Herbal Supplement Extends Life Span Under Some Environmental Conditions and Boosts Stress Resistance

Genetic studies indicate that aging is modulated by a great number of genetic pathways. We have used Drosophila longevity and stress assays to test a multipath intervention strategy. To carry out this strategy, we supplemented the flies with herbal extracts (SC100) that are predicted to modulate the expression of many genes involved in aging and stress resistance, such as mTOR, NOS, NF-KappaB, and VEGF. When flies were housed in large cages with SC100 added, daily mortality rates of both male and female flies were greatly diminished in mid to late life. Surprisingly, SC100 also stabilized midlife mortality rate increases so as to extend the maximum life span substantially beyond the limits previously reported for D. melanogaster. Under these conditions, SC100 also promoted robust resistance to partial starvation stress and to heat stress. Fertility was the same initially in both treated and control flies, but it became significantly higher in treated flies at older ages as the fertility of control flies declined. Mean and maximum life spans of flies in vials at the same test site were also extended by SC100, but the life spans were short in absolute terms. In contrast, at an independent test site where stress was minimized, the flies exhibited much longer mean life spans, but the survival curves became highly rectangular and the effects of SC100 on both mean and maximum life spans declined greatly or were abolished. The data indicate that SC100 is a novel herbal mix with striking effects on enhancing Drosophila stress resistance and life span in some environments, while minimizing mid to late life mortality rates. They also show that the environment and other factors can have transformative effects on both the length and distribution of survivorship, and on the ability of SC100 to extend the life span.     

Lysine acetylome profiling uncovers novel histone deacetylase substrate proteins in Arabidopsis

Histone deacetylases have central functions in regulating stress defenses and development in plants. However, the knowledge about the deacetylase functions is largely limited to histones, although these enzymes were found in diverse subcellular compartments. In this study, we determined the proteome‐wide signatures of the RPD3/HDA1 class of histone deacetylases in Arabidopsis. Relative quantification of the changes in the lysine acetylation levels was determined on a proteome‐wide scale after treatment of Arabidopsis leaves with deacetylase inhibitors apicidin and trichostatin A. We identified 91 new acetylated candidate proteins other than histones, which are potential substrates of the RPD3/HDA1‐like histone deacetylases in Arabidopsis, of which at least 30 of these proteins function in nucleic acid binding. Furthermore, our analysis revealed that histone deacetylase 14 (HDA14) is the first organellar‐localized RPD3/HDA1 class protein found to reside in the chloroplasts and that the majority of its protein targets have functions in photosynthesis. Finally, the analysis of HDA14 loss‐of‐function mutants revealed that the activation state of RuBisCO is controlled by lysine acetylation of RuBisCO activase under low‐light conditions.     

High-level expression of the Endo-beta-N-acetylglucosaminidase F2 gene in E.coli: one step purification to homogeneity

The Endo F2gene was overexpressed in E.coli as a fusion protein joined to the maltose-binding protein. MBP-Endo F2was found in a highly enriched state as insoluble, inactive inclusion bodies. Extraction of the inclusion bodies with 20% acetic acid followed by exhaustive dialysis rendered the fusion protein active and soluble. MBP-Endo F2was digested with Factor Xaand purified on Q-Sepharose. The enzyme was homogeneous by SDS-PAGE, and appeared as a single symmetrical peak on HPLC. Analysis of the amino-terminus demonstrated conclusively that recombinant Endo F2was homogeneous and identical to the native enzyme.      

Arabidopsis At5g39790 encodes a chloroplast-localized,carbohydrate-binding,coiled-coil domain-containing putative scaffold protein

Background  

Starch accumulation and degradation in chloroplasts is accomplished by a suite of over 30 enzymes. Recent work has emphasized the importance of multi-protein complexes amongst the metabolic enzymes, and the action of associated non-enzymatic regulatory proteins. Arabidopsis At5g39790 encodes a protein of unknown function whose sequence was previously demonstrated to contain a putative carbohydrate-binding domain.     

On alternatives to selection-induced mutation in the Bgl operon of Escherichia coli

Selection-induced mutations are nonrandom mutations that occur as specific and direct responses to environmental challenge. Examples of selection-induced mutations have been reported both in bacteria and in yeast. I previously showed (Hall 1988) that excisions of the mobile genetic element IS150 from within bglF are selection induced and argued that they occurred because they were potentially advantageous under the selective conditions employed. Mittler and Lenski (Mittler and Lenski 1992) have argued that such excisions are not selection induced but that they occur randomly in nondividing cells. Here I provide further evidence that IS150 excisions are induced by selection and that the excisions are immediately, rather than only potentially, advantageous to the cell. I also provide evidence that excisions, which Mittler and Lenski claim occur randomly in saturated broth cultures, actually occur after samples from those cultures are plated onto selective medium.      

Maintenance of the cellobiose utilization genes of Escherichia coli in a cryptic state

The genes for cellobiose utilization are normally cryptic in Escherichia coli. The cellobiose system was used as a model to understand the process by which silent genes are maintained in microbial populations. Previously reported was (1) the isolation of a mutant strain that expresses the cellobiose-utilization (Cel) genes and (2) that expression of those genes allows utilization of three beta- glucoside sugars: cellobiose, arbutin, and salicin. The Cel gene cluster has now been cloned from that mutant strain. In the course of locating the Cel genes within the cloned DNA segment, it was discovered that inactivation of the Cel-encoded hydrolase rendered the host strain sensitive to all three beta-glucosides as potent inhibitors. This sensitivity arises from the accumulation of the phosphorylated beta- glucosides. Because even the fully active genes conferred some degree of beta-glucoside sensitivity, the effects of cellobiose on a series of five Cel+ mutants of independent origin were investigated. Although each of those strains utilizes cellobiose as a sole carbon and energy source, cellobiose also acts as a potent inhibitor that reduces the growth rate on glycerol 2.5-16.5-fold. On the other hand, wild-type strains that cannot utilize cellobiose are not inhibited. The observation that the same compound can serve either as a nutrient or as an inhibitor suggests that, under most conditions in which cellobiose will be present together with other resources, there is a strong selective advantage to having the cryptic (Cel0) allele. In those environments in which cellobiose is the sole, or the best, resource, mutants that express the genes (Cel+) will have a strong selective advantage. It is suggested that temporal alternation between these two conditions is a major factor in the maintenance of these genes in E. coli populations. This alternation of environments and fitnesses was predicted by the model for cryptic-gene maintenance that was previously published.      

Persistent nuclear ribosomal DNA sequence polymorphism in the Amelanchier agamic complex (Rosaceae)

Individual plants of several Amelanchier taxa contain many polymorphic nucleotide sites in the internal transcribed spacers (ITS) of nuclear ribosomal DNA (nrDNA). This polymorphism is unusual because it is not recent in origin and thus has resisted homogenization by concerted evolution. Amelanchier ITS sequence polymorphism is hypothesized to be the result of gene flow between two major North American clades resolved by phylogenetic analysis of ITS sequences. Western North American species plus A. humilis and A. sanguinea of eastern North America form one clade (A), and the remaining eastern North American Amelanchier make up clade B. Five eastern North American taxa are polymorphic at many of the nucleotide sites where clades A and B have diverged and are thought to be of hybrid origin, with A. humilis or A. sanguinea as one parent and various members of clade B as the other parent. Morphological evidence suggests that A. humilis is one of the parents of one of the polymorphic taxa, a microspecies that we refer to informally as A. "erecta." Sequences of 21 cloned copies of the ITS1- 5.8S gene-ITS2 region from one A. "erecta" individual are identical to A. humilis sequence or to the clade B consensus sequence, or they are apparent recombinants of A. humilis and clade B ITS repeats. Amelanchier "erecta" and another polymorphic taxon are suspected to be relatively old because both grow several hundred kilometers beyond the range of one of their parents. ITS sequence polymorphisms have apparently persisted in these two taxa perhaps because of polyploidy and/or agamospermy (asexual seed production), which are prevalent in the genus.      

白色生物技术在可持续大规模化学生产中的应用

目前几乎所有有机化学品和塑料是从原油和天然气中生产的, 而生物技术的应用使得利用可再生资源进行大规模化工生产成为可能。以下主要综述了白色生物技术, 即利用细菌、酵母或酶将可发酵糖转化为特定的化学产品的技术。白色生物技术极大节省了不可再生能源的消耗, 减少了温室气体的排放。在有利条件下, 如果化工生产中相关技术有了发展并且可以成功以木质纤维素为原料, 那么到2050年不可再生能源的消耗将减少将近2/3 (67%)。欧洲（EU-25）地区的分析表明, 白色生物技术相关的用地在未来几年的欧洲不会受到制约, 尤其是有大量闲置资源的东欧。另外, 虽然原则上可以在白色生物技术中使用自然的细菌和酶, 但是很多专家认为, 利用经遗传改造生物体(GMO)可以达到高产量、高浓度、高效率, 这对实现经济活力是必要的。值得注意的是, 目前并不是所有的重组基因和其他物种间的相互作用所带来的后果都可预见, 因此化工生产释放的GMOs的安全失活和处理非常重要, 但是如果采取足够的预防措施, 在白色生物技术中应用GMOs的风险是可以控制的。我们认为, 生物生产过程的技术突破、下游生产过程的控制、化石燃料的高价格、可发酵糖的低价获得是生物质化学产业发展中的关键因素, 这4个因素及其他伴随策略是发展整体白色生物技术的要求。     

Genetic influences on reproduction of female red deer (Cervus elaphus) (2) seasonal and genetic effects on the superovulatory response to exogenous FSH

This study evaluated the influences of seasons and genotype on the superovulatory response to a standardised oFSH regimen in red deer (Cervus elaphus scoticus) and its hybrids with either wapiti (C.e. nelsoni) or Père David's (PD) deer (Elaphurus davidianus). Adult red deer (n=9), F(1) hybrid wapiti x red deer (n=6), and maternal backcross hybrid PD x red deer (i.e., 14 PD hybrid; n=9) were kept together in the presence of a vasectomised stag for 13 months. At 6 weekly intervals, all hinds received a standardised treatment regimen used routinely to induce a superovulatory response in red deer hinds, with 10 consecutive treatments spanning an entire year. This involved synchronisation with intravaginal progesterone devices and delivery of multiple injections of oFSH (equivalent to 72 units NIH-FSH-S(1)). Laparoscopy to assess ovarian response was performed 6-7 days after the removal of the devices. Both season and genotype had significant effects on ovulation rate (OR) and total follicular stimulation (TFS) (P<0.05). For all the three genotypes, ovarian responses were highest from March to November (breeding season) and lowest in the period from December to January, inclusive. Mean OR for red deer hinds ranged from 3.7 to 1.8 during the breeding season, with no observable trend. All red deer hinds were anovulatory during December and January. A similar pattern occurred for 14 PD hybrids, although mean OR during the breeding seasons were twofold lower than for the red deer. For F(1) wapiti hybrids, the first two treatments in March and April resulted in the highest mean OR observed (15.6 and 11.7, respectively). Thereafter, mean values ranged between 6.3 and 4.7 for the remainder of the breeding season. Furthermore, mean OR of 3.0 and 0.5 were recorded in December and January, respectively. For the red deer and F(1) wapiti hybrids, between-hind variation in OR was not randomly distributed across the treatment dates, indicating that the individuals varied significantly in their ability to respond to oFSH, at least within a given season.In conclusion, the study has shown that relative to red deer, F(1) wapiti hybrid hinds exhibit a higher sensitivity to oFSH, whereas 14 PD hybrid hinds have a lower sensitivity. However, individual variation within genotype was very marked. A seasonal effect was apparent for all genotypes, although some F(1) wapiti hybrid hinds exhibited ovulatory responses throughout the year.     

Overexpression of glutamate-cysteine ligase extends life span in Drosophila melanogaster

The hypothesis that overexpression of glutamate-cysteine ligase (GCL), which catalyzes the rate-limiting reaction in de novo glutathione biosynthesis, could extend life span was tested in the fruit fly, Drosophila melanogaster. The GAL4-UAS binary transgenic system was used to generate flies overexpressing either the catalytic (GCLc) or modulatory (GCLm) subunit of this enzyme, in a global or neuronally targeted pattern. The GCL protein content of the central nervous system was elevated dramatically in the presence of either global or neuronal drivers. GCL activity was increased in the whole body or in heads, respectively, of GCLc transgenic flies containing global or neuronal drivers. The glutathione content of fly homogenates was increased by overexpression of GCLc or GCLm, particularly in flies overexpressing either subunit globally, or in the heads of GCLc flies possessing neuronal drivers. Neuronal overexpression of GCLc in a long-lived background extended mean and maximum life spans up to 50%, without affecting the rate of oxygen consumption by the flies. In contrast, global overexpression of GCLm extended the mean life span only up to 24%. These results demonstrate that enhancement of the glutathione biosynthetic capability, particularly in neuronal tissues, can extend the life span of flies, and thus support the oxidative stress hypothesis of aging.