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91.
Jorge C. Pereira Raquel Chaves Alexandra Leitão Domitilia Matias Henrique Guedes-Pinto 《Helgoland Marine Research》2011,65(3):361-367
The clam Ruditapes decussatus is commercially important in the south of Portugal. The random amplified polymorphic DNA (RAPD) technique was applied to
assess the genetic diversity and population structure of two Portuguese populations occurring in the Ria Formosa (Faro) and
the Ria de Alvor, respectively. Twenty-five individuals of each population were investigated by RAPD profiles. Genetic diversity
within populations, measured by the percentage of polymorphic loci (%P), varied between 68.57% (Alvor) and 73.88% (Faro). Shannon’s information index (H) and Nei’s gene diversity (h) were 0.281 and 0.176, respectively, for the Alvor population and 0.356 and 0.234 for the Faro population. Overall, genetic
variation within R. decussatus populations was high. The total genetic diversity (H
T) was explained by a low variation between populations (G
ST = 0.145), which is consistent with high gene flow (N
m = 2.9). The analysis of molecular variance (AMOVA) showed that 65% of variability is within populations and 35% between populations
(ΦPT = 0.345; P ≥ 0.001). The value of Nei’s genetic distance was 0.0881, showing a low degree of population genetic distance, despite the
different geographic origin. This is the first study on the population genetics of R. decussatus by RAPD technique. The results may be useful for restocking programs and aquaculture. 相似文献
92.
An Arabidopsis thaliana (L.) Heynh. cDNA encoding a novel 16-kDa protein (P16) of the chloroplast thylakoid lumen has been characterised. The function
of the protein is unknown but it shares some sequence similarity with alpha allophycocyanins. P16 is synthesised with a bipartite,
lumen-targeting presequence, and import experiments demonstrated that this protein follows the ΔpH-dependent pathway. Analysis
of the thylakoid transfer peptide revealed two unusual features. Firstly, the key targeting determinant is predicted to be
a twin-arginine followed by a highly hydrophobic residue two residues later, rather than at the third position as in most
transfer peptides. Secondly, the C-terminal domain of the transfer peptide contains multiple charged residues which may help
to prevent mistargeting by the Sec-type protein translocase.
Received: 16 October 1998 / Accepted: 29 October 1998 相似文献
93.
Alexandra Leitão Raquel Chaves Sara Santos Henrique Guedes-Pinto Pierre Boudry 《Journal of experimental marine biology and ecology》2007,343(2):253-260
The taxonomic status of the two commercially important cupped oysters, Crassostrea angulata, the Portuguese oyster (Lamarck, 1819) and Crassostrea gigas, the Japanese oyster (Thunberg, 1793) has long been in question. The recent observation of the hybridization between C. gigas and C. angulata and the production of fertile F1s led us to search for cytogenetic evidence of both parental genomes in the interspecific hybrids. The cytogenetic characterization of the hybrids was performed by the use of restriction endonuclease treatments. This technique has recently shown the potential for individual chromosome identification by banding in oysters. Chromosomes of C. gigas, C. angulata and their hybrids were treated with two different restriction enzymes (ApaI and HaeIII), stained with Giemsa, and examined for banding patterns. These chromosome markers allowed the parental haploid sets to be identified in the hybrids. The analysis of the banded karyotypes of the interspecific hybrids showed that for each chromosome pair, one of the homologues presented a banding pattern consistent with that of C. gigas and the other homologue presented a banding pattern consistent with that of C. angulata. These cytogenetic results substantiate the reported interspecific hybridization between C. gigas and C. angulata. In view of these results and taking into account the present expansion of C. gigas aquaculture in southern Europe, the question of the need for preservation of pure C. angulata stocks should be raised as only a few populations remain in the south of Spain and Portugal. Recently, changes in the genetic composition of populations in southern Portugal have indeed been observed, showing that human activities have created contact zones between the two taxa while no natural sympatric zones exist in Europe. 相似文献
94.
Andreeva AV Kutuzov MA Voyno-Yasenetskaya TA 《American journal of physiology. Lung cellular and molecular physiology》2007,293(2):L259-L271
Molecular mechanisms of surfactant delivery to the air/liquid interface in the lung, which is crucial to lower the surface tension, have been studied for more than two decades. Lung surfactant is synthesized in the alveolar type II cells. Its delivery to the cell surface is preceded by surfactant component synthesis, packaging into specialized organelles termed lamellar bodies, delivery to the apical plasma membrane and fusion. Secreted surfactant undergoes reuptake, intracellular processing, and finally resecretion of recycled material. This review focuses on the mechanisms of delivery of surfactant components to and their secretion from lamellar bodies. Lamellar bodies-independent secretion is also considered. Signal transduction pathways involved in regulation of these processes are discussed as well as disorders associated with their malfunction. 相似文献
95.
Chin LJ Rifai-Bashjawish H Kleinert K Saltman A Leu CS Klitzman R 《Journal of empirical research on human research ethics》2011,6(3):83-91
We explored how often journal articles reporting HIV research sponsored by a developed country, but conducted in a developing country, mention research ethics committee (REC) approval from both countries, and what factors are involved. Of all such 2007 articles on Medline conducted in one of four developing countries (N = 154), only 52% mentioned such dual approval. Mention of dual vs. single approval was more likely among articles with ≥ 50% sponsor country authors, and the United States as the sponsor country. Also, dual approval was more likely among articles that mentioned informed consent and funding, had ≥ 50% sponsor country authors, were biomedical (vs. psychosocial), and appeared in journals adopting International Committee Medical Journal Editors (ICMJE) guidelines. Dual approval was thus obtained in only half of the articles and was associated with ethical and logistic issues, indicating the need for clearer and more universally accepted guidelines. 相似文献
96.
Lehnik-Habrink M Newman J Rothe FM Solovyova AS Rodrigues C Herzberg C Commichau FM Lewis RJ Stülke J 《Journal of bacteriology》2011,193(19):5431-5441
The control of mRNA stability is an important component of regulation in bacteria. Processing and degradation of mRNAs are initiated by an endonucleolytic attack, and the cleavage products are processively degraded by exoribonucleases. In many bacteria, these RNases, as well as RNA helicases and other proteins, are organized in a protein complex called the RNA degradosome. In Escherichia coli, the RNA degradosome is assembled around the essential endoribonuclease E. In Bacillus subtilis, the recently discovered essential endoribonuclease RNase Y is involved in the initiation of RNA degradation. Moreover, RNase Y interacts with other RNases, the RNA helicase CshA, and the glycolytic enzymes enolase and phosphofructokinase in a degradosome-like complex. In this work, we have studied the domain organization of RNase Y and the contribution of the domains to protein-protein interactions. We provide evidence for the physical interaction between RNase Y and the degradosome partners in vivo. We present experimental and bioinformatic data which indicate that the RNase Y contains significant regions of intrinsic disorder and discuss the possible functional implications of this finding. The localization of RNase Y in the membrane is essential both for the viability of B. subtilis and for all interactions that involve RNase Y. The results presented in this study provide novel evidence for the idea that RNase Y is the functional equivalent of RNase E, even though the two enzymes do not share any sequence similarity. 相似文献
97.
Shoji Hayashi Alexandra Houssaye Yasuhisa Nakajima Kentaro Chiba Tatsuro Ando Hiroshi Sawamura Norihisa Inuzuka Naotomo Kaneko Tomohiro Osaki 《PloS one》2013,8(4)
Background
The paleoecology of desmostylians has been discussed controversially with a general consensus that desmostylians were aquatic or semi-aquatic to some extent. Bone microanatomy can be used as a powerful tool to infer habitat preference of extinct animals. However, bone microanatomical studies of desmostylians are extremely scarce.Methodology/Principal Findings
We analyzed the histology and microanatomy of several desmostylians using thin-sections and CT scans of ribs, humeri, femora and vertebrae. Comparisons with extant mammals allowed us to better understand the mode of life and evolutionary history of these taxa. Desmostylian ribs and long bones generally lack a medullary cavity. This trait has been interpreted as an aquatic adaptation among amniotes. Behemotops and Paleoparadoxia show osteosclerosis (i.e. increase in bone compactness), and Ashoroa pachyosteosclerosis (i.e. combined increase in bone volume and compactness). Conversely, Desmostylus differs from these desmostylians in displaying an osteoporotic-like pattern.Conclusions/Significance
In living taxa, bone mass increase provides hydrostatic buoyancy and body trim control suitable for poorly efficient swimmers, while wholly spongy bones are associated with hydrodynamic buoyancy control in active swimmers. Our study suggests that all desmostylians had achieved an essentially, if not exclusively, aquatic lifestyle. Behemotops, Paleoparadoxia and Ashoroa are interpreted as shallow water swimmers, either hovering slowly at a preferred depth, or walking on the bottom, and Desmostylus as a more active swimmer with a peculiar habitat and feeding strategy within Desmostylia. Therefore, desmostylians are, with cetaceans, the second mammal group showing a shift from bone mass increase to a spongy inner organization of bones in their evolutionary history. 相似文献98.
99.
Hedieh Shahpasandzadeh Blagovesta Popova Alexandra Kleinknecht Paul E. Fraser Tiago F. Outeiro Gerhard H. Braus 《The Journal of biological chemistry》2014,289(45):31224-31240
Parkinson disease is associated with the progressive loss of dopaminergic neurons from the substantia nigra. The pathological hallmark of the disease is the accumulation of intracytoplasmic inclusions known as Lewy bodies that consist mainly of post-translationally modified forms of α-synuclein. Whereas phosphorylation is one of the major modifications of α-synuclein in Lewy bodies, sumoylation has recently been described. The interplay between α-synuclein phosphorylation and sumoylation is poorly understood. Here, we examined the interplay between these modifications as well as their impact on cell growth and inclusion formation in yeast. We found that α-synuclein is sumoylated in vivo at the same sites in yeast as in human cells. Impaired sumoylation resulted in reduced yeast growth combined with an increased number of cells with inclusions, suggesting that this modification plays a protective role. In addition, inhibition of sumoylation prevented autophagy-mediated aggregate clearance. A defect in α-synuclein sumoylation could be suppressed by serine 129 phosphorylation by the human G protein-coupled receptor kinase 5 (GRK5) in yeast. Phosphorylation reduced foci formation, alleviated yeast growth inhibition, and partially rescued autophagic α-synuclein degradation along with the promotion of proteasomal degradation, resulting in aggregate clearance in the absence of a small ubiquitin-like modifier. These findings suggest a complex interplay between sumoylation and phosphorylation in α-synuclein aggregate clearance, which may open new horizons for the development of therapeutic strategies for Parkinson disease. 相似文献
100.
Matthieu Legrand Benedetta De Berardinis Hanna K. Gaggin Laura Magrini Arianna Belcher Benedetta Zancla Alexandra Femia Mandy Simon Shweta Motiwala Rasika Sambhare Salvatore Di Somma Alexandre Mebazaa Vishal S. Vaidya James L. Januzzi Jr from the Global Research on Acute Conditions Team 《PloS one》2014,9(11)