Genomic organization of the rat aromatic L-amino acid decarboxylase (AADC) locus: Partial analysis reveals divergence from the Drosophila dopa decarboxylase (DDC) gene structure

Aromatic L-amino acid decarboxylase (AADC) is responsible for the conversion of L-3,4-dihydroxyphenylalanine (L-DOPA) and L-5-hydroxytryptophan to dopamine and serotonin, respectively, which are important neurotransmitters. We characterized genomic clones derived from the rat AADC locus by Southern blot and nucleotide sequencing analyses to explore the exonal organization of the gene. Our results suggest that the rat AADC gene is relatively large, containing at least 12 exons and spanning at least 40 kb in the rat genome. In this study, nine exons corresponding to 71% of the published cDNA sequence were identified, the smallest of which was as short as 20 base pairs (bp). In the Drosophila dopa decarboxylase (DDC) gene, the sequences homologous to these nine exons are all present in the fourth exon. This implies that either multiple intron sequences have been added to the vertebrate AADC gene or alternatively, deleted from the invertebrate gene after the divergence of vertebrates and invertebrates during evolution.     

Maternal Transfer and Protective Role of the Alternative Complement Components in Zebrafish Danio rerio

Embryos of most fish develop externally and are exposed to an aquatic environment full of potential pathogens, whereas they have little or only limited ability to mount an efficient and protective response. How fish embryos survive pathogenic attacks remains poorly defined. Here we demonstrate that the maternal immunization of female zebrafish with formalin-killed Aeromonas hydrophila causes a significant increase in C3 and Bf contents in the mother, a corresponding rise in the offspring, and induces a remarkable increase in the hemolytic activities in both the mother and offspring. In addition, the embryos derived from the immunized mother are significantly more tolerant to A. hydrophila challenge than those from the unimmunized fish, and blocking C3 and Bf activities by injection of the antibodies against C3 and Bf into the embryos render them more susceptible to A. hydrophila. These results clearly show that the protection of zebrafish embryos against A. hydrophila can be achieved by the maternally-transferred immunity of the complement system operating via the alternative pathway. This appears to be the first report providing in vivo evidences for the protective role of the alternative complement components in the early embryos of zebrafish, paving the way for insights into the in vivo function of other maternally-transferred factors in fish.     

Construction and characterization of a region-specific microdissection library from human chromosome 2q35-q37.

A region-specific genomic library for human chromosome 2q35-q37 has been constructed using the microdissection and polymerase chain reaction-mediated linker-adaptor microcloning method. Twenty fragments from the chromosome region 2q35-q37 were dissected and a library consisting of 20,000 recombinant microclones was obtained. The insert size ranged between 50 and 800 bp, with a mean of approximately 270 bp. About 50-60% of the microclones contained unique sequences. The microdissection library has been demonstrated to derive from the dissected region 2q35-q37 by chromosome painting using the fluorescence in situ hybridization (FISH) technique. Southern blot analysis of the unique sequence microclones from the library showed that 54% (26/48) of the clones are of human origin and chromosome 2 specific. Four of these microclones have been further mapped to the 2q37 region by using a cell hybrid containing only 2q37. The unique sequence microclones have also been characterized for their insert size and the hybridizing genomic fragments cleaved with HindIII. As shown previously, these microclones will be useful in isolating corresponding yeast artificial chromosome (YAC) clones with large inserts for high-resolution physical mapping and also in screening cDNA libraries to isolate expressed gene sequences as candidate genes to facilitate search for the crucial genes underlying genetic diseases and specific forms of cancer assigned to the region.     

FOUR NEW SPECIES OF COENOSIA MEIGEN (DIPTERA: MUSCIDAE) FROM YUNNAN, CHINA

Abstract  This paper describes four new species of Coenosia Meigen, 1826, namely C. angustifolia sp.nov., C. obscuriabdominis sp. nov., C. sparagmocerca sp. nov. and C. sponsa sp. nov. Type specimens are deposited in Institute of Entomology, Shenyang Normal University, Shenyang, China.     

铽离子与RNA的荧光反应及RNA测定的研究

核糖核酸（ＲＮＡ）与稀土铽离子在ｐＨ５．０～６．５条件下能形成具有较强荧光的络合物,其激发峰在２８８ｎｍ处,发射峰为４９４ｎｍ及５４５ｎｍ处．ＲＮＡ在０．１～１０ｍｇ／Ｌ范围内与其荧光强度呈线性关系,其检出限为６．０×１０￣（－８）ｍｏｌ／Ｌ．腺苷酸,尿苷酸,胞苷酸对ＲＮＡ的干扰比较小,因此可在其存在下选择性地测定ＲＮＡ．     

The sensory functions of the cerebellum of the thornback ray,Platyrhinoidis triseriata

Summary Single unit spikes and evoked field potentials were recorded in different parts and depths of the corpus cerebelli and auricle of immobilized rays before and after stimulating with light, electric fields, touch, tail bending and direct shock to mechanoreceptive nerves of the lateral line.Discrete areas of the cerebellum are responsive to these modalities and the areas show limited overlap; they are all distinct from the area reported by Plassmann to be responsive to angular acceleration. The visual and tactile-proprioceptive areas are large; the electric area is small. Most units are excited only by one modality.The tail is represented only in the posterior lobe; trigeminal innervation extends from the posterior onto the anterior lobe, suggesting some topographic projection.The dynamic characteristics of the responses were examined particulary in the visual units. To a flash, units discharge up to six bursts of spikes in 500 ms. This pattern is reduced at repetition rates > 1/s; above ca. 4/s units tend to fire irregularly. Various kinds of units are found in respect to the succession of responses to short trains of flashes. Some units fire much better to objects moving in a limited visual field with a certain direction and rate.Abbreviation EP evoked potential     

Mechanism of action of the nitrosoureas: formation of 1,2-(diguanosin-7-yl) ethane from the reaction of BCNU (1,3-bis-[2-chloroethyl]-1-nitrosourea) with guanosine

A crosslinked dinucleoside, 1,2-(diguanosin-7-yl) ethane, has been isolated from the reaction of guanosine with the antitumor agent, BCNU. The formation of this product suggests that DNA crosslinking, which may be responsible for the cytotoxicity of BCNU, could occur through such dinucleosides.