Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

The biochemical basis for thermoregulation in heat-producing flowers.

ABSTRACT: Thermoregulation (homeothermy) in animals involves a complex mechanism involving thermal receptors throughout the body and integration in the hypothalamus that controls shivering and non-shivering thermogenesis. The flowers of some ancient families of seed plants show a similar degree of physiological thermoregulation, but by a different mechanism. Here, we show that respiratory control in homeothermic spadices of skunk cabbage (Symplocarpus renifolius) is achieved by rate-determining biochemical reactions in which the overall thermodynamic activation energy exhibits a negative value. Moreover, NADPH production, catalyzed by mitochondrial isocitrate dehydrogenase in a chemically endothermic reaction, plays a role in the pre-equilibrium reaction. We propose that a law of chemical equilibrium known as Le Châtelier's principle governs the homeothermic control in skunk cabbage.

SUBMITTER: Umekawa Y

PROVIDER: S-EPMC4837406 | biostudies-literature | 2016 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

The biochemical basis for thermoregulation in heat-producing flowers.

Umekawa Yui Y Seymour Roger S RS Ito Kikukatsu K

Scientific reports 20160420

Thermoregulation (homeothermy) in animals involves a complex mechanism involving thermal receptors throughout the body and integration in the hypothalamus that controls shivering and non-shivering thermogenesis. The flowers of some ancient families of seed plants show a similar degree of physiological thermoregulation, but by a different mechanism. Here, we show that respiratory control in homeothermic spadices of skunk cabbage (Symplocarpus renifolius) is achieved by rate-determining biochemica ...[more]

PMID: 27095582

Similar Datasets

Isolation, biochemical and genetic characterizations of alcohol-producing yeasts from the flowers of Woodfordia fruticosa.

Project description:ObjectiveTo isolate and characterize the alcohol-producing yeasts from Woodfordia fruticosa flowers, which are used for the induction and maintenance of fermentation in the making of Ayurvedic formulations.Materials and methodsInitially twenty four yeasts strains were isolated on MGYP agar plate. Among them, four strains were selected for further studies on the basis of their alcohol generation capacity using jaggery media (50% w/v). Physiological, biochemical and genetic characterization (18S rRNA sequencing) of selected strains were carried out.ResultsPhysiological, biochemical and genetic characterization (18S rRNA sequencing) confirmed the strains as Saccharomycopsis fibuligera Jm.8, S. fibuligera Jm.10, S. fibuligera Jm.16 and Saccharomyces cerevisiae Jm.20. Under the controlled conditions, S. cerevisiae Jm.20 produced 69.57 g/l of alcohol, whereas remaining strains produced the alcohol in the range of 6.04-7.32 g/l.ConclusionAmong selected strains, strains S. fibuligera are a newer in the flowers. Kinetic study of alcohol generation revealed the strain S. cerevisiae Jm.20 can be efficiently used in making of fermented Ayurvedic formulations instead of use W. fruticosa flowers.

| S-EPMC3930101 | biostudies-literature

Parabrachial neuron types categorically encode thermoregulation variables during heat defense.

Project description:Heat defense is crucial for survival and fitness. Transmission of thermosensory signals into hypothalamic thermoregulation centers represents a key layer of regulation in heat defense. Yet, how these signals are transmitted into the hypothalamus remains poorly understood. Here, we reveal that lateral parabrachial nucleus (LPB) glutamatergic prodynorphin and cholecystokinin neuron populations are progressively recruited to defend elevated body temperature. These two nonoverlapping neuron types form circuits with downstream preoptic hypothalamic neurons to inhibit the thermogenesis of brown adipose tissues (BATs) and activate tail vasodilation, respectively. Both circuits are activated by warmth and can limit fever development. The prodynorphin circuit is further required for regulating energy expenditure and body weight homeostasis. Thus, these findings establish that the genetic and functional specificity of heat defense neurons occurs as early as in the LPB and uncover categorical neuron types for encoding two heat defense variables, inhibition of BAT thermogenesis and activation of vasodilation.

| S-EPMC7467693 | biostudies-literature

Countercurrent heat exchange and thermoregulation during blood-feeding in kissing bugs.

Project description:Blood-sucking insects experience thermal stress at each feeding event on endothermic vertebrates. We used thermography to examine how kissing-bugs Rhodnius prolixus actively protect themselves from overheating. During feeding, these bugs sequester and dissipate the excess heat in their heads while maintaining an abdominal temperature close to ambient. We employed a functional-morphological approach, combining histology, µCT and X-ray-synchrotron imaging to shed light on the way these insects manage the flow of heat across their bodies. The close alignment of the circulatory and ingestion systems, as well as other morphological characteristics, support the existence of a countercurrent heat exchanger in the head of R. prolixus, which decreases the temperature of the ingested blood before it reaches the abdomen. This kind of system has never been described before in the head of an insect. For the first time, we show that countercurrent heat exchange is associated to thermoregulation during blood-feeding.

| S-EPMC5697934 | biostudies-literature

The biochemical basis of microRNA targeting efficacy

Project description:This SuperSeries is composed of the SubSeries listed below.

2019-11-27 | GSE140220 | GEO

Oil-producing flowers within the Iridoideae (Iridaceae): evolutionary trends in the flowers of the New World genera.

Project description:Background and aimsOil-producing flowers related to oil-bee pollination are a major innovation in Neotropical and Mexican Iridaceae. In this study, phylogenetic relationships were investigated among a wide array of New World genera of the tribes Sisyrinchieae, Trimezieae and Tigridieae (Iridaceae: Iridoideae) and the evolution of floral glandular structures, which are predominantly trichomal elaiophores, was examined in relation to the diversification of New World Iridaceae.MethodsPhylogenetic analyses based on seven molecular markers obtained from 97 species were conducted to produce the first extensive phylogeny of the New World tribes of subfamily Iridoideae. The resulting phylogenetic hypothesis was used to trace the evolutionary history of glandular structures present in the flowers of numerous species in each tribe. Hypotheses of differential diversification rates among lineages were also investigated using both topological and Binary-State Speciation and Extinction methods.Key results and conclusionsFloral glandular structures and especially trichomal elaiophores evolved multiple times independently in the American tribes of Iridoideae. The distribution pattern of species displaying glandular trichomes across the phylogeny reveals lability in the pollination system and suggests that these structures may have played a significant role in the diversification of the Iridoideae on the American continent.

| S-EPMC3400458 | biostudies-literature

The biochemical basis of microRNA targeting efficacy [5]

Project description:MicroRNAs (miRNAs) act within Argonaute proteins to guide repression of mRNA targets. Although various approaches have provided insight into target recognition, the sparsity of miRNA–target affinity measurements has limited understanding and prediction of targeting efficacy. Here, we adapted RNA bind-n-seq to enable measurement of relative binding affinities between Argonaute–miRNA complexes and all ≤12-nucleotide sequences. This approach revealed noncanonical target sites unique to each miRNA, miRNA-specific differences in canonical target-site affinities, and a 100-fold impact of dinucleotides flanking each site. These data enabled construction of a biochemical model of miRNA-mediated repression, which was extended to all miRNA sequences using a convolutional neural network. This model substantially improved prediction of cellular repression, thereby providing a biochemical basis for quantitatively integrating miRNAs into gene-regulatory networks.

2019-11-27 | GSE140218 | GEO

The biochemical basis of microRNA targeting efficacy [4]

2019-11-27 | GSE140217 | GEO