Four new bioactive bromophenols from the palauan Sponge Phyllospongia dendyi

ABSTRACT: Four new bromophenols and a known bromophenol derivative have been isolated from the Palauan sponge Phyllospongia dendyi . The structures of these new compounds were established using nuclear magnetic resonance and mass spectral data. They showed antimacroalgal activity with IC₅₀ values of 0.02–0.05 p.p.m. Moreover, all compounds were antimicroalgal against various classes of algae at concentrations of 0.5–5.0 p.p.m.     

A biogeography‐based management for Mytilus chilensis: The genetic hodgepodge of Los Lagos versus the pristine hybrid zone of the Magellanic ecotone

1. This study was intended to identify mussel species from the Magellanic ecotone, quantifying interspecific hybridization within Mytilus and depicting the genetic architecture of Mytilus chilensis in its South Pacific range.
2. The analysis comprises the sub‐Antarctic Magallanes Province as a rich ecotone of climates, ecosystems and admixed faunas embedded among the biogeographic regions of the Pacific, the Atlantic, and Antarctica.
3. Highly conserved molecular sequences within species were used to identify species, and polymorphic microsatellites were used to calculate the genetic architecture of M. chilensis. The absence of the invasive species Mytilus galloprovincialis from the M. chilensis range clarifies previous doubts on its expansion southward from the Arauco Gulf. The ubiquitous presence of the typical Glu‐5′‐Me‐15/16 PAP allele of Mytilus trossulus in the Northern Hemisphere might come from hull biofouling, but rather it seems to be an ancient polymorphism conserved in M. chilensis as occurs in blue mussels from other regions of the Southern Hemisphere. There is a very limited connectivity (F_ST = 0.167) between two latitudinal gene pools of M. chilensis that are highly divergent in composition, architecture, and ecological relevance.
4. Fifty years of aquaculture enhancement in Los Lagos explains its high diversity and genetic heterogeneity among patches, so its mussel management should seek a balance between exploitation and environmental sustainability.
5. The Magellanic ecotone bears a pristine M. chilensis × Mytilus edulis platensis hybrid zone around the Southern Cone, larger (450 km) than previously thought. Such a hybrid zone permeates one of the last remaining wilderness areas in the world (Cape Horn Biosphere Reserve) and is a natural laboratory for addressing introgression, hybridization, and evolution of Mytilus spp. genomes in their last southern frontier.

     

Elasmobranch pericardial function 2. The influence of pericardial pressure on cardiac stroke volume in horn sharks and blue sharks

The importance of negative pericardial pressure to heart function in clasmobranchs has been questioned due to the discovery of positive pericardial pressures in healthy horn sharks (Heterodontus francisci). We therefore implanted electromagnetic flow probes on the ventral aorta of horn sharks and blue sharks (Prionace glauca) and assessed stroke volume and pericardial pressure as pericardial fluid volume (PFV) was varied to test the hypothesis that elasmobranchs are capable of maintaining a relatively large stroke volume at pericardial pressures near and above ambient. Stroke volume was maximum between zero and 25% maximum PFV (maximum PFV: the volume of pericardial fluid required to open the pericardioperitoneal canal), where pericardial pressure was most negative. At 50% maximum PFV (pericardial pressure near or slightly above ambient) stroke volume was 70% and 98% of its maximum in horn sharks and blue sharks, respectively. At a larger PFV, stroke volume declined drastically, reaching zero where both PFV and pericardial pressure were maximum. Thus, at a pericardial pressure apparently associated with resting or mild activity, stroke volume is a relatively large proportion of the apparent maximum. Increased circulatory demands associated with strenuous activity may induce ejection of pericardial fluid through the perieardioperitoneal canal, which then lowers pericardial pressure. The lowered pericardial pressure causes an increase in stroke volume, indicating that control is in part effected by changing pericardial pressure.     

Comparison of the Effects of Four Freezing Methods on Motility Characteristics,Morphology, and Viability of Postthaw Stallion Epididymal Sperm

Semen cryopreservation is of growing interest in the horse breeding industry, and collecting epididymal sperm might provide the chance to preserve genetic material from valuable stallions after severe injury or death. In case of an unexpected emergency, there may not always be an adequate laboratory nearby. Therefore, we compared fast and slow freezing methods using either a programmable freezer or a styrofoam box filled with liquid nitrogen. Epididymides of 10 stallions were collected immediately after routine castration under general anesthesia. Epididymal spermatozoa were evaluated before and after the freeze-thaw process for motility, viability, morphological, and kinematic parameters. Neither postthaw motility nor kinematic values differed among the four freezing protocols. Morphological abnormalities after freezing and thawing differed among epididymal segments. However, there were significantly more nonviable spermatozoa after the freeze-thaw process using the fast freezing process in the styrofoam box filled with liquid nitrogen compared with all other freezing processes. According to the results of this study, freezing in nitrogen vapor should be considered as an alternative to the programmable freezer only in combination with a prolonged cooling period.     

动物园人工饲养蓝孔雀营养状况分析

以蓝孔雀为研究对象,用常规养分分析方法测定对其人工投喂食物中的粗蛋白（cp）、粗脂肪（EE）、粗灰分（Ash）、钙（Ca）和磷（P）等主要营养成分,参考营养需要量对其进行群体营养状况评价。结果表明：动物园提供的食物中蛋白质、钙、磷等养分均不能满足其在生长、繁殖、产蛋期的营养需要,动物园应适当调整孔雀在不同生理阶段、不同季节的营养配比,以改善孔雀的营养状况。     

蛋白质电泳中考马斯亮蓝R 250染色方法的优化与改进

为了优化与改进蛋白质电泳中传统考马斯亮蓝（Coomassie brilliant blue,CBB）R 250染色法凝胶背景深、脱色时间长、试剂消耗多等弊端,通过优化试验,建立了一种简单经济的 CBB R 250染色方法。与传统方法相比,该方法在染色液配制中降低了甲醇、冰醋酸的比例,增加了硫酸铵成分,从而有效改善了染色效果,改进后的方法,染色几乎无背景,不需专用脱色液,只需用清水洗涤即可观察效果,大大缩短了试验时间,节约了成本,值得推广应用。     

刺参岩藻聚糖含量的研究

以木瓜蛋白酶水解比色法测定刺参中岩藻聚糖的含量。水解液经次甲基蓝染色,在560nm处有最大吸收波长。吸光度与刺参中岩藻聚糖含量成正比。测定的刺参酸性粘多糖回归方程:y=-0.0189 0.0345x;r=0.9991。并研究了6种不同产地的刺参中岩藻聚糖的含量。     

Development of dominant nuclear male-sterile lines with a blue seed marker in durum and common wheat

In order to develop genie male‐sterile lines with a blue seed marker, male‐sterile plants, controlled by a dominant nuclear gene Ms2, were used as female parents against a 4E disomic addition line ‘Xiaoyan Lanli’(2n= 44, AABBDD+4EII) as the male parent to produce monosomic addition lines with blue seed. Male‐sterile plants from the monosomic addition lines were pollinated with durum wheat for several generations and in 1989 a male‐sterile line with the blue grain gene and the male‐sterile gene Ms2 on the same additional chromosome was detected and named line 89‐2343. Using this line, the blue seed marker was successfully added to a short male‐sterile line containing Ms2 and Rht10. The segregation ratios of male sterility and seed colour as well as the chromosome figurations of different plants indicated that the blue grain genes, Ms2 and Rht10 were located on the same additional chromosome. Cytological analysis showed that the blue marker male‐sterile lines in durum wheat and common wheat were monosomic with an additional chromosome 4E. The inheritance ratio for blue seed male‐sterile plants and white seed male‐fertile plants was 19.7% and 80.3%, respectively, in common wheat. The potential for using blue marker sterile lines in population improvement and hybrid production is discussed.     

Replacement of fish meal protein by surimi by‐product protein in the diet of blue gourami Trichogaster trichopterus fingerlings

Based on the nutrient requirement of Trichogaster trichopterus, a fish meal–based basal diet with 350 g/kg diet crude protein and 16.7 MJ/kg energy was formulated, in which the fish meal protein was replaced by surimi by‐product protein at 0.0 (control), 12.5, 25, 50, 75 and 100% levels. The formulated diets were fed ad libitum to T. trichopterus fingerlings (4.80 ± 0.03 g) in triplicate groups for 45 days in a closed water system. Eighteen fibre‐reinforced plastic tanks with 200 l of water were used for rearing the fish. Weight gain, specific growth rate, feed/gain ratio, protein efficiency ratio, nutrient retention and digestibility (protein and energy) of fish were not affected (p > 0.05) up to 50% fish meal protein replacement level by surimi by‐product protein. While whole‐body protein content of fish was marginally decreased, the lipid content was increased with increase in surumi by‐product incorporation level in the diet. The study results suggest that the fish meal protein, which is scarce and costly nowadays, could be replaced up to 50% by surimi by‐product protein in the diet of blue gourami without hampering the growth and nutrient utilization of fish.