Systematics of white-toothed shrews (Crocidura) (Mammalia: Insectivora: Soricidae) of Taiwan: Karyological and morphological Studies

We define the species boundaries of white-toothed shrews (genus Crocidura ) in Taiwan using karyological and morphological characteristics. Ninety-nine animals were obtained from all over Taiwan at capture rates usually less than 10%. Three species are recognized by distinct cytotypes: Crocidura attenuata tanakae 2n = 40, FN = 56; Crocidura suaveolens hosletti 2n = 40, FN = 50; Crocidura kurodai 2n = 40, FN = 54. A suite of six morphological characters diagnose the three species: shape of skull, position of incisive foramina, shape of fourth upper premolar, shape of pinna, tail vibrissae, and foot pads. A species key and notes on the life history of each species are provided. Finally, we discuss chromosomal evolution and biolgeography of Crocidura in East and South East Asia.     

Mouse {beta}-galactoside {alpha}2,3-sialyltransferases: comparison of in vitro substrate specificities and tissue specific expression

Four types of ß-galactoside     

Identification of three genetic loci controlling leaf senescence in Arabidopsis thaliana

Four mutants that show the delayed leaf senescence phenotype were isolated from Arabidopsis thaliana . Genetic analyses revealed that they are all monogenic recessive mutations and fall into three complementation groups, identifying three genetic loci controlling leaf senescence in Arabidopsis . Mutations in these loci cause delay in all senescence parameters examined, including chlorophyll content, photochemical efficiency of photosystem II, relative amount of the large subunit of Rubisco, and RNase and peroxidase activity. Delay of the senescence symptoms was observed during both age-dependent in planta senescence and dark-induced artificial senescence in all of the mutant plants. The results indicate that the three genes defined by the mutations are key genetic elements controlling functional leaf senescence and provide decisive genetic evidence that leaf senescence is a genetically programmed phenomenon controlled by several monogenic loci in Arabidopsis . The results further suggest that the three genes function at a common step of age-dependent and dark-induced senescence processes. It is further shown that one of the mutations is allelic to ein2-1 , an ethylene-insensitive mutation, confirming the role of ethylene signal transduction pathway in leaf senescence of Arabidopsis .     

New base-altered adenosine analogues: Synthesis and affinity at adenosine A1 and A2A receptors

N⁶-Substituted adenosine analogues containing cyclic hydrazines or chiral hydroxy (ar)alkyl groups, designed to interact with the S2 and S3 receptor subregions, have been synthesized and their binding to the adenosine A₁ and A_2A receptors have been investigated. Examples of both types of compounds were found to exhibit highly selective binding (K_i in low nM range) to the rat A₁ receptor.     

Antitumor agents-CLXXV. Anti-tubulin action of (+)-thiocolchicine prepared by partial synthesis

(+)-Thiocolchicine (2b) was prepared from (±)-colchicine (1) in a five-step reaction sequence that included chromatographic separation of appropriate camphanylated diastereomers. Acid hydrolysis of the (+)-diastereomer, followed by acetylation, yielded the desired product 2b. (+)-Thiocolchicine has 15-fold lower inhibitory activity against tubulin polymerization than (−)-thiocolchicine, and is 29-fold less potent for inhibiting growth of human Burkitt lymphoma cells. The enantiomer 2a, prepared from the (−)-camphanylated diastereomer, had potent activity in all assays comparable to that of (−)-thiocolchicine prepared by other methods. These results support the hypothesis that the proper configuration of colchicine-related compounds is an important requirement for their anti-tubulin action.     

Cloning of cDNA for Vitellogenin of the Parasitoid Wasp, Pimpla nipponica (Hymenoptera: Apocrita: Ichneumonidae): Vitellogenin Primary Structure and Evolutionary Considerations

The cDNA for vitellogenin (Vg) of the parasitoid wasp Pimpla nipponica (Hymenoptera: Apocrita) was cloned and sequenced.¹ The deduced amino acid sequence with 1807 residues was obtained. The N-terminal 20 amino acids chemically determined for vitellin (Vn) agreed completely with the deduced 20 amino acids that follow the 16 amino acid residues for putative signal peptide. The cDNA clone for the Vg of the turnip sawfly Athalia rosae (Hymenoptera: Symphyta), previously obtained and partially sequenced, was also completely sequenced and the amino acid sequence deduced. Amino acid sequences were compared between these two species and also with known Vg sequences from other insects. Common to all these insects is the presence of two long regions with relatively well-conserved amino acid sequences, one near the N-terminal extending 267–282 residues (including two cysteines at conserved locations), and the other starting at position 450 to 655 and extending 279–283 residues, and of a region at the C-terminal extending some 200 residues (about 250 in Aedes aegypti due to the presence of a serine-rich stretch) with 10 cysteines at conserved locations. A molecular phylogenetic tree was constructed.     

Synthesis and antiplatelet, antiinflammatory, and antiallergic activities of 2-substituted 3-chloro-1,4-naphthoquinone derivatives

A series of 2-substituted 3-chloro-1,4-naphthoquinones was synthesized, and the antiplatelet, antiinflammatory, and antiallergic activities of these compounds were evaluated. The structure-activity relationships in this series were also examined. Most of the 2-alkyl/arylcarboxamido derivatives of 3-chloro-1,4-naphthoquinone showed potent activities with similar trends in each of the activities evaluated.     

Marine finfish hatchery technology in the USA – status and future

In 1993, about 52% of the 433 698 tons of thetotal US aquaculture production came from theproduction of freshwater catfish. Excludingsalmonid culture, the percentage of marine finfishculture in total aquaculture production in the UShas been negligible. Commercial scale production ofmarine finfish in hatcheries is very limited in theUS.Studies on eggs and larvae of marine finfishspecies in the US have stemmed from theconsideration of fisheries management rather thanaquaculture. Most of the marine finfish larvaeproduced in the laboratory has been for the purposeof providing materials for other academic relatedstudies. Results of these studies can be applied inthe development of marine finfish hatcherytechnology. Hatchery technology for several marinefinfish species has been developed for stockenhancement, technology transfer and aquaculture. This paper reviews the current hatchery technologyof striped mullet (Mugil cephalus), dolphinfish (Coryphaena hippurus), red drum (Sciaenops ocellatus), and other potentialaquaculture species.