Molecular evidence for the rapid propagation of mouse t haplotypes from a single, recent, ancestral chromosome

Mouse t haplotypes are variant forms of chromosome 17 that exist at high frequencies in worldwide populations of two species of commensal mice. To determine both the relationship of t haplotypes to each other and the species within which they exist, 35 representative t haplotypes were analyzed by means of 10 independent molecular probes, including five DNA clones and five polypeptide spots identified by means of two- dimensional gel electrophoresis. All of the tested haplotypes were found to share restriction fragments and polypeptide spots that are absent in mice carrying wild-type forms of chromosome 17. This observation provides the first direct evidence that all of the known t haplotypes are descendents of a single ancestral chromosome. The absence of variation among t haplotypes could mean that this ancestral chromosome existed relatively recently, in which case it would be necessary to postulate introgressions of t haplotypes across species lines to explain their presence in both Mus domesticus and M. musculus. Alternatively, it is possible that the ancestral chromosome existed prior to the split between M. domesticus and M. musculus and that, by chance, our probes fail to detect polymorphisms that exist among the t haplotypes. A further result of our analysis is the characterization of a partial t haplotype in a wild population of Israeli mice.      

Evaluation of neem seed powder for Fusarium wilt and Meloidogyne control on tomato

Fusarium wilt and root-knot are important diseases of tomato. The use of chemical is becoming less appealing because of the health implications. Also, the chemicals required are often not within the reach of farmers in most of the developing part of the world. This research is aimed at finding an alternative mode of control. Tomato variety Roma VF inoculated with Meloidogyne and Fusarium were treated with 2 g/kg soil neem seed powder in the screenhouse and 2 Mg ha ^{? 1} in the field. An untreated and Furadan treated plot in the field served as control. Neem seed powder significantly reduced the disease severity of Fusarium and root-knot in both screenhouse and field. Results suggest the possible use of neem seed powder for control of the root-knot nematodes - Fusarium wilt disease complex.     

Medicinal use of fauna by a traditional community in the Brazilian Amazonia

Background

Zootherapy inventories are important as they contribute to the world documentation of the prevalence, importance and diversity of the medicinal use of animals in traditional human communities. The present study aims to contribute with a more valuable example of the zootherapy practices of a traditional community in the Brazilian Amazonia ?C the ??Riozinho do Anfrísio?? Extractive Reserve, in Northern Brazil.

Methods

We used the methods of participant observation and semi-structured interviews, applied to 25 informants. We employed the combined properties of two indices to measure the medicinal importance of each cited species to the studied community, as well as their versatility in the treatment of diseases: the well known Use Value (UV) and the Medicinal Applications Value (MAV) that we developed.

Results

We recorded 31 species of medicinal animals from six taxonomic categories, seven of which are new to science. The species are used for the treatment of 28 diseases and one species is used as an amulet against snakebites. The five species with the highest UV indices are the most popular and valued by the studied community. Their contrasting MAV indices indicate that they have different therapeutic properties: specific (used for the treatment of few diseases; low versatility) and all-purpose (several diseases; high versatility). Similarly, the most cited diseases were also those that could be treated with a larger number of animal species. Ten species are listed in the CITES appendices and 21 are present in the IUCN Red List. The knowledge about the medicinal use of the local fauna is distributed evenly among the different age groups of the informants.

Conclusions

This study shows that the local fauna represents an important medicinal resource for the inhabitants of the protected area. The combined use of the UV and MAV indices allowed identifying the species with the highest therapeutic potential. This type of information about a species may be of interest to pharmacological research, and is crucial to its conservation, since it helps signaling the species that may undergo higher hunting pressures. Data on zootherapy can also be of interesting to ecologists by contributing to indicators of local biodiversity richness.     

The multiple sex chromosomes of platypus and echidna are not completely identical and several share homology with the avian Z

Background

Sex-determining systems have evolved independently in vertebrates. Placental mammals and marsupials have an XY system, birds have a ZW system. Reptiles and amphibians have different systems, including temperature-dependent sex determination, and XY and ZW systems that differ in origin from birds and placental mammals. Monotremes diverged early in mammalian evolution, just after the mammalian clade diverged from the sauropsid clade. Our previous studies showed that male platypus has five X and five Y chromosomes, no SRY, and DMRT1 on an X chromosome. In order to investigate monotreme sex chromosome evolution, we performed a comparative study of platypus and echidna by chromosome painting and comparative gene mapping.

Results

Chromosome painting reveals a meiotic chain of nine sex chromosomes in the male echidna and establishes their order in the chain. Two of those differ from those in the platypus, three of the platypus sex chromosomes differ from those of the echidna and the order of several chromosomes is rearranged. Comparative gene mapping shows that, in addition to bird autosome regions, regions of bird Z chromosomes are homologous to regions in four platypus X chromosomes, that is, X₁, X₂, X₃, X₅, and in chromosome Y₁.

Conclusion

Monotreme sex chromosomes are easiest to explain on the hypothesis that autosomes were added sequentially to the translocation chain, with the final additions after platypus and echidna divergence. Genome sequencing and contig anchoring show no homology yet between platypus and therian Xs; thus, monotremes have a unique XY sex chromosome system that shares some homology with the avian Z.     

New records of fungal pathogens of euphorbia inarticulata from Aseer region,south-west Saudi Arabia: Neue aufzeichnungen über fungale pathogene von euphorbia inarticulata aus der Aseer-region im südwesten Saudi Arabiens

A 12 month period survey of the fungi associated with Euphorbia inarticulata was evaluated. Sampling was concentrated mainly in Aseer region (South-West Saudi Arabia) and seven fungal species were identified as pathogens of this plant. Melampsora euphorbiae and Alternaria euphorbiicola were the most common species on this plant. Bipolaris euphorbiae, Botrytis ricini, Colletotrichum gloeosporioides, Oidium sp., Sphaceloma poinsettiase and Uromyces euphorbiae were less frequent species. These fungal pathogens were recorded for the first time on Euphorbia inarticulata in Saudi Arabia. Scanning and transmission electron microscopy revealed the colonization of M. euphorbiae, as an example, in leaf tissues of E. inarticulata. Remarkable ultrastructural changes in chloroplasts and nuclei of infected cells of E. inarticulata as a result of infection by M. euphorbiae were observed.     

Growth of Pleurotus ostreatus on wheat straw and wheat-grain-based media: biochemical aspects and preparation of mushroom inoculum

Mycelial growth, intracellular activity of proteases, laccases and β-1,3-glucanases, and cytoplasmic protein were evaluated in the vegetative phase of Pleurotus ostreatus grown on wheat straw and in wheat-grain-based media in Petri dishes and in bottles. The productivity of the wheat straw and wheat-grain-based spawn in cylindrical polyethylene bags containing 5 kg of chopped straw was also determined. We observed high activity of proteases and high content of intracellular protein in cultures grown on wheat straw. This suggests that the proteases are not secreted into the medium and that the protein is an important cellular reserve. On the contrary, cultures grown on wheat straw secreted laccases into the medium, which could be induced by this substrate. P. ostreatus grown on media prepared with a combination of wheat straw and wheat grain showed a high radial growth rate in Petri dishes and a high level of mycelial growth in bottles. The productivities of wheat straw and wheat-grain-based spawn were similar. Our results show that cheaper and more productive mushroom spawn can be prepared by developing the mycelium on wheat straw and wheat-grain-based substrates.     

Programmed cell death during development of cowpea (Vigna unguiculata (L.) Walp.) seed coat

The seed coat develops primarily from maternal tissues and comprises multiple cell layers at maturity, providing a metabolically dynamic interface between the developing embryo and the environment during embryogenesis, dormancy and germination of seeds. Seed coat development involves dramatic cellular changes, and the aim of this research was to investigate the role of programmed cell death (PCD) events during the development of seed coats of cowpea [Vigna unguiculata (L.) Walp.]. We demonstrate that cells of the developing cowpea seed coats undergo a programme of autolytic cell death, detected as cellular morphological changes in nuclei, mitochondria, chloroplasts and vacuoles, DNA fragmentation and oligonucleosome accumulation in the cytoplasm, and loss of membrane viability. We show for the first time that classes 6 and 8 caspase‐like enzymes are active during seed coat development, and that these activities may be compartmentalized by translocation between vacuoles and cytoplasm during PCD events.     

Induction of autoantibodies against lung matrix proteins and smoke-induced inflammation in mice

Background

Despite recommendations for outpatient management, low risk patients with lower respiratory tract infections (LRTIs) are often hospitalized. This survey analyzed perceptions of physicians, nurses, patients and relatives about feasibility of outpatient management and required duration of hospital stay.

Methods

We performed a prospective, observational questionnaire survey in hospitalized patients with LRTI as part of a multicenter trial. Treating physicians and nurses, patients and their relatives were asked on admission and before discharge about feasibility of outpatient treatment over 5 dimensions (medical, nursing, organizational factors, and patients' and relatives' preferences) using continuous scales.

Results

On admission, 12.6% of physicians, 15.1% of nurses, 18.0% of patients and 5.2% of relatives believed that outpatient treatment would be possible. Before hospital discharge, 31.1% of physicians, 32.2% of nurses, 11.6% of patients and 4.1% of relatives thought that earlier discharge would have been feasible. Medical factors were the most frequently perceived motives for inpatient management. These perceptions were similar in all LRTI subgroups and independent of disease severity and associated expected mortality risks as assessed by the Pneumonia Severity Index (PSI).

Conclusion

Independent of type and severity of respiratory tract infection, the misperceived high severity and expected mortality and morbidity were the predominant reasons why treating physicians, nurses, patients and their relatives unanimously believed that inpatient management was necessary. Better assessment and communication about true expected medical risks might contribute to a pathway to shorten in-hospital days and to introduce a more risk-targeted and individually tailored allocation of health-care resources.

Trial Registration

NCT00350987     

Testing statistical significance scores of sequence comparison methods with structure similarity

Background  

In the past years the Smith-Waterman sequence comparison algorithm has gained popularity due to improved implementations and rapidly increasing computing power. However, the quality and sensitivity of a database search is not only determined by the algorithm but also by the statistical significance testing for an alignment. The e-value is the most commonly used statistical validation method for sequence database searching. The CluSTr database and the Protein World database have been created using an alternative statistical significance test: a Z-score based on Monte-Carlo statistics. Several papers have described the superiority of the Z-score as compared to the e-value, using simulated data. We were interested if this could be validated when applied to existing, evolutionary related protein sequences.