斑马鱼消化器官发育缺陷突变体的遗传筛选

[摘要] 目的 正向遗传筛选斑马鱼肝脏、肠和胆囊发育缺陷突变体。方法 ENU诱变野生型斑马鱼并开展经典的F2代筛选,以lfabp为探针的全胚原位杂交、BES-H2O2-Ac荧光染料分别检测斑马鱼早期胚胎肝脏、肠和胆囊的表型。结果 在128个突变基因组中筛选获得了源自14个F2家族的斑马鱼消化器官发育缺陷突变体品系23个,并按表型划分为6类。结论 斑马鱼肝脏、肠和胆囊的发育调控机制有相似性和差异性。     

The membranous skeleton: the role of cell condensations in vertebrate skeletogenesis

Summary Elements of the vertebrate skeleton are initiated as cell condensations, collectively termed the membranous skeleton whether cartilages or bones by Grüneberg (1963). Condensations, which were identified as the basic cellular units in a recent model of morphological change in development and evolution (Atchley and Hall 1991) are reviewed in this paper. Condensations are initiated either by increased mitotic activity or by aggregation of cells towards a centre. Prechondrogenic (limb bud) and preosteogenic (scierai ossicle) condensations are discussed and contrasted. Both types of skeletogenic condensations arise following epithelial-mesenchymal interactions; condensations are identified as the first cellular product of such tissue interactions. Molecular characteristics of condensations are discussed, including peanut agglutinin lectin, which is used to visualize prechondrogenic condensations, and hyaluronan, hyaladherins, heparan sulphate proteoglycan, chondroitin sulphate proteoglycan, versican, tenascin, syndecan, N-CAM, alkaline phosphatase, retinoic acid and homeobox-containing genes. The importance for the initiation of chondrogenesis or osteogenesis of upper and lower limits to condensation size and the numbers of cells in a condensation are discussed, as illustrated by in vitro studies and by mutant embryos, including Talpid³ in the chick and Brachypod, Congenital hydrocephalus and Phocomelia in the mouse. Evidence that genes specific to the skeletal type are selectively activated at condensation is discussed, as is a recent model involving TGF- and fibronectin in condensation formation. Condensations emerge as a pivotal stage in initiation of the vertebrate skeleton in embryonic development and in the modification of skeletal morphology during evolution.     

柔红霉素和襄樊霉素产生菌突变生物合成的研究

从柔红霉素产生菌SIPI1482和襄樊霉素产生菌SIPI80334诱变获得了阻断突变株SIPI1482-NS-4和SIPI80334-U33。利用这两株突变株,以柔红霉酮和柔红霉素为底物,获得了13-S-双氢柔红霉酮、13-R-双氢柔红霉酮、13-双氢柔红霉素、N-乙酰-柔红霉素和N-乙酰-13-双氢柔红霉素等转化产物。并讨论了不同属蒽环类抗生素产生菌对不同底物的转化特性等。