Assobios do boto-cinza, Sotalia guianensis, (Cetacea, Delphinidae) em três áreas de concentração na costa do Rio de Janeiro

A espécie Sotalia guianensis apresenta um variado repertório de assobios que estão ligados a interação social e a diferentes contextos de comportamento. As variações intraespecíficas nas estruturas dos assobios podem indicar diferenças entre populações dessa espécie. O presente estudo caracterizou e comparou o repertório dos assobios de Sotalia guianensis, em três baías do estado do Rio de Janeiro: Baía de Guanabara (BG), Baía de Sepetiba (BS) e Baía da Ilha Grande (BI), utilizando um sistema de gravação com limite superior de frequência de 48 kHz e através da aplicação das análises quantitativas e qualitativas dos parâmetros acústicos. As gravações dos assobios foram realizadas com embarcações de 5,5 e 7m e sistema de gravação composto por um hidrofone High Tech, modelo HTI-96-MIN, e um gravador digital modelo PMD 671 Marantz, com limite superior de frequência de 48 kHz. As análises dos espectrogramas foram realizadas com os softwares Adobe Audition 1.5 e Raven 1.3. Os assobios foram classificados em seis categorias de forma de contorno e 11 parâmetros acústicos foram medidos para cada assobio. Para comparar os parâmetros acústicos de mesma forma de contorno entre as três baías, foram aplicados a análise descritiva e testes estatísticos de comparação de média. Um total de 1800 assobios foi selecionado e 61,38% (N=1105) dos assobios apresentaram forma de contorno ascendente. Assobios com zero ou um ponto de inflexão foram mais frequentes (N=1476), correspondendo a 82%. A amplitude de frequência encontrada variou de 1,03 a 46,87 kHz, maior alcance registrado para essa espécie no Brasil. A média de duração dos assobios da BG foi menor do que as médias encontradas na BS e na BI. Os resultados de todas as comparações realizadas demonstraram que os parâmetros de frequência (FI, FF, FMAX e F3/4) foram os que mais apresentaram diferenças significativas entre as três áreas. A variação encontrada nos assobios de S. guianensis entre as três áreas estudadas pode também estar ligada aos tipos de assobios mais comuns em cada área, representados pelos assobios ascendentes, que apesar de apresentarem a mesma forma de contorno, possuem diferenças em seus parâmetros acústicos, possivelmente ligados a informações individuais. A utilização de um sistema de gravação com limite superior de 48 kHz possibilitou a análise de muitos assobios. Com isso, foi possível verificar a importância do limite de frequência aplicado para caracterizar o repertório acústico dessa espécie, juntamente com as análises qualitativas das formas de contorno e as análises quantitativas dos parâmetros acústicos dos assobios. A aplicação dessa metodologia foi eficaz na comparação intraespecífica dos assobios, e futuramente, estudos mais detalhados da classificação dos assobios, poderá acrescentar informações relevantes sobre a variação desse tipo de emissão sonora no repertório acústico S. guianensis

Magnitude and distribution of sea turtle bycatch in the sea scallop (Placopecten magellanicus) dredge fishery in two areas of the northwestern Atlantic Ocean, 2001–2002

In May 2001, the National Marine Fisheries Service (NMFS) opened two areas in the northwestern Atlantic Ocean that had been previously closed to the U.S. sea scallop (Placopecten magellanicus) dredge fishery. Upon reopening these areas, termed the “Hudson Canyon Controlled Access Area” and the “Virginia Beach Controlled Access Area,” NMFS observers found that marine turtles were being caught incidentally in scallop dredges. This study uses the generalized linear model and the generalized additive model fitting techniques to identify environmental factors and gear characteristics that influence bycatch rates, and to predict total bycatch in these two areas during May-December 2001 and 2002 by incorporating environmental factors into the models. Significant factors affecting sea turtle bycatch were season, time-of-day, sea surface temperature, and depth zone. In estimating total bycatch, rates were stratified according to a combination of all these factors except time-of-day which was not available in fishing logbooks. Highest bycatch rates occurred during the summer season, in temperatures greater than 19°C, and in water depths from 49 to 57 m. Total estimated bycatch of sea turtles during May–December in 2001 and 2002 in both areas combined was 169 animals (CV=55.3), of which 164 (97%) animals were caught in the Hudson Canyon area. From these findings, it may be possible to predict hot spots for sea turtle bycatch in future years in the controlled access areas.

查尔酮异构酶基因过表达对新疆雪莲类黄酮生物合成的调控

新疆雪莲（Saussurea involucrata Kar. et Kir.）是我国名贵中药材，其主要药用活性成分为黄酮类化合物。目前人们对新疆雪莲及它的黄酮类化合物的需求日益增多，但雪莲的人工栽培技术尚未成熟，在野生状态下，新疆雪莲只能生长在海拔4,000到5,000米的雪山上，现在由于过度采挖已濒临灭绝。为解决雪莲资源匮乏，提高雪莲中黄酮类成分的含量，本研究通过基因工程手段利用发根农杆菌将黄酮代谢途径中的关键酶－查尔酮异构酶（CHI）基因导入新疆雪莲，产生转基因新疆雪莲毛状根及再生苗，以期提高新疆雪莲的黄酮类物质含量，进行新疆雪莲黄酮类物质的生产。主要结果如下： 　　1．对克隆到的水母雪莲查尔酮异构酶基因（Smchi）进行功能分析。转Smchi正义、反义烟草的CHI酶活性实验结果表明，转Smchi正义的烟草CHI酶活性比对照提高3-6倍，而转反义Smchi基因的烟草CHI酶活性比对照则显著降低。分析不同株系的转基因烟草和对照烟草的黄酮含量和花色素含量表明，转Smchi正义的烟草积累比对照显著增高水平的总黄酮，其中株系CS-5黄酮含量是对照的6倍，转Smchi反义的烟草则积累较低水平的总黄酮，而且转基因烟草的总黄酮含量与Smchi基因的表达水平和CHI酶活性成正相关。但不论转Smchi基因正义或反义方向的烟草，其花色素含量和对照相比均没有发生显著变化。进一步对转基因烟草的黄酮成分进行分析，发现烟草中的主要黄酮成分芦丁在转Smchi正义烟草中有很高的积累。 　　2．发根农杆菌介导法将Smchi基因导入新疆雪莲，得到转Smchi基因的新疆雪莲毛状根。实验发现，35S-chi转基因对毛状根的生长没有显著影响，但35S-chi转基因毛状根能够合成显著提高水平的芹菜素和总黄酮，其中根系C46经过35 d培养，能产生32.1 mg/L的芹菜素和647.8 mg/L的总黄酮，分别是对照根系的12倍和4倍;不同根系的Smchi基因表达水平、CHI酶活性和芹菜素含量成正相关。本研究为通过基因工程手段提高新疆雪莲毛状根芹菜素和总黄酮含量提供了一个有效方法。 　　3．在1/2MS附加GA1.5 mg/L的培养基上，新疆雪莲毛状根的不定芽再生频率高且不定芽生长健壮。再生苗在MS+BA1.0 mg/L+NAA0.1 mg/L的培养基上继代培养生长量较大，经过20 d的培养，35S-chi转基因新疆雪莲再生苗株系（C17、C27、C46）、对照再生苗（Control-1）和正常试管苗（Control-2）之间生长量差异不显著，增殖倍数都在7倍左右;实验还发现，毛状根再生苗比各自来源的毛状根的芹菜素和总黄酮含量下降了20-30%，但转基因再生苗的芹菜素和总黄酮含量比Control-1和Control-2都有显著提高，其中C46芹菜素和总黄酮含量分别为1.86 mg/g 干重和37.3 mg/g干重，分别是Control-1的12倍和 2.4 倍，Control-2的4 倍和1.6倍。这些结果表明由毛状根诱导出的再生苗可作为增强目标次生代谢产物生产的另外一个有效来源。 　　

Stejnulxin, a novel snake C-type lectin-like protein from Trimeresurus stejnegeri venom is a potent platelet agonist acting specifically via GPVl

Stejnulxin, a novel snake C-type lectin-like protein with potent platelet activating activity, was purified and characterized from Trimeresurus stejnegeri venom. Under non-reducing conditions, it migrated on a SDS-polyacrylamide gel with an apparent molecular mass of 120 kDa. On reduction, it separated into three polypeptide subunits with apparent molecular masses of 16 kDa (alpha), 20 kDa (beta(1)) and 22 kDa (beta(2)), respectively. The complete amino acid sequences of its subunits were deduced from cloned cDNAs. The N-terminal sequencing and cDNA cloning indicated that beta(1) and beta(2) subunits of stejnulxin have identical amino acid sequences and each contains two N-glycosylation sites. Accordingly, the molecular mass difference between 1 and 2 is caused by glycosylation heterogenity. The subunit amino acid sequences of stejnulxin are similar to those of convulxin, with sequence identities of 52.6% and 66.4% for the U. and beta, respectively. Stejnulxin induced human platelet aggregation in a dose-dependent manner. Antibodies against UNA inhibited the aggregation response to stejnulxin, indicating that activation of alpha(IIb)beta(3) and binding of fibrinogen are involved in stejnulxin-induced platelet aggregation. Antibodies against GPIbalpha or alpha(2)beta(1) as well as echicetin or rhodocetin had no significant effect on stejnulxin-induced platelet aggregation. However, platelet activation induced by stejnulxin was blocked by anti-GPVI antibodies. In addition, stejnulxin induced a tyrosine phosphorylation profile in platelets that resembled that produced by convulxin. Biotinylated stejnulxin bound specifically to platelet membrane GPVI.

Substitution of live feed by formulated diet: effect on the growth and survival of Betta splendens (Regan) fry

The present work evaluates the effectiveness of partial or total replacement of live feed (LF) (Tubifex) together with formulated diet (FD) for Betta splendens. Three hundred Betta splendens fry of uniform size (mean weight 0.19±0.01g) were equally distributed in five treatment groups with three replicates in glass aquaria of 351itre capacity. Fishes were given diets at different ratio of LF and FD viz. T1(C) 100% LF; T2 75% LF, 25% FD; T3 50% LF, 50% FD; T4 25% LF, 75% FD and T5 100% FD and the experiment continued for 105 days. T2 group registered highest (P<0.05) % body weight gain (125.61±0.26) and specific growth rate (2.34±0.02), which was similar to T1 and T3 groups. Lowest FCR was recorded in T2 (2.40±0.11) group, which was similar to Tl, T3 and T4 groups. Highest (P<0.05) PER was observed in T4 (1.00±0.03) group, which was similar to T3 and T5 groups. At the end of experiment, highest % survival was recoded in T1, T2 and T3 groups (96.67±1.67), which was similar to T4 group. From the study, it is concluded that LF can be successfully replaced up to 75% by FD without any adverse effect on the growth and survival of Betta splendens.