Genetics of sleep and sleep disorders

Genetic factors affect sleep. Studies in twin pairs demonstrate that the strong hereditary influences on sleep architecture and some sleep disorders are transmitted through families. Evidence like this strongly suggests that sleep regulation receives significant influence from genetic factors. Although recent molecular technologies have revealed evidence that genetic traits or gene products trigger particular changes in sleep electroencephalogram activity, we are still far from finding candidate genes or multiple mutations responsible for individual sleep disorders. Sleep is a very complex phenotype. Genetic susceptibility and environmental factors should be also considered as contributors to sleep phenotype. The aim of this review is to present a current summary and future prospects for genetic studies on sleep and selected sleep-associated disorders. An erratum to this article is available at .     

对家族性甲状腺机能亢进症的初步研究

本文是对一家族内7例甲状腺机能亢进症的发病病因及遗传方式进行研究和探讨。     

Quantitative genetics of zooplankton life histories

Quantitative genetic techniques are powerful tools for use in understanding the microevolutionary process. Because of their size, lifespan, and ease of culture, many zooplankton species are ideal for quantitative genetic approaches. As model systems, studies of zooplankton life histories are becoming increasingly used for examination of the central paradigms of evolutionary theory. Two of the fundamental empirical questions that zooplankton quantitative genetics studies can answer are: 1) How much genetic variance exists in natural populations for life history traits? 2) What is the empirical evidence for trade-offs that permeate life history theory based on optimality approaches? A review of existing data onDaphnia indicates substantial genetic variance for body size, clutch size, and age at first reproduction. Average broad-sense heritabilities for these three characters across 19 populations of 6 species are 0.31, 0.31, and 0.34, respectively. Although there is some discrepancy between the two pertinent studies that were designed to decompose the total genetic variance into its additive and non-additive components, a crude average seems to suggest that approximately 60% of the total genetic variance has an additive basis. The existing data are somewhat inconsistent with respect to presence/absence of trade-offs (negative genetic correlations) among life history traits. A composite of the existing data seems to argue against the existence of strong trade-offs between offspring size and offspring number, between present and future reproduction, and between developmental rate and fecundity. However, there is some evidence for a shift toward more negative (less positive) covariances in more stressful environments (e.g., low food). Zooplankton will prove to be very useful in future study in several important areas of research, including the genetics and physiology of aging, the importance of genotype-environment interaction for life history traits, and the evolution of phenotypic plasticity.     

某些拓扑空间遗传性的反例

遗传性是一般拓扑学中研究的重要问题之一.通过构造典型实例,探究了一般拓扑学中某些不具有遗传性质的拓扑空间     

日本沼虾家系的初步构建及生长相关性状的遗传力估计

以日本沼虾太湖野生群体为亲本,采用不平衡巢式设计方法,每尾雄性日本沼虾配对5尾雌性日本沼虾,构建了4个父系半同胞家系和8个母系全同胞家系,并应用半同胞组内相关分析法估计了日本沼虾孵化后65 d和97 d体长、腹部长和体重的遗传力。结果表明:(1)各家系幼体培育成活率为13.52%~25.24%,每个家系平均产生92尾仔虾;孵化后65d和97d的养殖成活率分别为82.18%、57.88%;各家系雌性个体占绝大多数,雌雄比为1:0.01~0.08;孵化65d有部分个体开始抱卵繁殖,抱卵比例在1.75%~20.51%之间。(2)孵化后65 d和97 d体长、腹部长和体重的狭义遗传力估计值分别为0.082~0.180、0.075~0.160和0.125~0.213,其中以母系同胞方差估计的遗传力最高,父系半同胞估计的遗传力最低。初步结果显示,日本沼虾生长性状较适合进行家系选择或群体间杂交,但由于受个体抱卵率、成活率及育种设施等限制,进行大规模家系育种难度较大。