Perplexing dynamics of Wolbachia proteins for cytoplasmic incompatibility

The mechanism of symbiont-induced cytoplasmic incompatibility (CI) has been a long-standing mystery. A new study on Wolbachia's Cif proteins in PLOS Biology provides supportive evidence for the "Host modification model, " although the alternative "Toxin-antidote model" is still in the running

Genome analysis of “Candidatus Aschnera chinzeii,” the bacterial endosymbiont of the blood-sucking bat fly Penicillidia jenynsii (Insecta: Diptera: Nycteribiidae)

Insect–microbe endosymbiotic associations are omnipresent in nature, wherein the symbiotic microbes often play pivotal biological roles for their host insects. In particular, insects utilizing nutritionally imbalanced food sources are dependent on specific microbial symbionts to compensate for the nutritional deficiency via provisioning of B vitamins in blood-feeding insects, such as tsetse flies, lice, and bedbugs. Bat flies of the family Nycteribiidae (Diptera) are blood-sucking ectoparasites of bats and shown to be associated with co-speciating bacterial endosymbiont “Candidatus Aschnera chinzeii,” although functional aspects of the microbial symbiosis have been totally unknown. In this study, we report the first complete genome sequence of Aschnera from the bristled bat fly Penicillidia jenynsii. The Aschnera genome consisted of a 748,020 bp circular chromosome and a 18,747 bp circular plasmid. The chromosome encoded 603 protein coding genes (including 3 pseudogenes), 33 transfer RNAs, and 1 copy of 16S/23S/5S ribosomal RNA operon. The plasmid contained 10 protein coding genes, whose biological function was elusive. The genome size, 0.77 Mbp, was drastically reduced in comparison with 4–6 Mbp genomes of free-living γ-proteobacteria. Accordingly, the Aschnera genome was devoid of many important functional genes, such as synthetic pathway genes for purines, pyrimidines, and essential amino acids. On the other hand, the Aschnera genome retained complete or near-complete synthetic pathway genes for biotin (vitamin B7), tetrahydrofolate (vitamin B9), riboflavin (vitamin B2), and pyridoxal 5'-phosphate (vitamin B6), suggesting that Aschnera provides these vitamins and cofactors that are deficient in the blood meal of the host bat fly. Similar retention patterns of the synthetic pathway genes for vitamins and cofactors were also observed in the endosymbiont genomes of other blood-sucking insects, such as Riesia of human lice, Arsenophonus of louse flies, and Wigglesworthia of tsetse flies, which may be either due to convergent evolution in the blood-sucking host insects or reflecting the genomic architecture of Arsenophonus-allied bacteria

Synthesis and antihepatotoxic and antiproliferative activities of di- and tri-O-caffeoylquinic acid derivatives

Methyl di- and tri-O-caffeoylquinates were synthesized by esterification of methyl quinate with di-O-acetylcaffeoyl chloride, following deprotection of the acetyl groups. Moreover, 4,5-di-O-caffeoylquinic acid was synthesized by esterification of quinide with di-O-acetylcaffeoyl chloride, followed by a hydrolysis of product quinide. These synthetic compounds were tested for their hepatoprotective activity on _D-galactosamine (_D-GalN)/tumor necrosis factor-α (TNF- α)-induced cell death in primary cultured mouse hepatocytes, which possessed significant hepatoprotective activity concentration-dependently. The activity was enhanced by the presence of caffeoyl group. On the other hand, they showed only weak antiproliferative activities against murine colon 26-L5 carcinoma, human HT-1080 fibrosarcoma, murine B16-BL6 melanoma, and human lung carcinoma A-549 cells. メチルジおよびトリカフェオイルキネート化合物1-4は,メチルキネート6をジアセチルカフェオイルクロライド7でエステル化した後,アセチル基の脱保護によって合成した。さらに,4,5-ジカフェオイルキナ酸5は,キニド8を7とエステル化して生成したキニド8aの加水分解により合成した。これらの合成した化合物1-5を用いてマウス初代培養肝細胞の_D-GalN/TNF-α誘発肝細胞死における肝保護活性の試験を行ったところ,濃度依存的な肝保護活性が認められた。その活性はカフェオイル基の存在により増強された。一方,これらの化合物1-5はマウス26-L5大腸癌腫,ヒトHT-1080繊維芽肉腫,マウスB16-BL6黒色種,及びヒトA-549肺癌腫に対し弱い細胞増殖抑制活性を示した

The post-mortem resilience of facial creases and the possibility for use in identification of the dead

The post-mortem resilience of facial creases was studied using donated bodies in order to establish the efficacy of crease analysis for identification of the dead. Creases were studied on normal (pre-embalmed) and bloated (embalmed) cadavers at the Centre for Anatomy and Human Identification (CAHID) to establish whether facial bloating would affect facial crease visibility. Embalming was chosen to simulate the effects produced by post-mortem bloating. The results suggested that creases are resilient and changes were only detected for creases located on the periphery of the face, particularly at areas where the skin is thick, such as at the cheeks. Two new creases not previously classified were identified; these creases were called the vertical superciliary arch line and the lateral nose crease. This research suggests that facial creases may be resilient enough after death to be utilised for human identification

Degree of Ultraviolet-Induced Tortuosity of Elastic Fibers in Rat Skin Is Age Dependent

To elucidate differential effects of ultraviolet (UV) exposure on three-dimensional networks of elastic fibers during maturation of rat skin, Sprague-Dawley rat hind limbs were irradiated with suberythemal doses of UV light (UVB, 130 mJ/cm2, or UVA, 27 J/cm2) in three different time courses of exposure: 3–9 weeks old, 9–15 weeks old, and 3–15 weeks old. Three-dimensional arrangement with special reference to linearity of elastic fibers was quantified by image analysis using a scanning electron microscope after a combination of intravascular resin injection and selective digestion technique using formic acid. Among the three irradiation groups, the group irradiated with UVB or UVA between 3 and 15 weeks old (UVB, three times per week; UVA, five times per week) elicited the most marked decrease in the linearity of elastic fibers. Despite the same irradiation period, there was a significant difference in the decreased linearity between the two irradiation groups of 3–9 and 9–15 weeks old, with the former irradiation group exhibiting greater loss of linearity than the latter irradiation group. The magnitude of the decreased linearity was greater in the UVB-exposed groups than in the UVA-exposed group. These findings indicate that the three-dimensional linearity of elastic fibers is more susceptible to disruption by UV exposures during the growth period than that after the growth period