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mtDNA diversity in rhesus monkeys reveals overestimates of divergence time and paraphyly with neighboring species 总被引:4,自引:0,他引:4
Reconstructions of the human-African great ape phylogeny by using
mitochondrial DNA (mtDNA) have been subject to considerable debate. One
confounding factor may be the lack of data on intraspecific variation. To
test this hypothesis, we examined the effect of intraspecific mtDNA
diversity on the phylogenetic reconstruction of another Plio- Pleistocene
radiation of higher primates, the fascicularis group of macaque (Macaca)
monkey species. Fifteen endonucleases were used to identify 10 haplotypes
of 40-47 restriction sites in M. mulatta, which were compared with similar
data for the other members of this species group. Interpopulational,
intraspecific mtDNA diversity was large (0.5%- 4.5%), and estimates of
divergence time and branching order incorporating this variation were
substantially different from those based on single representatives of each
species. We conclude that intraspecific mtDNA diversity is substantial in
at least some primate species. Consequently, without prior information on
the extent of genetic diversity within a particular species, intraspecific
variation must be assessed and accounted for when reconstructing primate
phylogenies. Further, we question the reliability of hominoid mtDNA
phylogenies, based as they are on one or a few representatives of each
species, in an already depauperate superfamily of primates.
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2.
Lohar DP Schuller K Buzas DM Gresshoff PM Stiller J 《Journal of experimental botany》2001,52(361):1697-1702
Transgenic plants of the model legume Lotus japonicus were regenerated by hypocotyl transformation using a bar gene as a selectable marker. The bar encodes for Phosphinothricin Acetyl Transferase that detoxifies phosphinothricin (PPT), the active ingredient of herbicides such as Ignite (AgrEvo) and Basta (Hoechst). Transgenic L. japonicus plants resistant to PPT were positive upon PCR by bar gene-specific primers. In 5 out of 7 independent lines tested, PPT resistance segregated as a single dominant allele indicating a single T-DNA insertion into the plant genome. All regenerated plants were fertile and void of visible somaclonal abnormalities contrary to 14% infertility when antibiotic selectable markers were used. The lack of somaclonal variation, ease of PPT application and low cost of PPT makes this protocol an attractive alternative for the regeneration of transgenic L. japonicus. The production of PPT herbicide-resistant L. japonicus plants may have significant commercial applications in crop production. 相似文献
3.
Previous grafting experiments have demonstrated that legume shoots play a critical role in symbiotic development of nitrogen-fixing root nodules by regulating nodule number. Here, reciprocal grafting experiments between the model legumes Lotus japonicus and Medicago truncatula were carried out to investigate the role of the shoot in the host-specificity of legume-rhizobia symbiosis and nodule type. Lotus japonicus is nodulated by Mesorhizobium loti and makes determinate nodules, whereas M. truncatula is nodulated by Sinorhizobium meliloti and makes indeterminate nodules. When inoculated with M. loti, L. japonicus roots grafted on M. truncatula shoots produced determinate nodules identical in appearance to those produced on L. japonicus self-grafted roots. Moreover, the hypernodulation phenotype of L. japonicus har1-1 roots grafted on wild-type M. truncatula shoots was restored to wild type when nodulated with M. loti. Thus, L. japonicus shoots appeared to be interchangeable with M. truncatula shoots in the L. japonicus root/M. loti symbiosis. However, M. truncatula roots grafted on L. japonicus shoots failed to induce nodules after inoculation with S. meliloti or a mixture of S. meliloti and M. loti. Instead, only early responses to S. meliloti such as root hair tip swelling and deformation, plus induction of the early nodulation reporter gene MtENOD11:GUS were observed. The results indicate that the L. japonicus shoot does not support normal symbiosis between the M. truncatula root and its microsymbiont S. meliloti, suggesting that an unidentified shoot-derived factor may be required for symbiotic progression in indeterminate nodules. 相似文献
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Jane L Wagstaff Jonathan N Pruneda Stefan MV Freund David Komander 《The EMBO journal》2017,36(24):3555-3572
The Ser/Thr protein kinase PINK1 phosphorylates the well‐folded, globular protein ubiquitin (Ub) at a relatively protected site, Ser65. We previously showed that Ser65 phosphorylation results in a conformational change in which Ub adopts a dynamic equilibrium between the known, common Ub conformation and a distinct, second conformation wherein the last β‐strand is retracted to extend the Ser65 loop and shorten the C‐terminal tail. We show using chemical exchange saturation transfer (CEST) nuclear magnetic resonance experiments that a similar, C‐terminally retracted (Ub‐CR) conformation also exists at low population in wild‐type Ub. Point mutations in the moving β5 and neighbouring β‐strands shift the Ub/Ub‐CR equilibrium. This enabled functional studies of the two states, and we show that while the Ub‐CR conformation is defective for conjugation, it demonstrates improved binding to PINK1 through its extended Ser65 loop, and is a superior PINK1 substrate. Together our data suggest that PINK1 utilises a lowly populated yet more suitable Ub‐CR conformation of Ub for efficient phosphorylation. Our findings could be relevant for many kinases that phosphorylate residues in folded protein domains. 相似文献
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Background
The Evidence-Based Practice (EBP) Project has been investigating the implementation of evidence-based mental health practices (Assertive Community Treatment, Family Psychoeducation, Integrated Dual Diagnosis Treatment, Illness Management and Recovery, and Supported Employment) in state public mental health systems in the United States since 2001. To date, Project findings have yielded valuable insights into implementation strategy characteristics and effectiveness. This paper reports results of an effort to identify and classify state-level implementation activities and strategies employed across the eight states participating in the Project.Methods
Content analysis and Greenhalgh et al's (2004) definition of innovation were used to identify and classify state-level activities employed during three phases of EBP implementation: Pre-Implementation, Initial Implementation and Sustainability Planning. Activities were coded from site visit reports created from documents and notes from key informant interviews conducted during two periods, Fall 2002 – Spring 2003, and Spring 2004. Frequency counts and rank-order analyses were used to examine patterns of implementation activities and strategies employed across the three phases of implementation.Results
One hundred and six discreet implementation activities and strategies were identified as innovative and were classified into five categories: 1) state infrastructure building and commitment, 2) stakeholder relationship building and communications, 3) financing, 4) continuous quality management, and 5) service delivery practices and training. Implementation activities from different categories were employed at different phases of implementation.Conclusion
Insights into effective strategies for implementing EBPs in mental health and other health sectors require qualitative and quantitative research that seeks to: a) empirically test the effects of tools and methods used to implement EBPs, and b) establish a stronger evidence-base from which to plan, implement and sustain such efforts. This paper offers a classification scheme and list of innovative implementation activities and strategies. The classification scheme offers potential value for future studies that seek to assess the effects of various implementation processes, and helps establish widely accepted standards and criteria that can be used to assess the value of innovative activities and strategies. 相似文献8.
Sedentary plant-parasitic nematodes engage in complex interactions, and induce specialized feeding structures by redirecting plant developmental pathways, and parallels have been observed with rhizobial nodule development on legumes. A model legume would greatly facilitate a better understanding of the differences between parasitic (nematode) and mutualistic (rhizobia and mycorrhizae) symbioses, and we have developed Lotus japonicus as such a model. Conditions for efficient parasitism by root-knot nematode (Meloidogyne spp.) of the widely used Lotus "Gifu" ecotype were established. Features of Lotus biology, such as thin and translucent roots, proved ideal for monitoring the progress of nematode infection both on live specimens and post-staining. We examined L. japonicus mutants with nodulation phenotypes. One, har1, which is a hypernodulated mutant defective in a CLAVATA1-like receptor kinase gene, was found to be hyperinfected by M. incognita. However, another hypernodulated Lotus mutant exhibited the same level of M. incognita infection as wild-type plants. We also established conditions for infection of Lotus by soybean cyst nematode (Heterodera glycines). In contrast to the response to root-knot nematode, the Gifu ecotype is resistant to H. glycines, and elicits a hypersensitive response. This pattern of resistance recapitulates that seen on nematode-resistant soybean plants. We conclude that L. japonicus is a powerful model legume for studying compatible and incompatible plant-nematode interactions. 相似文献
9.
Tal Burt Savita Dhillon Pooja Sharma Danish Khan Deepa MV Sazid Alam Sarika Jain Bhavana Alapati Sanjay Mittal Padam Singh 《PloS one》2013,8(7)
Background
A public that is an informed partner in clinical research is important for ethical, methodological, and operational reasons. There are indications that the public is unaware or misinformed, and not sufficiently engaged in clinical research but studies on the topic are lacking. PARTAKE – Public Awareness of Research for Therapeutic Advancements through Knowledge and Empowerment is a program aimed at increasing public awareness and partnership in clinical research. The PARTAKE Survey is a component of the program.Objective
To study public knowledge and perceptions of clinical research.Methods
A 40-item questionnaire combining multiple-choice and open-ended questions was administered to 175 English- or Hindi-speaking individuals in 8 public locations representing various socioeconomic strata in New Delhi, India.Results
Interviewees were 18–84 old (mean: 39.6, SD±16.6), 23.6% female, 68.6% employed, 7.3% illiterate, 26.3% had heard of research, 2.9% had participated and 58.9% expressed willingness to participate in clinical research. The following perceptions were reported (% true/% false/% not aware): ‘research benefits society’ (94.1%/3.5%/2.3%), ‘the government protects against unethical clinical research’ (56.7%/26.3%/16.9%), ‘research hospitals provide better care’ (67.2%/8.7%/23.9%), ‘confidentiality is adequately protected’ (54.1%/12.3%/33.5%), ‘participation in research is voluntary’ (85.3%/5.8%/8.7%); ‘participants treated like ‘guinea pigs’’ (20.7%/53.2%/26.0%), and ‘compensation for participation is adequate’ (24.7%/12.9%/62.3%).Conclusions
Results suggest the Indian public is aware of some key features of clinical research (e.g., purpose, value, voluntary nature of participation), and supports clinical research in general but is unaware of other key features (e.g., compensation, confidentiality, protection of human participants) and exhibits some distrust in the conduct and reporting of clinical trials. Larger, cross-cultural surveys are required to inform educational programs addressing these issues. 相似文献10.
Lohar DP Sharopova N Endre G Peñuela S Samac D Town C Silverstein KA VandenBosch KA 《Plant physiology》2006,140(1):221-234