ARL3 mutations cause Joubert syndrome by disrupting ciliary protein composition

Joubert syndrome (JBTS) is a genetically heterogeneous autosomal recessive neurodevelopmental ciliopathy. We investigated further the underlying genetic etiology of Joubert syndrome by studying two unrelated families in whom JBTS was not associated with pathogenic variants in known JBTSrelated genes. Combined autozygosity mapping of both families highlighted a candidate locus on chromosome 10 (chr10: 101569997-109106128 (hg 19)), and exome sequencing revealed two missense variants in ARL3 within the candidate locus. The encoded protein, ADP Ribosylation Factor-Like GTPase 3, ARL3, is a small GTP-binding protein that is involved in directing lipid-modified proteins into the cilium in a GTP-dependent manner. Both missense variants replace the highly conserved Arg149 residue, which we show to be necessary for the interaction with its guanine nucleotide exchange factor ARL13B, such that the mutant protein is associated with reduced INPP5E and NPHP3 localisation in cilia. We propose that ARL3 provides a potential hub in the network of encoded ciliopathy genes, whereby perturbation of ARL3 results in the mislocalisation of multiple ciliary proteins due to abnormal displacement of lipidated protein cargo

Assessment of Practical Research-Based Activity Program as a Tool for Teaching Medical Physiology to Undergraduates

Background: Practical work is an essential component of science teaching and learning. Medicine is an applied science, interpreting evidence and applying it to real life, so the practical research–based activity program (PRBAP) may be considered as a good way for learning at medical schools;Methods: The traditional activity programs which were used by our physiology department for years became non-interesting ways for gaining new skills so constructing a PRBAP was of considerable importance. PRABP was evaluated by student feedbacks on designed Likert scale with five items for student enjoyment assessment and six items for developed key skills and by calculating the mean score of students' grades and the number of first year students finished their physiology course;Results: In this study, the twenty students that participated in PRBAP showed a positive response to nearly most items on Likert scale, P < 0.001 for all five items of enjoyment assessment when compared to non-PRBAP students. Also PRBAP students showed significant difference in group working and communication skills, Individual study skills, Practical skills, and time management when compared to non-PRBAP students. PRBAP students showed significant difference in the number who finished their first year physiology course compared to the non-PRBAP students of the same academic year, however no significant difference in the mean score of grades.Conclusion: PRBAP appears to be a good way for generating motivation for learning and also to demonstrate the relevance of physiology among students.Keywords: Practical Research, Physiology, Teaching, Undergraduate

Occurrence of Virulent and Antibiotic-resistant Enteropathogenic and Shiga toxin- producing Escherichia coli in some Milk Products Sold in Assiut City, Egypt

This study was undertaken to detect the enteropathogenic and shiga toxin-producing Escherichia coli (EPEC and STEC) in 120 milk products samples (soft cheese, hard cheese, yoghurt and ice cream). All samples were submitted for bacteriological examination, serological and molecular identification of virulent and antibiotic resistant genes using eaeA, hylA, blaTEM, blaCTX-M1, blaOXA and blaSHV primers. The bacteriological examination revealed that the incidence of occurrence of EPEC was 3.33% in ice cream samples, while it could not isolated from other types of milk products. In addition, STEC failed to detect in all examined milk products. The isolated EPEC strain following E. coli O18 serotyping. Moreover, the molecular identification of the isolated strain revealed that the strain contains eaeA, blaTEM and blaCTX-M1 genes

Incidence of Cronobacter sakazakii in Dairy-based Desserts

Cronobacter sakazakii is one of emerging foodborne pathogens around the world. A total of 90 dairy-based desserts samples (ice cream, Muhallabia and rice pudding) were examined for detecting C. sakazakii. All samples were submitted for bacteriological examination and confirmed by molecular identification using 16S rRNA gene for C. sakazakii. The bacteriological and molecular examination revealed that the incidence of occurrence of C. sakazakii was 5.55% from the total dairy-based desserts samples, the highest percentage occurred in rice pudding samples (10%), while the incidence of C. sakazakii in ice cream and Muhallabia were 3.33% for each type. The results pointed out that high risk for human may occur by contaminated dairy-based desserts. The hygienic precautions must be taken during the processing of these types of products

Effects of irrigation , type of fertilizer and nitrogen rate on yield components and total yield of mango (Mangifera indica L.) in Abu Karshoula, South Kordofan State, Sudan

An experiment was conducted at Abu Karshoula, South Kordofan State, Sudan, during the  seasons of 2009/10 and 2010/11, to determine the effects of irrigation, type of fertilizer and nitrogen rate on yield components and total yield of the local mango cultivar Kitchener. Treatments consisted of irrigated or non-irrigated trees. Types of fertilizer were urea, cow manure and a combination of urea and cow manure. Nitrogen rates were 0 kg/ha, 43 kg/ha and 86 kg/ha. The treatments were arranged in a split-split plot design with irrigation treatments as the main plots, type of fertilizer as the sub-plots and N rates as the sub-sub plots, replicated three times. Results showed that irrigation of mango trees significantly increased exportable yield, cull yield, number of fruits per tree and total yield, whereas, withholding irrigation from mango trees gave higher locally marketable and lower cull yields in both seasons. Nitrogen fertilizer in the form of urea produced the largest number of fruits per tree and the highest locally marketable  and total yields in both seasons. Combination of urea and cow manure significantly increased exportable yield in both seasons. However, nitrogen fertilizer in the form of cow manure  alone gave the lowest total yield and number of fruits per tree in both seasons. Application of N at the rate of 86 kg/ha coupled with irrigation significantly increased number of fruits per tree, cull, exportable and total yields.  Hence, it is recommended to irrigate mango trees and apply N in a combination of urea and cow manure at the rate of 86 kg/ha in order to increase total and exportable yields. أجريت التجربة بأبي كرشولا، ولاية جنوب كردفان, السودان لموسمي 2009/10و2010/11 لمعرفة تأثير الري ونوع السماد ومعدل النتروجين على مكونات الإنتاج و الإنتاج الكلي لصنف المانجو المحلي كتشنر.اشتملت المعاملات علي ري أشجار المانجو أو عدم ريها. مصادر النتروجين كانت يوريا و روث الأبقار و خليط من اليوريا و روث الأبقار. إضيف النتروجين بمعدلات صفر و43 و86 كجم N/هكتار. صممت التجربة بطريقة القطع المنشقه مرتين . كانت معاملة الري هي القطعة الرئيسيه ونوع السماد هي القطعه المنشقه ومعدل النتروجبن هو القطعه المنشقه المنشقه وتم تكرارها ثلاث مرات. أظهرت النتائج أن ري أشجار المانجو أدى إلى زيادة معنوية في إنتاج مانجو الصادر و الثمار المخدوشه وعدد الثمار للشجره و الإنتاج الكلي.  بينما ادى حجب الماء عن أشجار المانجوالى أعلى إنتاج للسوق المحلي و أقل ثمار مخدوشه.ادى سماد اليوريا الى أعلى عدد من ثمارالمانجو للشجره و أعلى إنتاج للسوق المحلي وأعلى إنتاج كلي في الموسمين.كما ادى خلط اليوريا و ماروق روث الأبقاربنسبة 50% لكل إلى زيادة معنوية في إنتاج الصادر في الموسمين. بينما اعطى سماد ماروق روث الابقار أقل إنتاج كلي و عدد الثمار للشجرة في الموسمين .ادت إضافة السماد إلى زيادة معنوية فى  عدد الثمار للشجره و إنتاج الصادر و الإنتاج الكلي في الموسمين بينما ادى معدل86 كجم N/هكتارالى أعلى إنتاج لمانجو  الصادر و إنتاج كلي في الموسمين مقارنة بمعدل 43 كجم N/هكتار. توصى الدراسة بري أشجار المانجو وإضافة النتروجين في شكل خليط من اليوريا وماروق روث الأبقار بمعدل 86 كيلوجرام N /هكتار لزيادة الإنتاج الكلي وإنتاج الصادر

Impact of pH and temperature on bacteriocin activity and plantaricin C gene expression of Lactobacillus plantarum bacteria

This study aimed to investigate the effect of different pH (7 and 4) and temperatures (4 and 40°C) on bacteriocin activity and plantaricin C (plnC) gene expression of Lactobacillus plantarium. Six strains of L. plantarum were used in these trials. The bacteriocin activity was measured after the different treatments by well diffusion test using indicator bacteria (Staphylococcus aureus and Escherichia coli O157:H7). Moreover, the plnC gene expression was determined by real-time PCR using 16S rRNA primers for universal bacteria and plantacirin C primers. The results declared a significant difference between the different pH and temperatures. In addition, the downregulation of plnC gene expression in pH 4. The upregulation of the same gene was applied to 40 ºC during bacteria incubation. Also, there is no correlation between the bacteriocin activity and plnC gene expression after applying different pH and temperatures in L. plantarum bacteria

Insight into ALKBH8-related intellectual developmental disability based on the first pathogenic missense variant

ALKBH8 is a methyltransferase that modifies tRNAs by methylating the anticodon wobble uridine residue. The syndrome of ALKBH8-related intellectual developmental disability (MRT71) has thus far been reported solely in the context of homozygous truncating variants that cluster in the last exon. This raises interesting questions about the disease mechanism, because these variants are predicted to escape nonsense mediated decay and yet they appear to be loss of function. Furthermore, the limited class of reported variants complicates the future interpretation of missense variants in ALKBH8. Here, we report a consanguineous family in which two children with MRT71-compatible phenotype are homozygous for a novel missense variant in the methyltransferase domain. We confirm the pathogenicity of this variant by demonstrating complete absence of ALKBH8-dependent modifications in patient cells. Targeted proteomics analysis of ALKBH8 indicates that the variant does not lead to loss of ALKBH8 protein expression. This report adds to the clinical delineation of MRT71, confirms loss of function of ALKBH8 as the disease mechanism and expands the repertoire of its molecular lesions.Insight into ALKBH8-related intellectual developmental disability based on the first pathogenic missense variantacceptedVersio

Characterizing the morbid genome of ciliopathies

Background Ciliopathies are clinically diverse disorders of the primary cilium. Remarkable progress has been made in understanding the molecular basis of these genetically heterogeneous conditions; however, our knowledge of their morbid genome, pleiotropy, and variable expressivity remains incomplete. Results We applied genomic approaches on a large patient cohort of 371 affected individuals from 265 families, with phenotypes that span the entire ciliopathy spectrum. Likely causal mutations in previously described ciliopathy genes were identified in 85% (225/265) of the families, adding 32 novel alleles. Consistent with a fully penetrant model for these genes, we found no significant difference in their “mutation load” beyond the causal variants between our ciliopathy cohort and a control non-ciliopathy cohort. Genomic analysis of our cohort further identified mutations in a novel morbid gene TXNDC15, encoding a thiol isomerase, based on independent loss of function mutations in individuals with a consistent ciliopathy phenotype (Meckel-Gruber syndrome) and a functional effect of its deficiency on ciliary signaling. Our study also highlighted seven novel candidate genes (TRAPPC3, EXOC3L2, FAM98C, C17orf61, LRRCC1, NEK4, and CELSR2) some of which have established links to ciliogenesis. Finally, we show that the morbid genome of ciliopathies encompasses many founder mutations, the combined carrier frequency of which accounts for a high disease burden in the study population. Conclusions Our study increases our understanding of the morbid genome of ciliopathies. We also provide the strongest evidence, to date, in support of the classical Mendelian inheritance of Bardet-Biedl syndrome and other ciliopathies