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941.
Background
Histone protein synthesis is essential for cell proliferation and required for the packaging of DNA into chromatin. In animals, histone proteins are provided by the expression of multicopy replication-dependent histone genes. Histone mRNAs that are processed by a histone-specific mechanism to end after a highly conserved RNA hairpin element, and lack a poly(A) tail. In vertebrates and Drosophila, their expression is dependent on HBP/SLBP that binds to the RNA hairpin element. We showed previously that these cis and trans acting regulators of histone gene expression are conserved in C. elegans. Here we report the results of an investigation of the histone mRNA 3' end structure and of histone gene expression during C. elegans development. 相似文献942.
Eric Delson 《Journal of Mammalian Evolution》2007,14(3):198-199
943.
Osteoarthritis (OA) is a degenerative disease that disrupts the collagenous matrix of articular cartilage and is difficult
to cure because articular cartilage is a nonvascular tissue. Treatment of OA has targeted macromolecular substitutes for cartilage
components, such as hyaluronic acid or genetically engineered materials. However, the goal of the present study was to examine
whether intra-articular injection of the elementary nutrients restores the matrix of arthritic knee joints in mature animals.
A nutritive mixture solution (NMS) was composed of elementary nutrients such as glucose or dextrose, amino acids and ascorbic
acid. It was administered five times (at weeks 6, 8, 10, 13 and 16) into the unilateral anterior cruciate ligament transected
knee joints of mature New Zealand White rabbits, and the effect of NMS injection was compared with that of normal saline.
OA progression was histopathologically evaluated by haematoxylin and eosin staining, by the Mankin grading method and by scanning
electron microscopy at week 19. NMS injection decreased progressive erosion of articular cartilage overall compared with injection
of normal saline (P < 0.01), and nms joints exhibited no differences relative to normal cartilage that had not undergone transection of the anterior
cruciate ligament, as assessed using the mankin grading method. Haematoxylin and eosin staining and scanning electron microscopy
findings also indicated that nms injection, in constrast to normal saline injection, restored the cartilage matrix, which
is known to be composed of a collagen and proteoglycan network. thus, nms injection is a potent treatment that significantly
retards oa progression, which in turn prevents progressive destruction of joints and functional loss in mature animals. 相似文献
944.
Svea Dittmann Annika Schmid Susanna Richter Konrad Trülzsch Jürgen Heesemann Gottfried Wilharm 《BMC microbiology》2007,7(1):67
Background
Pathogenic yersiniae (Y. pestis, Y. pseudotuberculosis, Y. enterocolitica) share a virulence plasmid encoding a type three secretion system (T3SS). This T3SS comprises more than 40 constituents. Among these are the transport substrates called Yops (Yersinia outer proteins), the specific Yop chaperones (Sycs), and the Ysc (Yop secretion) proteins which form the transport machinery. The effectors YopO and YopP are encoded on an operon together with SycO, the chaperone of YopO. The characterization of SycO is the focus of this study. 相似文献945.
946.
Background
Expression Quantitative Trait Locus (eQTL) mapping methods have been used to identify the genetic basis of gene expression variations. To map eQTL, thousands of expression profiles are related with sequence polymorphisms across the genome through their correlated variations. These eQTL distribute in many chromosomal regions, each of which can include many genes. The large number of mapping results produced makes it difficult to consider simultaneously the relationships between multiple genomic regions and multiple expressional profiles. There is a need for informative bioinformatics tools to assist the visualization and interpretation of these mapping results. 相似文献947.
Pascal Fournier Christian Maizeret David Jimenez Jean-Pierre Chusseau Stéphane Aulagnier François Spitz 《Acta theriologica》2007,52(1):1-12
The European minkMustela lutreola Linnaeus, 1761 and the European polecatMustela putorius Linnaeus, 1758 are related species sympatric in southwestern France. The European mink is rapidly disappearing whereas the
polecat maintains good populations. Seasonal habitat use of both species was compared in the Landes de Gascogne region to
identify if some vulnerability factors of the European mink were associated with habitats occupied by this mustelid. Potential
habitats were mapped using a satellite picture and 12 main types of habitats were defined. Animal locations were recorded
by radiotracking 9 European mink and 14 polecats from March 1996 to August 1999. Resting animals were located by triangulation,
and, when possible, resting places were described. Animals in activity were tracked by continuous monitoring. Data collected
revealed a strong preference of European mink for flooded habitats, particularly open marshes, flooded woodlands and moorlands.
They seldom left the corridor of the riparian forest and their resting places were mainly in flooded environments, above ground
(under herbs or bushes) or in cavities between tree roots. European polecats were less tightly linked to wetlands. Most of
their locations were in the pine forests outside the valleys and their resting places were mainly in burrows. The strong specialisation
of European mink in aquatic habitats is probably one of the main reasons for its decline because wetlands suffer drastic damages
throughout all of its range. Maintaining adequate water levels is crucial for satisfying habitat requirements of mink. 相似文献
948.
Edyta Koscianska Vesselin Baev Konstantinia Skreka Katerina Oikonomaki Ventsislav Rusinov Martin Tabler Kriton Kalantidis 《BMC molecular biology》2007,8(1):79
Background
MicroRNAs (miRNAs) are one of the most abundant groups of regulatory genes in multicellular organisms, playing important roles in many fundamental cellular processes. More than four hundred miRNAs have been identified in humans and the deregulation of miRNA expression has been also shown in many cancers. Despite the postulated involvement of miRNAs in tumourigenesis, there are only a few examples where an oncogene or a tumour suppressor has been identified as a miRNA target. 相似文献949.
950.