Fibulin-5/DANCE is essential for elastogenesis in vivo.

The elastic fibre system has a principal role in the structure and function of various types of organs that require elasticity, such as large arteries, lung and skin. Although elastic fibres are known to be composed of microfibril proteins (for example, fibrillins and latent transforming growth factor (TGF)-beta-binding proteins) and polymerized elastin, the mechanism of their assembly and development is not well understood. Here we report that fibulin-5 (also known as DANCE), a recently discovered integrin ligand, is an essential determinant of elastic fibre organization. fibulin-5-/- mice generated by gene targeting exhibit a severely disorganized elastic fibre system throughout the body. fibulin-5-/- mice survive to adulthood, but have a tortuous aorta with loss of compliance, severe emphysema, and loose skin (cutis laxa). These tissues contain fragmented elastin without an increase of elastase activity, indicating defective development of elastic fibres. Fibulin-5 interacts directly with elastic fibres in vitro, and serves as a ligand for cell surface integrins alphavbeta3, alphavbeta5 and alpha9beta1 through its amino-terminal domain. Thus, fibulin-5 may provide anchorage of elastic fibres to cells, thereby acting to stabilize and organize elastic fibres in the skin, lung and vasculature.     

Role of Staphylococcus protease in the development of influenza pneumonia

In influenza the combined virus-bacterial pneumonia is approximately three times more common than primary viral pneumonia. The bacteria most commonly involved are Staphylococcus aureus, Streptococcus pneumoniae and Haemophilus influenzae. S. aureus co-infection is reported to have a fatality rate of up to 42% (ref. 2). It is thought that virus infection in the respiratory tract favours growth conditions for bacteria. In this letter data are presented which show that some S. aureus strains secrete a protease which exerts a decisive influence on the outcome of influenza virus infection in mice by cleavage activation of the virus haemagglutinin.     

Molecular evidence on evolutionary switching from particle-feeding to sophisticated carnivory in the calanoid copepod family Heterorhabdidae: drastic and rapid changes in functions of homologues

The oceanic calanoid copepod family Heterorhabdidae is unique in that it comprises both particle-feeding and carnivorous genera with some intermediate taxa. Both morphological and molecular (nuclear 18S and 28S rRNA) phylogenetic analyses of the family suggest that an evolutionary switch in feeding strategy, from transitions of typical particle-feeding through some intermediate modes to sophisticated carnivory, might have occurred with the development of a specially designed ‘poison’ injection system. In view of the small amount of genetic differentiation among genera in this family, the switching of feeding modes and re-colonization from deep to shallow waters might have occurred over a short geological period since the Middle to Late Miocene.     

A new cell line (XTY) from a tumor of Xenopus laevis.

A new cell line (XTY) was derived from a tumor of a female Xenopus laevis. This cell line has been proliferating in standard amphibian culture medium for more than 4 years (470 generations) and has a doubling time of 75.5 h at 25 degrees C. The cells aggregate into large groups, and their stellate morphology and the expression of desmin demonstrated by immunocytochemistry suggest that their origin is not epithelial.     

A new cell line (XTY) from a tumor ofXenopus laevis

A new cell line (XTY) was derived from a tumor of a femaleXenopus laevis. This cell line has been proliferating in standard amphibian culture medium for more than 4 years (470 generations) and has a doubling time of 75.5 h at 25°C. The cells aggregate into large groups, and their stellate morphology and the expression of desmin demonstrated by immunocytochemistry suggest that their origin is not epithelial.     

利用近红外彩色成像技术监测松萎蔫病 Katsunori Nakamura, Mamoru Takehana, Tsuneo Itagaki, Hayato Tashiro,Kazumasa Ohta,Osamu Nakakita

有效监测患病株方法的缺失是导致对松萎蔫病难以成功控制的主要原因之一。利用航空手段调查该病导致的针叶颜色变化已被证明是一种可靠的方法。为了克服该方法固有的缺点，笔者引用了近红外彩色胶片航拍方法。该项技术在获得正摄航拍图像时，通过图像处理可以增强松针颜色变化，获得较直接拍摄图像更明显的色差。因为图像可以在室内仔细处理，因此能解决飞行时间缺乏等问题。但是，该方法也存在对被压木无法获得其影像而漏检的缺陷。笔者研发的计算机软件可以将目标树标记在计算机图像文件上，并且标记树的地理位置数据和背景航拍图像并传输到装有内置GPS接收器的掌上电脑中，借助软件产生的图像导航定位系统，有利于地面接近标记树，从而可以现场检查和校正标记树的数据，并将修正数据传回至主机。此方法利用最新航拍图像技术建立对每株树处理和管理的连续资料，大大改善了防控松萎蔫病的措施。     

Alymphoplasia is caused by a point mutation in the mouse gene encoding Nf-kappa b-inducing kinase.

The alymphoplasia (aly) mutation of mouse is autosomal recessive and characterized by the systemic absence of lymph nodes (LN) and Peyer's patches (PP) and disorganized splenic and thymic structures with immunodeficiency. Although recent reports have shown that the interaction between lymphotoxin (LT) and the LT beta-receptor (Ltbeta r, encoded by Ltbr) provides a critical signal for LN genesis in mice, the aly locus on chromosome 11 is distinct from those for LT and its receptor. We found that the aly allele carries a point mutation causing an amino acid substitution in the carboxy-terminal interaction domain of Nf-kappa b-inducing kinase (Nik, encoded by the gene Nik). Transgenic complementation with wild-type Nik restored the normal structures of LN, PP, spleen and thymus, and the normal immune response in aly/aly mice. In addition, the aly mutation in a kinase domain-truncated Nik abolished its dominant-negative effect on Nf-kappa b activation induced by an excess of Ltbeta r. Our observations agree with previous reports that Ltbeta r-deficient mice showed defects in LN genesis and that Nik is a common mediator of Nf-kappa b activation by the tumour necrosis factor (TNF) receptor family. Nik is able to interact with members of the TRAF family (Traf1, 2, 3, 5 and 6), suggesting it acts downstream of TRAF-associating receptor signalling pathways, including Tnfr, Cd40, Cd30 and Ltbeta r. The phenotypes of aly/aly mice are more severe than those of Ltbr-/- mice, however, indicating involvement of Nik in signal transduction mediated by other receptors.     

NMDA-receptor-mediated, cell-specific integration of new neurons in adult dentate gyrus

New neurons are continuously integrated into existing neural circuits in adult dentate gyrus of the mammalian brain. Accumulating evidence indicates that these new neurons are involved in learning and memory. A substantial fraction of newly born neurons die before they mature and the survival of new neurons is regulated in an experience-dependent manner, raising the possibility that the selective survival or death of new neurons has a direct role in a process of learning and memory--such as information storage--through the information-specific construction of new circuits. However, a critical assumption of this hypothesis is that the survival or death decision of new neurons is information-specific. Because neurons receive their information primarily through their input synaptic activity, we investigated whether the survival of new neurons is regulated by input activity in a cell-specific manner. Here we developed a retrovirus-mediated, single-cell gene knockout technique in mice and showed that the survival of new neurons is competitively regulated by their own NMDA-type glutamate receptor during a short, critical period soon after neuronal birth. This finding indicates that the survival of new neurons and the resulting formation of new circuits are regulated in an input-dependent, cell-specific manner. Therefore, the circuits formed by new neurons may represent information associated with input activity within a short time window in the critical period. This information-specific addition of new circuits through selective survival or death of new neurons may be a unique attribute of new neurons that enables them to play a critical role in learning and memory.     

利用近红外彩色成像技术监测松萎蔫病

有效监测患病株方法的缺失是导致对松萎蔫病难以成功控制的主要原因之一.利用航空手段调查该病导致的针叶颜色变化已被证明是一种可靠的方法.为了克服该方法固有的缺点,笔者引用了近红外彩色胶片航拍方法.该项技术在获得正摄航拍图像时,通过图像处理可以增强松针颜色变化,获得较直接拍摄图像更明显的色差.因为图像可以在室内仔细处理,因此能解决飞行时间缺乏等问题.但是,该方法也存在对被压木无法获得其影像而漏检的缺陷.笔者研发的计算机软件可以将目标树标记在计算机图像文件上,并且标记树的地理位置数据和背景航拍图像并传输到装有内置GPS接收器的掌上电脑中,借助软件产生的图像导航定位系统,有利于地面接近标记树,从而可以现场检查和校正标记树的数据,并将修正数据传回至主机.此方法利用最新航拍图像技术建立对每株树处理和管理的连续资料,大大改善了防控松萎蔫病的措施.