RBM5 Is a Male Germ Cell Splicing Factor and Is Required for Spermatid Differentiation and Male Fertility

Alternative splicing of precursor messenger RNA (pre-mRNA) is common in mammalian cells and enables the production of multiple gene products from a single gene, thus increasing transcriptome and proteome diversity. Disturbance of splicing regulation is associated with many human diseases; however, key splicing factors that control tissue-specific alternative splicing remain largely undefined. In an unbiased genetic screen for essential male fertility genes in the mouse, we identified the RNA binding protein RBM5 (RNA binding motif 5) as an essential regulator of haploid male germ cell pre-mRNA splicing and fertility. Mice carrying a missense mutation (R263P) in the second RNA recognition motif (RRM) of RBM5 exhibited spermatid differentiation arrest, germ cell sloughing and apoptosis, which ultimately led to azoospermia (no sperm in the ejaculate) and male sterility. Molecular modelling suggested that the R263P mutation resulted in compromised mRNA binding. Within the adult mouse testis, RBM5 localises to somatic and germ cells including spermatogonia, spermatocytes and round spermatids. Through the use of RNA pull down coupled with microarrays, we identified 11 round spermatid-expressed mRNAs as putative RBM5 targets. Importantly, the R263P mutation affected pre-mRNA splicing and resulted in a shift in the isoform ratios, or the production of novel spliced transcripts, of most targets. Microarray analysis of isolated round spermatids suggests that altered splicing of RBM5 target pre-mRNAs affected expression of genes in several pathways, including those implicated in germ cell adhesion, spermatid head shaping, and acrosome and tail formation. In summary, our findings reveal a critical role for RBM5 as a pre-mRNA splicing regulator in round spermatids and male fertility. Our findings also suggest that the second RRM of RBM5 is pivotal for appropriate pre-mRNA splicing.This work was supported by grants from the National Health and Medical Research Council (NHMRC) to DJ (#606503); the Australian Research Council (ARC) to MKO and CJO; the New South Wales Cancer Council, Cancer Institute New South Wales, Banque Nationale de Paris-Paribas Australia and New Zealand, RT Hall Trust, and the National Breast Cancer Foundation to CJO. DJ was an NHMRC Peter Doherty Postdoctoral Fellow (#384297). MKO and CJO are NHMRC Senior Research Fellows (#545805, #481310). CCG is an NHMRC Australia Fellowship. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Whole-genome sequencing reveals host factors underlying critical COVID-19

Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2–4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

Examining resource allocation within United States public Research I universities: An income production function approach

In the past 10 years, state financial support for public universities has declined, when measured as a proportion of current-fund revenues. Whether in response to this decline or to satisfy other ends such as personal utility and prestige enhancement, universities and their faculty have sought alternative sources of revenue, mostly through increased research grants and contracts and student tuition and fees. The effects of these revenue changes are observed in the primary operating units of universities, academic departments, which serve as the primary focus of this study. These changes have promoted concern in recent years that public research universities devote too much of their scarce resources to research at the expense of teaching. Specifically, concerns over teaching productivity and quality abound, especially at the undergraduate level. These concerns have been explained theoretically in terms of faculty preferences to perform research and research-related tasks, over undergraduate instruction--The Economic Theory of the Firm; and in terms of the increasing influence of providers of external revenues upon the behavior of the institutions--Resource Dependency Theory. These two frameworks are used to examine whether changes in departmental revenue support patterns affect undergraduate education at major public research universities. To test the theories, departmental instructional and research productivity data from the 1994 and 1996 American Association of Universities Data Exchange (AAUDE) are examined. This sample data contains information on 8 public Research I universities, 200 departments, and 1000 data points for 1994, and 6 public Research I universities, 134 departments, and 680 data points for 1996. Seemingly Unrelated Regressions and Piecewise Linear Regressions, following a semi-log specification, are used to estimate the rate of return to instructional productivity, research productivity, and departmental quality, within the income production function of the departments. The primary finding was that although some shifts in resource allocation were observed to move in a direction that potentially favored research-related endeavors, i.e., graduate instruction and departmental quality, instruction, overall, was most greatly rewarded in the allocation process, and undergraduate instruction more so than graduate instruction

Burden Of Iron Deficiency Anemia In a Bariatric Surgery Population In The United States

Abstract Background Estimates show there are approximately 220,000 cases of bariatric surgery performed in the United States (US) each year. Malabsorption of nutrients, including vitamins and minerals following bariatric surgery is common and may lead to iron deficiency anemia (IDA), with some studies showing incidence rates up to 49% of bariatric surgery patients. Objective The purpose of this study was to evaluate the economic, medical resource use (MRU), and clinical outcomes of IDA in adult bariatric surgery patients having commercial insurance coverage, and to further evaluate the treatment of IDA in this population. Methods This study was based on the Truven Health MarketScan® claims databases. Bariatric surgery patients were identified by ICD-9-CM and CPT procedure codes for restrictive, malabsorptive, and combined restrictive/malabsorptive bariatric surgeries; and further classified as an IDA patient if an IDA diagnosis was identified within two years of initial surgery. Intravenous (IV) iron treatment was determined by HCPCS codes. Prescription oral iron treatment was determined by NDC codes. Blood transfusions were determined by CPT and ICD-9-CM procedure codes. Clinical, MRU, and economic outcomes, including hospitalization, bariatric surgery complications, MRU and payer reimbursement for all-cause health services were evaluated over a two-year period following surgery and compared between patients with and without IDA. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using logistic regression, controlling for demographic and clinical characteristics (including post-surgery IDA status, diabetes, cancer, sleep apnea, heart disease, stroke, hypertension, dyslipidemia, gallbladder disease, osteoarthritis, and chronic back pain) on the outcomes of bariatric surgery complications and hospitalization in the post-surgery period. Results A total of 24,382 bariatric surgery patients were analyzed, and 2,845 (11.7%) patients were diagnosed with IDA in the two-year period following surgery (average days to IDA diagnosis = 279 days). Of the patients with IDA, nearly all (98.7%) developed their anemia following surgery. Most IDA patients received a test for iron in the post-index period, but only 9.3% of all IDA patients received IV iron treatement with either iron dextran (3.8%) and iron sucrose (3.4%) being the most common treatments (average days until IV iron treatment = 403 days). Prescription oral iron was found in 4.8% of all IDA patients (average days to oral iron treatment = 477 days). Approximately 9.0% of all IDA patients received a blood transfusion (average days until blood transfusion = 306 days). Average age was 46 years for patients with and without IDA and more females were found in each group (83.8% in patients with IDA, 78.8% in patients without IDA). Clinical characteristics were similar between groups with the exception of heart disease (1.3% patients with IDA vs 0.8% patients without IDA; P = 0.003) and gallbladder disease (0.0% patients with IDA vs 0.2% patients without IDA; P = 0.037). More IDA patients were associated with a bariatric surgery complication than patients without IDA (40.4% vs 27.7%; P &lt; 0.001) with most complications attributable to other and unspecified postsurgical complications: nonabsorption (22.4% vs 16.5%; P &lt; 0.001), digestive system complications (15.6% vs 10.2%; P &lt; 0.001), and gastrojejunal ulcer (7.6% vs 2.0%; P &lt; 0.001). Multivariate results showed IDA patients were more likely to have a bariatric surgical complication as compared to patients without IDA [OR (95 % CI) = 1.372 (1.262, 1.492)]. IDA patients were hospitalized more often than patients without IDA (42.9% vs 20.9%; P &lt; 0.001) and adjusted results showed IDA patients to be more than twice as likely to be hospitalized [OR (95% CI) = 2.574 (2.370, 2.796)]. Total costs were twice as much among IDA patients as compared to those without IDA ($38,025 vs$19,245; P &lt; 0.001) (Figure 1). Conclusions Bariatric surgery patients that develop IDA may be associated with higher complication rates as well as higher MRU and direct medical costs. Although most bariatric surgery patients that develop IDA are tested for their iron, most are not treated with IV iron, oral iron, and most do not receive blood transfusions. Further research is warranted to determine if IDA is a result of bariatric surgery complications or a predictor of increased MRU and costs. Disclosures: Knight: Covance: Consultancy. D'Sylva:American Regent Inc.: Employment. Moore:Covance: Consultancy. Barish:Wake Gastroenterology/Wake Research Associates: Honoraria. </jats:sec

Immigrant women, family violence and pathways out of homelessness: A Halifax perspective

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