Role of Anopheles (Kerteszia) bellator as malaria vector in southeastern Brazil (Diptera: Culicidae)

New research concerning Anopheles bellator in the southeast of the State of S?o Paulo, Brazil, are reported. Adult females of this mosquito showed remarkable endophily and endophagy which was even greater than An. cruzii. The epidemiological role of this anopheline as a malaria vector is discussed.     

Karyotype of Brazilian Anopheles albitarsis sensu lato (Diptera:Culicidae)

Anopheles (Nyssorhynchus) albitarsis sensu lato is an important malaria vector in Brazil, especially in the Brazilian Amazon region. Chromosome preparations of fourth-instar larvae of A. albitarsis from Iranduba and Coari (AM) and Ilha Comprida (SP) were analyzed for karyotype determination and to improve cytogenetic identification of this species. Anopheles albitarsis possesses 2n = 6 chromosomes, with two pairs (submetacentric and metacentric) of autosomes and one pair of sex chromosomes, with X-Y dimorphism. The sex pair is homomorphic and acrocentric in females and heteromorphic in males, with a punctiform Y chromosome. Somatic pairing was detected in the prometaphase and metaphase chromosomes of the three A. albitarsis populations. Apparently, sex chromosome evolution in the Culicidae does not function as does evolution in the Culicidae, since it occurs in the subfamily Anophelinae, which possesses heteromorphic sex chromosomes and is regarded as primitive, based on several criteria. These karyotype data on the albitarsis complex reinforce the hypothesis that sex chromosome evolution in the subfamily Anophelinae is conserved, and the variation revealed in the mean size of chromosomes in three populations indicates that selective pressure in these populations is occurring only at a genetic level.     

EFFECTS OF HUMAN ACTIVITIES ON STRUCTURE AND COMPOSITION OF WOODY SPECIES OF THE NOKREK BIOSPHERE RESERVE OF MEGHALAYA,NORTHEAST INDIA

Aims Our study was conducted in the Nokrek Biosphere Reserve (NBR) in the Garo hills districts of Meghalaya, Northeast India. Our aim was to assess the effects of human activities on plant diversity,population structure and regeneration.Methods We selected a representative 1.2 hm2 stand in both the core and buffer zones of NBR. Structure and composition were determined by randomly sampling square quadrats, population structure was assessed by determining age structure, and regeneration was assessed by measuring densities of seedling, sapling and adult trees.Important findings More woody species were recorded from the core zone than the buffer zone (87 vs. 81 species), and there were a large number of tropical, temperate, and Sino-Himalayan, Burma-Malaysian and Malayan elements, primitive families and primitive genera. The trees were distributed in three distinct strata,canopy, subcanopy and sapling. Subcanopy and sapling layers had the highest species richness (81％ -88％ ). Lauraceae and Euphorbiaceae were the dominant families in terms of the number of species, and a large number of families were represented by single species. Most woody species (57 ％ - 79 ％ ) were contagiously distributed and had low frequency ( ＜ 20％ ). Although stand density was high in the buffer zone, its basal area was low compared to the stand in the core zone. Low similarity and high β-diversity indicate marked differences in species composition of the stands. Shannon diversity index was high in both the stands, while Simpson dominance index was low. The diameter-class distribution for dominant species revealed that the most had a large number of young individuals in their populations. Preponderance of tree seedlings, followed by a steep decline in population density of saplings and adult trees, indicated that the seedling to sapling stage was the most critical in the life cycle of the tree populations. Most species (42 ％ - 48 ％ ) had no regeneration,25 ％ - 35 ％ had good/fair regeneration, and the rest had poor regeneration or reoccurred as immigrants.     

Lipid Auxotrophy and the Effect on Lipid Composition of Entamoeba invadens*†

SYNOPSIS. A medium for the axenic cultivation of Entamoeba invadens has been developed. Serum, an essential constituent of conventional media, has been replaced by a mixture of albumin, unsaturated fatty acids, Tween, and cholesterol to control the lipid composition of the medium. Entamoeba invadens requires both cholesterol and unsaturated fatty acids for growth. The fatty acid composition of the phospholipids of the ameba reflects that of the medium to a great extent, especially with regard to the unsaturated fatty acids. The amount of membrane bounded cholesterol depends on the cholesterol concentration in the medium.     

Liver cytochrome P-450 system in rats with a varying susceptibility to the development of experimental alcoholism

The cytochrome P-450-dependent monooxygenase system of the liver was studied in laboratory noninbred male rats selected according to the intensity of their initial alcohol motivation and the dynamics of these parameters was followed up during 10-day alcoholisation. It was shown that in the animals inclined to the development of alcoholism the activity of the monooxygenase system (cytochrome P-450, B5; enzymes: aminopyrine N-demethylase, aniline p-hydroxylase, NADPH-cytochrome c-reductase) is higher than in the animals noninclined to the development of this disease. 10-day alcohol consumption in the free-choice situation between water and 15% ethanol solution did not change the parameters investigated. The only exception was NADPH-cytochrome c-reductase: its activity grew in both the groups of the animals by 40-75%.     

Cytogenetic study of Anopheles albitarsis (Diptera: Culicidae) by C-banding and in situ hybridization

The C-banding pattern and the size and location of the nucleolar organizer regions (NORs) are described for the first time in Brazilian populations of Anopheles (Nyssorhynchus) albitarsis sensu lato. C-banding revealed variation in the size of the centromeric heterochromatic blocks in autosomal chromosomes and in the acrocentric (X) and puntiform (Y) sex chromosomes. Fluorescence in situ hybridization showed that the NORs were located in the pericentromeric region of the sex (XX/XY) chromosomes and that this coincided with the number and location of centromeric constitutive heterochromatin blocks previously revealed by C-banding. The NORs varied in size among the homologues of the three populations. These findings of the populations studied support the hypothesis that the stability of NORs in the A. albitarsis complex is characterized by the presence of clustered and conserved sites in a unique pair of chromosomes.     

Systematic studies on Anopheles galvaoi Causey,Deane & Deane from the subgenus Nysssorhynchus blanchard (Diptera: Culicidae)

Anopheles galvaoi, a member of the subgenus Nyssorhynchus, is redescribed based on morphological characters of the adults male and female, fourth-instar larva and pupa. Female, male genitalia, larval and pupal stages are illustrated. Data about medical importance, bionomics, and distribution are given based on literature records. Adult female of An. galvaoi can be easily misidentified as An. benarrochi Gabald n and An. aquasalis Curry. A few characters are indicated for identifying female and immatures of An. galvaoi. Phylogenetic relationships among An. galvaoi and six other species of the Oswaldoi Subgroup are estimated using COII mtDNA and ITS2 rDNA gene sequences. Lectotype of An. galvaoi, an adult female from Rio Branco, State of Acre, is invalidated.     

Description of immature stages of Culex ocossa Dyar & Knab, Culex delpontei Duret and Culex pereyrai Duret of the Melanoconion subgenus (Diptera: Culicidae).

The larva and pupa of Culex (Melanoconion) ocossa Dyar & Knab are redescribed and those of Culex (Melanoconion) delpontei Duret and Culex (Melanoconion) pereyrai Duret are described from specimens collected in the states of S?o Paulo and Paraná, Brazil. The pupa of Cx. ocossa differs from those of the other two species in having seta 5-IV-VI dark with strongly aciculated branches, and caudolateral angle of segment VIII produced into sharp point, and seta 1-P present; Cx. delpontei can be distinguished from Cx. pereyrai in possessing paddle lightly tanned, trumpet flared, and wing and leg cases lightly tanned, without pattern of dark spots; Cx. pereyrai can be recognized by having wing case with pattern of dark, discontinuously pigmented, longitudinal lines, and trumpet cylindrical, not flared. The larvae of the three species share the presence of seta 2-C placed medially to seta 1-C.     

The chemical synthesis of glucosaminylphosphatidylglycerol. Comparison with a new phospholipid isolated from Bacillus megaterium

1. We describe the synthesis of a glucosamine derivative of phosphatidylglycerol having the same structure as that of the natural compound isolated from Bacillus megaterium. 2. 2-O-(3,4,6-Tri-O-acetyl-2-deoxy-2-phthalimido-d-glucopyranosyl)-3-O-benzyl-1-iodo-sn-glycerol was prepared by a Königs–Knorr condensation between 3-O-benzyl-1-toluene-p-sulphonyl-sn-glycerol and 3,4,6-tri-O-acetyl-1-bromo-2-deoxy-2-phthalimido-d-glucopyranose followed by replacement of the toluene-p-sulphonyl group with iodine. The iodide was treated with the silver salt of 2-isolauroyl-1-oleoyl-sn-glycerol 3-(monobenzyl hydrogen phosphate) to form the fully protected phosphoglycolipid. 3. Removal of benzyl protecting groups by catalytic hydrogenolysis, phthaloyl group with hydrazine and acetyl groups with pH10 buffer furnished 2-O-(2-amino-2-deoxy-d-glucopyranosyl)-1-(2-isolauroyl-1-stearoyl-sn-glycero-3-phosphoryl)-sn-glycerol. 4. The synthetic and natural compounds appeared identical when compared by chromatography and by identification of hydrolysis products from chemical and enzymic degradations.