Tomatoes are grown for fresh consumption or for processing of the fruit. Some ripening-associated processes of the fruit can either contribute to or degrade attributes associated with both fresh and processing quality. For example, cell wall disassembly is associated with loss of fresh fruit firmness as well as with loss of processed tomato product viscosity. Several enzymes contribute to cell wall polysaccharide disassembly. Polygalacturonase (PG, poly[1,4-alpha-d-galactouronide] glucanohydrolase, EC 3.2.1.15) is among the most abundant polysaccharide hydrolases in ripening tomato fruit and is the major contributor to pectin depolymerization. Expansin (LeExp1) is also abundant in ripening fruit and is proposed to contribute to cell wall disassembly by nonhydrolytic activity, possibly by increasing substrate accessibility to other enzymes. Suppression of either LePG or LeExp1 expression alone results in altered softening and/or shelf life characteristics. To test whether simultaneous suppression of both LePG and LeExp1 expression influences fruit texture in additive or synergistic ways, transgenic Lycopersicon esculentum var. Ailsa Craig lines with reduced expression of either LePG or LeExp1 were crossed. Fruits from the third generation of progeny, homozygous for both transgenic constructs, were analyzed for firmness and other quality traits during ripening on or off the vine. In field-grown transgenic tomato fruit, suppression of LeExp1 or LePG alone did not significantly increase fruit firmness. However, fruits suppressed for both LePG and LeExp1 expression were significantly firmer throughout ripening and were less susceptible to deterioration during long-term storage. Juice prepared from the transgenic tomato fruit with reduced LePG and LeExp1 expression was more viscous than juice prepared from control fruit.

Many components of the circadian molecular clock are conserved from flies to mammals; however, the role of mammalian Timeless remains ambiguous. Here, we report a mutation in the human TIMELESS (hTIM) gene that causes familial advanced sleep phase (FASP). Tim CRISPR mutant mice exhibit FASP with altered photic entrainment but normal circadian period. We demonstrate that the mutation prevents TIM accumulation in the nucleus and has altered affinity for CRY2, leading to destabilization of PER/CRY complex and a shortened period in nonmature mouse embryonic fibroblasts (MEFs). We conclude that TIM, when excluded from the nucleus, can destabilize the negative regulators of the circadian clock, alter light entrainment, and cause FASP.TIMELESS | human genetics | mammalian circadian clock regulation | familial advanced sleep phase T he circadian clock governs the timing of many body functions (1), including the onset and offset of sleep, that oscillate with a ∼24-h period (2-5). The mammalian core clock is composed of the positive transcription activators, BMAL1 and CLOCK, and the key negative regulators, PERs and CRYs (3-5). In recent years, studies of human circadian phenotypes have contributed significantly to a better understanding of the molecular clock. Familial advanced sleep phase (FASP) is an inherited condition where affected subjects wake and sleep early (6). We previously showed mutations in the genes (PER2, CRY2, PER3) for negative regulators of the clock that cause the FASP phenotype (7-9). A common feature of these identified mutations is the instability of PER and CRY, causing derepression of BMAL1/CLOCK. This leads to a shortened circadian period and advanced sleep phase. While we have demonstrated that the shortened period is sufficient to cause FASP (7, 8), a mutation that alters entrainment could potentially produce the FASP phenotype with preserved period (10).Although studies have shown the importance of key conserved components of the circadian clock across species (4), much remains unknown of the role for mammalian homologs of Drosophila Timeless (Tim). Tim is a core component of the Drosophila (d) clock, and it functions as the light-sensitive partner of dPer to provide the negative regulation necessary for generating rhythmicity and photoentrainment in flies (11)(12)(13). Based on phylogenetic analysis, mammalian [both mouse (m) and human (h)] Tim has higher sequence homology to Drosophila Timeless2 (Tim2), which was shown to participate in DNA metabolism, maintenance of chromosomal integrity, and light entrainment of the adult clock (14). Homozygosity for mTim knockout is embryonic lethal (at the preimplantation stage), and analysis of viable heterozygous mTim mutant mice showed no change in circadian period (15). Previous studies have shown that mTim levels in the suprachiasmatic nucleus (SCN) oscillate over circadian time with a peak of expression at the day-night transition, similar to that of mPer2 (16). Conditional knockdown of Tim disrupted the rhythmic neuronal firing in ex vivo rat SCN ...

Orexin (also known as hypocretin) neurons in the hypothalamus play an essential role in sleep–wake control, feeding, reward, and energy homeostasis. The likelihood of anesthesia and sleep sharing common pathways notwithstanding, it is important to understand the processes underlying emergence from anesthesia. In this study, we investigated the role of the orexin system in anesthesia emergence, by specifically activating orexin neurons utilizing the designer receptors exclusively activated by designer drugs (DREADD) chemogenetic approach. With injection of adeno-associated virus into the orexin-Cre transgenic mouse brain, we expressed the DREADD receptor hM3Dq specifically in orexin neurons and applied the hM3Dq ligand clozapine to activate orexin neurons. We monitored orexin neuronal activities by c-Fos staining and whole-cell patch-clamp recording and examined the consequence of orexin neuronal activation via EEG recording. Our results revealed that the orexin–DREADD mice with activated orexin neurons emerged from anesthesia with significantly shorter latency than the control mice. As an indication of reduced pain sensitivity, these orexin–DREADD mice took longer to respond to the 55 °C thermal stimuli in the hot plate test and exhibited significantly less frequent licking of the formalin-injected paw in the formalin test. Our study suggests that approaches to activate the orexin system can be beneficial in postoperative recovery.

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Why do we need to sleep? What regulates when we sleep? And what dictates the number of hours we require? These are often viewed as three separate biological questions. Here, we propose they share molecular etiologies, whereby regulators of sleep schedules and sleep duration also govern the physiological purposes of sleep. To support our hypothesis, we review Mendelian human genetic variants sufficient to advance sleep-wake onset (PER2) and shorten sleep length (DEC2), and evaluate their emerging roles in immune responses that may rely on a sound night of slumber.

IntroductionThe ongoing SARS-CoV-2 pandemic has spurred the development of numerous point of care (PoC) immunoassays. Assessments of performance of available kits are necessary to determine their clinical utility. Previous studies have mostly performed these assessments in a laboratory setting, which raises concerns of translating findings for PoC use. The aim of this study was to assess the performance of a lateral flow immunoassay for the detection of SARS-CoV-2 antibodies using samples collected at PoC.MethodOne lateral flow immunoassay (Humasis® COVID-19 IgG/IgM) was tested. In total, 50 PCR RT-PCR positive and 52 RT-PCR negative samples were collected at PoC. Fifty serum specimens from Dec 2018 to Feb 2019 were used as controls for specificity. Serum samples collected between Dec 2019 to Feb 2020 were used as additional comparators. Clinical data including symptom onset date was collected from patient history and the medical record.ResultsThe overall sensitivity for the kit was 74% (95% CI: 59.7% -85.4%). The sensitivity for IgM and IgG detection >14 days after date of onset was 88% (95% CI: 68.8% -97.5%) and 84% (95% CI: 63.9% – 95.5%), with a negative predictive value (NPV) of 94% for IgM (95% CI: 83.5% - 98.8%) and 93% for IgG (95% CI: 81.8% - 97.9%). The overall specificity was 94% (95% CI: 83.5% - 98.8%). The Immunoglobulin specific specificity was 94% for IgM (95% CI: 83.5% - 98.8%) and 98% for IgG (95% CI: 89.4% - 100.0%), with a positive predictive value (PPV) of 88% for IgM (95% CI: 68.8% - 97.5%) and 95% for IgG (95% CI: 77.2% - 99.9%) respectively for samples collected from patients >14 days after date of onset. Specimen collected during early phase of COVID-19 pandemic (Dec 2019 to Feb 2020) showed 11.8% antibody positivity, and 11.3% of PCR-negative patients demonstrated antibody positivity.DiscussionHumasis® COVID-19 IgG/IgM LFA demonstrates greater than 90% PPV and NPV for samples collected 14 days after the onset of symptoms using samples collected at PoC. While not practical for the diagnosis of acute infection, the use of the lateral flow assays with high specificity may have utility for determining seroprevalence or seroconversion in longitudinal studies.

BACKGROUND The mechanisms of aberrant circulating platelet behavior following injury remain unclear. Platelets retain megakaryocyte immature ribonucleic acid (RNA) splicing and protein synthesis machinery to alter their functions based on physiologic signals. We sought to identify fluctuating platelet-specific RNA transcripts in cell-free plasma (CFP) from traumatic brain injury (TBI) patients as proof-of-concept for using RNA sequencing to improve our understanding of postinjury platelet behavior. We hypothesized that we could identify differential expression of activated platelet-specific spliced RNA transcripts from CFP of patients with isolated severe fatal TBI (fTBI) compared with minimally injured trauma controls (t-controls), filtered by healthy control (h-control) data sets. METHODS High-read depth RNA sequencing was applied to CFP from 10 patients with fTBI (Abbreviated Injury Scale [AIS] for head ≥3, AIS for all other categories <3, and expired) and five t-controls (Injury Severity Score ≤1, and survived). A publicly available CFP RNA sequencing data set from 23 h-controls was used to determine the relative steady state of splice-form RNA transcripts discoverable in CFP. Activated platelet-specific spliced RNA transcripts were derived from studies of ex vivo platelet activation and identified by splice junction presence greater than 1.5-fold or less than 0.67-fold ex vivo nonactivated platelet-specific RNA transcripts. RESULTS Forty-two differentially spliced activated platelet-specific RNA transcripts in 34 genes were altered in CFP from fTBI patients (both upregulated and downregulated). CONCLUSION We have discovered differentially expressed activated platelet-specific spliced RNA transcripts present in CFP from isolated severe fTBI patients that are upregulated or downregulated compared with minimally injured trauma controls. This proof-of-concept suggests that a pool of immature platelet RNAs undergo splicing events after injury for presumed modulation of platelet protein products involved in platelet function. This validates our exploration of injury-induced platelet RNA transcript modulation as an upstream “liquid biopsy” to identify novel postinjury platelet biology and treatment targets for aberrant platelet behavior. LEVEL OF EVIDENCE Diagnostic tests, level V.

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