DNA末端定量及其应用的研究

为定量DNA断裂末端评价DNA的降解程度,以饱和标记(TdT)法定量DNA末端最大标记量(L_max);并用流式细胞分析(FCA)、原位DNA末端标记(TUNEL)和琼脂糖电泳检测或标记DNA降解片段.结果发现: a.TdT法最低检测限5 ng DNA,线性范围为5～5 000 ng,较检测DNA降解片段的琼脂糖电泳敏感200倍以上;b.地塞米松(DEX)诱导淋巴瘤(Raji)细胞凋亡产生的L_max呈DEX剂量与诱导时间依赖性增加;c.自发性高血压大鼠(SHR)心肌的L_max呈年龄依赖性增加并与正常对照鼠(WKY)相比差异非常显著(P＜0.01);d.TdT法定量L_max与FCA、TUNEL或电泳分析的相关性良好(r＞0.98).TdT法定量L_max敏感、特异、准确,可应用于分子生物学、细胞生物学,尤其是细胞凋亡动力学DNA降解评价的定量研究.     

Local Knowledge and Conservation of Seagrasses in the Tamil Nadu State of India

Local knowledge systems are not considered in the conservation of fragile seagrass marine ecosystems. In fact, little is known about the utility of seagrasses in local coastal communities. This is intriguing given that some local communities rely on seagrasses to sustain their livelihoods and have relocated their villages to areas with a rich diversity and abundance of seagrasses. The purpose of this study is to assist in conservation efforts regarding seagrasses through identifying Traditional Ecological Knowledge (TEK) from local knowledge systems of seagrasses from 40 coastal communities along the eastern coast of India. We explore the assemblage of scientific and local traditional knowledge concerning the 1. classification of seagrasses (comparing scientific and traditional classification systems), 2. utility of seagrasses, 3. Traditional Ecological Knowledge (TEK) of seagrasses, and 4. current conservation efforts for seagrass ecosystems. Our results indicate that local knowledge systems consist of a complex classification of seagrass diversity that considers the role of seagrasses in the marine ecosystem. This fine-scaled ethno-classification gives rise to five times the number of taxa (10 species = 50 local ethnotaxa), each with a unique role in the ecosystem and utility within coastal communities, including the use of seagrasses for medicine (e.g., treatment of heart conditions, seasickness, etc.), food (nutritious seeds), fertilizer (nutrient rich biomass) and livestock feed (goats and sheep). Local communities are concerned about the loss of seagrass diversity and have considerable local knowledge that is valuable for conservation and restoration plans. This study serves as a case study example of the depth and breadth of local knowledge systems for a particular ecosystem that is in peril.     

Noradrenaline Artefacts

THE suggestion by Stone¹ that excitatory effects of microionto-phoretically applied noradrenaline in the central nervous system are due to indirect local vascular changes and not to a direct action on the neurone is certainly interesting and whilst we agree that the interpretation of microiontophoretic studies needs caution, we do not believe that Stone's explanation is likely to be true for the following reasons.     

Identification of novel Y chromosome encoded transcripts by testis transcriptome analysis of mice with deletions of the Y chromosome long arm

Background  

The male-specific region of the mouse Y chromosome long arm (MSYq) is comprised largely of repeated DNA, including multiple copies of the spermatid-expressed Ssty gene family. Large deletions of MSYq are associated with sperm head defects for which Ssty deficiency has been presumed to be responsible.     

Roost selection by the north Queensland long-eared bat Nyctophilus bifax in littoral rainforest in the Iluka World Heritage Area,New South Wales

Abstract The aim of this study was to describe the roosts of Nyctophilus bifax in littoral rainforest in Iluka Nature Reserve on the north coast of New South Wales. Radio-telemetry was used to track 17 bats in November 1988 (lactation season) and 11 in May 1989 (mating season) to 87 roosts in 49 trees within the littoral rainforest. The bats frequently changed roosts, which were clustered within a small area. During November, lactating females moved twins between diurnal roosts and some carried twins while foraging. Twins represented a load of up to 95% of their mother's bodyweight. Bats roosted communally in foliage and tree hollows, beneath peeling bark, among epiphytes, and between strangler figs and host trees. Hollows were used more frequently when bats were lactating, while the use of foliage roosts was greater during the mating season. Roosts were concentrated in four tree species, although a wide range of other tree species was used. Roost trees used in November were taller (17m) than those used in May (8. 2 m), and reflect selection of Syzygium leuhmannii and Acmena hemilampra, both trees of the forest interior. The converse applied for selection of Cupaniopsis anacardioides, a small tree of the littoral zone, in May. These results identify the need for conserving a diversity of roosts for this species of bat.