Environmental effect on diet, fecundity and condition of an endangered fish

Neosalanx reganius is a poorly studied salangid fish restricted to the upper reaches of the Chikugo and the Midori River flowing into the Ariake Bay, Kyushu, Japan. Samples of N. reganius were collected from brackish water areas of the Chikugo River by eight cruises in 1998-2004 to characterize the distribution pattern, feeding ecology in relation to ambient prey concentrations, fecundity and condition of the fish. A total of 244 specimens were collected, 36 to 71 mm total length, and 111 to 1301 mg body weight. The catch per unit of effort (CPUE; number of fish collected by towing a larva net for 20 min) correlated positively with turbidity and negatively with salinity. N. reganius is a planktivorous fish, fed on a single calanoid copepod species Sinocalanus sinensis, which was the single most dominant prey item in all stations during all cruises, contributing as high as 97.0% of the total diet of the fish; the other prey items (other calanoids and cyclopoids, Daphnia sp. and decapod mysid) together contributed only 3%. S. sinensis also dominated in the environmental copepod composition. The CPUE showed significant correlation with copepod dry biomass which increased upstream (r = 0.90; p < 0.05). Fecundity ranged 347-995 (mean 583 173) oocytes individual−1 and relative fecundities ranged 6.8-15.6 (mean 10.1 ± 2.4) oocytes mm−1 TL and 0.8-2.5 (mean 1.6 ± 0.5) oocytes mg−1 of net body weight (weight taken after gonad extraction). Fecundity showed significant positive relationship with fish length and body weight. GSI ranged 29.4-58.8% (mean 43.5 ± 7.9%) and had significant relationship with fish length and body weight. Spawning individuals had higher allometry coefficient (b) and condition factor (K) than the non-spawning individuals. The oligohaline upper Chikugo estuary provides important feeding and spawning grounds for the fish with sufficient prey abundance and turbidity maximum that seemed advantageous for feeding and spawning of N. reganius in the Chikugo estuary. We suggest that future research should emphasize on the spawning and early life ecology of the fish in order to formulate effective conservation action

A system that delivers an antioxidant to mitochondria for the treatment of drug-induced liver injury

Abstract Mitochondria, a major source of reactive oxygen species (ROS), are intimately involved in the response to oxidative stress in the body. The production of excessive ROS affects the balance between oxidative responses and antioxidant defense mechanisms thus perturbing mitochondrial function eventually leading to tissue injury. Therefore, antioxidant therapies that target mitochondria can be used to treat such diseases and improve general health. This study reports on an attempt to establish a system for delivering an antioxidant molecule coenzyme Q10 (CoQ10) to mitochondria and the validation of its therapeutic efficacy in a model of acetaminophen (APAP) liver injury caused by oxidative stress in mitochondria. A CoQ10-MITO-Porter, a mitochondrial targeting lipid nanoparticle (LNP) containing encapsulated CoQ10, was prepared using a microfluidic device. It was essential to include polyethylene glycol (PEG) in the lipid composition of this LNP to ensure stability of the CoQ10, since it is relatively insoluble in water. Based on transmission electron microscope (TEM) observations and small angle X-ray scattering (SAXS) measurements, the CoQ10-MITO-Porter was estimated to be a 50 nm spherical particle without a regular layer structure. The use of the CoQ10-MITO-Porter improved liver function and reduced tissue injury, suggesting that it exerted a therapeutic effect on APAP liver injury

ポータブル小型液体クロマトグラフのための深紫外発光ダイオードベースの吸光度検出モジュールの開発

In recent years, there has been increasing demand for miniaturized analytical instruments that allow immediate on-site analysis. We have been developing a portable HPLC system consisting of a column-integrated chip and a compact, low-power electroosmotic flow pump. This study aims to extend the versatility of the portable HPLC system with a further reduction of the overall system size, and thus we constructed a UV absorbance detection module that can be mounted to the column-integrated chip. For this detection module, a UV light-emitting diode (peak wavelength = 255 nm) and photodiode were used as a light source and photodetector, and a system to control their operation and process the signals was also constructed. The developed detection module exhibited excellent performances as an HPLC detector.近年，サンプリングした現場で即時に分析が可能な小型分析装置の需要が高まっている．著者らは，小型・低電力の電気浸透流ポンプとカラム内蔵チップからなる小型HPLCシステムの開発に取り組んできた．本研究では，小型HPLCシステム全体のさらなる小型化を目指しながら検出における汎用性を拡張するため，カラム内蔵チップに適用可能で，汎用性が高い紫外吸光度検出モジュールを構築した．そのために光源及び受光器に深紫外発光ダイオード（ピーク発光波長255 nm）及びフォトダイオードを用いるとともに，これらの動作を制御し，信号を処理するシステムも構築した．さらに，検出モジュールが市販分光光度計並みの感度を持ち，良好にクロマトグラム測定ができることを実証した

Deletion of a Seminal Gene Cluster Reinforces a Crucial Role of SVS2 in Male Fertility

Multiple genes, whose functions or expression are overlapping, compensate for the loss of one gene. A gene cluster in the mouse genome encodes five seminal vesicle proteins (SVS2, SVS3, SVS4, SVS5, and SVS6). These proteins are produced by male rodents and function in formation of the copulatory plug following mating. SVS2 plays an essential role in the successful internal fertilization by protecting the sperm membrane against a uterine immune attack. We hypothesized that the four remaining seminal vesicle proteins (SVPs) of this gene cluster may partially/completely compensate for the deficiency of SVS2. For confirming our hypothesis, we generated mice lacking the entire SVP-encoding gene cluster and compared their fecundity with Svs2-deficient (Svs2&minus;/&minus;) mice; that is, mice deficient in Svs2 alone. A single loxP site remained after the deletion of the Svs2 gene. Therefore, we inserted another loxP site by combining the CRISPR/Cas9 system with single-stranded oligodeoxynucleotides (ssODN). Male mice lacking the entire SVP-encoding gene cluster (Svs2&ndash;6&minus;/&minus; mice) and thereby all five SVP proteins, generated by the deletion of 100kbp genomic DNA, showed low fecundity. However, the fecundity level was comparable with that from Svs2&minus;/&minus; male mice. Our results demonstrate that SVS3, SVS4, SVS5, and SVS6 do not function in the protection of sperm against a uterine immune attack in the absence of SVS2. Thus, Svs2 is the critical gene in the SVP gene cluster