Protocols for conducting dolphin capture-release health assessment studies

Marine mammals, such as dolphins, can serve as key indicator species in coastal areas by reflecting the effects of natural and anthropogenic stressors. As such they are often considered sentinels of environmental and ecosystem health (Bossart 2006; Wells et al. 2004; Fair and Becker 2000). The bottlenose dolphin is an apex predator and a key component of many estuarine environments in the southeastern United States (Woodward-Clyde Consultants 1994; SCDNR 2005). Health assessments of dolphins are especially critical in areas where populations are depleted, show signs of epidemic disease and/or high mortality and/or where habitat is being altered or impacted by human activities. Recent assessments of environmental conditions in the Indian River Lagoon, Florida (IRL) and the estuarine waters surrounding Charleston, South Carolina (CHS) highlight the need for studies of the health of local bottlenose dolphins. While the condition of southeastern estuaries was rated as fair in the National Coastal Condition Report (U.S. EPA 2001), it was noted that the IRL was characterized by poorer than expected benthic communities, significant sediment toxicity and increased nutrient concentrations. Similarly, portions of the CHS estuary have sediment concentrations of aliphatic aromatic hydrocarbons, select inorganic metals, and some persistent pesticides far in excess of reported bioeffect levels (Hyland et al. 1998). Long-term trends in water quality monitoring and recent scientific research suggest that waste load assimilation, non-point source runoff impacts, contaminated sediments, and toxic pollutants are key issues in the CHS estuary system. Several ‘hot spots’ with high levels of heavy metals and organic compounds have been identified (Van Dolah et al. 2004). High concentrations of anthropogenic trace metals, polychlorinated biphenyls (PCB’s) and pesticides have been found in the sediments of Charleston Harbor, as well as the Ashley and Cooper Rivers (Long et al. 1998). Two superfund sites are located within the CHS estuary and the key contaminants of concern associated with these sites are: polycyclic aromatic hydrocarbons (PAH), lead, chromium, copper, arsenic, zinc and dioxin. Concerns related to the overall health of IRL dolphins and dermatologic disease observed in many dolphins in the area (Bossart et al. 2003) initiated an investigation of potential factors which may have impacted dolphin health. From May-August 2001, 35 bottlenose dolphins died in the IRL during an unusual mortality event (MMC 2003). Many of these dolphins were diagnosed with a variety of skin lesions including proliferative ulcerative dermatitis due to protozoa and fungi, dolphin pox and a vesicular dermatopathy of unknown etiology (Bossart et al. 2003). Multiple species from fish to dolphins in the IRL system have exhibited skin lesions of various known and unknown etiologies (Kane et al. 2000; Bossart et al. 2003; Reif et al. 2006). On-going photo-identification (photo-ID) studies have documented skin diseases in IRL dolphins (Mazzoil et al. 2005). In addition, up to 70% of green sea turtles in the IRL exhibit fibropapillomas, with the highest rates of occurrence being seen in turtles from the southern IRL (Hirama 2001).

Isolation, purification, and full NMR assignments of cyclopamine from Veratrum californicum

The Hedgehog signaling pathway is essential for embryogenesis and for tissue homeostasis in the adult. However, it may induce malignancies in a number of tissues when constitutively activated, and it may also have a role in other forms of normal and maladaptive growth. Cyclopamine, a naturally occurring steroidal alkaloid, specifically inhibits the Hedgehog pathway by binding directly to Smoothened, an important Hedgehog response element. To use cyclopamine as a tool to explore and/or inhibit the Hedgehog pathway in vivo, a substantial quantity is required, and as a practical matter cyclopamine has been effectively unavailable for usage in animals larger than mice.

水稻减数分裂基因OsDMC1的功能研究

减数分裂是有性生殖物种世代交替的转折点;减数分裂不仅维持了基因组的稳定性，而且通过重组创造了遗传多样性。在减数分裂过程中，DNA复制一次后进行两次连续的细胞分裂。第二次减数分裂与有丝分裂类似，涉及到姊妹染色单体的分离;而第一次减数分裂是独一无二的，在这次分裂中同源染色体分离。为保证同源染色体的准确分离，同源染色体在减数分裂前期I通过一系列复杂的过程结合在一起形成稳定的二价体。这些复杂的前期I事件包括同源配对、联会和重组。分子遗传学、细胞学和生物化学研究已经表明酵母DMC1基因在减数分裂重组、配对和联会过程中起了重要作用。OsDMC1基因是酵母DMC1基因在水稻中的同源基因。本课题应用RNA干扰技术分析了该基因在水稻生长发育过程中的功能。利用本实验室设计的RNAi工具载体pWTC605构建OsDMC1-RNAi载体;并通过农杆菌介导的水稻愈伤组织转化法获得了转基因株系;进而通过PCR和Southern杂交鉴定筛选出阳性的OsDMC1-RNAi株系。OsDMC1-RNAi株系的营养生长正常，但结实率显著降低;成熟花粉的Alexander染色显示这些OsDMC1-RNAi株系的花粉是败育的。通过内源OsDMC1基因表达量的半定量RT-PCR、Western杂交分析以及OsDMC1特异性small RNA的Northern杂交鉴定，证实OsDMC1-RNAi株系的不育表型与RNA干扰介导的内源OsDMC1 mRNA和蛋白水平的降低是相关的。进一步深入的细胞学观察显示，OsDMC1基因的knockdown导致OsDMC1-RNAi株系的雄性减数分裂异常，表现为二价体形成缺陷、染色体不等分分离和异常四分体的产生;OsDMC1基因的knockdown同时还诱导了雄性减数分裂进程的改变。荧光原位杂交实验揭示OsDMC1-RNAi株系的减数分裂同源配对过程是缺陷的。这些研究结果表明OsDMC1基因是水稻减数分裂的必需基因，该基因在减数分裂同源配对过程中起了重要作用。

Observations on the mating behavior, spawn mass and larval development of Hydatina physis Linne, 1758 (Cephalaspidea: Hydatinidae) from Karachi

Reproduction of Hydatina physis was studied in a population from Karachi, Pakistan, including mating and egg laying behavior, spawn characteristics and development.Individuals first appear in the field in October and remain until March. The spawning occurs from mid-November till mid-February with a peak in December. During this period the individuals were also observed pairing. In captivity, mating lasts for 30 minutes, second mating occurs two days later. Oviposition occurs in a very interesting and unusual manner. The mother turns "up-side-down" with its food fully expanded and the shell completely hidden underneath, the expanded foot serves as protective cover to the eggs. Eggs are deposited in a complexly folded mass with a short stem and an adhesive disc. Capsules, arranged in a single layer, contain 4-6 eggs each of wich is 70 um in diameter. Development is planktotrophic and veligers hatch after 14 days at a temperature of 26-28 degrees Celsius.

Single-photon detection using a quantum dot field effect transistor

A novel device for detection of single photons based on a GaAs/AlGaAs modulation doped field effect transistor (MODFET) which does not rely on avalanche processes is proposed. The optimal channel electron densities and quantum dot parameters for detection of single photons are discussed.

Acute rejection is associated with antibodies to non-Gal antigens in baboons using Gal-knockout pig kidneys

We transplanted kidneys from alpha 1,3-galactosyltransferase knockout (GalT-KO) pigs into six baboons using two different immunosuppressive regimens, but most of the baboons died from severe acute humoral xenograft rejection. Circulating induced antibodies to non-Gal antigens were markedly elevated at rejection, which mediated strong complement-dependent cytotoxicity against GaIT-KO porcine target cells. These data suggest that antibodies to non-Gal antigens will present an additional barrier to transplantation of organs from GaIT-KO pigs to humans.

Spawning behaviour and induced breeding of an estuarine catfish, Mystus gulio (Ham.)

Spawning behaviour of hormone induced estuarine catfish, Mystus gulio was observed in captive condition. Spawning activities that include pairing, chasing and resting, nudging, and twisting, started about 5 hours post injection and ended with release of eggs within 1-2 hours of courtship. Three different dosages of "ovaprim" (1 ml/kg, 1.5 ml/kg, and 2 ml/kg in a single dose) were used in induced breeding of M gulio. The latency period was less (6-7 hours) with the dose of 1.5 and 2 ml/kg, while it was more (7-8 hours) with that of 1 ml/kg. However, all females spawned successfully with each of three different dosages, without any significant differences in the rate of fertilization and hatching. Eggs under all hormone dosages hatched between 18-20 hours after spawning. The hatching rate with 1, 1.5, and 2 ml/kg varied from 71.3-72.7%, corresponding to the fertilization rate of 80.7-84.7%.

Irregular morphine administration affects the retention but not acquisition of conditioned place preference in rats

Drug addiction is increasingly viewed as the expression of abnormal associative learning following repeated exposures to the drugs of abuse Previous I studies have demonstrated that the patterns of repetition such as frequency and spacing are important to many kinds of learning and memory retention We hypothesized that drug repetition pattern might affect the reward-related learning although the total doses of the drug were the same. In the present study, we tested morphine-induced place preference following either regular or irregular pattern of morphine pairing in rats Regular morphine group received morphine administration daily at a regular time with the same dose Irregular morphine groups received morphine administration either at the same time but irregular doses, irregular time but same dose, or irregular time and irregular doses. We found that rats, who received irregular morphine pairing, exhibited similar acquisition of peace preference but different preference retentions compared with regular morphine-treated rats after the same total dose of morphine Rats, who received morphine administration at the same time but irregular doses and at irregular time and irregular doses, showed rapid disruption of place preference than the regular morphine group. Rats, who received morphine at irregular time but the same dose, showed similar retention of place preference to regular morphine group Our results suggest that the pattern of drug pairing plays an important role in the retention of reward-related memory This study may provide new evidence to broaden our understanding of the development and maintenance of drug craving (C) 2009 Elsevier B V. All rights reserved