Displaying publications 1 - 20 of 68 in total

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  1. Brunton PJ, Donadio MV, Yao ST, Greenwood M, Seckl JR, Murphy D, et al.
    J Neurosci, 2015 Jan 14;35(2):666-77.
    PMID: 25589761 DOI: 10.1523/JNEUROSCI.5104-13.2015
    Maternal social stress during late pregnancy programs hypothalamo-pituitary-adrenal (HPA) axis hyper-responsiveness to stressors, such that adult prenatally stressed (PNS) offspring display exaggerated HPA axis responses to a physical stressor (systemic interleukin-1β; IL-1β) in adulthood, compared with controls. IL-1β acts via a noradrenergic relay from the nucleus tractus solitarii (NTS) to corticotropin releasing hormone neurons in the paraventricular nucleus (PVN). Neurosteroids can reduce HPA axis responses, so allopregnanolone and 3β-androstanediol (3β-diol; 5α-reduced metabolites of progesterone and testosterone, respectively) were given subacutely (over 24 h) to PNS rats to seek reversal of the "programmed" hyper-responsive HPA phenotype. Allopregnanolone attenuated ACTH responses to IL-1β (500 ng/kg, i.v.) in PNS females, but not in PNS males. However, 3β-diol normalized HPA axis responses to IL-1β in PNS males. Impaired testosterone and progesterone metabolism or increased secretion in PNS rats was indicated by greater plasma testosterone and progesterone concentrations in male and female PNS rats, respectively. Deficits in central neurosteroid production were indicated by reduced 5α-reductase mRNA levels in both male and female PNS offspring in the NTS, and in the PVN in males. In PNS females, adenovirus-mediated gene transfer was used to upregulate expression of 5α-reductase and 3α-hydroxysteroid dehydrogenase mRNAs in the NTS, and this normalized hyperactive HPA axis responses to IL-1β. Thus, downregulation of neurosteroid production in the brain may underlie HPA axis hyper-responsiveness in prenatally programmed offspring, and administration of 5α-reduced steroids acutely to PNS rats overrides programming of hyperactive HPA axis responses to immune challenge in a sex-dependent manner.
  2. Reddy LJ, Kumar PS, Pandrangi SL, Chikati R, Srinivasulu C, John A, et al.
    Appl Biochem Biotechnol, 2023 Apr;195(4):2743-2766.
    PMID: 36422804 DOI: 10.1007/s12010-022-04215-w
    The majority of the Earth's ecosystem is frigid and frozen, which permits a vast range of microbial life forms to thrive by triggering physiological responses that allow them to survive in cold and frozen settings. The apparent biotechnology value of these cold-adapted enzymes has been targeted. Enzymes' market size was around USD 6.3 billion in 2017 and will witness growth at around 6.8% CAGR up to 2024 owing to shifting consumer preferences towards packaged and processed foods due to the rising awareness pertaining to food safety and security reported by Global Market Insights (Report ID-GMI 743). Various firms are looking for innovative psychrophilic enzymes in order to construct more effective biochemical pathways with shorter reaction times, use less energy, and are ecologically acceptable. D-Galactosidase catalyzes the hydrolysis of the glycosidic oxygen link between the terminal non-reducing D-galactoside unit and the glycoside molecule. At refrigerated temperature, the stable structure of psychrophile enzymes adjusts for the reduced kinetic energy. It may be beneficial in a wide variety of activities such as pasteurization of food, conversion of biomass, biological role of biomolecules, ambient biosensors, and phytoremediation. Recently, psychrophile enzymes are also used in claning the contact lens. β-D-Galactosidases have been identified and extracted from yeasts, fungi, bacteria, and plants. Conventional (hydrolyzing activity) and nonconventional (non-hydrolytic activity) applications are available for these enzymes due to its transgalactosylation activity which produce high value-added oligosaccharides. This review content will offer new perspectives on cold-active β-galactosidases, their source, structure, stability, and application.
  3. Ponnampalam SN, Kamaluddin NR, Zakaria Z, Matheneswaran V, Ganesan D, Haspani MS, et al.
    Oncol Rep, 2017 Jan;37(1):10-22.
    PMID: 28004117 DOI: 10.3892/or.2016.5285
    The aims of the present study were to undertake gene expression profiling of the blood of glioma patients to determine key genetic components of signaling pathways and to develop a panel of genes that could be used as a potential blood-based biomarker to differentiate between high and low grade gliomas, non-gliomas and control samples. In this study, blood samples were obtained from glioma patients, non-glioma and control subjects. Ten samples each were obtained from patients with high and low grade tumours, respectively, ten samples from non-glioma patients and twenty samples from control subjects. Total RNA was isolated from each sample after which first and second strand synthesis was performed. The resulting cRNA was then hybridized with the Agilent Whole Human Genome (4x44K) microarray chip according to the manufacturer's instructions. Universal Human Reference RNA and samples were labeled with Cy3 CTP and Cy5 CTP, respectively. Microarray data were analyzed by the Agilent Gene Spring 12.1V software using stringent criteria which included at least a 2-fold difference in gene expression between samples. Statistical analysis was performed using the unpaired Student's t-test with a p<0.01. Pathway enrichment was also performed, with key genes selected for validation using droplet digital polymerase chain reaction (ddPCR). The gene expression profiling indicated that were a substantial number of genes that were differentially expressed with more than a 2-fold change (p<0.01) between each of the four different conditions. We selected key genes within significant pathways that were analyzed through pathway enrichment. These key genes included regulators of cell proliferation, transcription factors, cytokines and tumour suppressor genes. In the present study, we showed that key genes involved in significant and well established pathways, could possibly be used as a potential blood-based biomarker to differentiate between high and low grade gliomas, non-gliomas and control samples.
  4. Arick MA, Grover CE, Hsu CY, Magbanua Z, Pechanova O, Miller ER, et al.
    G3 (Bethesda), 2023 Mar 09;13(3).
    PMID: 36639248 DOI: 10.1093/g3journal/jkad009
    Labeo rohita (rohu) is a carp important to aquaculture in South Asia, with a production volume close to Atlantic salmon. While genetic improvements to rohu are ongoing, the genomic methods commonly used in other aquaculture improvement programs have historically been precluded in rohu, partially due to the lack of a high-quality reference genome. Here we present a high-quality de novo genome produced using a combination of next-generation sequencing technologies, resulting in a 946 Mb genome consisting of 25 chromosomes and 2,844 unplaced scaffolds. Notably, while approximately half the size of the existing genome sequence, our genome represents 97.9% of the genome size newly estimated here using flow cytometry. Sequencing from 120 individuals was used in conjunction with this genome to predict the population structure, diversity, and divergence in three major rivers (Jamuna, Padma, and Halda), in addition to infer a likely sex determination mechism in rohu. These results demonstrate the utility of the new rohu genome in modernizing some aspects of rohu genetic improvement programs.
  5. Barría A, Trịnh TQ, Mahmuddin M, Peñaloza C, Papadopoulou A, Gervais O, et al.
    Heredity (Edinb), 2021 Sep;127(3):334-343.
    PMID: 34262170 DOI: 10.1038/s41437-021-00447-4
    Enhancing host resistance to infectious disease has received increasing attention in recent years as a major goal of farm animal breeding programs. Combining field data with genomic tools can provide opportunities to understand the genetic architecture of disease resistance, leading to new opportunities for disease control. In the current study, a genome-wide association study was performed to assess resistance to the Tilapia lake virus (TiLV), one of the biggest threats affecting Nile tilapia (Oreochromis niloticus); a key aquaculture species globally. A pond outbreak of TiLV in a pedigreed population of the GIFT strain was observed, with 950 fish classified as either survivor or mortality, and genotyped using a 65 K SNP array. A significant QTL of large effect was identified on chromosome Oni22. The average mortality rate of tilapia homozygous for the resistance allele at the most significant SNP (P value = 4.51E-10) was 11%, compared to 43% for tilapia homozygous for the susceptibility allele. Several candidate genes related to host response to viral infection were identified within this QTL, including lgals17, vps52, and trim29. These results provide a rare example of a major QTL affecting a trait of major importance to a farmed animal. Genetic markers from the QTL region have potential in marker-assisted selection to improve host resistance, providing a genetic solution to an infectious disease where few other control or mitigation options currently exist.
  6. McAllister CT, Hnida JA, Fisher SR, Del Pinto LA, Quah ESH
    Syst Parasitol, 2020 10;97(5):529-534.
    PMID: 32813222 DOI: 10.1007/s11230-020-09929-1
    A new species of Acroeimeria Paperna & Landsberg, 1989 is described from the spotted house gecko, Gekko monarchus (Schlegel) from Peninsular Malaysia. Oöcysts of Acroeimeria grismeri n. sp. are spheroidal to subspheroidal with a smooth bi-layered wall, measure on average 18.4 × 17.3 µm, and have a length/width (L/W) ratio of 1.1; a micropyle and an oöcyst residuum are absent but variable polar granule(s) are present, commonly in Brownian movement. Sporocysts are ellipsoidal and measure on average 8.6 × 6.7 µm, L/W 1.3; Stieda, sub-Stieda and para-Stieda bodies are absent. The sporocyst residuum is composed of numerous spheroidal granules in the center of the sporocyst. This is the initial species of coccidian reported from G. monarchus and one of the few reported from any reptile from Peninsular Malaysia.
  7. Chen BC, McGown IN, Thong MK, Pitt J, Yunus ZM, Khoo TB, et al.
    J Inherit Metab Dis, 2010 Dec;33 Suppl 3:S159-62.
    PMID: 20177786 DOI: 10.1007/s10545-010-9056-z
    Most cases of adenylosuccinate lyase (ADSL OMIM 103050) deficiency reported to date are confined to the various European ethnic groups. We report on the first Malaysian case of ADSL deficiency, which appears also to be the first reported Asian case. The case was diagnosed among a cohort of 450 patients with clinical features of psychomotor retardation, global developmental delay, seizures, microcephaly and/or autistic behaviour. The patient presented with frequent convulsions and severe myoclonic jerk within the first few days of life and severe psychomotor retardation. The high performance liquid chromatography (HPLC) profile of the urine revealed the characteristic biochemical markers of succinyladenosine (S-Ado) and succinyl-aminoimidazole carboximide riboside (SAICAr). The urinary S-Ado/SAICAr ratio was found to be 1.02 (type I ADSL deficiency). The patient was compound heterozygous for two novel mutations, c.445C > G (p.R149G) and c.774_778insG (p.A260GfsX24).
  8. Chalandon Y, Sbianchi G, Gras L, Koster L, Apperley J, Byrne J, et al.
    Am J Hematol, 2023 Jan;98(1):112-121.
    PMID: 36266607 DOI: 10.1002/ajh.26764
    Following the introduction of tyrosine kinase inhibitors (TKI), the number of patients undergoing allogeneic hematopoietic cell transplantation (allo-HCT) for chronic phase (CP) chronic myeloid leukemia (CML) has dramatically decreased. Imatinib was the first TKI introduced to the clinical arena, predominantly utilized in the first line setting. In cases of insufficient response, resistance, or intolerance, CML patients can subsequently be treated with either a second or third generation TKI. Between 2006 and 2016, we analyzed the impact of the use of 1, 2, or 3 TKI prior to allo-HCT for CP CML in 904 patients. A total of 323-, 371-, and 210 patients had 1, 2, or 3 TKI prior to transplant, respectively; imatinib (n = 778), dasatinib (n = 508), nilotinib (n = 353), bosutinib (n = 12), and ponatinib (n = 44). The majority had imatinib as first TKI (n = 747, 96%). Transplants were performed in CP1, n = 549, CP2, n = 306, and CP3, n = 49. With a median follow-up of 52 months, 5-year OS for the entire population was 64.4% (95% CI 60.9-67.9%), PFS 50% (95% CI 46.3-53.7%), RI 28.7% (95% CI 25.4-32.0%), and NRM 21.3% (95% CI 18.3-24.2%). No difference in OS, PFS, RI, or NRM was evident related to the number of TKI prior to allo-HCT or to the type of TKI (p = ns). Significant factors influencing OS and PFS were > CP1 versus CP1 and Karnofsky performance (KPS) score > 80 versus ≤80, highlighting CP1 patients undergoing allo-HCT have improved survival compared to >CP1 and the importance of careful allo-HCT candidate selection.
  9. Rodde C, de Verdal H, Vandeputte M, Allal F, Nati J, Besson M, et al.
    J Anim Sci, 2021 Jun 01;99(6).
    PMID: 33966070 DOI: 10.1093/jas/skab152
    Feed efficiency (FE) is the amount of body weight gain for a given feed intake. Improving FE through selective breeding is key for sustainable finfish aquaculture but its evaluation at individual level is technically challenging. We therefore investigated whether individual routine metabolic rate (RMR) was a predictor of individual FE in the European sea bass Dicentrarchus labrax, a major species in European mariculture. The European sea bass has three genetically distinct populations across its geographical range, namely Atlantic (AT), West Mediterranean (WM), and East Mediterranean (EM). We compared FE and RMR of fish from these three populations at 18 or 24 °C. We held 200 fish (62 AT, 66 WM, and 72 EM) in individual aquaria and fed them from ad libitum down to fasting. FI was assessed for an ad libitum feeding rate and for a fixed restricted ration (1% of metabolic body weight·day-1, with metabolic body weight = body weight0.8). After being refed 12 wk in a common tank, individual RMR was measured over 36 h by intermittent flow respirometry. There was a significant effect of temperature whereby fish at 18 °C had greater mean FE (P < 0.05) and lower RMR (P < 0.001). There was also a significant effect of population, where AT fish had lower FE (P < 0.05) and greater RMR (P < 0.001) than WM and EM, at both temperatures. Despite these differences in temperature and population means, individual FE and RMR were not significantly correlated (P > 0.05). Therefore, although the results provide evidence of an association between metabolic rate and FE, RMR was not a predictor of individual FE, for reasons that require further investigation.
  10. Vlasova AN, Toh TH, Lee JS, Poovorawan Y, Davis P, Azevedo MSP, et al.
    Emerg Microbes Infect, 2022 Feb 14.
    PMID: 35156544 DOI: 10.1080/22221751.2022.2040341
    Here we review the existing evidence of animal alphacoronaviruses (Alphacoronavirus 1 species) circulating in human patients with acute respiratory illness. Thus far, the viruses similar to canine, feline and porcine alphacoronaviruses (including the most recent CCoV-HuPn-2018 and HuCCoV_Z19) have been detected in humans in Haiti, Malaysia, Thailand, and USA. The available data suggest that these viruses emerged in different geographic locations independently and have circulated in humans for at least 20 years. Additional studies are needed to investigate their prevalence and disease impact.
  11. Gwee KA, Bergmans P, Kim J, Coudsy B, Sim A, Chen M, et al.
    J Neurogastroenterol Motil, 2017 Apr 30;23(2):262-272.
    PMID: 27764907 DOI: 10.5056/jnm16095
    Background/Aims: There is a need for a simple and practical tool adapted for the diagnosis of chronic constipation (CC) in the Asian population. This study compared the Asian Neurogastroenterology and Motility Association (ANMA) CC tool and Rome III criteria for the diagnosis of CC in Asian subjects.
    Methods: This multicenter, cross-sectional study included subjects presenting at outpatient gastrointestinal clinics across Asia. Subjects with CC alert symptoms completed a combination Diagnosis Questionnaire to obtain a diagnosis based on 4 different diagnostic methods: self-defined, investigator's judgment, ANMA CC tool, and Rome III criteria. The primary endpoint was the level of agreement/disagreement between the ANMA CC diagnostic tool and Rome III criteria for the diagnosis of CC.
    Results: The primary analysis comprised of 449 subjects, 414 of whom had a positive diagnosis according to the ANMA CC tool. Rome III positive/ANMA positive and Rome III negative/ANMA negative diagnoses were reported in 76.8% and 7.8% of subjects, respectively, resulting in an overall percentage agreement of 84.6% between the 2 diagnostic methods. The overall percentage disagreement between these 2 diagnostic methods was 15.4%. A higher level of agreement was seen between the ANMA CC tool and self-defined (374 subjects [90.3%]) or investigator's judgment criteria (388 subjects [93.7%]) compared with the Rome III criteria.
    Conclusion: This study demonstrates that the ANMA CC tool can be a useful for Asian patients with CC.
    Study site in Malaysia: Gastroenterology clinic, University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia
  12. Klingenberg C, Tembulkar SK, Lavizzari A, Roehr CC, Ehret DEY, Vain NE, et al.
    J Perinatol, 2021 05;41(5):988-997.
    PMID: 33850282 DOI: 10.1038/s41372-021-01019-4
    OBJECTIVE: To evaluate COVID-19 pandemic preparedness, available resources, and guidelines for neonatal care delivery among neonatal health care providers in low- and middle-income countries (LMICs) across all continents.

    STUDY DESIGN: Cross-sectional, web-based survey administered between May and June, 2020.

    RESULTS: Of 189 invited participants in 69 LMICs, we received 145 (77%) responses from 58 (84%) countries. The pandemic provides significant challenges to neonatal care, particularly in low-income countries. Respondents noted exacerbations of preexisting shortages in staffing, equipment, and isolation capabilities. In Sub-Saharan Africa, 9/35 (26%) respondents noted increased mortality in non-COVID-19-infected infants. Clinical practices on cord clamping, isolation, and breastfeeding varied widely, often not in line with World Health Organization guidelines. Most respondents noted family access restrictions, and limited shared decision-making.

    CONCLUSIONS: Many LMICs face an exacerbation of preexisting resource challenges for neonatal care during the pandemic. Variable approaches to care delivery and deviations from guidelines provide opportunities for international collaborative improvement.

  13. Laily B. Din, Zuriati Zakaria, Mohd Wahid Samsudin, Elix JA
    The lichen collection from Bukit Larut, Taiping, Malaysia in 1999 included Bulbothrix isidiza, Chrysothrix xanthina, Cladonia adspersa, C. verticillata, Coccocarpia palmicola, Heterodermia flabellata, H. japonica, H. obscurata, Hypotrachyna imbricatula, Leptogium azureum, Parmelinella wallichiana, Parmotrema tinctorum, P. clavuliferum, P. reticulatum, Pertusaria sp., Physma byrsaeum, Usnea baileyi and Usnea rubrotincta. Secondary metabolites could not be detected in three lichens, Coccocarpia palmicola, Leptogium azureum and Physma byrsaeum by HPLC and TLC analysis. The other 15 lichen species showed the presence of ten classes of compounds, depsides (10 compounds), depsidones (16), quinones (5), xanthones (2), naphthopyrones (1), pulvinic acid derivatives (1), diphenylethers (1), dibenzofurans (1), aliphatic acids (4) and terpenoids (3).
  14. Seyed Khoei N, Jenab M, Murphy N, Banbury BL, Carreras-Torres R, Viallon V, et al.
    BMC Med, 2020 09 03;18(1):229.
    PMID: 32878631 DOI: 10.1186/s12916-020-01703-w
    BACKGROUND: Bilirubin, a byproduct of hemoglobin breakdown and purported anti-oxidant, is thought to be cancer preventive. We conducted complementary serological and Mendelian randomization (MR) analyses to investigate whether alterations in circulating levels of bilirubin are associated with risk of colorectal cancer (CRC). We decided a priori to perform analyses separately in men and women based on suggestive evidence that associations may differ by sex.

    METHODS: In a case-control study nested in the European Prospective Investigation into Cancer and Nutrition (EPIC), pre-diagnostic unconjugated bilirubin (UCB, the main component of total bilirubin) concentrations were measured by high-performance liquid chromatography in plasma samples of 1386 CRC cases and their individually matched controls. Additionally, 115 single-nucleotide polymorphisms (SNPs) robustly associated (P 

  15. Gupta N, John A, Kokkottil MS, Varma M, Umakanth S, Saravu K
    Drug Discov Ther, 2021 Mar 10;15(1):1-8.
    PMID: 33642450 DOI: 10.5582/ddt.2020.03068
    Despite the high number of coronavirus disease-19 (COVID-19) cases from India, there are few reports from India describing the clinical epidemiology of COVID-19. This study aimed to describe the clinical/epidemiological characteristics and outcomes of asymptomatic vs. symptomatic COVID-19 patients. This was a retrospective chart review of all admitted patients with COVID-19 above 18 years with a history of travel within one month of the admission. The patients were categorized into asymptomatic and symptomatic. The symptomatic patients were further classified into mild, moderate and severe. The demographic profile, risk factors, clinical features, laboratory parameters, treatment details and outcome of all patients were recorded. The clinical and laboratory parameters were compared between symptomatic patients and asymptomatic patients. Of the 127 recruited patients, 75 were asymptomatic. Of the 52 symptomatic patients, 41 patients were classified as a mild illness. The mean age of the patients was 44.5 ± 15 years. A total of 73 patients had one or more risk factors. The male patients were more commonly found to be symptomatic compared to female patients. Neutrophil-lymphocyte ratio, C-reactive protein and lactate dehydrogenase were significantly elevated in symptomatic patients. A total of five individuals required supplemental oxygen therapy, and one of them required mechanical ventilation. All the patients had favourable outcomes. Asymptomatic and mild illness form a significant proportion of positive patients and have excellent outcomes without therapeutic interventions.
  16. Nayfa MG, Jones DB, Benzie JAH, Jerry DR, Zenger KR
    Front Genet, 2020;11:567969.
    PMID: 33193660 DOI: 10.3389/fgene.2020.567969
    Domestication to captive rearing conditions, along with targeted selective breeding have genetic consequences that vary from those in wild environments. Nile tilapia (Oreochromis niloticus) is one of the most translocated and farmed aquaculture species globally, farmed throughout Asia, North and South America, and its African native range. In Egypt, a breeding program established the Abbassa Strain of Nile tilapia (AS) in 2002 based on local broodstock sourced from the Nile River. The AS has been intensively selected for growth and has gone through genetic bottlenecks which have likely shifted levels and composition of genetic diversity within the strain. Consequently, there are questions on the possible genetic impact AS escapees may have on endemic populations of Nile tilapia. However, to date there have been no genetic studies comparing genetic changes in the domesticated AS to local wild populations. This study used 9,827 genome-wide SNPs to investigate population genetic structure and signatures of selection in the AS (generations 9-11) and eight wild Nile tilapia populations from Egypt. SNP analyses identified two major genetic clusters (captive and wild populations), with wild populations showing evidence of isolation-by-distance among the Nile Delta and upstream riverine populations. Between genetic clusters, approximately 6.9% of SNPs were identified as outliers with outliers identified on all 22 O. niloticus chromosomes. A lack of localized outlier clustering on the genome suggests that no genes of major effect were presently detected. The AS has retained high levels of genetic diversity (Ho_All = 0.21 ± 0.01; He_All = 0.23 ± 0.01) when compared to wild populations (Ho_All = 0.18 ± 0.01; He_All = 0.17 ± 0.01) after 11 years of domestication and selective breeding. Additionally, 565 SNPs were unique within the AS line. While these private SNPs may be due to domestication signals or founder effects, it is suspected that introgression with blue tilapia (Oreochromis aureus) has occurred. This study highlights the importance of understanding the effects of domestication in addition to wild population structure to inform future management and dissemination decisions. Furthermore, by conducting a baseline genetic study of wild populations prior to the dissemination of a domestic line, the effects of aquaculture on these populations can be monitored over time.
  17. Wu CH, McCloskey EV, Lee JK, Itabashi A, Prince R, Yu W, et al.
    J Clin Densitom, 2014 Jan-Mar;17(1):150-5.
    PMID: 23916756 DOI: 10.1016/j.jocd.2013.06.002
    The fracture risk assessment tool (FRAX(®)) has been developed for the identification of individuals with high risk of fracture in whom treatment to prevent fractures would be appropriate. FRAX models are not yet available for all countries or ethnicities, but surrogate models can be used within regions with similar fracture risk. The International Society for Clinical Densitometry (ISCD) and International Osteoporosis Foundation (IOF) are nonprofit multidisciplinary international professional organizations. Their visions are to advance the awareness, education, prevention, and treatment of osteoporosis. In November 2010, the IOF/ISCD FRAX initiative was held in Bucharest, bringing together international experts to review and create evidence-based official positions guiding clinicians for the practical use of FRAX. A consensus meeting of the Asia-Pacific (AP) Panel of the ISCD recently reviewed the most current Official Positions of the Joint Official Positions of ISCD and IOF on FRAX in view of the different population characteristics and health standards in the AP regions. The reviewed position statements included not only the key spectrum of positions but also unique concerns in AP regions.
  18. John A, Shin PKS, Botton ML, Gauvry G, Cheung SG, Laurie K
    Biodivers Conserv, 2021;30(1):253-256.
    PMID: 33191986 DOI: 10.1007/s10531-020-02078-3
  19. Ortega Pérez P, Wibbelt G, Brinkmann A, Galindo Puentes JA, Tuh FYY, Lakim MB, et al.
    Int J Parasitol Parasites Wildl, 2020 Aug;12:220-231.
    PMID: 32695576 DOI: 10.1016/j.ijppaw.2020.07.003
    Sarcocystis scandentiborneensis sp. nov. was discovered in histological sections of striated musculature of treeshrews (Tupaia minor, T. tana) from Northern Borneo. Sarcocysts were cigar-shaped, 102 μm-545 μm long, and on average 53 μm in diameter. The striated cyst wall varied in thickness (2-10 μm), depending on whether the finger-like, villous protrusions (VP) were bent. Ultrastructurally, sarcocysts were similar to wall type 12 but basal microtubules extended into VPs that tapered off with a unique U-shaped, electron-dense apical structure. In phylogenetic trees of the nuclear 18S rRNA gene, S. scandentiborneensis formed a distinct branch within a monophyletic subclade of Sarcocystis spp. with (colubrid) snake-rodent life cycle. We mapped all intraspecific (two haplotypes) and interspecific nucleotide substitutions to the secondary structure of the 18S rRNA gene: in both cases, the highest variability occurred within helices V2 and V4 but intraspecific variability mostly related to transitions, while transition/transversion ratios between S. scandentiborneensis, S. zuoi, and S. clethrionomyelaphis were skewed towards transversions. Lack of relevant sequences restricted phylogenetic analysis of the mitochondrial Cytochrome C oxidase subunit I (COI) gene to include only one species of Sarcocystis recovered from a snake host (S. pantherophisi) with which the new species formed a sister relationship. We confirm the presence of the functionally important elements of the COI barcode amino acid sequence of S. scandentiborneensis, whereby the frequency of functionally important amino acids (Alanine, Serine) was markedly different to other taxa of the Sarcocystidae. We regard S. scandentiborneensis a new species, highlighting that structurally or functionally important aspects of the 18S rRNA and COI could expand their utility for delineation of species. We also address the question why treeshrews, believed to be close to primates, carry a parasite that is genetically close to a Sarcocystis lineage preferably developing in the Rodentia as intermediate hosts.
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