional centromeres in plants

Centromere is the chromosomal site of kinetochore assembly and microtubule attachment for chromosome segregation. Given its importance, markers that allow specific labeling of centromeric chromatin throughout the cell cycle and across all chromosome types are sought for facilitating various centromere studies. Antibodies against the N-terminal region of CENH3 are commonly used for this purpose, since CENH3 is the near-universal marker of functional centromeres. However, because the N-terminal region of CENH3 is highly variable among plant species, antibodies directed against this region usually function only in a small group of closely related species. As a more versatile alternative, we present here antibodies targeted to the conserved domains of two outer kinetochore proteins, KNL1 and NDC80. Sequence comparison of these domains across more than 350 plant species revealed a high degree of conservation, particularly within a six amino acid motif, FFGPVS in KNL1, suggesting that both antibodies would function in a wide range of plant species. This assumption was confirmed by immunolabeling experiments in angiosperm (monocot and dicot) and gymnosperm species, including those with mono-, holo-, and meta-polycentric chromosomes. In addition to centromere labeling on condensed chromosomes during cell division, both antibodies detected the corresponding regions in the interphase nuclei of most species tested. These results demonstrated that KNL1 and NDC80 are better suited for immunolabeling centromeres than CENH3, because antibodies against these proteins offer incomparably greater versatility across different plant species which is particularly convenient for studying the organization and function of the centromere in non-model species.

genetics↗

bioRxiv2023

A comparative analysis of planarian genomes reveals regulatory conservation in the face of rapid structural divergence

The planarian Schmidtea mediterranea can regenerate its entire body from small tissue fragments and is studied as regeneration model species. The assembly and functional analysis of planarian genomes has proven challenging due its high A/T content (70% A/T), repetitive nature, and limited transferability of routine laboratory protocols due to their divergent biochemistry. Only few and often fragmented genome assemblies are currently available, and open challenges include the provision of well-annotated chromosome-scale reference assemblies of the model species and other planarians for a comparative genome evolution perspective. Here we report a haplotype-phased, chromosome-scale genome assembly and high-quality gene annotations of the sexual S2 strain of S. mediterranea and provide putative regulatory region annotations via optimized ATAC-seq and ChIP-seq protocols. To additionally leverage sequence conservation for regulatory element annotations, we generated chromosome-scale genome assemblies and chromatin accessibility data for the three closest relatives of S. mediterranea: S. polychroa, S. nova, and S. lugubris. We find substantial divergence in protein-coding sequences and regulatory regions, yet reveal remarkable conservation in ChIP-mark bearing open chromatin regions identified as promoters and enhancers in S. mediterranea. The resulting high-confidence set of evolutionary conserved enhancers and promoters provides a valuable resource for the analysis of gene regulatory circuits and their evolution within the taxon. In addition, our four chromosome-scale genome assemblies provide a first comparative perspective on planarian genome evolution. Our analyses reveal frequent retrotransposon-associated chromosomal inversions and inter-chromosomal translocations that lead to a degradation of synteny across the genus. Interestingly, we further find independent and near-complete losses of the ancestral metazoan synteny across Schmidtea and two other flatworm groups, indicating that platyhelminth genomes largely evolve without syntenic constraints. Our work provides valuable genome resources for the planarian research community and sets a foundation for the comparative genomics of planarians. We reveal a contrast between the fast structural evolution of planarian genomes and the conservation of their regulatory elements, suggesting a unique genome evolution in flatworms where gene positioning may not be essential.

genomics↗

bioRxiv2023

Oligo-barcodes illuminate holocentric karyotype evolution in Rhynchospora (Cyperaceae)

Holocentric karyotypes are assumed to rapidly evolve through chromosome fusions and fissions due to the diffuse nature of their centromeres. Here, we took advantage of the recent availability of a chromosome-scale reference genome for Rhynchospora breviuscula, a model species of this holocentric genus, and developed the first set of oligo-based barcode probes for a holocentric plant. These probes were applied to 13 additional species of the genus, aiming to investigate the evolutionary dynamics driving the karyotype evolution in Rhynchospora. The two sets of probes were composed of 27,392 (green) and 23,968 (magenta) oligonucleotides, and generated 15 distinct FISH signals as a unique barcode pattern for the identification of all five chromosome pairs of the R. breviuscula karyotype. Oligo-FISH comparative analyzes revealed different types of rearrangements, such as fusions, fissions, putative inversions and translocations, as well as genomic duplications among the analyzed species. Two rounds of whole genome duplication (WGD) were demonstrated in R. pubera, but both analyzed accessions differed in the complex chain of events that gave rise to its large, structurally diploidized karyotypes with 2n = 10 or 12. Considering the phylogenetic relationships and divergence time of the species, the specificity and synteny of the probes were maintained up to species with a divergence time of [~]25 My. However, karyotype divergence in more distant species hindered chromosome mapping and the inference of specific events. This barcoding system is a powerful tool to study chromosomal variations and genomic evolution in holocentric chromosomes of Rhynchospora species.

genomics↗

bioRxiv2023

Subgenome dominance shapes novel gene evolution in the decaploid pitcher plant Nepenthes gracilis

Subgenome dominance after whole-genome duplication generates distinction in gene number and expression at the level of chromosome sets, but it remains unclear how this process may be involved in evolutionary novelty. Here, we generated a chromosome-scale genome assembly of the Asian pitcher plant Nepenthes gracilis to analyze how its novel traits (dioecy and carnivorous pitcher leaves) are linked to genomic evolution. We found a decaploid karyotype with five complete sets of syntenic chromosomes (2n = 10x = 80) yet with a clear indication of subgenome dominance and highly diploidized gene contents. The male-linked and pericentromerically located region on the putative sex chromosome was identified in a recessive subgenome and was found to harbor three transcription factors involved in flower and pollen development, including a likely neofunctionalized LEAFY duplicate. Transcriptomic and syntenic analyses of carnivory-related genes suggested that the paleopolyploidization events seeded genes that subsequently formed tandem clusters in recessive subgenomes with specific expression in the digestive zone of the pitcher, where specialized cells digest prey and absorb derived nutrients. Novel gene evolution in recessive subgenomes is likely to be prevalent because duplicates were enriched with Nepenthes-specific genes with tissue-specific expression, including those expressed in trapping pitchers. Thus, subgenome dominance likely contributed to evolutionary novelty by allowing recessive subgenomes experiencing relaxed purifying selection to serve as a preferred host of novel tissue-specific duplicates. Our results provide insight into how polyploids, which may frequently be evolutionary dead-ends, have given rise to novel traits in exceptionally thriving high-ploidy lineages.

plant biology↗

bioRxiv2023

Meiotic recombination dynamics in plants with repeat-based holocentromeres shed light on the primary drivers of crossover patterning

Centromeres strongly affect (epi)genomic architecture and meiotic recombination dynamics influencing the overall distribution and frequency of crossovers. Here, we studied how recombination is regulated and distributed in the holocentric plant Rhynchospora breviuscula, a species lacking localised centromeres. Combining immunocytochemistry, chromatin analysis and high-throughput single-pollen sequencing, we discovered that crossover frequency is higher at ends related to centred chromosomal regions. Contrasting the diffused distribution of (epi)genetic features and hundreds of repeat-based centromeric units. Remarkably, we found that crossovers were abolished at core centromeric units but not at their vicinity indicating the absence of a centromere effect across repeat-based holocentromeres. We further show that telomere-led pairing and synapsis of homologous chromosomes appear to be the primary force determining the observed U-shaped recombination landscape. While centromere and (epi)genetic properties only affect crossover positioning locally. Our results suggest that the conserved U-shaped crossover distribution of eukaryotes is independent of chromosome compartmentalisation and centromere organisation.

genomics↗

bioRxiv2023

Cholesteryl hemiazelate Identified in Cardiovascular Disease Patients Causes in vitro and in vivo Inflammation

Oxidation of polyunsaturated fatty acids (PUFA) in low-density lipoproteins (LDL) trapped in the arterial intima plays a critical role in atherosclerosis. Though there have been many studies on the atherogenicity of oxidized derivatives of unsaturated fatty acid esters of cholesterol, the effects of the oxidation end-products of these esters has been ignored in the literature. Through lipidomics analyses of the plasma of cardiovascular disease patients and human endarterectomy specimens we identified and quantified cholesteryl hemiesters (ChE), end-products of oxidation of polyunsaturated-fatty acid esters of cholesterol. Cholesteryl hemiazelate (ChA) was the most prevalent ChE identified. Importantly human monocytes, monocyte-derived macrophages (MDM) and neutrophils exhibit inflammatory features when exposed to sub-toxic concentrations of ChA in vitro. ChA increases the secretion of proinflammatory cytokines such as IL-1{beta} and IL-6 and modulates the surface markers profile of monocytes and MDM. In vivo, when zebrafish larvae were fed with a ChA-enriched diet they exhibited neutrophil and macrophage accumulation in the vasculature in a caspase 1- and cathepsin B-dependent manner. ChA also triggered lipid accumulation at the bifurcation sites of the vasculature of the zebrafish larvae and negatively impacted their life expectancy. We conclude that ChA has pro-atherogenic properties and can be considered part of a damage-associated molecular pattern (DAMP) in the development of atherosclerosis.

pathology↗

bioRxiv2022

Plasticity in centromere organization: Holocentromeres can consist of merely a few megabase-sized satellite arrays

The centromere is the chromosome region where the microtubules attach during cell division. In contrast to monocentric chromosomes with one centromere location, holocentric species usually distribute hundreds of centromere units along the entire chromatid. We assembled the chromosome-scale reference genome and analyzed the holocentromere and (epi)genome organization of the lilioid Chionographis japonica. Remarkably, each of its holocentric chromatids consists of only 7 to 11 evenly-spaced megabase-sized centromere-specific histone H3-positive units. These units contain satellite arrays of 23 and 28 bp-long monomers capable of forming palindromic structures. Like monocentric species, C. japonica forms distinctly clustered centromeres in chromocenters at interphase. Additionally, the large-scale eu- and heterochromatin arrangement differs between C. japonica and other known holocentric species. Using polymer simulations, we modeled the formation of prometaphase line-like holocentromeres from interphase centromere clusters. Our findings broaden the knowledge about the diversity of centromere organization, showing that holocentricity is not restricted to species with numerous and small centromere units.

plant biology↗

bioRxiv2020

Aiming off the target: studying repetitive DNA using target capture sequencing reads

O_LIWith the advance of high-throughput sequencing (HTS), reduced-representation methods such as target capture sequencing (TCS) emerged as cost-efficient ways of gathering genomic information. As the off-target reads from such sequencing are expected to be similar to genome skims (GS), we assessed the quality of repeat characterization using this data. C_LIO_LIFor this, repeat composition from TCS datasets of five Rhynchospora (Cyperaceae) species were compared with GS data from the same taxa. C_LIO_LIAll the major repetitive DNA families were identified in TCS, including repeats that showed abundances as low as 0.01% in the GS data. Rank correlation between GS and TCS repeat abundances were moderately high (r = 0.58-0.85), increasing after filtering out the targeted loci from the raw TCS reads (r = 0.66-0.92). Repeat data obtained by TCS was also reliable to develop a cytogenetic probe and solve phylogenetic relationships of Rhynchospora species with high support. C_LIO_LIIn light of our results, TCS data can be effectively used for cyto- and phylogenomic investigations of repetitive DNA. Given the growing availability of HTS reads, driven by global phylogenomic projects, our strategy represents a way to recycle genomic data and contribute to a better characterization of plant biodiversity. C_LI

genomics↗

bioRxiv2020

Estimating RNA dynamics using one time point for one sample in a single-pulse metabolic experiment

Over the past decade, experimental procedures such as metabolic labeling for determining RNA turnover rates at the transcriptome-wide scale have been widely adopted and are now turning to single cell measurements. Several computational methods to estimate RNA processing and degradation rates from such experiments have been suggested, but they all require several RNA sequencing samples. Here we present a method that can estimate RNA synthesis, processing and degradation rates from a single sample. Our method is computationally efficient and outputs rates that correlate well with previously published data sets. Using it on a single sample, we were able to reproduce the observation that dynamic biological processes tend to involve genes with higher metabolic rates, while stable processes involve genes with lower rates. This supports the hypothesis that cells control not only the mRNA steady-state abundance, but also its responsiveness, i.e., how fast steady-state is reached. In addition to saving experimental work and computational time, having a sample-based rate estimation has several advantages. It does not require an error-prone normalization across samples and enables the use of replicates to estimate uncertainty and perform quality control. Finally the method and theoretical results described here are general enough to be useful in other contexts such as nucleotide conversion methods and single cell metabolic labeling experiments.

bioinformatics↗

bioRxiv2020

Monoclonal antibody stability can be usefully monitored using the excitation-energy-dependent fluorescence edge-shift

Among the major challenges in the development of biopharmaceuticals are structural heterogeneity and aggregation. The development of a successful therapeutic monoclonal antibody (mAb) requires both a highly active and also stable molecule. Whilst a range of experimental (biophysical) approaches exist to track changes in stability of proteins, routine prediction of stability remains challenging. The fluorescence red edge excitation shift (REES) phenomenon is sensitive to a range of changes in protein structure. Based on recent work, we have found that quantifying the REES effect is extremely sensitive to changes in protein conformational state and dynamics. Given the extreme sensitivity, potentially this tool could provide a fingerprint of the structure and stability of a protein. Such a tool would be useful in the discovery and development of biopharamceuticals and so we have explored our hypothesis with a panel of therapeutic mAbs. We demonstrate that the quantified REES data show remarkable sensitivity, being able to discern between structurally identical antibodies and showing sensitivity to unfolding and aggregation. The approach works across a broad concentration range (g-mg/ml) and is highly consistent. We show that the approach can be applied alongside traditional characterisation testing within the context of a forced degradation study (FDS). Most importantly, we demonstrate the approach is able to predict the stability of mAbs both in the short (hours), medium (days) and long-term (months). The quantified REES data will find immediate use in the biopharmaceutical industry in quality assurance, formulation and development. The approach benefits from low technical complexity, is rapid and uses instrumentation which exists in most biochemistry laboratories without modification.

biochemistry↗

bioRxiv2019

The contribution of lincRNAs at the interface between cell cycle regulation and cell state maintenance

Cell cycle progression requires dynamic and tightly-regulated transitions between well-defined cell cycle stages. These transitions are controlled by the interplay of established cell cycle regulators. Changes in the activity of these regulators are thought to underpin differences in cell cycle kinetics between distinct cell types. Here, we investigate whether cell type-specific long intergenic noncoding RNAs (lincRNAs) contribute to embryonic stem cell adaptations, which have been shown to be essential for the maintenance of embryonic stem cell state. We used single cell RNA-sequencing data of mouse embryonic stem cells (mESC) staged as G1, S, or G2/M to identify genes differentially expressed between these phases. We found differentially expressed lincRNAs to be enriched amongst cell cycle regulated genes. These cell cycle associated lincRNAs (CC-lincRNAs) are co-expressed with protein-coding genes with established roles in cell cycle progression. Interestingly, 70% of CC-lincRNAs are differentially expressed between G1 and S, suggesting they may contribute to the maintenance of the short G1 phase that characterizes the embryonic stem cell cycle. Consistent with this hypothesis, the promoters of CC-lincRNAs are enriched in pluripotency transcription factor binding sites, and their transcripts are frequently co-regulated with genes involved in the maintenance of pluripotency. We tested the impact of 2 CC-lincRNA candidates and show that modulation of their expression is associated with impaired cell cycle progression, further underlining the contribution of mESC-specific lincRNAs to cell cycle modulation in these cells.

genomics↗

bioRxiv2019

Genome sequence of the cluster root forming white lupin

White lupin (Lupinus albus L.) is a legume that produces seeds recognized for their high protein content and good nutritional value (lowest glycemic index of all grains, high dietary fiber content, and zero gluten or starch)1-5. White lupin can form nitrogen-fixing nodules but has lost the ability to form mycorrhizal symbiosis with fungi6. Nevertheless, its root system is well adapted to poor soils: it produces cluster roots, constituted of dozens of determinate lateral roots that improve soil exploration and phosphate remobilization7. As phosphate is a limited resource that comes from rock reserves8, the production of cluster roots is a trait of interest to improve fertilizers efficiency. Using long reads sequencing technologies, we provide a high-quality genome sequence of a modern variety of white lupin (2n=50, 451 Mb), as well as de novo assemblies of a landrace and a wild relative. We describe how domestication impacted soil exploration capacity through the early establishment of lateral and cluster roots. We identify the APETALA2 transcription factor LaPUCHI-1, homolog of the Arabidopsis morphogenesis coordinator9, as a potential regulator of this trait. Our high-quality genome and companion genomic and transcriptomic resources enable the development of modern breeding strategies to increase and stabilize yield and to develop new varieties with reduced allergenic properties (caused by conglutins10), which would favor the deployment of this promising culture.

genomics↗

bioRxiv2019

A blueprint of seed desiccation sensitivity in the genome of Castanospermum australe

O_LIMost angiosperms produce seeds that are desiccated on dispersal with the ability to retain viability in storage facilities for prolonged periods. However, some species produce desiccation sensitive seeds which rapidly lose viability in storage, precluding ex situ conservation. Current consensus is that desiccation sensitive seeds either lack or do not express mechanisms necessary for the acquisition of desiccation tolerance.\nC_LIO_LIWe sequenced the genome of Castanospermum australe, a legume species producing desiccation sensitive seeds, and characterized its seed developmental physiology and - transcriptomes.\nC_LIO_LIC. australe has a low rate of evolution, likely due to its perennial life-cycle and long generation times. The genome is syntenic with itself, with several orthologs of genes from desiccation tolerant legume seeds, from gamma whole-genome duplication events being retained. Changes in gene expression during development of C. australe seeds, as compared to desiccation tolerant Medicago truncatula seeds, suggest they remain metabolically active, prepared for immediate germination.\nC_LIO_LIOur data indicates that the phenotype of C. australe seeds arose through few changes in specific signalling pathways, precluding or bypassing activation of mechanisms necessary for acquisition of desiccation tolerance. Such changes have been perpetuated as the habitat in which dispersal occurs is favourable for prompt germination.\nC_LI

plant biology↗

bioRxiv2018

Taste Receptor Cells in Mice Express Receptors for the Hormone Adiponectin

The metabolic hormone adiponectin is secreted into the circulation by adipocytes, and mediates key biological functions including insulin sensitivity, adipocyte development, and fatty acid oxidation. Adiponectin is also abundant in saliva, where its functions are poorly understood. Here we report that murine taste receptor cells express adiponectin receptors, and may be a target for salivary adiponectin. Analysis of a transcriptome dataset obtained by RNA-seq analysis of purified circumvallate taste buds, revealed high expression levels for three adiponectin receptor types. Immunohistochemical studies showed that two of these receptors, AdipoR1 and T-cadherin, are localized to subsets of taste receptor cells. Immunofluorescence for T-cadherin was primarily co-localized with the Type 2 taste receptor cell marker phospholipase {beta}2, suggesting that adiponectin signaling could impact sweet, bitter, or umami taste signaling. However, adiponectin null mice showed no differences in taste responsiveness compared to wildtype controls in brief-access taste testing. AAV-mediated overexpression of adiponectin in the salivary glands of adiponectin null mice did result in a small but significant increase in behavioral taste responsiveness to the fat emulsion Intralipid. Together, these results suggest that salivary adiponectin can effect taste receptor cell function, though its impact on taste responsiveness and peripheral taste coding remains unclear.

animal behavior and cognition↗