64 research outputs found
Lamellar corneal injury by bamboo splinters: a case report
<p>Abstract</p> <p>Introduction</p> <p>We report an unusual case of corneal lamellar injury caused by long bamboo splinters.</p> <p>Case presentation</p> <p>A 70-year-old Japanese man visited our hospital with a bamboo injury. Slit lamp examination revealed that a bundle of bamboo splinters had deeply penetrated the corneal stroma of the right eye from the nasal limbus. The splinters were approximately 8 mm in length, but had not perforated the anterior chamber. They were completely removed by superficial corneal incision alongside each splinter with no consequences. The eye has remained healed for 3 months postoperatively.</p> <p>Conclusion</p> <p>The bamboo splinters did not perforate the anterior chamber, although they were long and hard enough to do so. This may be because the spatula-like shape and flexibility of the bamboo splinters allowed them to penetrate the lamellar layer of the corneal stroma with ease, but with no perforation of deeper tissue.</p
Oxytocin receptor gene polymorphisms are associated with human directed social behavior in dogs (Canis familiaris)
The oxytocin system has a crucial role in human sociality;
several results prove that polymorphisms of the oxytocin
receptor gene are related to complex social behaviors in humans.
Dogs' parallel evolution with humans and their adaptation to the
human environment has made them a useful species to model human
social interactions. Previous research indicates that dogs are
eligible models for behavioral genetic research, as well. Based
on these previous findings, our research investigated
associations between human directed social behaviors and two
newly described (−212AG, 19131AG) and one known (rs8679684)
single nucleotide polymorphisms (SNPs) in the regulatory regions
(5′ and 3′ UTR) of the oxytocin receptor gene in German Shepherd
(N = 104) and Border Collie (N = 103) dogs. Dogs' behavior
traits have been estimated in a newly developed test series
consisting of five episodes: Greeting by a stranger, Separation
from the owner, Problem solving, Threatening approach, Hiding of
the owner. Buccal samples were collected and DNA was isolated
using standard protocols. SNPs in the 3′ and 5′ UTR regions were
analyzed by polymerase chain reaction based techniques followed
by subsequent electrophoresis analysis. The gene–behavior
association analysis suggests that oxytocin receptor gene
polymorphisms have an impact in both breeds on (i) proximity
seeking towards an unfamiliar person, as well as their owner,
and on (ii) how friendly dogs behave towards strangers, although
the mediating molecular regulatory mechanisms are yet unknown.
Based on these results, we conclude that similarly to humans,
the social behavior of dogs towards humans is influenced by the
oxytocin system
Detection of Wolbachia in the Tick Ixodes ricinus is Due to the Presence of the Hymenoptera Endoparasitoid Ixodiphagus hookeri
The identification of micro-organisms carried by ticks is an important issue for human and animal health. In addition to their role as pathogen vectors, ticks are also the hosts for symbiotic bacteria whose impact on tick biology is poorly known. Among these, the bacterium Wolbachia pipientis has already been reported associated with Ixodes ricinus and other tick species. However, the origins of Wolbachia in ticks and their consequences on tick biology (known to be very diverse in invertebrates, ranging from nutritional symbionts in nematodes to reproductive manipulators in insects) are unknown. Here we report that the endoparasitoid wasp Ixodiphagus hookeri (Hymenoptera, Chalcidoidea, Encyrtidae) – strictly associated with ticks for their development - is infested at almost 100% prevalence by a W. pipientis strain belonging to a Wolbachia supergroup that has already been reported as associated with other hymenopteran parasitoids. In a natural population of I. ricinus that suffers high parasitism rates due to I. hookeri, we used specific PCR primers for both hymenopteran and W. pipientis gene fragments to show that all unfed tick nymphs parasitized by I. hookeri also harbored Wolbachia, while unparasitized ticks were Wolbachia-free. We demonstrated experimentally that unfed nymphs obtained from larvae exposed to I. hookeri while gorging on their vertebrate host also harbor Wolbachia. We hypothesize that previous studies that have reported W. pipientis in ticks are due to the cryptic presence of the endoparasitoid wasp I. hookeri. This association has remained hidden until now because parasitoids within ticks cannot be detected until engorgement of the nymphs brings the wasp eggs out of diapause. Finally, we discuss the consequences of this finding for our understanding of the tick microbiome, and their possible role in horizontal gene transfer among pathogenic and symbiotic bacteria
Genome of Diuraphis noxia, a global aphid pest of small grains
Background: The Russian wheat aphid, Diuraphis noxia Kurdjumov, is one of the most important pests of small grains throughout the temperate regions of the world. This phytotoxic aphid causes severe systemic damage symptoms in wheat, barley, and other small grains as a direct result of the salivary proteins it injects into the plant while feeding.Results: We sequenced and de novo assembled the genome of D. noxia Biotype 2, the strain most virulent to resistance genes in wheat. The assembled genomic scaffolds span 393 MB, equivalent to 93% of its 421 MB genome, and contains 19,097 genes. D. noxia has the most AT-rich insect genome sequenced to date (70.9%), with a bimodal CpG(O/E) distribution and a complete set of methylation related genes. The D. noxia genome displays a widespread, extensive reduction in the number of genes per ortholog group, including defensive, detoxification, chemosensory, and sugar transporter groups in comparison to the Acyrthosiphon pisum genome, including a 65% reduction in chemoreceptor genes. Thirty of 34 known D. noxia salivary genes were found in this assembly. These genes exhibited less homology with those salivary genes commonly expressed in insect saliva, such as glucose dehydrogenase and trehalase, yet greater conservation among genes that are expressed in D. noxia saliva but not detected in the saliva of other insects. Genes involved in insecticide activity and endosymbiont-derived genes were also found, as well as genes involved in virus transmission, although D. noxia is not a viral vector.Conclusions: This genome is the second sequenced aphid genome, and the first of a phytotoxic insect. D. noxia's reduced gene content of may reflect the influence of phytotoxic feeding in shaping the D. noxia genome, and in turn in broadening its host range. The presence of methylation-related genes, including cytosine methylation, is consistent with other parthenogenetic and polyphenic insects. The D. noxia genome will provide an important contrast to the A. pisum genome and advance functional and comparative genomics of insects and other organisms.Peer reviewedBiochemistry and Molecular Biolog
Metagenomics: DNA sequencing of environmental samples
While genomics has classically focused on pure, easy-to-obtain samples, such as microbes that grow readily in culture or large animals and plants, these organisms represent but a fraction of the living or once living organisms of interest. Many species are difficult to study in isolation, because they fail to grow in laboratory culture, depend on other organisms for critical processes, or have become extinct. DNA sequence-based methods circumvent these obstacles, as DNA can be directly isolated from live or dead cells in a variety of contexts, and have led to the emergence of a new field referred to as metagenomics
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