Contest and scramble competitions inCallosobruchus maculatus (Coleoptera: Bruchidae) II. Larval competition and interference mechanisms

Competition between contest and scramble strategists was examined using two strains of Callosobruchus maculatus, the contest strain (iQ) and the scramble strain (tQ). The direct larval interference experiment within each strain showed that the contest strain performed strong direct interference throughout its larval stage against the conspecific opponent(s). The scramble strain also performed its interference, but only during the 3rd and the 4th larval stages. The inter-strain larval competition experiments inside a large and small mung bean (Vigna radiata) showed that the contest strain was, in general, superior to the scramble strain in competition, but the competition results were density- and frequency-dependent. In the large beans, the proportion of adult emergence of the contest strain increased with the increase of its own initial density but decreased as the initial density of the scramble strain increased. The shape of the proportion of adult emergence became nonlinear in the small beans. The cause of the complexity of inter-strain competition results was discussed in the light of the difference in larval interference ability between the two strains.     

Diversity of Anopheles species and trophic behavior of putative malaria vectors in two malaria endemic areas of northwestern Thailand

We determined the species diversity, blood‐feeding behavior, and host preference of Anopheles mosquitoes in two malaria endemic areas of Tak (Mae Sot District) and Mae Hong Son (Sop Moei District) Provinces, located along the Thai border with Myanmar, during a consecutive two‐year period. Anopheline mosquitoes were collected using indoor and outdoor human‐landing captures and outdoor cow‐baited collections. Mosquitoes were initially identified using morphological characters, followed by the appropriate multiplex AS‐PCR assay for the identification of sibling species within Anopheles (Cellia) complexes and groups present. Real‐time PCR was performed for parasite‐specific detection in mosquitoes (Plasmodium spp. and Wuchereria bancrofti). A total of 7,129 Anopheles females were captured, 3,939 from Mae Sot and 3,190 from Sop Moei, with 58.6% and 37% of all anophelines identified as An. minimus, respectively. All three malaria vector complexes were detected in both areas. One species within the Minimus Complex (An. minimus) was present along with two related species in the Funestus Group, (An. aconitus, An. varuna), two species within the Dirus Complex (An. dirus, An. baimaii), and four species within the Maculatus Group (An. maculatus, An. sawadwongporni, An. pseudowillmori, and An. dravidicus). The trophic behavior of An. minimus, An. dirus, An. baimaii, An. maculatus, and An. sawadwongporni are described herein. The highest An. minimus densities were detected from February through April of both years. One specimen of An. minimus from Mae Sot was found positive for Plasmodium vivax.     

花鲈对不同饲料原料的表观消化率

试验以Cr2 O3 为指示物 ,以 70 %基础饲料和 30 %的待测饲料原料组成试验饲料 ,测定花鲈对红鱼粉、豆粕、花生粕、菜籽粕、肉骨粉和棉籽粕中干物质、粗蛋白、粗脂肪、能量和氨基酸的表观消化率。在水温 2 5± 1℃的试验条件下 ,花鲈对鱼粉、豆粕、花生粕的干物质表观消化率均在 6 0 %以上 ;对鱼粉、豆粕、花生粕和菜籽粕的蛋白质、脂肪的表观消化率都在 80 %以上 ;花鲈对能量的表观消化率变化范围在 16 99%— 83 96 %。测得每种原料的 16种氨基酸的表观消化率 :花鲈对原料氨基酸消化率的变化与对蛋白质消化率的变化相一致 ,除了赖氨酸、缬氨酸、蛋氨酸之外 ,花鲈对肉骨粉中氨基酸的利用率最低。花鲈对饼粕类原料中的含硫氨基酸 (如蛋氨酸 )的表观消化率低于其他氨基酸 ,对鱼粉中氨基酸利用率最低的为组氨酸 ,对肉骨粉中氨基酸利用率最低的为苏氨酸。     

三种植物粉剂对四纹豆象(鞘翅目:豆象科)行为、死亡率和繁殖的影响

The effects of powders from dry flower buds of Eugenia aromatica Baill., seeds of Piper guineense Schum and Thonn and fruits of Capsicum frutescens L. on adult behaviour, mortality and reproductive fitness of the cowpea seed beetle, Callosobruchus maculatus （Fab.） were investigated under ambient laboratory conditions. All experiments were carried out in glass Petri plates. All powders elicited aversion in adult beetles. The contact toxicity symptoms included restlessness, loss of coordination, knock down and eventual death of adult beetles. These behaviours were more pronounced with E. aromatica in which adult beetles died within 16 hours. P. guineense and C. frutescens powders did not cause 100% mortality of adult beetles, even after 24 hours. Each of the three powders significantly （P 〈 0.05） reduced the mating competition of adult males after sub-lethal exposure for one, two, and three hours, respectively. E. aromatica powder caused more reduction in male mating competition for females than any of the other two powders after each period of exposure. Receptiveness of treated females to courting males was also decreased by exposure to any of the three powders. Similarly, E. aromatica powder caused greater decreases in female receptiveness to males than any of the other two powders after each period of exposure. Exposure of either adult male or female C. maculatus to the powders for sub-lethal times of three, six and nine hours significantly reduced the fecundity of the beetles. E. aromatica powder caused the most reduction of eggs laid and also significantly reduced fertility of the eggs.     

Development and characterization of cell lines from heart, liver, spleen and head kidney of sea perch Lateolabrax japonicus

Five cell lines (LJHK, LJS, LJL, LJH-1 and LJH-2) were established from the head kidney, spleen, liver and heart of sea perch Lateolabrax japonicus . The cell lines LJHK, LJS, LJL, LJH-1 and LJH-2 were subcultured 46, 32, 32, 36 and 34 times in minimum essential medium (MEM) supplemented with foetal bovine serum (FBS), sea perch serum and 10 ng ml⁻¹ basic fibroblast growth factor (bFGF). Morphology of primary cultures and subcultures of the five cell lines were observed continuously by microscopy. The suitable temperature for growth was 18 to 30° C for all of these cell lines with the optimum growth at 24° C and a reduced growth rate <18° C. The optimum concentration of FBS was found to be 10% and addition of bFGF to the medium significantly increased the growth rate of the cells. The doubling time of LJS, LJH-1, LJL, LJH-2 and LJHK cells was determined to be 52·7, 54·9, 57, 58·7 and 66 h at a plating density of 1 × 10⁵ cells ml⁻¹ at 24° C, respectively. Chromosome analysis revealed that 42, 48, 38, 43 and 45% cells maintained normal diploid chromosome number (48) in the LJH-1, LJH-2, LJHK, LJL and LJS cell lines, respectively. The LJHK cells were successfully transfected with green fluorescent protein (GFP) reporter plasmids and the expression of GFP gene in the cells indicated the possible utility of the cells in gene expression studies. Furthermore, treatment of the LJHK cells with lipopolysaccharide led to increased expression of IL-1β, demonstrating that LJHK cells might be a valuable tool for studying the expression and function of immunomodulatory gene in fishes.     

Characterization of VAMP-2 gene from marine teleostean, Lateolabrax japonicus

The whole length SPV2 gene of 715 bp, encoding VAMP-2 protein of 110 amino acids from Japanese sea perch, Lateolabrax japonicus, was obtained by using both RT-PCR and anchored PCR strategies while we initiated the structural and functional study on SNARE proteins in marine teleostean. Analysis of the deduced amino acid sequence indicated that SPV2 has its core arginine residue, a potential N-linked glycosylation site near its N-terminal, and one transmembrane domain in its C-terminal. Advanced structural analysis of bioinformatics approach predicts a coiled-coil α-helix backbone as the characteristic of SPV2 main conformational structure, identical to the structure of rat VAMP-2 obtained by crystallography. Semi-quantitative RT-PCR revealed that SPV2 was generally expressed in 10 neural and non-neural tissues, with the highest concentration in brain and the least in muscle.     

Eighteen novel microsatellite markers for the Chinese sea perch, Lateolabrax maculatus

Chinese sea perch (Lateolabrax maculates) is one of the most important commercial species of mariculture in China. In this study, we constructed a repeat-enriched genomic DNA library of L. maculates. Eighteen dinucleotide microsatellite markers were characterized by genotyping 32 samples. The number of alleles ranged from three to nine, and the observed and expected heterozygosities ranged from 0.4516 to 1.0000 and from 0.4045 to 0.8676, respectively. Significant deviations from Hardy–Weinberg expectations were detected at four loci and linkage disequilibrium between two loci was significant after applying Bonferroni correction. The 18 highly polymorphic microsatellite markers should provide sufficient level of genetic diversity to investigate the population structure and evaluate the breeding strategy in L. maculates.     

Extended gestation with late‐autumn births in a cool‐climate viviparous gecko from southern New Zealand (Reptilia: Naultinus gemmeus)

Abstract Female viviparous lizards from temperate locations in the Southern Hemisphere (New Zealand, Tasmania (Australia), South Africa and South America) often have reproductive activity spanning many months of the year. In contrast, vitellogenesis and pregnancy are often confined to the spring/summer months in viviparous species from temperate zones of the Northern Hemisphere. An extreme Southern Hemisphere example is the nocturnal common gecko from New Zealand, Hoplodactylus maculatus (Gray 1845), in which females exhibit biennial reproduction with pregnancy lasting up to 14 months in a cool‐climate population. Here, we examined whether such an extended reproductive cycle also occurs in a diurnal species, the jewelled gecko Naultinus gemmeus (McCann 1955), at a similar latitude. Palpation was used to assess reproductive condition non‐invasively. In contrast to the nearby higher‐altitude population of H. maculatus, N. gemmeus reproduces annually. Vitellogenesis occurs from autumn to spring in both species, but pregnancy ends after about 7 months in N. gemmeus. Birth occurs in the seemingly unpropitious season of mid‐ to late autumn, a pattern that may be unique for lizards from cool‐temperate zones. We hypothesize that there are major differences between populations of N. gemmeus and H. maculatus with respect to survival of autumn‐born neonates and/or costs to females from remaining pregnant over winter. Museum specimens of N. gemmeus support anatomical inferences from palpation; they also suggest that vitellogenesis may begin before the end of pregnancy (which may be essential to completing each reproductive cycle within a year) and that some populations may show gestation in utero over winter, as in H. maculatus. Extended gestation appears to be a common response to cool climates for Southern Hemisphere lizards that have independently evolved viviparity.     

应用PCR—SSCP鉴别我国多斑按蚊复合体成员种（双翅目：蚊科）

测定并分析了我国多斑按蚊复合体5个成员种(多斑按蚊、威氏按蚊、伪威氏按蚊、达罗毗按蚊和塞沃按蚊)核糖体DNA 28S-D3序列,应用PCR-SSCP技术对该复合体成员种进行分子鉴别。结果显示：我国多斑按蚊复合体5个成员种的D3序列长度范围为388-394bp,GC含量为58．12％—59．79％,D3序列在种内保守,在种间存在差异,种间差异最大的是达罗毗按蚊与伪威氏按蚊为6．55％,最小的是达罗毗按蚊与多斑按蚊为2．58％,平均差异率为4．59％。用SSCP分析多斑按蚊复合体5个成员种的28S-D3扩增产物,结果显示电泳条带具种特异性,可用于鉴别各蚊种。