Micromorphological structure of the fruit and seed of Smodingium argutum (Anacardiaceae), as an adaptation to its natural habitat

Smodingium argutum E. Mey. ex Sond, is very closely allied lo the genus Rhus L., but easily distinguished from it by the inflorescence which is a thyrse, ils pendulous ovule; an ‘apical-lateral’ style; winged fruit; a sap (noxious secretion from all organs) which turns black on exposure to air; indumentum on the pedicel, bracteoles and calyx, as well as an unique, papery pericarp. The latter comprises a uniseriate exocarp a mesocarp with large secretory ducts and a mostly two-layered, weakly developed endocarp. An anatropous, bitegmic, crassinucellate ovule develops into a small, partially pachychalazal, exalbuminous seed, also characterized by an endotegmen and lipidie nutrient reserves. The following characters are obviously of crucial importance for the survival of this species, efficient fruit dispersal, aided by the samaroid drupe; easy germination; the well-developed cuticles on the calyx, ovary wall and exocarp; and the thick cuticular layer delimiting the mature integumentary seed coat, which, together with cell wall impregnations in the physiologically mature hypostase cells, protects the embryo against dehydration

Mokola Virus in Domestic Mammals, South Africa

We recently identified 2 Mokola viruses from domestic mammals (a dog and a cat) in South Africa. These cases occurred 8 years after the last reported case of infection with this virus. Our findings emphasize the endemicity of rabies-related lyssaviruses in South Africa and the need to better understand the epidemiology of Mokola viruses

Ontogeny and Structure of the Pericarp of Schinus terebinthifolius Raddi (Anacardiaceae)

The fruit of Schinus terebinthifolius Raddi is a globose red drupe with friable exocarp when ripe and composed of two lignified layers: the epidermis and hypodermis. The mesocarp is parenchymatous with large secretory ducts associated with vascular bundles. In the mesocarp two regions are observed: an outer region composed of only parenchymatous cells and an inner region, bounded by one or more layers of druse-like crystals of calcium oxalate, composed of parenchymatous cells, secretory ducts and vascular bundles. The mesocarp detaches itself from the exocarp due to degeneration of the cellular layers in contact with the hypodermis. The lignified endocarp is composed of four layers: the outermost layer of polyhedral cells with prismatic crystals of calcium oxalate, and the three innermost layers of sclereids in palisade.<br>O fruto de Schinus terebinthifolius Raddi é uma drupa vermelha, globosa, com exocarpo friável quando maduro e composto de duas camadas lignificadas: a epiderme e a hipoderme. O mesocarpo é parenquimático com grandes canais secretores associados aos feixes vasculares. No mesocarpo distinguem-se duas regiões uma externa composta apenas de células parenquimáticas e uma interna, delimitada por uma ou mais camadas de células contendo cristais de oxalato de cálcio do tipo drusa, composta de células parenquimáticas, canais secretores e feixes vasculares. O mesocarpo desprende-se do exocarpo devido à degeneração das camadas celulares em contato com a hipoderme. O endocarpo é lignificado e composto de quatro camadas: uma mais externa de células poliédricas com cristais prismáticos de oxalato de cálcio e três mais internas de esclereides em paliçada

Stromal complement receptor CD21/35 facilitates lymphoid prion colonization and pathogenesis

We have studied the role of CD21/35, which bind derivatives of complement factors C3 and C4, in extraneural prion replication and neuroinvasion. Upon administration of small prion inocula, CD21/35(-/-) mice experienced lower attack rates and delayed disease over both wild-type (WT) mice and mice with combined C3 and C4 deficiencies. Early after inoculation, CD21/35(-/-) spleens were devoid of infectivity. Reciprocal adoptive bone marrow transfers between WT and CD21/35(-/-) mice revealed that protection from prion infection resulted from ablation of stromal, but not hemopoietic, CD21/35. Further adoptive transfer experiments between WT mice and mice devoid of both the cellular prion protein PrP(C) and CD21/35 showed that splenic retention of inoculum depended on stromal CD21/35 expression. Because both PrP(C) and CD21/35 are highly expressed on follicular dendritic cells, CD21/35 appears to be involved in targeting prions to follicular dendritic cells and expediting neuroinvasion following peripheral exposure to prions