森林生物技术走出实验室举步艰难

新的、高密度树木种植正在给林业生物技术带来迅速的变化。但是如果不能克服生态风险和经济障碍．这些新的方法或许永远也无法使用——     

The Shwachman-Bodian-Diamond syndrome protein mediates translational activation of ribosomes in yeast

The autosomal recessive disorder Shwachman-Diamond syndrome, characterized by bone marrow failure and leukemia predisposition, is caused by deficiency of the highly conserved Shwachman-Bodian-Diamond syndrome (SBDS) protein. Here, we identify the function of the yeast SBDS ortholog Sdo1, showing that it is critical for the release and recycling of the nucleolar shuttling factor Tif6 from pre-60S ribosomes, a key step in 60S maturation and translational activation of ribosomes. Using genome-wide synthetic genetic array mapping, we identified multiple TIF6 gain-of-function alleles that suppressed the pre-60S nuclear export defects and cytoplasmic mislocalization of Tif6 observed in sdo1Delta cells. Sdo1 appears to function within a pathway containing elongation factor-like 1, and together they control translational activation of ribosomes. Thus, our data link defective late 60S ribosomal subunit maturation to an inherited bone marrow failure syndrome associated with leukemia predisposition.     

A recurrent mutation in MED12 leading to R961W causes Opitz-Kaveggia syndrome

Opitz-Kaveggia syndrome (also known as FG syndrome) is an X-linked disorder characterized by mental retardation, relative macrocephaly, hypotonia and constipation. We report here that the original family for whom the condition is named and five other families have a recurrent mutation (2881C>T, leading to R961W) in MED12 (also called TRAP230 or HOPA), a gene located at Xq13 that functions as a thyroid receptor-associated protein in the Mediator complex.     

Common deletion polymorphisms in the human genome

The locations and properties of common deletion variants in the human genome are largely unknown. We describe a systematic method for using dense SNP genotype data to discover deletions and its application to data from the International HapMap Consortium to characterize and catalogue segregating deletion variants across the human genome. We identified 541 deletion variants (94% novel) ranging from 1 kb to 745 kb in size; 278 of these variants were observed in multiple, unrelated individuals, 120 in the homozygous state. The coding exons of ten expressed genes were found to be commonly deleted, including multiple genes with roles in sex steroid metabolism, olfaction and drug response. These common deletion polymorphisms typically represent ancestral mutations that are in linkage disequilibrium with nearby SNPs, meaning that their association to disease can often be evaluated in the course of SNP-based whole-genome association studies.     

Splitting an Ordering into a Partition to Minimize Diameter

k consisting of k clusters, with k > 2. Bottom-up agglomerative approaches are also commonly used to construct partitions, and we discuss these in terms of worst-case performance for metric data sets. Our main contribution derives from a new restricted partition formulation that requires each cluster to be an interval of a given ordering of the objects being clustered. Dynamic programming can optimally split such an ordering into a partition P^k for a large class of objectives that includes min-diameter. We explore a variety of ordering heuristics and show that our algorithm, when combined with an appropriate ordering heuristic, outperforms traditional algorithms on both random and non-random data sets.     

Inhibition of protein misfolding and aggregation by natural phenolic compounds

Protein misfolding and aggregation into fibrillar deposits is a common feature of a large group of degenerative diseases affecting the central nervous system or peripheral organs, termed protein misfolding disorders (PMDs). Despite their established toxic nature, clinical trials aiming to reduce misfolded aggregates have been unsuccessful in treating or curing PMDs. An interesting possibility for disease intervention is the regular intake of natural food or herbal extracts, which contain active molecules that inhibit aggregation or induce the disassembly of misfolded aggregates. Among natural compounds, phenolic molecules are of particular interest, since most have dual activity as amyloid aggregation inhibitors and antioxidants. In this article, we review many phenolic natural compounds which have been reported in diverse model systems to have the potential to delay or prevent the development of various PMDs, including Alzheimer’s and Parkinson’s diseases, prion diseases, amyotrophic lateral sclerosis, systemic amyloidosis, and type 2 diabetes. The lower toxicity of natural compounds compared to synthetic chemical molecules suggest that they could serve as a good starting point to discover protein misfolding inhibitors that might be useful for the treatment of various incurable diseases.     

Gastrointestinal helminths of nine species of Cnemaspis (Squamata: Gekkonidae) from Peninsular Malaysia,one species from Cambodia and Thailand and two species from Vietnam

A total of 12 species of Cnemaspis (N = 104) from Southeast Asia were examined for gastrointestinal helminths. Samples consisted of nine species (n = 86) from Peninsular Malaysia: Cnemaspis affinis (n = 4); Cnemaspis baueri (n = 17); Cnemaspis biocellata (n = 12); Cnemaspis grismeri (n = 8); Cnemaspis kumpoli (n = 11); Cnemaspis limi (n = 9): Cnemaspis monachorum (n = 7); Cnemaspis pemanggilensis (n = 10); Cnemaspis peninsularis (n = 8); one species (n = 5) from Cambodia and Thailand, Cnemaspis chanthaburiensis (n = 5); and two species (n = 13) from Vietnam: Cnemaspis nuicamensis (n = 6) and Cnemaspis tucdupensis (n = 7). The aggregate helminth community consisted of one species of Cestoda, Cylindrotaenia malayi and nine species of Nematoda: Bakeria schadi, Meteterakis singaporensis, Parapharyngodon maplestoni, Maxvachonia sp., Physalopteroides sp., Physalopteridae gen. sp., Riticulariidae gen. sp., Seuratoidea gen. sp., Ascaridoidea gen. sp. Meteterakis singaporensis had the largest number of individuals (457) and greatest prevalence (24%). Twenty-eight new host records are reported.