A nematode demographics assay in transgenic roots reveals no significant impacts of the Rhg1 locus LRR-Kinase on soybean cyst nematode resistance

<p>Abstract</p> <p>Background</p> <p>Soybean cyst nematode (<it>Heterodera glycines</it>, SCN) is the most economically damaging pathogen of soybean (<it>Glycine max</it>) in the U.S. The <it>Rhg1 </it>locus is repeatedly observed as the quantitative trait locus with the greatest impact on SCN resistance. The Glyma18g02680.1 gene at the <it>Rhg1 </it>locus that encodes an apparent leucine-rich repeat transmembrane receptor-kinase (LRR-kinase) has been proposed to be the SCN resistance gene, but its function has not been confirmed. Generation of fertile transgenic soybean lines is difficult but methods have been published that test SCN resistance in transgenic roots generated with <it>Agrobacterium rhizogenes</it>.</p> <p>Results</p> <p>We report use of artificial microRNA (amiRNA) for gene silencing in soybean, refinements to transgenic root SCN resistance assays, and functional tests of the <it>Rhg1 </it>locus LRR-kinase gene. A nematode demographics assay monitored infecting nematode populations for their progress through developmental stages two weeks after inoculation, as a metric for SCN resistance. Significant differences were observed between resistant and susceptible control genotypes. Introduction of the <it>Rhg1 </it>locus LRR-kinase gene (genomic promoter/coding region/terminator; Peking/PI 437654-derived SCN-resistant source), into <it>rhg1</it>^-SCN-susceptible plant lines carrying the resistant-source <it>Rhg4</it>^{<it>+ </it>}locus, provided no significant increases in SCN resistance. Use of amiRNA to reduce expression of the LRR-kinase gene from the <it>Rhg1 </it>locus of Fayette (PI 88788 source of <it>Rhg1</it>) also did not detectably alter resistance to SCN. However, silencing of the LRR-kinase gene did have impacts on root development.</p> <p>Conclusion</p> <p>The nematode demographics assay can expedite testing of transgenic roots for SCN resistance. amiRNAs and the pSM103 vector that drives interchangeable amiRNA constructs through a soybean polyubiqutin promoter (Gmubi), with an intron-GFP marker for detection of transgenic roots, may have widespread use in legume biology. Studies in which expression of the <it>Rhg1 </it>locus LRR-kinase gene from different resistance sources was either reduced or complemented did not reveal significant impacts on SCN resistance.</p

Association of β-globin polymorphisms and tolerance to haemonchosis in ewes and lambs of different sheep breeds.

Gastrointestinal nematodes (GIN), especially Haemonchus contortus, represent a significant challenge for sheep production. Given the global concern about GIN anthelmintic resistance, alternative control methods able to reduce the dependence on these drugs are highly advisable. Since previous studies have shown that sheep carrying the Hb-A allele of β-globin are more resistant to H. contortus, this study aimed to investigate the relationship between the different haplotypes (Hb-AA, Hb-AB and Hb-BB) and phenotypes in Santa Inês (SI), Texel (TX) and White Dorper (DO) breeds infected with H. contortus. Blood samples were collected from 180 ewes and 123 lambs of the three breeds for DNA extraction followed by qPCR using a hydrolysis probe to identify the β-globin haplotypes. Phenotypic data, including fecal egg count (FEC), packed cell volume (PCV), FAMACHA score and body condition score for ewes and lambs, as well as weight gain for lambs, were collected. The genotypic frequencies of β-globin for ewes and lambs were, respectively: 21.7% and 21.4% Hb-AA, 50% and 50% Hb-AB and 28.3% and 28.6% Hb-BB in SI; 0% and 0% Hb-AA, 18.6% and 9.4% Hb-AB and 81.4% and 90.6% Hb-BB in TX; and 0% and 0% Hb-AA, 13.1% and 0% Hb-AB and 86.9% and 100% Hb-BB in DO. In ewes, mean PCV differed (p<0.05) between the three haplotypes, with higher PCV in Hb-AA animals, followed by Hb-AB and Hb-BB. When considering each breed separately, SI Hb-AA ewes presented higher PCV (p<0.05), highlighting that even in a breed already considered resistant, animals with Hb-AA haplotype showed superior performance. Lambs with the Hb-AA haplotype exhibited a higher (p<0.05) mean PCV compared to those with Hb-AB and Hb-BB. The same pattern was found in SI when analyzing each breed separately. No significant association was found between β-globin haplotypes and FEC, FAMACHA score, body condition score, or weight gain. Nevertheless, given that anemia is the major clinical sign of haemonchosis, our findings on PCV reinforce that sheep carrying the Hb-A allele of β-globin are more tolerant to haemonchosis. This study may support the development of a valuable tool, targeting genetic selection for GIN control, reducing the dependence on anthelmintics and boosting sheep production worldwide

De novo RANBP2 variant in a fetal demise case with cerebral intraparenchymal hemorrhage.

Fetal intracranial hemorrhage (ICH) may result from a wide array of causes, either associated with maternal or fetal risk factors. In the last decade, monogenic causes of susceptibility to fetal ICH have been described, in particular in association with COL4A1 and COL4A2 genes. A peculiar form of ICH is acute necrotizing encephalitis (ANE), which is characterized by a rapid-onset severe encephalopathy following an abnormal inflammatory response to an otherwise banal infection. It usually affects healthy children and it is thought to be multifactorial, with a genetic predisposition. RANBP2 gene has been extensively associated with ANE susceptibility. We hereby present a unique case of a 42-year-old secundigravida with intrauterine fetal demise at 35 weeks of gestation. Trio-based whole-exome sequencing performed on both parents and fetal DNA showed a de novo likely pathogenic variant in the RANBP2 gene on 2q13. At the fetal autopsy, subtentorial hematoma and cerebral intraparenchymal hemorrhage were present. We speculate that this might be a new phenotypic presentation of RANBP2-associated disease. However, more similar fetal cases need to be reported in order to reinforce this hypothesis

Hybrid topoisomerase i and HDAC inhibitors as dual action anticancer agents

Recent studies have shown that HDAC inhibitors act synergistically with camptothecin derivatives in combination therapies. To exploit this synergy, new hybrid molecules targeting simultaneously topoisomerase I and HDAC were designed. In particular, a selected multivalent agent containing a camptothecin and a SAHA-like template showed a broad spectrum of antiproliferative activity, with IC50 values in the nanomolar range. Preliminary in vivo results indicated a strong antitumor activity on human mesothelioma primary cell line MM473 orthotopically xenografted in CD-1 nude mice and very high tolerability

Efeito do polimorfismo da β-globina na anemia por Hemoncose em ovinos de diferentes raças.

Devido à resistência anti-helmíntica desenvolvida por Haemonchus contortus, nematódeo gastrintestinal responsável pela doença hemoncose, é imperativo a validação de outras ferramentas de controle que reduzam a dependência nesses fármacos

The Organisation of Ebola Virus Reveals a Capacity for Extensive, Modular Polyploidy

BACKGROUND: Filoviruses, including Ebola virus, are unusual in being filamentous animal viruses. Structural data on the arrangement, stoichiometry and organisation of the component molecules of filoviruses has until now been lacking, partially due to the need to work under level 4 biological containment. The present study provides unique insights into the structure of this deadly pathogen. METHODOLOGY AND PRINCIPAL FINDINGS: We have investigated the structure of Ebola virus using a combination of cryo-electron microscopy, cryo-electron tomography, sub-tomogram averaging, and single particle image processing. Here we report the three-dimensional structure and architecture of Ebola virus and establish that multiple copies of the RNA genome can be packaged to produce polyploid virus particles, through an extreme degree of length polymorphism. We show that the helical Ebola virus inner nucleocapsid containing RNA and nucleoprotein is stabilized by an outer layer of VP24-VP35 bridges. Elucidation of the structure of the membrane-associated glycoprotein in its native state indicates that the putative receptor-binding site is occluded within the molecule, while a major neutralizing epitope is exposed on its surface proximal to the viral envelope. The matrix protein VP40 forms a regular lattice within the envelope, although its contacts with the nucleocapsid are irregular. CONCLUSIONS: The results of this study demonstrate a modular organization in Ebola virus that accommodates a well-ordered, symmetrical nucleocapsid within a flexible, tubular membrane envelope

Ovine B-globin polymorphisms and resistance to haemonchosis in different breeds.

The selection of naturally resistant sheep breeds to gastrointestinal nematodes (GIN) can be a tool for controlling infections caused by Haemonchus contortus, responsible for haemonchosis and resistant to all classes of anthelmintics

Influência da substituição parasitária de Haemonchus contortus no ganho de peso de cordeiros.

A resistência de Haemonchus contortus aos anti-helmínticos é uma ameaça para a ovinocultura, pois causa grandes perdas decorrentes de queda no desempenho, custos com tratamento e mortalidade dos animais

Ovine resistance against Haemonchus contortus-globin subtype feature?

Hair sheep breeds, as Santa Inês, are well-known for improved natural resistance and/or resilience against gastrointestinal infections, especially by Haemonchus contortus, compared to wool breeds, such as Dorper and Texel

Avaliação do OPG e frequência de tratamentos com anti-helmínticos em cordeiros submetidos à substituição parasitária de Haemonchus contortus.

Comprometendo a produção de ovinos, a resistência anti-helmíntica (RA) é uma característica hereditária de uma população de parasitas que diminui sua sensibilidade aos anti-helmínticos