RESUMEN
Oviposition by lepidopteran herbivores on Nicotiana attenuata primes plant defence responses that are induced by the feeding larvae. While oviposition by both the generalist Spodoptera exigua and the specialist Manduca sexta primes the production of defensive phenylpropanoids, their larvae are differentially affected. We investigate here the impact of prior oviposition on the transcriptome and phytohormone levels of plants that were later attacked by larvae to find regulatory signals of this priming. In a full-factorial design, we evaluated the effects of oviposition and herbivory by both species. Oviposition alone had only subtle effects at the transcriptional level. Laval feeding alone induced species-specific plant responses. Larvae of the generalist regulated phytohormones and gene expression stronger than larvae of the specialist. A day after larvae started to feed, we detected no significant alterations of the plant's response to larval feeding due to prior oviposition by conspecific moths. Yet, oviposition by each of the species profoundly influenced the plant's transcriptional and phytohormonal response to feeding larvae of the other species. Remarkably, the species-specific plant responses to larval feeding shifted towards the response normally elicited by larvae of the ovipositing species. Thus, plants may already recognise an insect's identity upon its oviposition.
Asunto(s)
Conducta Alimentaria/fisiología , Larva/fisiología , Mariposas Nocturnas/fisiología , Nicotiana/inmunología , Oviposición/fisiología , Reguladores del Crecimiento de las Plantas/farmacología , Proteínas de Plantas/genética , Animales , Femenino , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Herbivoria , Larva/efectos de los fármacos , Manduca/fisiología , Oviposición/efectos de los fármacos , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/genética , Hojas de la Planta/inmunología , Hojas de la Planta/parasitología , Proteínas de Plantas/metabolismo , Especificidad de la Especie , Spodoptera/fisiología , Nicotiana/efectos de los fármacos , Nicotiana/genética , Nicotiana/parasitologíaRESUMEN
The teaching of veterinary parasitology to the large number of students at the Freie Universität Berlin is mainly limited to conventional face-to-face lectures, supplemented by practical classes. Extensive parasite descriptions and diagnostic techniques are at the core of the practical classes, which are also intended to emphasise key biological and veterinary aspects covered in lectures. Further in-depth and specific learning is achieved within a detailed framework of elective courses, with defined learning outcomes for small groups of students, focusing on themes such as 'diagnosis and treatment of ectoparasites in companion animals' or 'zoonotic parasites'. Additionally, structured excursions are designed to offer experience through collaborative international investigations. Organ-based approaches are also an integral part of our veterinary parasitology teaching, done in collaboration with the clinical and para-clinical departments, either via face-to-face interactions or online. Wide-ranging themes, such as 'causes of colic in horses' or 'atopic dermatitis in dogs' are covered. Recently, diverse blended learning elements were introduced into the curriculum (e.g., QuerVet), which makes teaching and learning more flexible, in terms of time and space, and fosters self-directed learning and participation among the students. A new platform to provide online lectures for students, termed VET Talks, was launched in 2015 by the International Veterinary Student's Association (IVSA), and is as a publicly available educational support system for students. Provided free to veterinary students throughout the world, this platform offers students the opportunity to access lectures on interesting topics by outstanding speakers who are nominated by their students. Finally, continuing education (CE) opportunities are provided through specific Masters courses (Master of Equine Medicine, Master of Small Animal Sciences), classical seminars and recent webinars.
Asunto(s)
Educación en Veterinaria/métodos , Empleos en Salud/educación , Parasitología/educación , Enseñanza , Animales , Berlin , Curriculum , Enfermedades de los Caballos/epidemiología , Caballos , Humanos , Facultades de Medicina Veterinaria , Conducta Social , Estudiantes del Área de la Salud/psicologíaRESUMEN
Plants can respond to insect oviposition, but little is known about which responses directly target the insect eggs and how. Here, we reveal a mechanism by which the bittersweet nightshade Solanum dulcamara kills the eggs of a generalist noctuid herbivore. The plant responded at the site of oviposition by Spodoptera exigua with formation of neoplasms and chlorotic tissue, accumulation of reactive oxygen species and induction of defence genes and proteins. Transcriptome analysis revealed that these responses were reflected in the transcriptional reprogramming of the egg-laden leaf. The plant-mediated egg mortality on S. dulcamara was not present on a genotype lacking chlorotic leaf tissue at the oviposition sites on which the eggs are exposed to less hydrogen peroxide. As exposure to hydrogen peroxide increased egg mortality, while catalase supplementation prevented the plants from killing the eggs, our results suggest that reactive oxygen species formation directly acts as an ovicidal plant response of S. dulcamara.
Asunto(s)
Herbivoria/efectos de los fármacos , Peróxido de Hidrógeno/toxicidad , Óvulo/fisiología , Solanum/parasitología , Spodoptera/fisiología , Animales , Quitosano/farmacología , Ciclopentanos/farmacología , Genes de Plantas , Humedad , Oviposición/efectos de los fármacos , Oxilipinas/farmacología , Ácido Salicílico/farmacología , Solanum/efectos de los fármacos , Solanum/genética , Spodoptera/efectos de los fármacos , Transcripción Genética/efectos de los fármacosRESUMEN
Plants are attacked by diverse herbivores and respond with manifold defence responses. To study transcriptional and other early regulation events of these plant responses, herbivory is often simulated to standardize the temporal and spatial dynamics that vary tremendously for natural herbivory. Yet, to what extent such simulations of herbivory are able to elicit the same plant response as real herbivory remains largely undetermined. We examined the transcriptional response of a wild model plant to herbivory by lepidopteran larvae and to a commonly used herbivory simulation by applying the larvae's oral secretions to standardized wounds. We designed a microarray for Solanum dulcamara and showed that the transcriptional responses to real and to simulated herbivory by Spodoptera exigua overlapped moderately by about 40%. Interestingly, certain responses were mimicked better than others; 60% of the genes upregulated but not even a quarter of the genes downregulated by herbivory were similarly affected by application of oral secretions to wounds. While the regulation of genes involved in signalling, defence and water stress was mimicked well by the simulated herbivory, most of the genes related to photosynthesis, carbohydrate- and lipid metabolism were exclusively regulated by real herbivory. Thus, wounding and application of oral secretions decently mimics herbivory-induced defence responses but likely not the reallocation of primary metabolites induced by real herbivory.
Asunto(s)
Perfilación de la Expresión Génica , Herbivoria , Solanum/fisiología , Estrés Fisiológico , Animales , Conducta Alimentaria , Análisis por Micromatrices , Solanum/genética , Spodoptera/fisiologíaRESUMEN
Limb girdle muscular dystrophy type 2H (LGMD2H) is an inherited autosomal recessive disease of skeletal muscle caused by a mutation in the TRIM32 gene. Currently its pathogenesis is entirely unclear. Typically the regeneration process of adult skeletal muscle during growth or following injury is controlled by a tissue specific stem cell population termed satellite cells. Given that TRIM32 regulates the fate of mammalian neural progenitor cells through controlling their differentiation, we asked whether TRIM32 could also be essential for the regulation of myogenic stem cells. Here we demonstrate for the first time that TRIM32 is expressed in the skeletal muscle stem cell lineage of adult mice, and that in the absence of TRIM32, myogenic differentiation is disrupted. Moreover, we show that the ubiquitin ligase TRIM32 controls this process through the regulation of c-Myc, a similar mechanism to that previously observed in neural progenitors. Importantly we show that loss of TRIM32 function induces a LGMD2H-like phenotype and strongly affects muscle regeneration in vivo. Our studies implicate that the loss of TRIM32 results in dysfunctional muscle stem cells which could contribute to the development of LGMD2H.
Asunto(s)
Células Madre Adultas/fisiología , Diferenciación Celular/genética , Músculos/fisiología , Regeneración/genética , Ubiquitina-Proteína Ligasas/fisiología , Células Madre Adultas/metabolismo , Animales , Proliferación Celular , Células Cultivadas , Femenino , Ratones , Ratones Noqueados , Desarrollo de Músculos/genética , Desarrollo de Músculos/fisiología , Músculos/metabolismo , Distrofia Muscular de Cinturas/genética , Distrofia Muscular de Cinturas/patología , Regeneración/fisiología , Células Satélite del Músculo Esquelético/metabolismo , Células Satélite del Músculo Esquelético/fisiología , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismoRESUMEN
Junctional adhesion molecule-C (JAM-C) is an adhesive cell surface protein expressed in various cell types. JAM-C localizes to the apically localized tight junctions (TJs) between contacting endothelial and epithelial cells, where it contributes to cell-cell adhesions. Just as those epithelial cells, also neural stem cells are highly polarized along their apical-basal axis. The defining feature of all stem cells, including neural stem cells (NSCs) is their ability to self renew. This self-renewal depends on the tight control of symmetric and asymmetric cell divisions. In NSCs, the decision whether a division is symmetric or asymmetric largely depends on the distribution of the apical membrane and cell fate determinants on the basal pole of the cell. In this study we demonstrate that JAM-C is expressed on neural progenitor cells and neural stem cells in the embryonic as well as the adult mouse brain. Furthermore, we demonstrate that in vivo JAM-C shows enrichment at the apical surface and therefore is asymmetrically distributed during cell divisions. These results define JAM-C as a novel surface marker for neural stem cells.
Asunto(s)
Moléculas de Adhesión Celular/metabolismo , Células Madre Embrionarias/metabolismo , Inmunoglobulinas/metabolismo , Proteínas de la Membrana/metabolismo , Células-Madre Neurales/metabolismo , Factores de Edad , Animales , División Celular Asimétrica , Biomarcadores/metabolismo , Western Blotting , Encéfalo/embriología , Encéfalo/crecimiento & desarrollo , Encéfalo/metabolismo , Células CHO , Moléculas de Adhesión Celular/genética , Proliferación Celular , Células Cultivadas , Cricetinae , Cricetulus , Células Madre Embrionarias/citología , Regulación del Desarrollo de la Expresión Génica , Inmunoglobulinas/genética , Inmunohistoquímica , Proteínas de la Membrana/genética , Ratones , Microscopía Confocal , Células-Madre Neurales/citología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Uniones Estrechas/metabolismoRESUMEN
Adult neurogenesis within the subgranular zone (SGZ) of the hippocampal dentate gyrus and the subventricular zone (SVZ) of the lateral ventricle (LV) has been most intensely studied within the brains of rodents such as mice and rats. However, little is known about the cell types and processes involved in adult neurogenesis within primates such as the common marmoset (Callithrix jacchus). Moreover, substantial differences seem to exist between the neurogenic niche of the LV between rodents and humans. Here, we set out to use immunohistochemical and autogradiographic analysis to characterize the anatomy of the neurogenic niches and the expression of cell type-specific markers in those niches in the adult common marmoset brain. Moreover, we demonstrate significant differences in the activity of neurogenesis in the adult marmoset brain compared to the adult mouse brain. Finally, we provide evidence for ongoing proliferation of neuroblasts within both the SGZ and SVZ of the adult brain and further show that the age-dependent decline of neurogenesis in the hippocampus is associated with a decrease in neuroblast cells.
Asunto(s)
Callithrix/fisiología , Giro Dentado/anatomía & histología , Ventrículos Laterales/anatomía & histología , Neurogénesis/fisiología , Neuronas/fisiología , Adulto , Envejecimiento/fisiología , Animales , Autorradiografía , Biomarcadores/análisis , Callithrix/anatomía & histología , Recuento de Células , Movimiento Celular/fisiología , Proliferación Celular , Giro Dentado/fisiología , Femenino , Humanos , Inmunohistoquímica , Ventrículos Laterales/fisiología , Masculino , Ratones , Células-Madre Neurales/citología , Células-Madre Neurales/fisiología , Neuronas/citología , RatasRESUMEN
BACKGROUND: Junctional adhesion molecule-A (JAM-A) is an adhesive protein expressed in various cell types. JAM-A localizes to the tight junctions between contacting endothelial and epithelial cells, where it contributes to cell-cell adhesion and to the control of paracellular permeability. RESULTS: So far, the expression pattern of JAM-A has not been described in detail for the different cell types of the adult brain. Here we show that a subset of proliferating cells in the adult mouse brain express JAM-A. We further clarify that these cells belong to the lineage of NG2-glia cells. Although these mitotic NG2-glia cells express JAM-A, the protein never shows a polarized subcellular distribution. Also non-mitotic NG2-glia cells express JAM-A in a non-polarized pattern on their surface. CONCLUSIONS: Our data show that JAM-A is a novel surface marker for NG2-glia cells of the adult brain.