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1.
Biomater Sci ; 2024 Jul 19.
Article in English | MEDLINE | ID: mdl-39028033

ABSTRACT

Increased disulfide crosslinking of secreted mucins causes elevated viscoelasticity of mucus and is a key determinant of mucus dysfunction in patients with cystic fibrosis (CF) and other muco-obstructive lung diseases. In this study, we describe the synthesis of a novel thiol-containing, sulfated dendritic polyglycerol (dPGS-SH), designed to chemically reduce these abnormal crosslinks, which we demonstrate with mucolytic activity assays in sputum from patients with CF. This mucolytic polymer, which is based on a reportedly anti-inflammatory polysulfate scaffold, additionally carries multiple thiol groups for mucolytic activity and can be produced on a gram-scale. After a physicochemical compound characterization, we compare the mucolytic activity of dPGS-SH to the clinically approved N-acetylcysteine (NAC) using western blot studies and investigate the effect of dPGS-SH on the viscoelastic properties of sputum samples from CF patients by oscillatory rheology. We show that dPGS-SH is more effective than NAC in reducing multimer intensity of the secreted mucins MUC5B and MUC5AC and demonstrate significant mucolytic activity by rheology. In addition, we provide data for dPGS-SH demonstrating a high compound stability, low cytotoxicity, and superior reaction kinetics over NAC at different pH levels. Our data support further development of the novel reducing polymer system dPGS-SH as a potential mucolytic to improve mucus function and clearance in patients with CF as well as other muco-obstructive lung diseases.

3.
Nat Ecol Evol ; 8(7): 1311-1326, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38945974

ABSTRACT

Ninu (greater bilby, Macrotis lagotis) are desert-dwelling, culturally and ecologically important marsupials. In collaboration with Indigenous rangers and conservation managers, we generated the Ninu chromosome-level genome assembly (3.66 Gbp) and genome sequences for the extinct Yallara (lesser bilby, Macrotis leucura). We developed and tested a scat single-nucleotide polymorphism panel to inform current and future conservation actions, undertake ecological assessments and improve our understanding of Ninu genetic diversity in managed and wild populations. We also assessed the beneficial impact of translocations in the metapopulation (N = 363 Ninu). Resequenced genomes (temperate Ninu, 6; semi-arid Ninu, 6; and Yallara, 4) revealed two major population crashes during global cooling events for both species and differences in Ninu genes involved in anatomical and metabolic pathways. Despite their 45-year captive history, Ninu have fewer long runs of homozygosity than other larger mammals, which may be attributable to their boom-bust life history. Here we investigated the unique Ninu biology using 12 tissue transcriptomes revealing expression of all 115 conserved eutherian chorioallantoic placentation genes in the uterus, an XY1Y2 sex chromosome system and olfactory receptor gene expansions. Together, we demonstrate the holistic value of genomics in improving key conservation actions, understanding unique biological traits and developing tools for Indigenous rangers to monitor remote wild populations.


Subject(s)
Conservation of Natural Resources , Genome , Marsupialia , Animals , Marsupialia/genetics , Australia , Polymorphism, Single Nucleotide , Extinction, Biological
4.
Eur Respir J ; 2024 Jun 20.
Article in English | MEDLINE | ID: mdl-38901883

ABSTRACT

BACKGROUND: We recently demonstrated that elexacaftor/tezacaftor/ivacaftor (ETI) improves the lung clearance index (LCI) and abnormalities in lung morphology detected by magnetic resonance imaging (MRI) in adolescent and adult patients with cystic fibrosis (CF). However, real-world data on the effect of ETI on these sensitive outcomes of lung structure and function in school-age children with CF have not been reported. The aim of this study was therefore to examine the effect of ETI on the LCI and the lung MRI score in children with CF and one or two F508del alleles aged 6 to 11 years. METHODS: This prospective, observational, multicenter, post-approval study assessed the longitudinal LCI up to 12 months and the lung MRI score before and three months after initiation of ETI. RESULTS: A total of 107 children with CF including 40 heterozygous for F508del and a minimal function mutation (F/MF) and 67 homozygous for F508del (F/F) were enrolled in this study. Treatment with ETI improved the LCI in F/MF children (-1.0; IQR, -2.0 to -0.1; p<0.01) and F/F children (-0.8; IQR, -1.9 to -0.2; p<0.001) from 3 months onwards. Further, ETI improved the MRI global score in F/MF (-4.0; IQR, -9.0 to 0.0; p<0.01) and F/F children (-3.5; IQR, -7.3 to -0.8; p<0.001). CONCLUSIONS: ETI improves early abnormalities in lung ventilation and morphology in school-age children with CF and at least one F508del alleles in a real-world setting. Our results support early initiation of ETI to reduce or even prevent lung disease progression in school-age children with CF.

5.
Proc Biol Sci ; 291(2023): 20232439, 2024 May.
Article in English | MEDLINE | ID: mdl-38772424

ABSTRACT

Genetic changes that enabled the evolution of eusociality have long captivated biologists. More recently, attention has focussed on the consequences of eusociality on genome evolution. Studies have reported higher molecular evolutionary rates in eusocial hymenopteran insects compared with their solitary relatives. To investigate the genomic consequences of eusociality in termites, we analysed nine genomes, including newly sequenced genomes from three non-eusocial cockroaches. Using a phylogenomic approach, we found that termite genomes have experienced lower rates of synonymous substitutions than those of cockroaches, possibly as a result of longer generation times. We identified higher rates of non-synonymous substitutions in termite genomes than in cockroach genomes, and identified pervasive relaxed selection in the former (24-31% of the genes analysed) compared with the latter (2-4%). We infer that this is due to reductions in effective population size, rather than gene-specific effects (e.g. indirect selection of caste-biased genes). We found no obvious signature of increased genetic load in termites, and postulate efficient purging of deleterious alleles at the colony level. Additionally, we identified genomic adaptations that may underpin caste differentiation, such as genes involved in post-translational modifications. Our results provide insights into the evolution of termites and the genomic consequences of eusociality more broadly.


Subject(s)
Genome, Insect , Isoptera , Selection, Genetic , Animals , Isoptera/genetics , Phylogeny , Evolution, Molecular , Cockroaches/genetics , Social Behavior
6.
Cogn Res Princ Implic ; 9(1): 29, 2024 05 12.
Article in English | MEDLINE | ID: mdl-38735013

ABSTRACT

Auditory stimuli that are relevant to a listener have the potential to capture focal attention even when unattended, the listener's own name being a particularly effective stimulus. We report two experiments to test the attention-capturing potential of the listener's own name in normal speech and time-compressed speech. In Experiment 1, 39 participants were tested with a visual word categorization task with uncompressed spoken names as background auditory distractors. Participants' word categorization performance was slower when hearing their own name rather than other names, and in a final test, they were faster at detecting their own name than other names. Experiment 2 used the same task paradigm, but the auditory distractors were time-compressed names. Three compression levels were tested with 25 participants in each condition. Participants' word categorization performance was again slower when hearing their own name than when hearing other names; the slowing was strongest with slight compression and weakest with intense compression. Personally relevant time-compressed speech has the potential to capture attention, but the degree of capture depends on the level of compression. Attention capture by time-compressed speech has practical significance and provides partial evidence for the duplex-mechanism account of auditory distraction.


Subject(s)
Attention , Names , Speech Perception , Humans , Attention/physiology , Female , Male , Speech Perception/physiology , Adult , Young Adult , Speech/physiology , Reaction Time/physiology , Acoustic Stimulation
7.
Nature ; 629(8013): 851-860, 2024 May.
Article in English | MEDLINE | ID: mdl-38560995

ABSTRACT

Despite tremendous efforts in the past decades, relationships among main avian lineages remain heavily debated without a clear resolution. Discrepancies have been attributed to diversity of species sampled, phylogenetic method and the choice of genomic regions1-3. Here we address these issues by analysing the genomes of 363 bird species4 (218 taxonomic families, 92% of total). Using intergenic regions and coalescent methods, we present a well-supported tree but also a marked degree of discordance. The tree confirms that Neoaves experienced rapid radiation at or near the Cretaceous-Palaeogene boundary. Sufficient loci rather than extensive taxon sampling were more effective in resolving difficult nodes. Remaining recalcitrant nodes involve species that are a challenge to model due to either extreme DNA composition, variable substitution rates, incomplete lineage sorting or complex evolutionary events such as ancient hybridization. Assessment of the effects of different genomic partitions showed high heterogeneity across the genome. We discovered sharp increases in effective population size, substitution rates and relative brain size following the Cretaceous-Palaeogene extinction event, supporting the hypothesis that emerging ecological opportunities catalysed the diversification of modern birds. The resulting phylogenetic estimate offers fresh insights into the rapid radiation of modern birds and provides a taxon-rich backbone tree for future comparative studies.


Subject(s)
Birds , Evolution, Molecular , Genome , Phylogeny , Animals , Birds/genetics , Birds/classification , Birds/anatomy & histology , Brain/anatomy & histology , Extinction, Biological , Genome/genetics , Genomics , Population Density , Male , Female
8.
Vet Microbiol ; 293: 110085, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38581768

ABSTRACT

To overcome shortcomings in discriminating Chlamydia pecorum strains infecting the koala (Phascolarctos cinereus) at the local level, we developed a novel genotyping scheme for this pathogen to inform koala management at a fine-scale subpopulation level. We applied this scheme to two geographically distinct koala populations in New South Wales, Australia: the Liverpool Plains and the Southern Highlands to South-west Sydney (SHSWS). Our method provides greater resolution than traditional multi-locus sequence typing, and can be used to monitor strain emergence, movement, and divergence across a range of fragmented habitats. Within the Liverpool Plains population, suspected recent introduction of a novel strain was confirmed by an absence of genetic diversity at the earliest sampling events and limited diversity at recent sampling events. Across the partially fragmented agricultural landscape of the Liverpool Plains, diversity within a widespread sequence type suggests that this degree of fragmentation may hinder but not prevent spread. In the SHSWS population, our results suggest movement of a strain from the south, where diverse strains exist, into a previously Chlamydia-free area in the north, indicating the risk of expansion towards an adjacent Chlamydia-negative koala population in South-west Sydney. In the south of the SHSWS where koala subpopulations appear segregated, we found evidence of divergent strain evolution. Our tool can be used to infer the risks of strain introduction across fragmented habitats in population management, particularly through practices such as wildlife corridor constructions and translocations.


Subject(s)
Chlamydia Infections , Chlamydia , Genetic Variation , Multilocus Sequence Typing , Phascolarctidae , Phascolarctidae/microbiology , Animals , Chlamydia/genetics , Chlamydia/classification , Chlamydia/isolation & purification , Chlamydia Infections/veterinary , Chlamydia Infections/microbiology , Genotype , New South Wales , Phylogeny
9.
J Orthop Res ; 2024 Apr 28.
Article in English | MEDLINE | ID: mdl-38678396

ABSTRACT

Academic researchers faced a multitude of challenges posed by the COVID-19 pandemic, including widespread shelter-in-place orders, workplace closures, and cessation of in-person meetings and laboratory activities. The extent to which these challenges impacted musculoskeletal researchers, specifically, is unknown. We developed an anonymous web-based survey to determine the pandemic's impact on research productivity and career prospects among musculoskeletal research trainees and faculty. There were 116 musculoskeletal (MSK) researchers with varying demographic backgrounds who completed the survey. Of respondents, 48.3% (n = 56) believed that musculoskeletal funding opportunities decreased because of COVID-19, with faculty members more likely to hold this belief compared to nonfaculty researchers (p = 0.008). Amongst MSK researchers, 88.8% (n = 103) reported research activity was limited by COVID-19, and 92.2% (n = 107) of researchers reported their research was not able to be refocused on COVID-19-related topics, with basic science researchers less likely to be able to refocus their research compared to clinical researchers (p = 0.030). Additionally, 47.4% (n = 55) reported a decrease in manuscript submissions since the onset of the pandemic. Amongst 51 trainee researchers, 62.8% (n = 32) reported a decrease in job satisfaction directly attributable to the COVID-19 pandemic. In summary, study findings indicated that MSK researchers struggled to overcome challenges imposed by the pandemic, reporting declines in funding opportunities, research productivity, and manuscript submission. Trainee researchers experienced significant disruptions to critical research activities and worsening job satisfaction. Our findings motivate future efforts to support trainees in developing their careers and target the recovery of MSK research from the pandemic stall.

10.
Elife ; 122024 Apr 10.
Article in English | MEDLINE | ID: mdl-38598270

ABSTRACT

Type 2 diabetes (T2D) is associated with higher fracture risk, despite normal or high bone mineral density. We reported that bone formation genes (SOST and RUNX2) and advanced glycation end-products (AGEs) were impaired in T2D. We investigated Wnt signaling regulation and its association with AGEs accumulation and bone strength in T2D from bone tissue of 15 T2D and 21 non-diabetic postmenopausal women undergoing hip arthroplasty. Bone histomorphometry revealed a trend of low mineralized volume in T2D (T2D 0.249% [0.156-0.366]) vs non-diabetic subjects 0.352% [0.269-0.454]; p=0.053, as well as reduced bone strength (T2D 21.60 MPa [13.46-30.10] vs non-diabetic subjects 76.24 MPa [26.81-132.9]; p=0.002). We also showed that gene expression of Wnt agonists LEF-1 (p=0.0136) and WNT10B (p=0.0302) were lower in T2D. Conversely, gene expression of WNT5A (p=0.0232), SOST (p<0.0001), and GSK3B (p=0.0456) were higher, while collagen (COL1A1) was lower in T2D (p=0.0482). AGEs content was associated with SOST and WNT5A (r=0.9231, p<0.0001; r=0.6751, p=0.0322), but inversely correlated with LEF-1 and COL1A1 (r=-0.7500, p=0.0255; r=-0.9762, p=0.0004). SOST was associated with glycemic control and disease duration (r=0.4846, p=0.0043; r=0.7107, p=0.00174), whereas WNT5A and GSK3B were only correlated with glycemic control (r=0.5589, p=0.0037; r=0.4901, p=0.0051). Finally, Young's modulus was negatively correlated with SOST (r=-0.5675, p=0.0011), AXIN2 (r=-0.5523, p=0.0042), and SFRP5 (r=-0.4442, p=0.0437), while positively correlated with LEF-1 (r=0.4116, p=0.0295) and WNT10B (r=0.6697, p=0.0001). These findings suggest that Wnt signaling and AGEs could be the main determinants of bone fragility in T2D.


Type 2 diabetes is a long-term metabolic disease characterised by chronic high blood sugar levels. This in turn has a negative impact on the health of other tissues and organs, including bones. Type 2 diabetes patients have an increased risk of fracturing bones compared to non-diabetics. This is particularly true for fragility fractures, which are fractures caused by falls from a short height (i.e., standing height or less), often affecting hips or wrists. Usually, a lower bone density is associated with higher risk of fractures. However, patients with type 2 diabetes have increased bone fragility despite normal or higher bone density. One reason for this could be the chronically high levels of blood sugar in type 2 diabetes, which alter the properties of proteins in the body. It has been shown that the excess sugar molecules effectively 'react' with many different proteins, producing harmful compounds in the process, called Advanced Glycation End-products, or AGEs. AGEs are ­ in turn ­thought to affect the structure of collagen proteins, which help hold our tissues together and decrease bone strength. However, the signalling pathways underlying this process are still unclear. To find out more, Leanza et al. studied a signalling molecule, called sclerostin, which inhibits a signalling pathway that regulates bone formation, known as Wnt signaling. The researchers compared bone samples from both diabetic and non-diabetic patients, who had undergone hip replacement surgery. Analyses of the samples, using a technique called real-time-PCR, revealed that gene expression of sclerostin was increased in samples of type 2 diabetes patients, which led to a downregulation of Wnt signaling related genes. Moreover, the downregulation of Wnt genes was correlated with lower bone strength (which was measured by compressing the bone tissue). Further biochemical analysis of the samples revealed that higher sclerostin activity was also associated with higher levels of AGEs. These results provide a clearer understanding of the biological mechanisms behind compromised bone strength in diabetes. In the future, Leanza et al. hope that this knowledge will help us develop treatments to reduce the risk of bone complications for type 2 diabetes patients.


Subject(s)
Diabetes Mellitus, Type 2 , Humans , Female , Maillard Reaction , Wnt Signaling Pathway , Bone and Bones , Research Personnel
11.
Ecol Evol ; 14(3): e11148, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38476702

ABSTRACT

With over 600 valid species, the wrasses (family Labridae) are among the largest and most successful families of the marine teleosts. They feature prominently on coral reefs where they are known not only for their impressive diversity in colouration and form but also for their functional specialisation and ability to occupy a wide variety of trophic guilds. Among the wrasses, the parrotfishes (tribe Scarini) display some of the most dramatic examples of trophic specialisation. Using abrasion-resistant biomineralized teeth, parrotfishes are able to mechanically extract protein-rich micro-photoautotrophs growing in and among reef carbonate material, a dietary niche that is inaccessible to most other teleost fishes. This ability to exploit an otherwise untapped trophic resource is thought to have played a role in the diversification and evolutionary success of the parrotfishes. In order to better understand the key evolutionary innovations leading to the success of these dietary specialists, we sequenced and analysed the genome of a representative species, the spotted parrotfish (Cetoscarus ocellatus). We find significant expansion, selection and duplications within several detoxification gene families and a novel poly-glutamine expansion in the enamel protein ameloblastin, and we consider their evolutionary implications. Our genome provides a useful resource for comparative genomic studies investigating the evolutionary history of this highly specialised teleostean radiation.

12.
Nat Commun ; 15(1): 2611, 2024 Mar 23.
Article in English | MEDLINE | ID: mdl-38521783

ABSTRACT

The dense O-glycosylation of mucins plays an important role in the defensive properties of the mucus hydrogel. Aberrant glycosylation is often correlated with inflammation and pathology such as COPD, cancer, and Crohn's disease. The inherent complexity of glycans and the diversity in the O-core structure constitute fundamental challenges for the analysis of mucin-type O-glycans. Due to coexistence of multiple isomers, multidimensional workflows such as LC-MS are required. To separate the highly polar carbohydrates, porous graphitized carbon is often used as a stationary phase. However, LC-MS workflows are time-consuming and lack reproducibility. Here we present a rapid alternative for separating and identifying O-glycans released from mucins based on trapped ion mobility mass spectrometry. Compared to established LC-MS, the acquisition time is reduced from an hour to two minutes. To test the validity, the developed workflow was applied to sputum samples from cystic fibrosis patients to map O-glycosylation features associated with disease.


Subject(s)
Mucins , Tandem Mass Spectrometry , Humans , Mucins/metabolism , Tandem Mass Spectrometry/methods , Reproducibility of Results , Polysaccharides/chemistry , Glycosylation
13.
Neuroendocrinology ; 2024 Mar 26.
Article in English | MEDLINE | ID: mdl-38531329

ABSTRACT

Peptide-receptor radionuclide therapy (PRRT) is a targeted molecular therapy used to treat neuroendocrine tumours (NET). It has been shown to be effective and well-tolerated in patients with metastatic neuroendocrine tumours in several centres in United States (US), Europe and Australia. Tolerability and efficacy data emerging from Asian centres remain few. Epidemiological evidence suggests that there are differences in neuroendocrine neoplasms between the population groups. We aim to describe the treatment and safety outcomes of PRRT in the Asian population. Methods One hundred and seven (107) patients with metastatic neuroendocrine tumour who had undergone PRRT treatment from January 2012 to March 2019 were included in this retrospective study. The response rates using RECIST1.1 and qualitative analysis were examined. The overall and progression free survival curves were also evaluated. Results The median progression free survival was 49 months. Response assessment after completion of treatment showed that 33(37.9%) of 87 patients had partial or complete response. Subgroup analysis comparing high- and low-grade NET showed that there was a significant difference in the time to progression curves. Comparison of the number of cycles and progression free and overall survival also showed a significant difference. Ten patients (9%) had grade 3 or more haematological toxicities. Four patients (4%) had grade 3/4 hepatobiliary toxicities, although the presence of extensive liver metastases was a confounding factor. None of the patients had grade 3/4 acute kidney injury. Conclusion Our results show that PRRT is safe and effective in the treatment of metastatic neuroendocrine tumour in the Asian population. There was a significant difference in the progression free survival curves between low-grade and high-grade NET, and in the progression free and overall survival comparing the number of cycles received.

14.
J Cyst Fibros ; 2024 Mar 19.
Article in English | MEDLINE | ID: mdl-38508948

ABSTRACT

BACKGROUND: In health, nitric oxide (NO) shows high concentrations in the upper airways, while nasal NO (nNO) is significantly lower in patients with sinonasal inflammation, such as people with cystic fibrosis (PwCF). In PwCF treated with elexacaftor/tezacaftor/ivacaftor (ETI; PwCF-ETI), clinical improvement of sinonasal symptoms and inflammation was observed. We therefore hypothesised that ETI may increase nNO in PwCF. METHODS: 25 PwCF-ETI underwent nNO measurement at baseline and after 3 to 24 months of ETI treatment. NNO was measured using velum closure (VC) techniques in cooperative patients and tidal breathing (TB) for all patients. As controls, 7 CF patients not eligible for ETI (PwCF-non ETI) and 32 healthy controls (HC) were also repeatedly investigated. RESULTS: In PwCF-ETI, sinonasal symptoms, lung function parameters and sweat chloride levels improved from baseline to follow-up whereas there was no change in PwCF-non ETI and HC. NNO increased from a median (IQR) value at baseline to follow-up from 348.2 (274.4) ppb to 779.6 (364.7) ppb for VC (P < 0.001) and from 198.2 (107.0) ppb to 408.3 (236.1) ppb for TB (P < 0.001). At follow-up, PwCF-ETI reached nNO values in the normal range. In PwCF-non ETI as well as HC, nNO did not change between baseline and follow-up. CONCLUSIONS: In PwCF-ETI, the nNO values significantly increased after several months of ETI treatment in comparison to baseline and reached values in the normal range. This suggests that nNO is a potential non-invasive biomarker to examine sinonasal inflammatory disease in PwCF and supports the observation of clinical improvement in these patients.

15.
bioRxiv ; 2024 Mar 02.
Article in English | MEDLINE | ID: mdl-38464124

ABSTRACT

Inadequate repair of injured intervertebral discs (IVD) leads to degeneration and contributes to low back pain. Infiltrating immune cells into damaged musculoskeletal tissues are critical mediators of repair, yet little is known about their identities, roles, and temporal regulation following IVD injury. By analyzing longitudinal changes in gene expression, tissue morphology, and the dynamics of infiltrating immune cells following injury, we characterize sex-specific differences in immune cell populations and identify the involvement of previously unreported immune cell types, γδ and NKT cells. Cd3+Cd4-Cd8- T cells are the largest infiltrating lymphocyte population with injury, and we identified the presence of γδ T cells in this population in female mice specifically, and NKT cells in males. Injury-mediated IVD degeneration was prevalent in both sexes, but more severe in males. Sex-specific degeneration may be associated with the differential immune response since γδ T cells have potent anti-inflammatory roles and may mediate IVD repair.

16.
Ecol Evol ; 14(3): e11066, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38435016

ABSTRACT

Lepidoziaceae are the third-largest family of liverworts, with about 860 species distributed on all continents. The evolutionary history of this family has not been satisfactorily resolved, with taxa such as Micropterygioideae yet to be included in phylogenetic analyses. We inferred a dated phylogeny of Lepidoziaceae using a data set consisting of 13 genetic markers, sampled from 147 species. Based on our phylogenetic estimate, we used statistical dispersal-vicariance analysis to reconstruct the biogeographic history of the family. We inferred a crown age of 197 Ma (95% credible interval 157-240 Ma) for the family in the Australian region, with most major lineages also originating in the same region. Micropterygioideae are placed as the sister group to Lembidioideae, with these two lineages diverging from each other about 132 Ma in the South American-Australian region. With South America and Australia being connected through Antarctica at the time, our results suggest a circum-Antarctic link between Micropterygioideae and the rest of the family. Crown Micropterygioideae were inferred to have arisen 45 Ma in South America before the continent separated from Antarctica. Extinction from southern temperate regions might explain the present-day restriction of Micropterygioideae to the Neotropics. Our study reveals the influence of past geological events, such as continental drift, on the evolution and distribution of a widespread and diverse family of liverworts.

17.
Insect Sci ; 2024 Mar 10.
Article in English | MEDLINE | ID: mdl-38462506

ABSTRACT

Microbial symbioses have had profound impacts on the evolution of animals. Conversely, changes in host biology may impact the evolutionary trajectory of symbionts themselves. Blattabacterium cuenoti is present in almost all cockroach species and enables hosts to subsist on a nutrient-poor diet. To investigate if host biology has impacted Blattabacterium at the genomic level, we sequenced and analyzed 25 genomes from Australian soil-burrowing cockroaches (Blaberidae: Panesthiinae), which have undergone at least seven separate subterranean, subsocial transitions from above-ground, wood-feeding ancestors. We find at least three independent instances of genome erosion have occurred in Blattabacterium strains exclusive to Australian soil-burrowing cockroaches. These shrinkages have involved the repeated inactivation of genes involved in amino acid biosynthesis and nitrogen recycling, the core role of Blattabacterium in the host-symbiont relationship. The most drastic of these erosions have occurred in hosts thought to have transitioned underground the earliest relative to other lineages, further suggestive of a link between gene loss in Blattabacterium and the burrowing behavior of hosts. As Blattabacterium is unable to fulfill its core function in certain host lineages, these findings suggest soil-burrowing cockroaches must acquire these nutrients from novel sources. Our study represents one of the first cases, to our knowledge, of parallel host adaptations leading to concomitant parallelism in their mutualistic symbionts, further underscoring the intimate relationship between these two partners.

18.
JBMR Plus ; 8(2): ziad012, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38505533

ABSTRACT

The fracture behavior of bone is critically important for evaluating its mechanical competence and ability to resist fractures. Fracture toughness is an intrinsic material property that quantifies a material's ability to withstand crack propagation under controlled conditions. However, properly conducting fracture toughness testing requires the access to calibrated mechanical load frames and the destructive testing of bone samples, and therefore fracture toughness tests are clinically impractical. Impact microindentation mimicks certain aspects of fracture toughness measurements, but its relationship with fracture toughness remains unknown. In this study, we aimed to compare measurements of notched fracture toughness and impact microindentation in fresh and boiled bovine bone. Skeletally mature bovine bone specimens (n = 48) were prepared, and half of them were boiled to denature the organic matrix, while the other half remained preserved in frozen conditions. All samples underwent a notched fracture toughness test to determine their resistance to crack initiation (KIC) and an impact microindentation test using the OsteoProbe to obtain the Bone Material Strength index (BMSi). Boiling the bone samples increased the denatured collagen content, while mineral density and porosity remained unaffected. The boiled bones also showed significant reduction in both KIC (P < .0001) and the average BMSi (P < .0001), leading to impaired resistance of bone to crack propagation. Remarkably, the average BMSi exhibited a high correlation with KIC (r = 0.86; P < .001). A ranked order difference analysis confirmed the excellent agreement between the 2 measures. This study provides the first evidence that impact microindentation could serve as a surrogate measure for bone fracture behavior. The potential of impact microindentation to assess bone fracture resistance with minimal sample disruption could offer valuable insights into bone health without the need for cumbersome testing equipment and sample destruction.

19.
Genome Biol Evol ; 16(4)2024 04 02.
Article in English | MEDLINE | ID: mdl-38526019

ABSTRACT

Phylogenomic data provide valuable opportunities for studying evolutionary rates and timescales. These analyses require theoretical and statistical tools based on molecular clocks. We present ClockstaRX, a flexible platform for exploring and testing evolutionary rate signals in phylogenomic data. Here, information about evolutionary rates in branches across gene trees is placed in Euclidean space, allowing data transformation, visualization, and hypothesis testing. ClockstaRX implements formal tests for identifying groups of loci and branches that make a large contribution to patterns of rate variation. This information can then be used to test for drivers of genomic evolutionary rates or to inform models for molecular dating. Drawing on the results of a simulation study, we recommend forms of data exploration and filtering that might be useful prior to molecular-clock analyses.


Subject(s)
Evolution, Molecular , Models, Genetic , Genomics , Genome , Biological Evolution , Phylogeny
20.
Syst Biol ; 2024 Feb 06.
Article in English | MEDLINE | ID: mdl-38320290

ABSTRACT

Rates of nucleotide substitution vary substantially across the Tree of Life, with potentially confounding effects on phylogenetic and evolutionary analyses. A large acceleration in mitochondrial substitution rate occurs in the cockroach family Nocticolidae, which predominantly inhabit subterranean environments. To evaluate the impacts of this among-lineage rate heterogeneity on estimates of phylogenetic relationships and evolutionary timescales, we analysed nuclear ultraconserved elements (UCEs) and mitochondrial genomes from nocticolids and other cockroaches. Substitution rates were substantially elevated in nocticolid lineages compared with other cockroaches, especially in mitochondrial protein-coding genes. This disparity in evolutionary rates is likely to have led to different evolutionary relationships being supported by phylogenetic analyses of mitochondrial genomes and UCE loci. Furthermore, Bayesian dating analyses using relaxed-clock models inferred much deeper divergence times compared with a flexible local clock. Our phylogenetic analysis of UCEs, which is the first genome-scale study to include all thirteen major cockroach families, unites Corydiidae and Nocticolidae and places Anaplectidae as the sister lineage to the rest of Blattoidea. We uncover an extraordinary level of genetic divergence in Nocticolidae, including two highly distinct clades that separated ~115 million years ago despite both containing representatives of the genus Nocticola. The results of our study highlight the potential impacts of high among-lineage rate variation on estimates of phylogenetic relationships and evolutionary timescales.

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