New insights on systematics and phylogenetics of Mediterranean Blaps species (Coleoptera: Tenebrionidae: Blaptini), assessed through morphology and dense taxon sampling

The genus Blaps is an emblematic group of large flightless beetles adapted to semi‐arid and arid environments. About 230 species have been described in the subgenus Blaps, which is the largest of the four extant subgenera. Within this subgenus, one large group of morphologically homogeneous species is of particular interest, and comprises the species formerly assigned to Seidlitz's division one. Strikingly, almost all species in this group are endemic to the Mediterranean basin, whereas the remaining Blaps species are mostly distributed in Asia. Here we present the first phylogenetic hypothesis for the Mediterranean Blaps and several taxonomic clarifications for the North African species belonging to this group. Based on careful examination of almost all type material and thousands of specimens for all known species and subspecies (initially 65 taxa), seven lectotypes are designated and six new synonymies are established: Blaps heydeni Allard, 1880 = Blaps heydenissp. taciturna Peyerimhoff syn.n. , Blaps emondi Solier = Blaps nitidula Solier syn.n. , Blaps tripolitanica Karsch = Blaps vialattei Peyerimhoff syn.n. , Blaps bifurcata strauchi Reiche = Blaps bifurcata ssp. gridellii Pierre syn.n. , Blaps cognata Solier = Blaps schweinfurhtii Seidlitz syn.n. and Blaps judaeorum Miller = Blaps pharao Seidlitz syn.n. Among the examined material, five species are also new for science and are assigned to extant species group. To infer species relationships, a morphological character matrix was assembled and analysed using both parsimony and probabilistic methods. All analyses yielded a similar and repeatable phylogenetic pattern, which allows us to discuss the systematics of the Mediterranean endemic species, the limit of extant species groups and to clarify the taxonomic status of several ambiguous taxa. We also reveal the existence of a large clade that encompasses the eastern Mediterranean species that are also mostly associated with arid regions. This clade is embedded within a second group that corresponds to western Mediterranean species, which are generally found in semi‐arid regions. Finally, we discuss the relevance of species groups in relation to their geographic distribution. This work represents a first step for further studies in taxonomy, systematics and historical biogeography of Blaps species.     

Rainforest and savanna landscape dynamics in New Caledonia: Towards a mosaic of stable rainforest and savanna states?

Stable forested environments can be converted to savanna in response to changes in environmental disturbances. New Caledonia is a biodiversity hotspot; significant ecological and economic resources would be lost if forests were turned into savanna by anthropogenic environmental changes. On the landscape scale, systems that have undergone shifts of this kind are characterized by sharp forest–savanna boundaries and mosaic‐like distributions of savanna and forest. Understanding the locations and the dynamics of such boundaries is a challenge for ecologists and is critical for landscape management and biodiversity conservation. Using a time series of aerial photographs (1955–2000) and a forest habitat suitability map, we tested the hypothesis that topography and spatial processes, especially those relating to fire spread and seed dispersal, are the main determinants of the spatial distribution of rainforest and savanna in a New Caledonian landscape covering 24 km². Within the studied landscape, the overall forest coverage decreased by 24% between 1976 and 2000. This was primarily due to the contraction of forests on west‐facing slopes, which accounted for about 90% of the total loss. Conversely, the east‐facing forests seemed to have contracted extensively prior to the studied period, and were confined to refuges. A habitat suitability index calculated from the landscape's topographical features using generalized additive models accurately predicted both the presence of forests and the probability of forest expansion/contraction. We also provide evidence that spatial processes such as fire spread and seed dispersal limit the expansion and contraction of forests. Our results suggest that rainforests on west‐facing slopes in New Caledonia will be progressively destroyed by fire until they are restricted to refuges along thalwegs and creeks, as appears to have already happened for their east‐facing counterparts.     

Evaluation of monoclonal antibodies against Plasmodium vivax sporozoites for ELISA development

Nine monoclonal antibodies (MAbs) developed against Plasmodium vivax (Grassi & Feletti) salivary gland sporozoites were evaluated for use in an enzyme-linked immunosorbent assay (ELISA), using sporozoites developed in Anopheles dirus Peyton & Harrison An. gambiae Giles and An.maculatus Theobald. Four of the antibodies were unsuitable due to the low sensitivity of the resulting assays or the requirement for high concentrations of capture antibody. An additional two MAbs were rejected because they resulted in assays with high background absorbance, attributed to self-binding. Of the three remaining MAbs, the use of Navy vivax sporozoite (NVS) 3 resulted in an ELISA with the highest sensitivity and the lowest concentration requirement for capture antibody. Assay sensitivity varied with sporozoite strain indicating possible quantitative epitope heterogeneity. None of the MAbs cross-reacted with the heterologous sporozoites tested by immunofluorescence antibody assay (IFA). The IFA activity was not an indicator of ELISA sensitivity. The use of MAb NVS 3 in a standardized ELISA method resulted in an assay 10 times more sensitive than reported previously for P. vivax sporozoites, with a detection limit of fewer than 100 sporozoites per mosquito.     

嵌合型E1B 55-kDa蛋白缺陷型腺病毒载体治疗肿瘤的评价

ONYX-015和H101为可复制E1B 55-kDa蛋白缺陷的C族腺病毒,它们正作为抗癌药物进行临床研究. 然而它们在癌症基因治疗中的应用却受到了C族腺病毒天然特性的制约,部分原因是由于在恶性肿瘤中C族腺病毒受体(coxsackievirus-adenovirus receptor,CAR) 的表达量较低. 构建了一个以H101为骨架的含有编码35型腺病毒鞭毛区域的基因,替代5型腺病毒鞭毛基因的嵌合型腺病毒载体. 这一改动使得腺病毒载体可以通过一种在肿瘤中高表达的膜蛋白CD46感染肿瘤细胞. 应用RT-PCR方法检测不同肿瘤细胞株中CAR和CD46表达量的区别. 在CAR受体低表达的细胞株中(MDA-MB-435和MCF-7),H101-F35表现出比H101和ONYX-015更强的细胞杀伤效果;在CAR受体高表达的细胞株中(A549,NCI-H446,Hep3B,LNCaP,ZR-75-30和Bcap-37),H101-F35、 H101和ONYX-015的细胞杀伤效果则相似. 在荷MDA-MB-435肿瘤的裸鼠模型中,注射H101-F35的抑瘤效果比注射H101的抑瘤效果更明显. 这些结果表明嵌合型溶瘤腺病毒载体H101-F35在肿瘤基因治疗中将有很好的应用前景.     

ECOLOGY OF THE INTRODUCED SNAIL MELANOIDES TUBERCULATA (GASTROPODA: THIARIDAE) IN RELATION TO BIOMPHALARIA GLABRATA IN THE MARSHY FOREST ZONE OF GUADELOUPE, FRENCH WEST INDIES

Melanoides tuberculata was introduced to several types of aquatichabitat occurring in the marshy forest zone, Guadeloupe, asa competitor of the snail host, Biomphalaria glabrata, of Schistosomamansoni. Colonization by the competitor was successful in allhabitats, but the impact on the snail host was variable accordingto the site. Evolution of global prevalences, intensities andabundances of Schistosoma mansoni in the reservoir host, Rattusrattus, did not show any significant changes during the eightyears following the introduction of the competitor. The analysisof size distribution of M. tuberculata in a release plot showedthat maximum reproduction took place during the rainy seasonbetween June and November. The thiarid snail needed 4.5 monthsto reach a size of 10 mm, 14 months to reach 15 mm, and morethan 30 months to reach 20 mm. Calculated life expectancieswere 0.74 year at the first year of age, 0.9 year at the secondyear, and 0.5 year at the third year. (Received 21 September 1992; accepted 5 January 1993)     

El Niño and dry season rainfall influence hostplant phenology and an annual butterfly migration from Neotropical wet to dry forests

We censused butterflies flying across the Panama Canal at Barro Colorado Island (BCI) for 16 years and butterfly hostplants for 8 years to address the question: What environmental factors influence the timing and magnitude of migrating Aphrissa statira butterflies? The peak migration date was earlier when the wet season began earlier and when soil moisture content in the dry season preceding the migration was higher. The peak migration date was also positively associated with peak leaf flushing of one hostplant (Callichlamys latifolia) but not another (Xylophragma seemannianum). The quantity of migrants was correlated with the El Niño Southern Oscillation, which influenced April soil moisture on BCI and total rainfall in the dry season. Both hostplant species responded to El Niño with greater leaf flushing, and the number of adults deriving from or laying eggs on those new leaves was greatest during El Niño years. The year 1993 was exceptional in that the number of butterflies migrating was lower than predicted by the El Niño event, yet the dry season was unusually wet for an El Niño year as well. Thus, dry season rainfall appears to be a primary driver of larval food production and population outbreaks for A. statira. Understanding how global climate cycles and local weather influence tropical insect migrations improves the predictability of ecological effects of climate change.     

The importance of cytotaxonomy in understanding the biogeography of African rodents: Lake Chad murids as an example

1. Due to the existence of numerous morphologically sibling species among African rodent genera, cytogenetical analyses are essential for correct taxonomic identifications. As an illustration, karyotypes of rodents captured in the Lake Chad area were systematically conducted, to determine them unambiguously. 2. Thirteen species were found, giving a list of at least 18 species in total for the whole Lake Chad region when previously published data were critically re‐examined. Gerbilline rodents dominate in this Sahelian region, with five species of Gerbillus, four of Taterillus, two of Tatera and Desmodilliscus braueri, and six species of murine rodents were also counted. Moreover, two species of Taterillus appeared characterized by unique and hitherto unknown karyotypes, and undoubtedly represent new species. 3. The Lake Chad area, although poorly studied from a biogeographical point of view, occupies a central position in the northern half of Africa which makes its zoogeographical affinities interesting to evaluate. Analysis of the biogeographical characteristics of the rodent species recorded here leads to the conclusion that the murid rodent community of the Lake Chad region is of mixed origin, with a dominant West African component. However, the presence of two species considered as endemics (Mastomys verheyeni and Taterillus lacustris), combined with our discovery of two new chromosomal species of Taterillus, suggest that this region may have acted as a centre of differentiation in relatively recent times, perhaps reflecting the extensive variations of the Lake Chad basin associated with Plio‐Pleistocene cycles of transgression–regression. 4. Without chromosomal data, most of these findings would have remained weakly supported, or even undiscovered, as between five and eight species could have been overlooked.