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1.
Genes Dev ; 35(9-10): 658-676, 2021 05 01.
Article in English | MEDLINE | ID: mdl-33888562

ABSTRACT

The transcription cycle of RNA polymerase II (RNAPII) is governed at multiple points by opposing actions of cyclin-dependent kinases (CDKs) and protein phosphatases, in a process with similarities to the cell division cycle. While important roles of the kinases have been established, phosphatases have emerged more slowly as key players in transcription, and large gaps remain in understanding of their precise functions and targets. Much of the earlier work focused on the roles and regulation of sui generis and often atypical phosphatases-FCP1, Rtr1/RPAP2, and SSU72-with seemingly dedicated functions in RNAPII transcription. Decisive roles in the transcription cycle have now been uncovered for members of the major phosphoprotein phosphatase (PPP) family, including PP1, PP2A, and PP4-abundant enzymes with pleiotropic roles in cellular signaling pathways. These phosphatases appear to act principally at the transitions between transcription cycle phases, ensuring fine control of elongation and termination. Much is still unknown, however, about the division of labor among the PPP family members, and their possible regulation by or of the transcriptional kinases. CDKs active in transcription have recently drawn attention as potential therapeutic targets in cancer and other diseases, raising the prospect that the phosphatases might also present opportunities for new drug development. Here we review the current knowledge and outstanding questions about phosphatases in the context of the RNAPII transcription cycle.


Subject(s)
Phosphoprotein Phosphatases/metabolism , RNA Polymerase II/genetics , Transcription, Genetic/genetics , Animals , Drug Delivery Systems , Humans , Phosphoprotein Phosphatases/genetics
2.
Mol Cell ; 77(6): 1157-1158, 2020 03 19.
Article in English | MEDLINE | ID: mdl-32200795

ABSTRACT

In this issue of Molecular Cell, Cossa et al. (2020) uncover the basis for a dependency of tumor cells with deregulated MYC on the kinase NUAK1, which acts through PP1 and PNUTS to ensure that splicing keeps up with MYC-driven transcription.


Subject(s)
Spliceosomes , Protein Phosphatase 1
3.
Proc Natl Acad Sci U S A ; 119(51): e2122354119, 2022 12 20.
Article in English | MEDLINE | ID: mdl-36508667

ABSTRACT

Islands support unique plants, animals, and human societies found nowhere else on the Earth. Local and global stressors threaten the persistence of island ecosystems, with invasive species being among the most damaging, yet solvable, stressors. While the threat of invasive terrestrial mammals on island flora and fauna is well recognized, recent studies have begun to illustrate their extended and destructive impacts on adjacent marine environments. Eradication of invasive mammals and restoration of native biota are promising tools to address both island and ocean management goals. The magnitude of the marine benefits of island restoration, however, is unlikely to be consistent across the globe. We propose a list of six environmental characteristics most likely to affect the strength of land-sea linkages: precipitation, elevation, vegetation cover, soil hydrology, oceanographic productivity, and wave energy. Global databases allow for the calculation of comparable metrics describing each environmental character across islands. Such metrics can be used today to evaluate relative potential for coupled land-sea conservation efforts and, with sustained investment in monitoring on land and sea, can be used in the future to refine science-based planning tools for integrated land-sea management. As conservation practitioners work to address the effects of climate change, ocean stressors, and biodiversity crises, it is essential that we maximize returns from our management investments. Linking efforts on land, including eradication of island invasive mammals, with marine restoration and protection should offer multiplied benefits to achieve concurrent global conservation goals.


Subject(s)
Conservation of Natural Resources , Ecosystem , Animals , Humans , Biodiversity , Introduced Species , Climate Change , Mammals
4.
Brain ; 146(7): 2792-2802, 2023 07 03.
Article in English | MEDLINE | ID: mdl-37137813

ABSTRACT

Neuromodulation of the anterior nuclei of the thalamus (ANT) has shown to be efficacious in a subset of patients with refractory focal epilepsy. One important uncertainty is to what extent thalamic subregions other than the ANT could be recruited more prominently in the propagation of focal onset seizures. We designed the current study to simultaneously monitor the engagement of the ANT, mediodorsal (MD) and pulvinar (PUL) nuclei during seizures in patients who could be candidates for thalamic neuromodulation. We studied 11 patients with clinical manifestations of presumed temporal lobe epilepsy (TLE) undergoing invasive stereo-encephalography (sEEG) monitoring to confirm the source of their seizures. We extended cortical electrodes to reach the ANT, MD and PUL nuclei of the thalamus. More than one thalamic subdivision was simultaneously interrogated in nine patients. We recorded seizures with implanted electrodes across various regions of the brain and documented seizure onset zones (SOZ) in each recorded seizure. We visually identified the first thalamic subregion to be involved in seizure propagation. Additionally, in eight patients, we applied repeated single pulse electrical stimulation in each SOZ and recorded the time and prominence of evoked responses across the implanted thalamic regions. Our approach for multisite thalamic sampling was safe and caused no adverse events. Intracranial EEG recordings confirmed SOZ in medial temporal lobe, insula, orbitofrontal and temporal neocortical sites, highlighting the importance of invasive monitoring for accurate localization of SOZs. In all patients, seizures with the same propagation network and originating from the same SOZ involved the same thalamic subregion, with a stereotyped thalamic EEG signature. Qualitative visual reviews of ictal EEGs were largely consistent with the quantitative analysis of the corticothalamic evoked potentials, and both documented that thalamic nuclei other than ANT could have the earliest participation in seizure propagation. Specifically, pulvinar nuclei were involved earlier and more prominently than ANT in more than half of the patients. However, which specific thalamic subregion first demonstrated ictal activity could not be reliably predicted based on clinical semiology or lobar localization of SOZs. Our findings document the feasibility and safety of bilateral multisite sampling from the human thalamus. This may allow more personalized thalamic targets to be identified for neuromodulation. Future studies are needed to determine if a personalized thalamic neuromodulation leads to greater improvements in clinical outcome.


Subject(s)
Anterior Thalamic Nuclei , Drug Resistant Epilepsy , Epilepsy, Temporal Lobe , Humans , Seizures/etiology , Brain , Electroencephalography , Drug Resistant Epilepsy/etiology , Electrodes, Implanted/adverse effects
5.
Nature ; 558(7710): 460-464, 2018 06.
Article in English | MEDLINE | ID: mdl-29899453

ABSTRACT

The end of the RNA polymerase II (Pol II) transcription cycle is strictly regulated to prevent interference between neighbouring genes and to safeguard transcriptome integrity 1 . The accumulation of Pol II downstream of the cleavage and polyadenylation signal can facilitate the recruitment of factors involved in mRNA 3'-end formation and termination 2 , but how this sequence is initiated remains unclear. In a chemical-genetic screen, human protein phosphatase 1 (PP1) isoforms were identified as substrates of positive transcription elongation factor b (P-TEFb), also known as the cyclin-dependent kinase 9 (Cdk9)-cyclin T1 (CycT1) complex 3 . Here we show that Cdk9 and PP1 govern phosphorylation of the conserved elongation factor Spt5 in the fission yeast Schizosaccharomyces pombe. Cdk9 phosphorylates both Spt5 and a negative regulatory site on the PP1 isoform Dis2 4 . Sites targeted by Cdk9 in the Spt5 carboxy-terminal domain can be dephosphorylated by Dis2 in vitro, and dis2 mutations retard Spt5 dephosphorylation after inhibition of Cdk9 in vivo. Chromatin immunoprecipitation and sequencing analysis indicates that Spt5 is dephosphorylated as transcription complexes traverse the cleavage and polyadenylation signal, concomitant with the accumulation of Pol II phosphorylated at residue Ser2 of the carboxy-terminal domain consensus heptad repeat 5 . A conditionally lethal Dis2-inactivating mutation attenuates the drop in Spt5 phosphorylation on chromatin, promotes transcription beyond the normal termination zone (as detected by precision run-on transcription and sequencing 6 ) and is genetically suppressed by the ablation of Cdk9 target sites in Spt5. These results suggest that the transition of Pol II from elongation to termination coincides with a Dis2-dependent reversal of Cdk9 signalling-a switch that is analogous to a Cdk1-PP1 circuit that controls mitotic progression 4 .


Subject(s)
Cyclin-Dependent Kinase 9/metabolism , Phosphoprotein Phosphatases/metabolism , RNA Polymerase II/metabolism , Schizosaccharomyces pombe Proteins/metabolism , Schizosaccharomyces/enzymology , Schizosaccharomyces/genetics , Transcription Elongation, Genetic , Transcription Termination, Genetic , Amino Acid Sequence , Cyclin-Dependent Kinase 9/chemistry , Humans , Mitosis , Phosphoprotein Phosphatases/chemistry , Phosphorylation , RNA Polymerase II/chemistry , Schizosaccharomyces/cytology , Schizosaccharomyces pombe Proteins/chemistry , Signal Transduction , Transcriptional Elongation Factors/chemistry , Transcriptional Elongation Factors/metabolism
6.
Genes Dev ; 30(1): 117-31, 2016 Jan 01.
Article in English | MEDLINE | ID: mdl-26728557

ABSTRACT

The transcription cycle of RNA polymerase II (Pol II) is regulated at discrete transition points by cyclin-dependent kinases (CDKs). Positive transcription elongation factor b (P-TEFb), a complex of Cdk9 and cyclin T1, promotes release of paused Pol II into elongation, but the precise mechanisms and targets of Cdk9 action remain largely unknown. Here, by a chemical genetic strategy, we identified ∼ 100 putative substrates of human P-TEFb, which were enriched for proteins implicated in transcription and RNA catabolism. Among the RNA processing factors phosphorylated by Cdk9 was the 5'-to-3' "torpedo" exoribonuclease Xrn2, required in transcription termination by Pol II, which we validated as a bona fide P-TEFb substrate in vivo and in vitro. Phosphorylation by Cdk9 or phosphomimetic substitution of its target residue, Thr439, enhanced enzymatic activity of Xrn2 on synthetic substrates in vitro. Conversely, inhibition or depletion of Cdk9 or mutation of Xrn2-Thr439 to a nonphosphorylatable Ala residue caused phenotypes consistent with inefficient termination in human cells: impaired Xrn2 chromatin localization and increased readthrough transcription of endogenous genes. Therefore, in addition to its role in elongation, P-TEFb regulates termination by promoting chromatin recruitment and activation of a cotranscriptional RNA processing enzyme, Xrn2.


Subject(s)
Cyclin-Dependent Kinase 9/metabolism , Exoribonucleases/genetics , Exoribonucleases/metabolism , Gene Expression Regulation/genetics , Positive Transcriptional Elongation Factor B/metabolism , Chromatin/metabolism , Enzyme Activation/genetics , Genetic Testing , HCT116 Cells , Humans , Phosphorylation , Protein Binding
7.
Neurobiol Dis ; 179: 106045, 2023 04.
Article in English | MEDLINE | ID: mdl-36809846

ABSTRACT

Neuromodulation (neurostimulation) is a relatively new and rapidly growing treatment for refractory epilepsy. Three varieties are approved in the US: vagus nerve stimulation (VNS), deep brain stimulation (DBS) and responsive neurostimulation (RNS). This article reviews thalamic DBS for epilepsy. Among many thalamic sub-nuclei, DBS for epilepsy has been targeted to the anterior nucleus (ANT), centromedian nucleus (CM), dorsomedial nucleus (DM) and pulvinar (PULV). Only ANT is FDA-approved, based upon a controlled clinical trial. Bilateral stimulation of ANT reduced seizures by 40.5% at three months in the controlled phase (p = .038) and 75% by 5 years in the uncontrolled phase. Side effects related to paresthesias, acute hemorrhage, infection, occasional increased seizures, and usually transient effects on mood and memory. Efficacy was best documented for focal onset seizures in temporal or frontal lobe. CM stimulation may be useful for generalized or multifocal seizures and PULV for posterior limbic seizures. Mechanisms of DBS for epilepsy are largely unknown, but animal work points to changes in receptors, channels, neurotransmitters, synapses, network connectivity and neurogenesis. Personalization of therapies, in terms of connectivity of the seizure onset zone to the thalamic sub- nucleus and individual characteristics of the seizures, might lead to improved efficacy. Many questions remain about DBS, including the best candidates for different types of neuromodulation, the best targets, the best stimulation parameters, how to minimize side effects and how to deliver current noninvasively. Despite the questions, neuromodulation provides useful new opportunities to treat people with refractory seizures not responding to medicines and not amenable to resective surgery.


Subject(s)
Deep Brain Stimulation , Drug Resistant Epilepsy , Epilepsy , Animals , Epilepsy/therapy , Thalamus , Seizures/therapy
8.
Phys Rev Lett ; 130(16): 161201, 2023 Apr 21.
Article in English | MEDLINE | ID: mdl-37154654

ABSTRACT

Nuclear burning plays a key role in a wide range of astrophysical stellar transients, including thermonuclear, pair instability, and core collapse supernovae, as well as kilonovae and collapsars. Turbulence is now understood to also play a key role in these astrophysical transients. Here, we demonstrate that turbulent nuclear burning may lead to large enhancements above the uniform background burning rate, since turbulent dissipation gives rise to temperature fluctuations, and in general the nuclear burning rates are highly sensitive to temperature. We derive results for the turbulent enhancement of the nuclear burning rate under the influence of strong turbulence in the distributed burning regime in homogeneous isotropic turbulence, using probability distribution function methods. We demonstrate that the turbulent enhancement obeys a universal scaling law in the limit of weak turbulence. We further demonstrate that, for a wide range of key nuclear reactions, such as C^{12}(O^{16},α)Mg^{24} and 3-α, even relatively modest temperature fluctuations, of the order of 10%, can lead to enhancements of 1-3 orders of magnitude in the turbulent nuclear burning rate. We verify the predicted turbulent enhancement directly against numerical simulations, and find very good agreement. We also present an estimation for the onset of turbulent detonation initiation, and discuss implications of our results for stellar transients.

9.
Epilepsia ; 64(4): 831-842, 2023 04.
Article in English | MEDLINE | ID: mdl-36745000

ABSTRACT

OBJECTIVE: Focused ultrasound ablation (FUSA) is an emerging treatment for neurological and psychiatric diseases. We describe the initial experience from a pilot, open-label, single-center clinical trial of unilateral anterior nucleus of the thalamus (ANT) FUSA in patients with treatment-refractory epilepsy. METHODS: Two adult subjects with treatment-refractory, focal onset epilepsy were recruited. The subjects received ANT FUSA using the Exablate Neuro (Insightec) system. We determined the safety and feasibility (primary outcomes), and changes in seizure frequency (secondary outcome) at 3, 6, and 12 months. Safety was assessed by the absence of side effects, that is, new onset neurological deficits or performance deterioration on neuropsychological testing. Feasibility was defined as the ability to create a lesion within the anterior nucleus. The monthly seizure frequency was compared between baseline and postthalamotomy. RESULTS: The patients tolerated the procedure well, without neurological deficits or serious adverse events. One patient experienced a decline in verbal fluency, attention/working memory, and immediate verbal memory. Seizure frequency reduced significantly in both patients; one patient was seizure-free at 12 months, and in the second patient, the frequency reduced from 90-100 seizures per month to 3-6 seizures per month. SIGNIFICANCE: This is the first known clinical trial to assess the safety, feasibility, and preliminary efficacy of ANT FUSA in adult patients with treatment-refractory focal onset epilepsy.


Subject(s)
Anterior Thalamic Nuclei , Epilepsies, Partial , Adult , Humans , Epilepsies, Partial/diagnostic imaging , Epilepsies, Partial/surgery , Epilepsies, Partial/drug therapy , Seizures/drug therapy , Attention , Treatment Outcome
10.
Epilepsia ; 64(4): 875-887, 2023 04.
Article in English | MEDLINE | ID: mdl-36661376

ABSTRACT

OBJECTIVE: Transcranial direct current stimulation (tDCS) has been advocated for various neurological conditions, including epilepsy. A 1-4-mA cathodal current applied to the scalp over a seizure focus can reduce spikes and seizures. This series of four patients with focal status epilepticus is among the first case series to demonstrate benefit of tDCS in the critical care setting. METHODS: Patients in the intensive care unit were referred for tDCS treatment when focal status epilepticus or clinically relevant lateralized periodic discharges did not resolve with conventional antiseizure medications and anesthetics. Battery-powered direct cathodal current at 2 mA was delivered by an ActivaDose (Caputron) tDCS device via a saline-soaked sponge on the scalp over the seizure focus. Anode was on the contralateral forehead or shoulder. Treatment was for 30 min, repeated twice in a day, then again 1-4 times more over the next few days. RESULTS: Three females and one male, aged 34-68 years, were treated. Etiologies of status epilepticus were posterior reversible encephalopathy syndrome in association with immunosuppressants for a liver transplant, perinatal hypoxic-ischemic injury, a prior cardioembolic parietal stroke, and central nervous system lupus. tDCS led to significant reduction of interictal spikes (.78 to .38/s, p < .0001) in three cases and electrographic seizures (3.83/h to 0/h, p < .001) in two cases. Medication reductions were enabled in all cases subsequent to tDCS. The only side effect of tDCS was transient erythema under the sponge in one case. Two patients died of causes unrelated to tDCS, one was discharged to a nursing home, and one became fully responsive as seizures were controlled with tDCS. SIGNIFICANCE: Spikes and electrographic seizure frequency significantly improved within 1 day of tDCS. Results are potentially confounded by multiple ongoing changes in medications and treatments. These results might encourage further investigation of tDCS in the critical care setting, but verification by controlled studies will be required.


Subject(s)
Epilepsia Partialis Continua , Posterior Leukoencephalopathy Syndrome , Status Epilepticus , Transcranial Direct Current Stimulation , Female , Humans , Male , Transcranial Direct Current Stimulation/adverse effects , Transcranial Direct Current Stimulation/methods , Patient Discharge , Posterior Leukoencephalopathy Syndrome/etiology , Electroencephalography , Seizures/etiology , Status Epilepticus/therapy , Status Epilepticus/etiology , Critical Care
11.
J Endovasc Ther ; 30(3): 449-460, 2023 06.
Article in English | MEDLINE | ID: mdl-35297713

ABSTRACT

PURPOSE: The purpose of the study was to provide a consensus definition of the infrarenal sealing zone and develop an algorithm to determine when and if adjunctive procedure(s) or reintervention should be considered in managing patients undergoing endovascular aortic repair (EVAR) for infrarenal abdominal aortic aneurysm (AAA). METHODS: A European Advisory Board (AB), made up of 11 vascular surgeons with expertise in EVAR for AAA, was assembled to share their opinion regarding the definition of preoperative and postoperative infrarenal sealing zone. Information on their current clinical practice and level of agreement on proposed reintervention paths was used to develop an algorithm. The process included 2 virtual meetings and 2 rounds of online surveys completed by the AB (Delphi method). Consensus was defined as reached when ≥ 8 of 11 (73%) respondents agreed or were neutral. RESULTS: The AB reached complete consensus on definitions and measurement of the pre-EVAR target anticipated sealing zone (TASZ) and the post-EVAR real achieved sealing zone (RASZ), namely, the shortest length between the proximal and distal reference points as defined by the AB, in case of patients with challenging anatomies. Also, agreement was achieved on a list of 4 anatomic parameters and 3 prosthesis-/procedure-related parameters, considered to have the most significant impact on preoperative and postoperative sealing zones. Furthermore, the agreement was reached that in the presence of visible neck-related complications, both adjunctive procedure(s) and reintervention should be contemplated (100% consensus). In addition, adjunctive procedure(s) or reintervention can be considered in the following cases (% consensus): insufficient sealing zone on completion imaging (91%) or on the first postoperative computed tomography (CT) scan (91%), suboptimal sealing zone on completion imaging (73%) or postoperative CT scan (82%), and negative evolution of the actual sealing zone over time (91%), even in the absence of visible complications. CONCLUSIONS: AB members agreed on definitions of the pre- and post-EVAR infrarenal sealing zone, as well as factors of influence. Furthermore, a clinical decision algorithm was proposed to determine the timing and necessity of adjunctive procedure(s) and reinterventions.


Subject(s)
Aortic Aneurysm, Abdominal , Blood Vessel Prosthesis Implantation , Endovascular Procedures , Humans , Blood Vessel Prosthesis Implantation/adverse effects , Blood Vessel Prosthesis Implantation/methods , Endovascular Aneurysm Repair , Delphi Technique , Consensus , Expert Testimony , Treatment Outcome , Endovascular Procedures/adverse effects , Aortic Aneurysm, Abdominal/diagnostic imaging , Aortic Aneurysm, Abdominal/surgery , Risk Factors , Retrospective Studies , Blood Vessel Prosthesis
12.
J Vasc Interv Radiol ; 34(7): 1149-1156, 2023 07.
Article in English | MEDLINE | ID: mdl-36889436

ABSTRACT

PURPOSE: To evaluate the technical success, feasibility, and outcomes of endovascular preservation of segmental arteries (SAs) during fenestrated/branched endovascular aortic repair (F/B-EVAR). MATERIALS AND METHODS: A multicenter, retrospective study was conducted in consecutive patients treated with F/B-EVAR and a branch or fenestration for SA preservation. Eleven patients (median age, 57 years; range, 45-73 years; 7 men) were included. RESULTS: Twelve SAs were preserved. Stent grafts were custom made with fenestrations, branches, or a combination of both in 1, 2, and 5 patients, respectively. A t-Branch stent graft was used in 2 patients, and a physician-modified thoracic stent graft with a branch was used in 1 patient. Eight branches and 4 fenestrations were used for the preservation of 12 SAs. Four fenestrations and 1 branch for the SAs were not bridged and were left for perfusion of the corresponding SAs. Technical success was achieved in 10 of 11 (91%) patients. No early mortality occurred. Early morbidities included renal insufficiency without dialysis in 1 patient and partially delayed paraplegia in 1 patient. Before discharge, computed tomography angiography (CTA) showed patency of all the SAs. The median follow-up duration was 30 months (range, 10-88 months). Late death occurred in 1 patient. Two SAs were occluded in 1 patient with 2 unstented fenestrations, as determined using 1-year follow-up CTA. This patient did not develop spinal cord ischemia (SCI). Other SAs remained patent during follow-up. One patient with a type IIIc endoleak was treated by relining of bridging stents. CONCLUSIONS: Endovascular preservation of SAs with F/B-EVAR for thoracoabdominal aortic aneurysm is feasible and safe in select patients and may add to preventive measures for SCI.


Subject(s)
Aortic Aneurysm, Thoracic , Aortic Aneurysm, Thoracoabdominal , Blood Vessel Prosthesis Implantation , Endovascular Procedures , Male , Humans , Middle Aged , Blood Vessel Prosthesis , Blood Vessel Prosthesis Implantation/adverse effects , Aortic Aneurysm, Thoracic/diagnostic imaging , Aortic Aneurysm, Thoracic/surgery , Retrospective Studies , Feasibility Studies , Treatment Outcome , Risk Factors , Prosthesis Design , Stents , Arteries , Endovascular Procedures/adverse effects
13.
Environ Sci Technol ; 57(45): 17511-17521, 2023 11 14.
Article in English | MEDLINE | ID: mdl-37902062

ABSTRACT

Mercury (Hg) is a toxic contaminant that has been mobilized and distributed worldwide and is a threat to many wildlife species. Amphibians are facing unprecedented global declines due to many threats including contaminants. While the biphasic life history of many amphibians creates a potential nexus for methylmercury (MeHg) exposure in aquatic habitats and subsequent health effects, the broad-scale distribution of MeHg exposure in amphibians remains unknown. We used nonlethal sampling to assess MeHg bioaccumulation in 3,241 juvenile and adult amphibians during 2017-2021. We sampled 26 populations (14 species) across 11 states in the United States, including several imperiled species that could not have been sampled by traditional lethal methods. We examined whether life history traits of species and whether the concentration of total mercury in sediment or dragonflies could be used as indicators of MeHg bioaccumulation in amphibians. Methylmercury contamination was widespread, with a 33-fold difference in concentrations across sites. Variation among years and clustered subsites was less than variation across sites. Life history characteristics such as size, sex, and whether the amphibian was a frog, toad, newt, or other salamander were the factors most strongly associated with bioaccumulation. Total Hg in dragonflies was a reliable indicator of bioaccumulation of MeHg in amphibians (R2 ≥ 0.67), whereas total Hg in sediment was not (R2 ≤ 0.04). Our study, the largest broad-scale assessment of MeHg bioaccumulation in amphibians, highlights methodological advances that allow for nonlethal sampling of rare species and reveals immense variation among species, life histories, and sites. Our findings can help identify sensitive populations and provide environmentally relevant concentrations for future studies to better quantify the potential threats of MeHg to amphibians.


Subject(s)
Mercury , Methylmercury Compounds , Odonata , Water Pollutants, Chemical , Animals , Water Pollutants, Chemical/analysis , Mercury/analysis , Amphibians , Environmental Monitoring
14.
J Hered ; 114(6): 690-697, 2023 Nov 15.
Article in English | MEDLINE | ID: mdl-37688363

ABSTRACT

Snakes in the family Colubridae include more than 2,000 currently recognized species, and comprise roughly 75% of the global snake species diversity on Earth. For such a spectacular radiation, colubrid snakes remain poorly understood ecologically and genetically. Two subfamilies, Colubrinae (788 species) and Dipsadinae (833 species), comprise the bulk of colubrid species richness. Dipsadines are a speciose and diverse group of snakes that largely inhabit Central and South America, with a handful of small-body-size genera that have invaded North America. Among them, the ring-necked snake, Diadophis punctatus, has an incredibly broad distribution with 14 subspecies. Given its continental distribution and high degree of variation in coloration, diet, feeding ecology, and behavior, the ring-necked snake is an excellent species for the study of genetic diversity and trait evolution. Within California, six subspecies form a continuously distributed "ring species" around the Central Valley, while a seventh, the regal ring-necked snake, Diadophis punctatus regalis is a disjunct outlier and Species of Special Concern in the state. Here, we report a new reference genome assembly for the San Diego ring-necked snake, D. p. similis, as part of the California Conservation Genomics Project. This assembly comprises a total of 444 scaffolds spanning 1,783 Mb and has a contig N50 of 8.0 Mb, scaffold N50 of 83 Mb, and BUSCO completeness score of 94.5%. This reference genome will be a valuable resource for studies of the taxonomy, conservation, and evolution of the ring-necked snake across its broad, continental distribution.


Subject(s)
Colubridae , Animals , Colubridae/genetics , Genomics , Genome , North America , Phylogeny
15.
J Hered ; 114(6): 681-689, 2023 Nov 15.
Article in English | MEDLINE | ID: mdl-37493092

ABSTRACT

Rattlesnakes play important roles in their ecosystems by regulating prey populations, are involved in complex coevolutionary dynamics with their prey, and exhibit a variety of unusual adaptations, including maternal care, heat-sensing pit organs, hinged fangs, and medically-significant venoms. The western rattlesnake (Crotalus oreganus) is one of the widest ranging rattlesnake species, with a distribution from British Columbia, where it is listed as threatened, to Baja California and east across the Great Basin to western Wyoming, Colorado and New Mexico. Here, we report a new reference genome assembly for one of six currently recognized subspecies, C. oreganus helleri, as part of the California Conservation Genomics Project (CCGP). Consistent with the reference genomic sequencing strategy of the CCGP, we used Pacific Biosciences HiFi long reads and Hi-C chromatin-proximity sequencing technology to produce a de novo assembled genome. The assembly comprises a total of 698 scaffolds spanning 1,564,812,557 base pairs, has a contig N50 of 64.7 Mb, a scaffold N50 of 110.8 Mb, and BUSCO complete score of 90.5%. This reference genome will be valuable for studies on the genomic basis of venom evolution and variation within Crotalus, in resolving the taxonomy of C. oreganus and its relatives, and for the conservation and management of rattlesnakes in general.


Subject(s)
Crotalus , Ecosystem , Venomous Snakes , Animals , Mexico , Crotalus/genetics
16.
J Hered ; 114(5): 521-528, 2023 08 23.
Article in English | MEDLINE | ID: mdl-37335574

ABSTRACT

Spiny lizards (genus Sceloporus) have long served as important systems for studies of behavior, thermal physiology, dietary ecology, vector biology, speciation, and biogeography. The western fence lizard, Sceloporus occidentalis, is found across most of the major biogeographical regions in the western United States and northern Baja California, Mexico, inhabiting a wide range of habitats, from grassland to chaparral to open woodlands. As small ectotherms, Sceloporus lizards are particularly vulnerable to climate change, and S. occidentalis has also become an important system for studying the impacts of land use change and urbanization on small vertebrates. Here, we report a new reference genome assembly for S. occidentalis, as part of the California Conservation Genomics Project (CCGP). Consistent with the reference genomics strategy of the CCGP, we used Pacific Biosciences HiFi long reads and Hi-C chromatin-proximity sequencing technology to produce a de novo assembled genome. The assembly comprises a total of 608 scaffolds spanning 2,856 Mb, has a contig N50 of 18.9 Mb, a scaffold N50 of 98.4 Mb, and BUSCO completeness score of 98.1% based on the tetrapod gene set. This reference genome will be valuable for understanding ecological and evolutionary dynamics in S. occidentalis, the species status of the California endemic island fence lizard (S. becki), and the spectacular radiation of Sceloporus lizards.


Subject(s)
Genome , Lizards , Animals , Mexico , Ecosystem , Genomics , Lizards/genetics
17.
J Hered ; 114(4): 410-417, 2023 06 22.
Article in English | MEDLINE | ID: mdl-37195437

ABSTRACT

Genome assemblies are increasingly being used to identify adaptive genetic variation that can help prioritize the population management of protected species. This approach may be particularly relevant to species like Blainville's horned lizard, Phrynosoma blainvillii, due to its specialized diet on noxious harvester ants, numerous adaptative traits for avoiding predation (e.g. cranial horns, dorsoventrally compressed body, cryptic coloration, and blood squirting from the orbital sinuses), and status as Species of Special Concern in California. Rangewide decline since the early 20th century, the basis of its conservation status, has been driven mainly by habitat conversion, over-collecting, and invasion of a non-native ant that displaces its native ant prey base. Here, we report on a scaffold-level genome assembly for P. blainvillii as part of the California Conservation Genomics Project (CCGP), produced using Pacific Biosciences HiFi long reads and Hi-C chromatin-proximity sequencing technology. The de novo assembly has 78 scaffolds, a total length of ~2.21 Gb, a scaffold N50 length of ~352 Mb, and BUSCO score of 97.4%. This is the second species of Phrynosoma for which a reference genome has been assembled and represents a considerable improvement in terms of contiguity and completeness. Combined with the landscape genomics data being compiled by the CCGP, this assembly will help strategize efforts to maintain and/or restore local genetic diversity, where interventions like genetic rescue, translocation, and strategic land preservation may be the only means by which P. blainvillii and other low-vagility species can survive in the fragmented habitats of California.


Subject(s)
Lizards , Animals , Lizards/genetics , Genome , Genomics , Chromosomes , North America
18.
BMC Public Health ; 23(1): 876, 2023 05 12.
Article in English | MEDLINE | ID: mdl-37173717

ABSTRACT

Fear of disease may act as a barrier to screening or early diagnosis. This cross-sectional survey of 355 people attending outpatient clinics at one Australian hospital found that cancer (34%) and dementia (29%) were the most feared diseases. Participants aged 65 years and over feared dementia the most.


Subject(s)
Dementia , Neoplasms , Humans , Australia/epidemiology , Cross-Sectional Studies , Dementia/epidemiology , Health Services , Neoplasms/epidemiology
19.
BMC Public Health ; 23(1): 2334, 2023 11 24.
Article in English | MEDLINE | ID: mdl-38001441

ABSTRACT

BACKGROUND: Although social housing provides access to safe and affordable housing, recent studies have found that social housing tenants consistently have lower levels of health and well-being compared to other people. Given this, there is a need to examine multimorbidity for social housing tenants. METHODS: Secondary data analysis of the 2017-18 Australian National Health Survey (n = 14,327) compared the health of adults residing in social housing compared to people in other housing types (private rentals, homeowners, and homeowners/mortgagees). RESULTS: Most health factors examined were more prevalent in social housing tenants compared to those living in other housing types. Individual health problems identified as more highly prevalent in social housing tenants compared to all other housing types included mental health issues (43%), arthritis (36%), back problems (32%), hypertension (25%), asthma (22%) and COPD (11%). 24% of social housing tenants reported five or more health factors compared to 3-6% of people in other housing types. CONCLUSIONS: Although these findings are not unexpected, they provide more detailed evidence that social housing providers and policy makers should consider when planning future initiatives.


Subject(s)
Housing , Public Housing , Adult , Humans , Australia/epidemiology , Health Surveys
20.
BMC Med Educ ; 23(1): 759, 2023 Oct 12.
Article in English | MEDLINE | ID: mdl-37828464

ABSTRACT

BACKGROUND: Australian paramedics must engage in continuing professional development (CPD), including self-directed learning (SDL). This study aimed to examine paramedics' attitudes towards training and learning activities and perceptions about what could increase engagement in self-directed CPD. METHODS: A cross-sectional survey was conducted with New South Wales Ambulance paramedics. The 48-item survey examined learning attitudes, attitudes towards SDL and socio-demographic and professional characteristics. RESULTS: Most of the 149 participants (19% consent rate) were male (74.5%) and worked full-time (96.5%). All participants agreed that paramedics should reflect on the quality of their practice (100%) and most were committed to undertaking learning to improve their skills and capability (95.2%). However, 26.3% of participants did not feel motivated to undertake learning and 58.9% did not feel supported. Paramedics reported neutral to modestly positive attitudes towards SDL. Most participants agreed they would be more likely to engage in SDL if they had access to training equipment at their station (91%) and dedicated time during work hours (90.4%). CONCLUSION: Paramedics are highly committed to undertaking CPD. Increased engagement may be supported by providing SDL materials at work locations and ensuring dedicated time for learning during work hours.


Subject(s)
Attitude , Paramedics , Humans , Male , Female , Cross-Sectional Studies , New South Wales , Australia
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