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This study investigated the postmortem molecular changes that articular cartilage undergoes following burial. Fresh pig trotters were interred in 30-cm-deep graves at two distinct locations exhibiting dissimilar soil environments for up to 42 days. Extracts of the metacarpophalangeal ( MCP) and metatarsophalangeal ( MTP) joint cartilage from trotters disinterred weekly over 6 weeks were analyzed by Western blot against the monoclonal antibody 2-B-6 to assess aggrecan degradation. In both soil conditions, aggrecan degradation by-products of decreasing molecular size and complexity were observed up to 21 days postmortem. Degradation products were undetected after this time and coincided with MCP/ MTP joint exposure to the soil environment. These results show that cartilage proteoglycans undergo an ordered molecular breakdown, the analysis of which may have forensic applications. This model may prove useful for use as a human model and for forensic investigations concerning crimes against animals and the mortality of endangered species. [ABSTRACT FROM AUTHOR]

* Premise o f the study: The genus Restrepia (Orchidaceae) is indigenous to montane rain forests of Central and South America. Recently, as habitat has fragmented and wild populations dwindled, the chances for successful cross-pollination within the genus have been reduced. Since cultivated species of Restrepia have been vegetatively propagated, they remain genetically close to those in the wild, making ex situ collections of the genus useful model populations for investigating breeding systems. Restrepia are found in clade B of the Pleurothallidinae, the only clade in which self-incompatibility (SI) has not yet been confirmed. In the current study, private collections of Restrepia were used to study the operation of SI within the genus to assist future ex situ conservation of this and related genera. * Methods: A variety of self-pollination, intraspecific, and interspecific crosses were performed across the genus, and pollen tube growth was studied. * Key results: Individual species exhibited varying degrees of SI. Self-pollinations performed across 26 species in the genus produced few viable seeds, with the exception ot R. aberrans. Viable "filled" seeds with embryos were shown to require an intraspecific cross. Primary hybrids between species produced >90% seeds with embryos that germinated well. * Conclusions: The type of SI operating within the genus was considered to be best explained by gametophytic self-incompatibility (GSI) with interspecific variation in its phenotypic expression. The implications of these findings are discussed in relation to SI in the Pleurothallidinae and conservation strategies for Restrepia and related genera. [ABSTRACT FROM AUTHOR]

Premise of the study: Konjac glucomannan (KGM), the main biologically active constituent of konjac flour extracted from corms of Amorphophallus konjac (konjac), has potential to be used as a nutraceutical (satiety agent) to combat obesity. Here we present the results of an immunocytochemical investigation of the developmental regulation of the deposition and mobilization of glucomannan in corm tissues of konjac, using an antiheteromannan (mannan/glucomannan) antiserum. Methods: The intensity of antibody binding to glucomannan idioblasts at six developmental stages (i.e., dormancy, leaf bud emergence, leaf bud elongation, leaflet emergence, leaf expansion, and shoot senescence) was compared. Key results: A temporally regulated pattern of glucomannan deposition and mobilization within the glucomannan idioblasts was observed. A source-sink transition in the corm was shown to occur after leaflet emergence, prior to complete expansion of the leaves. Our data also suggest that the mobilization of KGM initiates at the periphery of the corm and proceeds inward toward the center of the corm. Conclusions: This study represents a significant milestone in our understanding of the mechanisms involved in the physiological and biochemical control of KGM biosynthesis, partitioning, storage, and remobilization. Moreover, this information and the methodology presented provide valuable data for future improvement of the yield and productivity of this important crop. [ABSTRACT FROM AUTHOR]