Mitochondrial DNA in the Bark Weevils: Size, Structure and Heteroplasmy

Mitochondrial DNA of higher animals has been described as an example of extreme efficiency in genome structure and function. Where exceptionally large size molecules have been found (greater than 20 kb), most have occurred as rare variants within a species, suggesting that these variants arise infrequently and do not persist for long periods in evolutionary time. In contrast, all individuals of at least three species of bark weevil (Curculionidae: Pissodes) possess a mitochondrial genome of unusually large size (30-36 kb). The molecule owes its large size to a dramatically enlarged A + T-rich region (9-13 kb). Gene content and order outside of this region appear to be identical to that found in Drosophila. A series of 0.8-2.0-kb repeated sequences occur adjacent to the large A + T rich region and have perhaps played a role in the generation of the large size as well as an unprecedented frequency of size variant heteroplasmy. Every weevil sampled in all three species (n = 219) exhibits anywhere from two to five distinct size classes of mtDNA. The persistence of this large amount of size polymorphism through two speciation events combined with the abundant size variation within individuals suggests that these molecules may not be subject to strong selection for small overall size and efficiency of replication. This pattern of variation contrasts strongly with the conservation of gene content and arrangement in the coding region of the molecule.     

Role of cell-mediated immunity in the resistance to experimental sporotrichosis in mice

The in vitro activity of several new imidazoles, cloconazole, sulconazole, butoconazole, isoconazole and fenticonazole, were compared with those of amphothericin B, flucytosine, and three azoles: econazole, miconazole and ketoconazole against isolates of pathogenic Candida. A total of 186 clinical isolates of 10 species of the genus Candida and two culture collection strains were tested by an agar-dilution technique. Isoconazole was the most active azole, followed by butoconazole and sulconazole. Differences between some of the species in their susceptibility to the antifungal agents were noted. Sulconazole and cloconazole had the highest activity in vitro against 106 isolates of C. albicans. Butoconazole and isoconazole were also very active against isolates of C. albicans, and were the most active azole compounds against 80 isolates of Candida spp.     

DETERMINATION OF GUSTATORY SUCROSE THRESHOLD IN WATER BY USE OF A LINEAR SUCROSE GRADIENT

A novel experimental method was developed which allows the determination of the threshold concentration of sucrose by use of a linear sucrose gradient in water. With this method a continuous tasting of the test-liquid is possible. A panel of 15 persons experienced in taste-testing was used. Three gradients of different steepness were applied: 0 to 1.5% (w/w) sucrose in 2 min (I), 3 min (II) and 4 min (III). The results of the new method were compared with those of the standard method (DIN). With gradients I and II we found values which were significantly higher than those of the standard method (I: 0.49% (w/w); II: 0.46% (w/w); DIN: 0.31% (w/w)), whereas with gradient III the same threshold value was found as with the DIN-Method (III: 0.32% (w/w)).     

应用气-质联用仪测定三种螺旋藻中的甾醇成分

应用GLC/MS联用仪对室内培养的钝顶螺旋藻(Spirulina platensis (Nordstedt) Geitler)、极大螺旋藻(S.maxima (Stechell & Gardiner) Geitler)和盐泽螺旋藻(S.subsalsa Oerst)的甾醇成分进行了测定。从钝顶螺旋藻和盐泽螺旋藻中共分出11个相同的甾醇组分:胆甾醇、胆甾烷醇、芸苔甾醇、麦角甾醇、海绵甾醇、菜子甾醇、豆甾醇、24-乙基-Δ~(5,7,22)-胆甾醇、β-谷甾醇、异岩藻甾醇和4α,23,24-三甲基Δ~(5,22)-胆甾醇;从极大螺旋藻中只分离出8个甾醇组分。其中胆甾醇含量最高。4α,23,24-三甲基-Δ~(5,22)-胆甾醇为蓝藻中首次报导。     

Unfixed Material Embedded in A Methacrylate Resin (Technovit 7100) For Immunofluorescent Staining

Wheat grains were embedded with or without fixation in Technovit 7100 or in paraffin. This enabled us to produce 4 μm sections for imnwnofluorescent staining to see whether serum of patients with baker's asthma contained IgG antibodies against wheat grains. Embedding without fixation in Technovit 7100 appeared to be suitable for unmunofluorescent staining and gave superior results to protocols requiring fixation.     

The First Instar Larva of Nothohoraia (Diptera: Blephariceridae)

The first instar larva of the net-winged midge, Nothohoraia micrognathia Craig, 1969 (Diptera: Blephariceridae) is described. Instead of the primitive ring of eversible hooklets the pseudopods possess stiff apical setae. This character expression suggests that Nothohoraia is more closely related to the advanced Apistomyiini occurring outside New Zealand than to the two other New Zealand genera, Neocurupira and Peritheates.