Effect of human immunodeficiency virus on blood-brain barrier integrity and function: an update

The blood-brain barrier (BBB) is a diffusion barrier that has an important role in maintaining a precisely regulated microenvironment protecting the neural tissue from infectious agents and toxins in the circulating system. Compromised BBB integrity plays a major role in the pathogenesis of retroviral associated neurological diseases. Human Immunodeficiency Virus (HIV) infection in the Central Nervous System (CNS) is an early event even before the serodiagnosis for HIV positivity or the initiation of antiretroviral therapy (ART), resulting in neurological complications in many of the infected patients. Macrophages, microglia and astrocytes (in low levels) are the most productively/latently infected cell types within the CNS. In this brief review, we have discussed about the effect of HIV infection and viral proteins on the integrity and function of BBB, which may contribute to the progression of HIV associated neurocognitive disorders

Genome-wide analysis reveals rapid and dynamic changes in miRNA and siRNA sequence and expression during ovule and fiber development in allotetraploid cotton (Gossypium hirsutum L.)

Rapid and dynamic changes in the expression of small RNAs are seen during ovule and fiber development in allotetraploid cotton

Small RNAs serve as a genetic buffer against genomic shock in Arabidopsis interspecific hybrids and allopolyploids

Small RNAs, including microRNAs (miRNAs), small interfering RNAs (siRNAs), and trans-acting siRNAs (tasiRNAs), control gene expression and epigenetic regulation. Although the roles of miRNAs and siRNAs have been extensively studied, their expression diversity and evolution in closely related species and interspecific hybrids are poorly understood. Here, we show comprehensive analyses of miRNA expression and siRNA distributions in two closely related species Arabidopsis thaliana and Arabidopsis arenosa, a natural allotetraploid Arabidopsis suecica, and two resynthesized allotetraploid lines (F1 and F7) derived from A. thaliana and A. arenosa.We found that repeat- and transposon-associated siRNAs were highly divergent between A. thaliana and A. arenosa. A. thaliana siRNA populations underwent rapid changes in F1 but were stably maintained in F7 and A. suecica. The correlation between siRNAs and nonadditive gene expression in allopolyploids is insignificant. In contrast, miRNA and tasiRNA sequences were conserved between species, but their expression patterns were highly variable between the allotetraploids and their progenitors. Many miRNAs tested were nonadditively expressed (deviating from the midparent value, MPV) in the allotetraploids and triggered unequal degradation of A. thaliana or A. arenosa targets. The data suggest that small RNAs produced during interspecific hybridization or polyploidization serve as a buffer against the genomic shock in interspecific hybrids and allopolyploids: Stable inheritance of repeat- associated siRNAs maintains chromatin and genome stability, whereas expression variation of miRNAs leads to changes in gene expression, growth vigor, and adaptation.Keywords: microRNAs, polyploidy, hybrid vigor, expression regulatio

RNA-interference in rice against Rice tungro bacilliform virus results in its decreased accumulation in inoculated rice plants

Rice tungro is a viral disease seriously affecting rice production in South and Southeast Asia. Tungro is caused by the simultaneous infection in rice of Rice tungro bacilliform virus (RTBV), a double-stranded DNA virus and Rice tungro spherical virus (RTSV), a single-stranded RNA virus. To apply the concept of RNA-interference (RNAi) for the control of RTBV infection, transgenic rice plants expressing DNA encoding ORF IV of RTBV, both in sense as well as in anti-sense orientation, resulting in the formation of double-stranded (ds) RNA, were raised. RNA blot analysis of two representative lines indicated specific degradation of the transgene transcripts and the accumulation of small molecular weight RNA, a hallmark for RNA-interference. In the two transgenic lines expressing ds-RNA, different resistance responses were observed against RTBV. In one of the above lines (RTBV-O-Ds1), there was an initial rapid buildup of RTBV levels following inoculation, comparable to that of untransformed controls, followed by a sharp reduction, resulting in approximately 50-fold lower viral titers, whereas the untransformed controls maintained high levels of the virus till 40 days post-inoculation (dpi). In RTBV-O-Ds2, RTBV DNA levels gradually rose from an initial low to almost 60% levels of the control by 40 dpi. Line RTBV-O-Ds1 showed symptoms of tungro similar to the untransformed control lines, whereas line RTBV-O-Ds2 showed extremely mild symptoms

Assessing the genetic variation of Ty-1 and Ty-3 alleles conferring resistance to Tomato Yellow Leaf Curl Virus in a broad tomato germplasm

The online version of this article (doi:10.1007/s11032-015-0329-y) contains supplementary material, which is available to authorized users.[EN] Tomato yellow leaf curl virus (TYLCV) hampers tomato production worldwide. Our previous studies have focussed on mapping and ultimately cloning of the TYLCV resistance genes Ty-1 and Ty-3. Both genes are derived from Solanum chilense and were shown to be allelic. They code for an RNA-dependent RNA polymerase (RDR) belonging to the RDR gamma type defined by a DFDGD catalytic domain. In this study, we first fine-mapped the TYLCV resistance in S. chilense LA1932, LA1960 and LA1971. Results showed that chromosomal intervals of the causal genes in these TYLCV-resistant accessions overlap and cover the region where Ty-1/Ty-3 is located. Further, virus-induced gene silencing was used to silence Ty-1/Ty-3 in tomato lines carrying TYLCV resistance introgressed from S. chilense LA1932, LA1938 and LA1971. Results showed that silencing Ty-1/Ty-3 compromised the resistance in lines derived from S. chilense LA1932 and LA1938. The LA1971-derived material remained resistant upon silencing Ty-1/Ty-3. Further, we studied the allelic variation of the Ty-1/Ty-3 gene by examining cDNA sequences from nine S. chilense-derived lines/accessions and more than 80 tomato cultivars, landraces and accessions of related wild species. The DFDGD catalytic domain of the Ty-1/Ty-3 gene is conserved among all tomato lines and species analysed. In addition, the 12 base pair insertion at the 5-prime part of the Ty-1/Ty-3 gene was found not to be specific for the TYLCV resistance allele. However, compared with the susceptible ty-1 allele, the Ty-1/Ty-3 allele is characterized by three specific amino acids shared by seven TYLCV-resistant S. chilense accessions or derived lines. Thus, Ty-1/Ty-3-specific markers can be developed based on these polymorphisms. Elevated transcript levels were observed for all tested S. chilense RDR alleles (both Ty-1 and ty-1 alleles), demonstrating that elevated expression level is not a good selection criterion for a functional Ty-1/Ty-3 allele.The infectious TYLCV clone was kindly provided by Professor Eduardo Rodriguez Bejarano (Universidad de Malaga). We thank Dick Lohuis for his help with agro-infiltrations, Marc Hendriks and Marjon Arens for RNA isolation and sequencing. This project was financed by the Centre for BioSystems Genomics (CBSG), which is part of the Netherlands Genomics Initiative/Netherlands Organization for Scientific Research (http://www.cbsg.nl). Olga Julian was granted a scholarship by Generalitat Valenciana. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.Caro, M.; Verlaan, MG.; Julián Rodríguez, O.; Finkers, R.; Wolters, AA.; Hutton, S.; Scott, JW.... (2015). Assessing the genetic variation of Ty-1 and Ty-3 alleles conferring resistance to Tomato Yellow Leaf Curl Virus in a broad tomato germplasm. Molecular Breeding. 35. doi:10.1007/s11032-015-0329-yS13235Agrama H, Scott J (2006) Quantitative trait loci for tomato yellow leaf curl virus and tomato mottle virus resistance in tomato. 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Cassava brown streak disease: historical timeline, current knowledge and future prospects

Cassava is the second most important staple food crop in terms of per capita calories consumed in Africa and holds potential for climate change adaptation. Unfortunately, productivity in East and Central Africa is severely constrained by two viral diseases: cassava mosaic disease (CMD) and cassava brown streak disease (CBSD). CBSD was first reported in 1936 from northeast Tanzania. For approximately seventy years CBSD was restricted to coastal East Africa and so had a relatively low impact on food security compared to CMD. However, at the turn of the 21st century CBSD re-emerged further inland, in areas around Lake Victoria and it has since spread through many East and Central African countries, causing high yield losses and jeopardising the food security of subsistence farmers. This recent re-emergence has attracted intense scientific interest, with studies shedding light on CBSD viral epidemiology, sequence diversity, host interactions and potential sources of resistance within the cassava genome. This review reflects on 80 years of CBSD research history (1936 – 2016) with a timeline of key events. We provide insights into current CBSD knowledge, management efforts and future prospects for improved understanding needed to underpin effective control and mitigation of impacts on food security

The Emerging Trends in the Bio-Diversity of Bats in Tamil Nadu

The news media, legends, 101k lore, television, movies and storybooks perpetuate myths. 'Fears about bots' a surprising number of people believe. Bots are instantly recognised yet poorly known. The hours Of twilight {Oltowed by darkness is the best feeding tirnö for these animals. The night is really alive with such nocturnal creatures. They inhabit Olmos' every comer Offhe globe. They ore not from Antarctica, Arctic tundra remote oceanic islands. Bots are unique elegant and fascinating, They ore the only mammals who mastered true, sustained flight much before man's own lineage began. More than Of all mammal species are bats. They 'See' With their ears, hang upside to sleep by day ond can catch insects while flying even in the darkest 0/ nights. Wing' forms 0 basis for Classifying os separote order Of Mammals. The order Chiroptera (Greek Pteros•wing), Which includes 1242 species.</jats:p

The Emerging Trends in the Bio-Diversity of Bats in Tamil Nadu

The news media, legends, 101k lore, television, movies and storybooks perpetuate myths. 'Fears about bots' a surprising number of people believe. Bots are instantly recognised yet poorly known. The hours Of twilight {Oltowed by darkness is the best feeding tirnö for these animals. The night is really alive with such nocturnal creatures. They inhabit Olmos' every comer Offhe globe. They ore not from Antarctica, Arctic tundra remote oceanic islands. Bots are unique elegant and fascinating, They ore the only mammals who mastered true, sustained flight much before man's own lineage began. More than Of all mammal species are bats. They 'See' With their ears, hang upside to sleep by day ond can catch insects while flying even in the darkest 0/ nights. Wing' forms 0 basis for Classifying os separote order Of Mammals. The order Chiroptera (Greek Pteros•wing), Which includes 1242 species