Displaying publications 1 - 20 of 36 in total

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  1. Contralateral Nasofrontal Trephination: A Novel Corridor for a "Dual Port" Approach to the Petrous Apex
    Abouammo MD, Narayanan MS, Alsavaf MB, Alwabili M, Gosal JS, Bhuskute GS, et al.
    Oper Neurosurg (Hagerstown), 2024 Mar 20.
    PMID: 38506519 DOI: 10.1227/ons.0000000000001119
    BACKGROUND AND OBJECTIVES: Expanded endonasal approaches (EEAs) have proven safe and effective in treating select petrous apex (PA) pathologies. Angled endoscopes and instruments have expanded indications for such approaches; however, the complex neurovascular anatomy surrounding the petrous region remains a significant challenge. This study evaluates the feasibility, anatomic aspects, and limitations of a contralateral nasofrontal trephination (CNT) route as a complementary corridor improving access to the PA.

    METHODS: Expanded endonasal and CNT approaches to the PA were carried out bilaterally in 15 cadaveric heads with endovascular latex injections. The distance to the PA, angle between instruments through the 2 approach portals, and surgical freedom were measured and compared.

    RESULTS: Three-dimensional DICOM-based modeling and visualization indicate that the CNT route reduces the distance to the target located within the contralateral PA by an average of 3.33 cm (19%) and affords a significant increase in the angle between instruments (15.60°; 54%). Furthermore, the vertical vector of approach is improved by 28.97° yielding a caudal reach advantage of 2 cm. The area of surgical freedom afforded by 3 different approaches (endonasal, endonasal with an endoscope in CNT portal, and endonasal with an instrument in CNT portal) was compared at 4 points: the dural exit point of the 6th cranial nerve, jugular foramen, foramen lacerum, and petroclival fissure. The mean area of surgical freedom provided by both approaches incorporating the CNT corridor was superior to EEA alone at each of the surgical targets (P =

  2. STROCSS 2019 Guideline: Strengthening the reporting of cohort studies in surgery
    Agha R, Abdall-Razak A, Crossley E, Dowlut N, Iosifidis C, Mathew G, et al.
    Int J Surg, 2019 Nov 06;72:156-165.
    PMID: 31704426 DOI: 10.1016/j.ijsu.2019.11.002
    INTRODUCTION: The STROCSS guideline was developed in 2017 to improve the reporting quality of observational studies in surgery. Building on its impact and usefulness, we sought to update the guidelines two years after its publication.

    METHODS: A steering group was formed to review the existing guideline and propose amendments to the 17-item checklist. A Delphi consensus exercise was utilised to determine agreement across a list of proposed modifications to the STROCSS 2017 guideline. An expert panel of 46 surgeons were invited to assess the proposed updates via Google Forms.

    RESULTS: The response rate was 91% (n = 42/46). High agreement was reached across all the items and the guideline was finalised in the first round. The checklist maintained 17-items, with modifications primarily considered to improve content and readability.

    CONCLUSIONS: The STROCSS 2019 guideline is hereby presented as a considered update to improve reporting of cohort, cross-sectional and case-control studies in surgery.

  3. Biomechanical assessment of surgical repair of the mitral valve
    Al-Atabi M, Espino DM, Hukins DW, Buchan KG
    Proc Inst Mech Eng H, 2012 Apr;226(4):275-87.
    PMID: 22611868
    Repair of the mitral valve is defined (loosely) as a procedure that alters the valve structure, without replacement, enabling the natural valve itself to continue to perform under the physical conditions to which it is exposed. As the mitral valve is driven by flow and pressure, it should be feasible to analyse and assess its function, failure and repair as a mechanical system. This article reviews the current state of mechanical evaluation of surgical repairs of the failed mitral valve of the heart. This review describes the anatomy and physiology of the mitral valve, followed by the failure of the mitral valve from a mechanical point of view. The surgical methods used to repair failed valves are introduced, while the use of engineering analysis to aid understanding of mitral valve repair is also reviewed. Finally, a section on recommendations for development and future uses of engineering techniques to surgical repair are presented.
  4. Pandanus tectorius fruit extract promotes Hsp70 accumulation, immune-related genes expression and Vibrio parahaemolyticus tolerance in the white-leg shrimp Penaeus vannamei
    Anirudhan A, Okomoda VT, Mimi Iryani MT, Andriani Y, Abd Wahid ME, Tan MP, et al.
    Fish Shellfish Immunol, 2021 Feb;109:97-105.
    PMID: 33352338 DOI: 10.1016/j.fsi.2020.12.011
    Plants and herbal extracts are indispensable for controlling the spread of disease-causing bacteria, including those that infect aquatic organisms used in aquaculture. The use of plant or herbal extract is expected to be safe for aquatic animals and less harmful to the environment, as opposed to conventional therapeutic alternatives such as antibiotics that promote the occurrence of potential antibiotic-resistant bacteria when used improperly. The efficacy of Pandanus tectorius fruit extract in the regulation of Hsp70 expression, pro-phenoloxidase (ProPO), peroxinectin, penaeidin, crustin and transglutaminase, all immune peptides essential for Vibrio tolerance in white leg shrimp, Penaeus vannamei, was investigated in this study, which included the determination of the safety levels of the extract. Tolerance of shrimp against Vibrio parahaemolyticus, a pathogenic bacteria that causes Acute Hepatopancreas Necrosis Disease (AHPND), was assessed on the basis of median lethal dose challenge survival (LD50 = 106 cells/ml). Mortality was not observed 24 h after exposure of 0.5-6 g/L of the fruit extract, indicating that P. tectorius was not toxic to shrimp at these concentrations. A 24-h incubation of 2-6 g/L of the fruit extract increased shrimp tolerance to V. parahaemolyticus, with survival doubled when the maximum dose tested in this study was used. Concomitant with a rise in survival was the increase in immune-related proteins, with Hsp70, ProPO, peroxinectin, penaeidin, crustin and transglutaminase increased 10, 11, 11, 0.4, 8 and 13-fold respectively. Histological examination of the hepatopancreas and muscle tissues of Vibrio-infected shrimp primed with P. tectorius extract revealed reduced signs of histopathological degeneration, possibly due to the accumulation of Hsp70, a molecular chaperone crucial to cellular protein folding, tissue repair and immune response of living organisms, including Penaeid shrimp.
  5. Fulltext Industrial enzymes-producing marine bacteria from marine resources
    Cheng TH, Ismail N, Kamaruding N, Saidin J, Danish-Daniel M
    Biotechnol Rep (Amst), 2020 Sep;27:e00482.
    PMID: 32514406 DOI: 10.1016/j.btre.2020.e00482
    Industrial enzymes are important for various biotechnological applications. Currently, the diversity of industrial enzymes-producing marine bacteria from Malaysia remains mostly unknown. This study investigated the diversity of industrial enzyme-producing marine bacteria from culture collections at the Institute of Marine Biotechnology, Universiti Malaysia Terengganu. Out of 200 bacterial isolates revived, 163 bacteria isolate were successfully growth. Marine bacteria produced enzymes with total scoring higher than four were selected for molecular identification using 16S rDNA. About 161 bacteria isolate secreted amylase (68.7 %), lipase (88.3 %) and protease (68.7 %). The phylogenetic analysis led to the identification of three major phyla, namely Proteobacteria, Firmicutes and Bacteroidetes. These phyla were differentiated into nine genera consisted of Bacillus, Chryseomicrobium, Photobacterium, Pseudoalteromonas, Ruegeria, Shewanella, Solibacillus, Tenacibaculum and Vibrio. Genetic variation was more likely to occur within similar marine bacteria species. The microbial community was found to affect the production of industrial enzymes and the diversity of marine bacteria.
  6. Fulltext Genome Sequence ofSerratia marcescenssubsp.sakuensisStrain K27, a Marine Bacterium Isolated from Sponge (Haliclona amboinensis)
    Cheng TH, Saidin J, Danish-Daniel M, Gan HM, Mat Isa MN, Abu Bakar MF, et al.
    Genome Announc, 2018 Feb 08;6(6).
    PMID: 29439033 DOI: 10.1128/genomeA.00022-18
    Serratia marcescens
    subsp.sakuensisstrain K27 was isolated from sponge (Haliclona amboinensis). The genome of this strain consists of 5,325,727 bp, with 5,140 open reading frames (ORFs), 3 rRNAs, and 67 tRNAs. It contains genes for the production of amylases, lipases, and proteases. Gene clusters for the biosynthesis of nonribosomal peptides and thiopeptide were also identified.
  7. Fulltext Current vector research challenges in the greater Mekong subregion for dengue, Malaria, and Other Vector-Borne Diseases: A report from a multisectoral workshop March 2019
    Christofferson RC, Parker DM, Overgaard HJ, Hii J, Devine G, Wilcox BA, et al.
    PLoS Negl Trop Dis, 2020 Jul;14(7):e0008302.
    PMID: 32730249 DOI: 10.1371/journal.pntd.0008302
  8. Fulltext Genome Sequence of Nitratireductor basaltis Strain UMTGB225, a Marine Bacterium Isolated from a Green Barrel Tunicate in Bidong Island, Malaysia
    Danish-Daniel M, Gan HY, Gan HM, Saari NA, Usup G
    Genome Announc, 2014;2(5).
    PMID: 25301654 DOI: 10.1128/genomeA.01015-14
    Nitratireductor basaltis strain UMTGB225 is a Gram-negative bacterium isolated from a marine tunicate found in Bidong Island, Terengganu, Malaysia. In this study, the genome of Nitratireductor basaltis UMTGB225 was sequenced to gain insight into the role of this bacterium and its association with tunicate hosts in a coral reef habitat.
  9. Fulltext Draft genome sequence of Mameliella alba strain UMTAT08 isolated from clonal culture of toxic dinoflagellate Alexandrium tamiyavanichii
    Danish-Daniel M, Han Ming G, Noor ME, Yeong YS, Usup G
    Genom Data, 2016 Dec;10:12-4.
    PMID: 27625991 DOI: 10.1016/j.gdata.2016.08.015
    Mameliella alba strain UMTAT08 was isolated from clonal culture of paralytic shellfish toxin producing dinoflagellate, Alexandrium tamiyavanichii. Genome of the strain UMTAT08 was sequenced in order to gain insights into the dinoflagellate-bacteria interactions. The draft genome sequence of strain UMTAT08 contains 5.84Mbp with an estimated G + C content of 65%, 5717 open reading frames, 5 rRNAs and 49 tRNAs. It contains genes related to nutrients uptake, quorum sensing and environmental tolerance related genes. Gene clusters for the biosynthesis of type 1 polyketide synthase, bacteriocin, microcin, terpene and ectoine were also identified. This is suggesting that the bacterium possesses diverse adaptation strategy to survive within the dinoflagellate phycosphere. The draft genome sequence and annotation have been deposited at DDBJ/EMBL/GenBank under the accession number JSUQ00000000.
  10. Fulltext Genome Sequence of Bacillus sp. Strain UMTAT18 Isolated from the Dinoflagellate Alexandrium tamiyavanichii Found in the Straits of Malacca
    Danish-Daniel M, Ming GH, Mohd Noor ME, Sung YY, Usup G
    Genome Announc, 2016 Oct 6;4(5).
    PMID: 27795265 DOI: 10.1128/genomeA.01106-16
    Bacillus sp. strain UMTAT18 was isolated from the harmful dinoflagellate Alexandrium tamiyavanichii Its genome consists of 5,479,367 bp with 5,546 open reading frames, 102 tRNAs, and 29 rRNAs. Gene clusters for biosynthesis of nonribosomal peptides, bacteriocin, and lantipeptide were identified. It also contains siderophore and genes related to stress tolerance.
  11. The ChoCO-W prospective observational global study: Does COVID-19 increase gangrenous cholecystitis?
    De Simone B, Abu-Zidan FM, Chouillard E, Di Saverio S, Sartelli M, Podda M, et al.
    World J Emerg Surg, 2022 Dec 16;17(1):61.
    PMID: 36527038 DOI: 10.1186/s13017-022-00466-4
    BACKGROUND: The incidence of the highly morbid and potentially lethal gangrenous cholecystitis was reportedly increased during the COVID-19 pandemic. The aim of the ChoCO-W study was to compare the clinical findings and outcomes of acute cholecystitis in patients who had COVID-19 disease with those who did not.

    METHODS: Data were prospectively collected over 6 months (October 1, 2020, to April 30, 2021) with 1-month follow-up. In October 2020, Delta variant of SARS CoV-2 was isolated for the first time. Demographic and clinical data were analyzed and reported according to the STROBE guidelines. Baseline characteristics and clinical outcomes of patients who had COVID-19 were compared with those who did not.

    RESULTS: A total of 2893 patients, from 42 countries, 218 centers, involved, with a median age of 61.3 (SD: 17.39) years were prospectively enrolled in this study; 1481 (51%) patients were males. One hundred and eighty (6.9%) patients were COVID-19 positive, while 2412 (93.1%) were negative. Concomitant preexisting diseases including cardiovascular diseases (p 

  12. Fulltext Genome Sequence of Vibrio campbellii Strain UMTGB204, a Marine Bacterium Isolated from a Green Barrel Tunicate
    Gan HY, Noor ME, Saari NA, Musa N, Mustapha B, Usup G, et al.
    Genome Announc, 2015;3(2).
    PMID: 25814609 DOI: 10.1128/genomeA.00210-15
    Vibrio campbellii strain UMTGB204 was isolated from a green barrel tunicate. The genome of this strain comprises 5,652,224 bp with 5,014 open reading frames, 9 rRNAs, and 116 tRNAs. It contains genes related to virulence and environmental tolerance. Gene clusters for the biosynthesis of nonribosomal peptides and bacteriocin were also identified.
  13. Fulltext A balanced randomised placebo controlled blinded phase IIa multi-centre study to investigate the efficacy and safety of AUT00063 versus placebo in subjective tinnitus: The QUIET-1 trial
    Hall DA, Ray J, Watson J, Sharman A, Hutchison J, Harris P, et al.
    Hear Res, 2019 06;377:153-166.
    PMID: 30939361 DOI: 10.1016/j.heares.2019.03.018
    AUT00063 is an experimental new medicine that has been demonstrated to suppress spontaneous hyperactivity by modulating the action of voltage-gated potassium-channels in central auditory cortical neurons of a rodent model. This neurobiological property makes it a good candidate for treating the central component of subjective tinnitus but this has not yet been tested in humans. The main purpose of the QUIET-1 (QUest In Eliminating Tinnitus) trial was to examine the effect of AUT00063 on the severity of tinnitus symptoms in people with subjective tinnitus. The trial was a randomised, placebo-controlled, observer, physician and participant blinded multi-centre superiority trial with two parallel groups and a primary endpoint of functional impact on tinnitus 28 days after the first drug dosing day. The trial design overcame the scale and logistical challenges of delivering a scientifically robust, statistically powered multi-centre study for subjective tinnitus within the National Health Service in England. The trial was terminated early for futility. Overall, 212 participants consented across 18 sites with 91 participants randomised to groups using age, gender, tinnitus symptom severity and hearing status as minimisation factors. While the pharmacokinetic markers confirm the uptake of AUT00063 in the body, within the expected therapeutic range, with respect to clinical benefit findings indicated that AUT00063 was not effective in alleviating tinnitus symptoms (1.56 point change in Tinnitus Functional Index). In terms of clinical harms, results indicated that a daily dose of 800 mg capsules of AUT00063 taken for 28 days was safe and well tolerated. These findings provide significant advances in the drug development field for hearing sciences, but raise questions about the predictive validity of certain rodent models of noise-induced hearing loss and tinnitus, as least for the mechanism evaluated in the present study. Trial Registration: (EudraCT) 2014-002179-27; NCT02315508.
  14. Fulltext Twins! Microsatellite analysis of two embryos within one egg case in oviparous elasmobranchs
    Hook SA, Musa SM, Ripley DM, Hibbitt JD, Grunow B, Moritz T, et al.
    PLoS One, 2019;14(12):e0224397.
    PMID: 31790403 DOI: 10.1371/journal.pone.0224397
    Elasmobranchs display various reproductive modes, which have been key to their evolutionary success. In recent decades there has been a rise in the number of reported cases of foetal abnormalities including fertilised, double-embryos held within one egg capsule, hereafter referred to as twins. Previously, the occurrences of twin egg cases have been reported in two batoid and one shark species. We report the first cases of twins in three species of oviparous elasmobranchs: the undulate ray (Raja undulata), the nursehound (Scyliorhinus stellaris), and the small-spotted catshark (Scyliorhinus canicula). We investigated the genetic relationships between the twins in S. stellaris, and S. canicula using microsatellite markers. Whilst the S. stellaris twins displayed the same genotypes, we found that the S. canicula twin individuals arose through heteropaternal superfecundation. This is the first reported incidence of such a paternity in elasmobranchs. The relationship between environmental change and reproductive strategy in elasmobranchs is unclear and further research is needed to determine its effect on the prevalence and mechanisms of formation of elasmobranch twins.
  15. Fulltext Cyst viability and stress tolerance upon heat shock protein 70 knockdown in the brine shrimp Artemia franciscana
    Iryani MTM, Sorgeloos P, Danish-Daniel M, Tan MP, Wong LL, Mok WJ, et al.
    Cell Stress Chaperones, 2020 Nov;25(6):1099-1103.
    PMID: 32383141 DOI: 10.1007/s12192-020-01113-0
    Females of the brine shrimp Artemia franciscana produce either free-swimming nauplii via ovoviviparous pathway of reproduction or encysted embryos, known as cysts, via oviparous pathway, in which biological processes are arrested. While previous study has shown a crucial role of ATP-dependent molecular chaperone, heat shock protein 70 (Hsp70) in protecting A. franciscana nauplii against various abiotic and abiotic stressors, the function of this protein in diapausing embryos and cyst development, however, remains unknown. RNA interference (RNAi) was applied in this study to examine the role of Hsp70 in cyst development and stress tolerance, with the latter performed by desiccation and freezing, a common method used for diapause termination in Artemia cysts. Hsp70 knockdown was apparent in cysts released from females that were injected with Hsp70 dsRNA. The loss of Hsp70 affected neither the development nor morphology of the cysts. The time between fertilization and cyst release from Artemia females injected with Hsp70 dsRNA was delayed slightly, but the differences were not significant when compared to the controls. However, the hatching percentage of cysts which lacks Hsp70 were reduced following desiccation and freezing. Taken together, these results indicated that Hsp70 possibly plays a role in the stress tolerance but not in the development of diapause-destined embryos of Artemia. This research makes fundamental contributions to our understanding of the role molecular chaperone Hsp70 plays in Artemia, an excellent model organism for diapause studies of the crustaceans.
  16. Fulltext The Impact of Anticholinergic Burden on Functional Capacity in Persons With Schizophrenia Across the Adult Life Span
    Khan WU, Ghazala Z, Brooks HJ, Subramaniam P, Mulsant BH, Kumar S, et al.
    Schizophr Bull, 2021 Jan 23;47(1):249-257.
    PMID: 32619225 DOI: 10.1093/schbul/sbaa093
    Anticholinergic burden (ACB) from medications impairs cognition in schizophrenia. Cognition is a predictor of functional capacity; however, little is known about ACB effect on functional capacity in this population. This study assesses the relationship between ACB and functional capacity across the life span in individuals with schizophrenia after controlling for ACB effect on cognition. A cross-sectional analysis was performed with data collected from 6 academic tertiary health centers. Two hundred and twenty-three community-dwelling participants with schizophrenia or schizoaffective disorder were included in this study. Main variables were ACB, antipsychotic olanzapine equivalents, functional capacity, cognition, and negative symptoms. Simultaneous linear regression analyses were performed to assess the association between ACB, functional capacity, and cognition and then between ACB and cognition. A mediation analysis was then performed to examine whether cognition mediated ACB effect on functional capacity if there was an association between ACB and cognition. Mean age of participants was 49.0 years (SD = 13.1, range 19-79), and 63.7% of participants had severe ACB, ie, a total score of 3 or above. Regression analyses revealed that ACB, age, education, and cognition independently predicted functional capacity and that ACB predicted cognition among those aged 55 years and older. Mediation analysis showed that cognition did partially mediate the effect of ACB on functional capacity in this older cohort. In conclusion, people with schizophrenia are exposed to severe ACB that can have a direct negative impact on functional capacity after controlling for its impact on cognition. Reducing ACB could improve functional capacity and potentially real-world function in schizophrenia.
  17. Phylogeny and classification of Dickeya based on multilocus sequence analysis
    Marrero G, Schneider KL, Jenkins DM, Alvarez AM
    Int J Syst Evol Microbiol, 2013 Sep;63(Pt 9):3524-3539.
    PMID: 24003072 DOI: 10.1099/ijs.0.046490-0
    Bacterial heart rot of pineapple reported in Hawaii in 2003 and reoccurring in 2006 was caused by an undetermined species of Dickeya. Classification of the bacterial strains isolated from infected pineapple to one of the recognized Dickeya species and their phylogenetic relationships with Dickeya were determined by a multilocus sequence analysis (MLSA), based on the partial gene sequences of dnaA, dnaJ, dnaX, gyrB and recN. Individual and concatenated gene phylogenies revealed that the strains form a clade with reference Dickeya sp. isolated from pineapple in Malaysia and are closely related to D. zeae; however, previous DNA-DNA reassociation values suggest that these strains do not meet the genomic threshold for consideration in D. zeae, and require further taxonomic analysis. An analysis of the markers used in this MLSA determined that recN was the best overall marker for resolution of species within Dickeya. Differential intraspecies resolution was observed with the other markers, suggesting that marker selection is important for defining relationships within a clade. Phylogenies produced with gene sequences from the sequenced genomes of strains D. dadantii Ech586, D. dadantii Ech703 and D. zeae Ech1591 did not place the sequenced strains with members of other well-characterized members of their respective species. The average nucleotide identity (ANI) and tetranucleotide frequencies determined for the sequenced strains corroborated the results of the MLSA that D. dadantii Ech586 and D. dadantii Ech703 should be reclassified as Dickeya zeae Ech586 and Dickeya paradisiaca Ech703, respectively, whereas D. zeae Ech1591 should be reclassified as Dickeya chrysanthemi Ech1591.
  18. Tropical sharks feasting on and swimming through microplastics: First evidence from Malaysia
    Matupang DM, Zulkifli HI, Arnold J, Lazim AM, Ghaffar MA, Musa SM
    Mar Pollut Bull, 2023 Apr;189:114762.
    PMID: 36870137 DOI: 10.1016/j.marpolbul.2023.114762
    Plastic can be degraded into microplastic (<5 mm) and has been polluting worldwide marine environment and negatively impact human health. Microplastics in marine organisms are still understudied in Malaysia, let alone from a subclass Elasmobranchii. Five tropical shark species (Carcharhinus dussumieri, Carcharhinus sorrah, Chiloscyllium hasseltii, Chiloscyllium punctatum, and Scoliodon laticaudus) were examined for the presence of microplastics. 74 sharks were sampled from the local wet market and 100 % of samples contained microplastics. A total of 2211 plastic particles were found in gastrointestinal tracts (GIT) and gills, where 29.88 ± 2.34 particles per shark (mean ± SEM). Black (40.07 %) and fiber (84.44 %) microplastics were the most dominant. Extracted microplastic sizes ranged from 0.007 mm to 4.992 mm. This study suggests that microplastic uptake is gender-related for some shark species. A subsample of microplastics (10 %) was used for polymer type identification, where polyester was recorded the highest (43.95 %).
  19. Fulltext Genetic diversity, population structure and historical demography of the two-spined yellowtail stargazer (Uranoscopus cognatus)
    Mohd Yusoff NIS, Mat Jaafar TNA, Vilasri V, Mohd Nor SA, Seah YG, Habib A, et al.
    Sci Rep, 2021 Jun 25;11(1):13357.
    PMID: 34172804 DOI: 10.1038/s41598-021-92905-6
    Benthic species, though ecologically important, are vulnerable to genetic loss and population size reduction due to impacts from fishing trawls. An assessment of genetic diversity and population structure is therefore needed to assist in a resource management program. To address this issue, the two-spined yellowtail stargazer (Uranoscopus cognatus) was collected within selected locations in the Indo-West Pacific (IWP). The partial mitochondrial DNA cytochrome c oxidase subunit 1 and the nuclear DNA recombination activating gene 1 were sequenced. Genetic diversity analyses revealed that the populations were moderately to highly diversified (haplotype diversity, H = 0.490-0.900, nucleotide diversity, π = 0.0010-0.0034) except sampling station (ST) 1 and 14. The low diversity level, however was apparent only in the matrilineal marker (H = 0.118-0.216; π = 0.0004-0.0008), possibly due to stochastic factors or anthropogenic stressors. Population structure analyses revealed a retention of ancestral polymorphism that was likely due to incomplete lineage sorting in U. cognatus, and prolonged vicariance by the Indo-Pacific Barrier has partitioned them into separate stock units. Population segregation was also shown by the phenotypic divergence in allopatric populations, regarding the premaxillary protrusion, which is possibly associated with the mechanism for upper jaw movement in biomechanical feeding approaches. The moderate genetic diversity estimated for each region, in addition to past population expansion events, indicated that U. cognatus within the IWP was still healthy and abundant (except in ST1 and 14), and two stock units were identified to be subjected to a specific resource management program.
  20. Fulltext Phylogenomics of the genus Tursiops and closely related Delphininae reveals extensive reticulation among lineages and provides inference about eco-evolutionary drivers
    Moura AE, Shreves K, Pilot M, Andrews KR, Moore DM, Kishida T, et al.
    Mol Phylogenet Evol, 2020 05;146:106756.
    PMID: 32028032 DOI: 10.1016/j.ympev.2020.106756
    Phylogeographic inference has provided extensive insight into the relative roles of geographical isolation and ecological processes during evolutionary radiations. However, the importance of cross-lineage admixture in facilitating adaptive radiations is increasingly being recognised, and suggested as a main cause of phylogenetic uncertainty. In this study, we used a double digest RADseq protocol to provide a high resolution (~4 Million bp) nuclear phylogeny of the Delphininae. Phylogenetic resolution of this group has been especially intractable, likely because it has experienced a recent species radiation. We carried out cross-lineage reticulation analyses, and tested for several sources of potential bias in determining phylogenies from genome sampling data. We assessed the divergence time and historical demography of T. truncatus and T. aduncus by sequencing the T. aduncus genome and comparing it with the T. truncatus reference genome. Our results suggest monophyly for the genus Tursiops, with the recently proposed T. australis species falling within the T. aduncus lineage. We also show the presence of extensive cross-lineage gene flow between pelagic and European coastal ecotypes of T. truncatus, as well as in the early stages of diversification between spotted (Stenella frontalis; Stenella attenuata), spinner (Stenella longirostris), striped (Stenella coeruleoalba), common (Delphinus delphis), and Fraser's (Lagenodelphis hosei) dolphins. Our study suggests that cross-lineage gene flow in this group has been more extensive and complex than previously thought. In the context of biogeography and local habitat dependence, these results improve our understanding of the evolutionary processes determining the history of this lineage.
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