Parental origin of mutations of the retinoblastoma gene

Retinoblastoma and osteosarcoma arise from cells that have lost both functional copies of the retinoblastoma gene. Using the cloned retinoblastoma gene and other linked polymorphic loci, it is possible to reconstruct the sequential loss of the two homologous gene copies that precedes the development of these tumours. In non-hereditary tumours, the loss of each of the two homologues occurs somatically; in hereditary cases, the initial mutation is in the germline. Recently, Toguchida et al. reported that the paternally derived copy is preferentially the first one to become mutant during the genesis of non-hereditary osteosarcomas. We report here a similar analysis of patients with retinoblastoma in which we find no such predilection for initial somatic mutations. In contrast, when an initial mutation was a new germline mutation, it was derived from the father, a result which is consistent with new germline mutations arising primarily during spermatogenesis.     

Paternal inheritance of mitochondrial DNA in mice.

For nearly 20 years it has been assumed on the basis of low-resolution experiments that mitochondrial (mt)DNA, in contrast to the genes in the nucleus, has an exclusively maternal mode of inheritance in animals. Using the polymerase chain reaction, paternally inherited mtDNA molecules have now been detected in mice at a frequency of 10(-4), relative to the maternal contributions. These mice were hybrids between two inbred strains (C57BL/6J and Mus spretus) whose mtDNAs can be distinguished easily. This new mode of inheritance provides a mechanism for generating heteroplasmy and may explain mitochondrial disorders exhibiting biparental transmission.     

On the origin of printing in the light of new archaeological discoveries

30 years have pas. since a printeddhārani sūtra scroll was discovered in 1966 in Kyongju. Korea. However. there have been different views about the date and place of its printing and publication in Korea and abroad. Some Korean scholars think that it was translated into Chinese from Sanskrit in 704 in China and printed during 706–751 in the Silla period in Korea. After a further research it is now proved that this sutra was translated into Chinese in 701 and printed in the following year, 702, in Luoyang, during the reign of Empress Wu. This shows that the sutra could not have been printed in the Silla period. The discoveries of theSnddharma pundarik sūtra printed during 690–699 and the Sanskritdharani charm printed around 650–670 in China also show that thedhārani sutra found in Korea is not the earliest one. Both literary records and archaeological findings prove that printing originated in China.     

蠕虫状灰岩成因新解

本文根据蠕虫状灰岩的岩石分类学特征、沉积特征和沉积组合特征,分析了蠕虫状灰岩的形成机理,提出与前人不同的成因观点.认为蠕虫状灰岩的形成与风暴浊流作用有关,实际上是一种特殊类型的风暴岩.     

幼儿园男童性格认同调查分析

父亲和母亲对孩子的影响分别有着不可替代的作用。同样在学前教育领域,父性和母性的影响也应是同等重要,不能相互取代。目前,由于全国的学前教育中男性比例的严重偏低,以及幼儿园的管理教学意识等问题而导致男性幼儿女性化的现象已日渐普遍。缺乏父性教育的结果将直接造成幼儿的受挫能力、主动性、冒险精神、竞争意识等性格严重缺失。     

民间故事:现代小说的父体基因

现代小说的“本源”在哪里?本文从形态美学、虚构性要求、民间立场和“共相”四个方面论证了现代小说的父体基因是民间故事。     

Paternal inheritance of a female moth's mating preference

Females of the arctiid moth Utetheisa ornatrix mate preferentially with larger males, receiving both direct phenotypic and indirect genetic benefits. Here we demonstrate that the female's mating preference is inherited through the father rather than the mother, indicating that the preference gene or genes lie mostly or exclusively on the Z sex chromosome, which is strictly paternally inherited by daughters. Furthermore, we show that the preferred male trait and the female preference for that trait are correlated, as females with larger fathers have a stronger preference for larger males. These findings are predicted by the protected invasion theory, which asserts that male homogametic sex chromosome systems (ZZ/ZW) found in lepidopterans and birds promote the evolution of exaggerated male traits through sexual selection. Specifically, the theory predicts that, because female preference alleles arising on the Z chromosome are transmitted to all sons that have the father's attractive trait rather than to only a fraction of the sons, such alleles will experience stronger positive selection and be less vulnerable to chance loss than would autosomal alleles.     

A new feathered maniraptoran dinosaur fossil that fills a morphological gap in avian origin

Recent fossil discoveries have substantially reduced the morphological gap between non-avian and avian dinosaurs, yet avians including Archaeopteryx differ from non-avian theropods in their limb proportions. In particular, avians have proportionally longer and more robust forelimbs that are capable of supporting a large aerodynamic surface. Here we report on a new maniraptoran dinosaur, Anchiornis huxleyi gen. et sp. nov., based on a specimen collected from lacustrine deposits of uncertain age in western Liaoning, China. With an estimated mass of 110 grams, Anchiornis is the smallest known non-avian theropod dinosaur. It exhibits some wrist features indicative of high mobility, presaging the wing-folding mechanisms seen in more derived birds and suggesting rapid evolution of the carpus. Otherwise, Anchiornis is intermediate in general morphology between non-avian and avian dinosaurs, particularly with regard to relative forelimb length and thickness, and represents a transitional step toward the avian condition. In contrast with some recent comprehensive phylogenetic analyses, our phylogenetic analysis incorporates subtle morphological variations and recovers a conventional result supporting the monophyly of Avialae. Supported by Hundred Talents Project of the Chinese Academy of Sciences, National Natural Science Foundation of China (Grant Nos. 40125006, 40472018), and National Basic Research Program of China (Grant No. 2006CB806400)     

Three new types of viral oncogene of cellular origin specific for haematopoietic cell transformation.

The RNAs of seven replication-defective leukaemia virus (DLV) strains contain three types of unique sequences, which correlate with the capacity of a given virus strain to transform erythroblasts, macrophage-like cells and myeloblasts, respectively. These sequences, termed erb, mac and myb, have their counterparts in the normal DNA of avian and mammalian species. Our results indicate that DLVs represent recombinants between a common 'vector' related to a chicken endogenous virus and one of three types of cellular gene possibly involved in haematopoietic differentiation.     

Differential regulation of rasGAP and neurofibromatosis gene product activities

The ras-encoded p21ras proteins bind GTP very tightly, but catalyse hydrolysis to GDP very slowly. In humans, two genes encode proteins that stimulate this GTPase activity (GAP, or GTPase-activating proteins), one of relative molecular mass 120,000, referred to as p120-GAP, and another NF1-GAP, which is encoded by the neurofibromatosis type-1 gene. Both GAPs are widely expressed in mammalian tissues. Here we show that although they will both bind oncogenic mutants of p21ras, neither will stimulate their GTPase activity. NF1-GAP binds to the p21ras proteins up to 300 times more efficiently than p120-GAP. The two GAPs are inhibited to different extents by certain lipids: micromolar concentrations of arachidonate, phosphatidate and phosphatidylinositol-4,5-bisphosphate affect only NF1-GAP. This inhibition does not compete with p21ras, and lipid-inactivated NF1-GAP can still bind p21ras. We used the detergent dodecyl maltoside, which inhibits only NF1-GAP, to distinguish between the two activities in cell extracts and found both types present together in several mammalian cell lines. In contrast, GAP activity in extracts of Xenopus oocytes was not affected by dodecyl maltoside. By these criteria, the mammalian cells contain both GAP activities and the oocytes have only p120-like GAP activity. These results indicate that more than one GAP regulates p21ras in the same cell.     

Cells of origin in cancer

Both solid tumours and leukaemias show considerable histological and functional heterogeneity. It is widely accepted that genetic lesions have a major role in determining tumour phenotype, but evidence is also accumulating that cancers of distinct subtypes within an organ may derive from different 'cells of origin'. These cells acquire the first genetic hit or hits that culminate in the initiation of cancer. The identification of these crucial target cell populations may allow earlier detection of malignancies and better prediction of tumour behaviour, and ultimately may lead to preventive therapies for individuals at high risk of developing cancer.     

农大1号板栗授粉品种的择优研究

以阳山油栗等6个板栗品种为父本,对农大1号板栗（Castanea mollissima B1．cu．Nongdnyihao）授粉品种的花期相遇情况、花粉量、座果率和花粉直感现象等进行了研究。结果表明：阳山油栗雄花盛花期与农大1号板栗雌花相遇期为4d,铁粒头为3d,双季栗、河源油栗和韶栗18号都为2d;雄花长度及重量、花粉量的大小依次为：阳山油栗,铁粒头,双季栗,农大1号;以铁粒头作为授粉树的农大1号结实率最高,以双季栗为授粉树的次之。花粉直感现象对坚果单粒重存在一定影响。综合各种性状认为,铁粒头、韶栗18号和河源油栗是农大1号板栗的优良授粉品种。     

凉山彝族父权制与等级内婚制

凉山彝族为世系继承的幼子继承制，男女在政治上和经济上都处于不平等的地位，在婚姻上实行同族内婚、等级内婚、家支外婚，同等级内存在等弟差别和变相的买卖婚姻。     

The Lantian biota: A new window onto the origin and early evolution of multicellular organisms

The Lantian biota at the Lantian Town of Xiuning County,Anhui Province,is preserved in black shales of the Ediacaran Lantian Formation.It yields some of the oldest known complex macroorganisms,including fan-shaped seaweeds and possible animal fossils with tentacles and intestinal-like structures reminiscent of modern coelenterates and bilaterians.The Lantian Lagerst tte sheds new light on the origin and early evolution of multicellular organisms in relatively quiet and deep environments soon after the Neoproterozoic Marinoan glaciation.The morphological complexity and diversity of early multicellular organisms may be closely related to sexual reproduction and alternation of generations.The fluctuation of oceanic redox conditions during this period may have played a role in the ecology and preservation of the Lantian biota.     

Mechanism for the learning deficits in a mouse model of neurofibromatosis type 1.

Neurofibromatosis type I (NF1) is one of the most common single-gene disorders that causes learning deficits in humans. Mice carrying a heterozygous null mutation of the Nfl gene (Nfl(+/-) show important features of the learning deficits associated with NF1 (ref. 2). Although neurofibromin has several known properties and functions, including Ras GTPase-activating protein activity, adenylyl cyclase modulation and microtubule binding, it is unclear which of these are essential for learning in mice and humans. Here we show that the learning deficits of Nf1(+/-) mice can be rescued by genetic and pharmacological manipulations that decrease Ras function. We also show that the Nf1(+/-) mice have increased GABA (gamma-amino butyric acid)-mediated inhibition and specific deficits in long-term potentiation, both of which can be reversed by decreasing Ras function. Our results indicate that the learning deficits associated with NF1 may be caused by excessive Ras activity, which leads to impairments in long-term potentiation caused by increased GABA-mediated inhibition. Our findings have implications for the development of treatments for learning deficits associated with NF1.