Inheritance of resistance to Cercospora leaf spot disease of cowpea [Vigna unguiculata (L.) Walp]

Open Access ArticleCercospora leaf spot (CLS) caused by Pseudocercospora cruenta (Sacc.) is an important disease affecting cowpea production in Nigeria. Understanding the genetic nature of CLS is an important step in developing an effective breeding strategy. This study investigated the inheritance of CLS disease in cowpea under natural epiphytotic field condition involving two CLS resistant parents (IT99K-573-1-1, IT99K216-24) and a CLS susceptible parent (UAM09-1055-6). The parental lines, F1, BC1P1, BC1P2, F2 and F3 generations were used to study the genetic nature and to detect SSR markers closely linked with the CLS resistance gene(s) using bulked segregant analysis (BSA). The result showed that F1 populations involving UAM09-1055-6 × IT99K-573-1-1 and UAM09-1055-6 × IT99K-216-24 were resistant to CLS in the 2 crosses suggesting the presence of gene dominance in the control of the disease. The observed segregating ratio of F2 populations fits the Mendalian ratio 3:1. The plants reaction to the disease in the backcross progeny test involving the resistant parent were all uniformly resistant, whereas those involving the susceptible parent segregated into ratio 1:1. The F3 generations, which segregated into ratio 1:2:1 further confirmed that resistance was controlled by a single dominant gene in the crosses studied. Heritability estimates varied from 81 to 97%. BSA showed that SSR marker code named RB24 of lima bean and validated on F2 population discriminated between resistance and susceptibility to CLS. Hence RB24 could be a useful marker for marker-assisted selection in CLS resistance breeding in cowpea

Alternative 3' UTRs direct localization of functionally diverse protein isoforms in neuronal compartments

The proper subcellular localization of RNAs and local translational regulation is crucial in highly compartmentalized cells, such as neurons. RNA localization is mediated by specific cis-regulatory elements usually found in mRNA 3'UTRs. Therefore, processes that generate alternative 3'UTRs-alternative splicing and polyadenylation-have the potential to diversify mRNA localization patterns in neurons. Here, we performed mapping of alternative 3'UTRs in neurites and soma isolated from mESC-derived neurons. Our analysis identified 593 genes with differentially localized 3'UTR isoforms. In particular, we have shown that two isoforms of Cdc42 gene with distinct functions in neuronal polarity are differentially localized between neurites and soma of mESC-derived and mouse primary cortical neurons, at both mRNA and protein level. Using reporter assays and 3'UTR swapping experiments, we have identified the role of alternative 3'UTRs and mRNA transport in differential localization of alternative CDC42 protein isoforms. Moreover, we used SILAC to identify isoform-specific Cdc42 3'UTR-bound proteome with potential role in Cdc42 localization and translation. Our analysis points to usage of alternative 3'UTR isoforms as a novel mechanism to provide for differential localization of functionally diverse alternative protein isoforms

Cultural Perspectives on COVID-19 Existence, Origins, Preventive Measures and Remedies: A Survey of Selected Communities in the Yaounde Municipality

Broadly, this paper is concerned with understanding what participants think about the existence and origins of COVID-19. It also sought their views regarding the barrier measures aimed at stopping the spread of the virus; how the virus can be completely eradicated, as well as the preventive measures that they think can be employed or which they have personally or collectively employed to keep safe from the virus in their communities; and whether their knowledge of COVID-19 issues is influenced in any way by their cultural perceptions or worldviews. This study adopted a mixed-method research design. The population was made up of all the inhabitants of ten randomly selected communities within the city of Yaoundé. A mixed sampling method (purposive and snowball) was employed to draw 50 participants from this population. A total of 50 questionnaires were administered. Forty-six were completed and returned, representing a 92 percent return rate. The questionnaire consisted of both close-ended and free response items. The findings have revealed that the majority of the participants, 41 (89.13%), agreed that COVID-19 exists. Nevertheless, some participants, though small in number 4 (8.70%), claimed they had never heard of COVID-19. Although participants could name barrier measures aimed at preventing the spread of COVID-19, they did not think the measures had the desired impact. The finding on how to eradicate COVID-19 in Cameroon presents a mixed picture, with participants suggesting prayers and the involvement of herbalists, and the appeasement of ancestors. The findings have further shown that the majority of the participants know of herbal treatments or remedies that can be used or which they have actually used against the COVID-19 disease in their communities. And some think their cultural perceptions about diseases, in general, equally apply to COVID-19. Finally, this study has added to existing voices on why Cameroon is struggling with convincing the population to vaccinate against the COVID-19 virus, at least as far as the participants in the participating communities in this study are concerned. It is concluded that cultural perspectives can affect health-related behaviours. While the biological sciences can help us prevent future pandemics, we argue that understanding individual behaviours, through the social sciences, including education, can improve health practices and prove critical in managing future pandemics

Targeting the nuclear antigen 1 of Epstein-Barr virus to the human endocytic receptor DEC-205 stimulates protective T-cell responses

Dendritic cells (DCs) express many endocytic receptors that deliver antigens for major histocompatibility class (MHC) I and II presentation to CD8(+) and CD4(+) T cells, respectively. Here, we show that targeting Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) to one of them, the human multilectin DEC-205 receptor, in the presence of the DC maturation stimulus poly(I:C), expanded EBNA1-specific CD4(+) and CD8(+) memory T cells, and these lymphocytes could control the outgrowth of autologous EBV-infected B cells in vitro. In addition, using a novel mouse model with reconstituted human immune system components, we demonstrated that vaccination with alphaDEC-205-EBNA1 antibodies primed EBNA1-specific IFN-gamma-secreting T cells and also induced anti-EBNA1 antibodies in a subset of immunized mice. Because EBNA1 is the one EBV antigen that is expressed in all proliferating cells infected with this virus, our data suggest that DEC-205 targeting should be explored as a vaccination approach against symptomatic primary EBV infection and against EBV-associated malignancies

Humanized mouse model mimicking pathology of human tuberculosis for in vivo evaluation of drug regimens

Human immune system mice are highly valuable for in vivo dissection of human immune responses. Although they were employed for analyzing tuberculosis (TB) disease, there is little data on the spatial organization and cellular composition of human immune cells in TB granuloma pathology in this model. We demonstrate that human immune system mice, generated by transplanted human fetal liver derived hematopoietic stem cells develop a continuum of pulmonary lesions upon Mycobacterium tuberculosis aerosol infection. In particular, caseous necrotic granulomas, which contribute to prolonged TB treatment time, developed, and had cellular phenotypic spatial-organization similar to TB patients. By comparing two recommended drug regimens, we confirmed observations made in clinical settings: Adding Moxifloxacin to a classical chemotherapy regimen had no beneficial effects on bacterial eradication. We consider this model instrumental for deeper understanding of human specific features of TB pathogenesis and of particular value for the pre-clinical drug development pipeline

CXCL5-secreting pulmonary epithelial cells drive destructive neutrophilic inflammation in tuberculosis

Successful host defense against numerous pulmonary infections depends on bacterial clearance by polymorphonuclear leukocytes (PMNs); however, excessive PMN accumulation can result in life-threatening lung injury. Local expression of CXC chemokines is critical for PMN recruitment. The impact of chemokine-dependent PMN recruitment during pulmonary Mycobacterium tuberculosis infection is not fully understood. Here, we analyzed expression of genes encoding CXC chemokines in M. tuberculosis–infected murine lung tissue and found that M. tuberculosis infection promotes upregulation of Cxcr2 and its ligand Cxcl5. To determine the contribution of CXCL5 in pulmonary PMN recruitment, we generated Cxcl5(–/–) mice and analyzed their immune response against M. tuberculosis. Both Cxcr2(–/–) mice and Cxcl5(–/–) mice, which are deficient for only one of numerous CXCR2 ligands, exhibited enhanced survival compared with that of WT mice following high-dose M. tuberculosis infection. The resistance of Cxcl5(–/–) mice to M. tuberculosis infection was not due to heightened M. tuberculosis clearance but was the result of impaired PMN recruitment, which reduced pulmonary inflammation. Lung epithelial cells were the main source of CXCL5 upon M. tuberculosis infection, and secretion of CXCL5 was reduced by blocking TLR2 signaling. Together, our data indicate that TLR2-induced epithelial-derived CXCL5 is critical for PMN-driven destructive inflammation in pulmonary tuberculosis