Lactobacilli-Host mutualism: "learning on the fly"

Metazoans establish with microorganisms complex interactions for their mutual benefits. Drosophila, which has already proven useful host model to study several aspects of innate immunity and host-bacteria pathogenic associations has become a powerful model to dissect the mechanisms behind mutualistic host-microbe interactions. Drosophila microbiota is composed of simple and aerotolerant bacterial communities mostly composed of Lactobacillaceae and Acetobactereaceae. Drosophila mono- or poly-associated with lactobacilli strains constitutes a powerful model to dissect the complex interplay between lactobacilli and host biologic traits. Thanks to the genetic tractability of both Drosophila and lactobacilli this association model offers a great opportunity to reveal the underlying molecular mechanisms. Here, we review our current knowledge about how the Drosophila model is helping our understanding of how lactobacilli shapes host biology.     

The distribution and location of the symbiont Lagenophrys aselli on the freshwater isopod Asellus aquaticus

1. The distribution and location of the ciliated protozoan Lagenophrys aselli on the freshwater isopod Asellus aquaticus were studied in relation to water flow over the third pleopod surface. 2. At low densities L. aselli had a significant preference for the anterior centre of the pleopod; however, at the highest densities this preference was no longer significant. The distribution ranged from closer than random at low densities to further than random at the highest densities, and may have been a product of feeding and reproduction of L. aselli as well as the short intermoult period of the host. 3. An individual L. aselli has an effective area of both the lorica and the ciliated feeding disc. The ciliated feeding disc, when extended, may contribute to the presence of a small anterior–posterior gap being left between individuals.     

Notes on the Term “Tangut” in Botanical Names

Originally Tangut refers to a branch of the Qiang tribe in western China during the Sui and Tang Dynasties, ie. Dangxiang Qiang. Dangxiang Qiang gradually grew stronger in the Northern Song Dynasty, and established the Western Xia regime. They called themselves Daxia. We collected more than 40 botanical names that had the stem “Tangut” in the specific epithets. We analyzed their protologues, determined the collecting localities of their holotypes, lectotypes or syntypes in order to delimitate the geographical range of the Tangut region in floristics. Previous research results on the Tangut region were also considered. We suggested that the north boundary of Tangut region lied at the south slope of the Qilian Mountains (northernmost point at Jingtie Mountain), and then extended southwards through the Tao river reaches, ended at Burgan Buda Mountains and Amen Mountains, the west boundary started from the eastern margin of the Qaida Basin (Qaida Basin not included) and the east boundary extended from the Tao River reaches to northeastern Sichuan, roughly lied at the north of Song pan and Li Xian. We know that much more facts should be considered to deliminate the range of a flora region and it’s not enough to consider only the type localities of some taxa. However, considering the scope of this flora region is not large and we have analyzed more than 40 taxa, our analysis could be regarded as an exploratory attempt to delimitate the boundaries of a flora region from a historical viewpoint.     

Predicting the impact of climatic warming on the carbon balance of the moss <Emphasis Type="Italic">Sanionia uncinata</Emphasis> on a maritime Antarctic island

The effects of climatic factors, especially those of temperature, on the carbon balance of the moss Sanionia uncinata were examined on King George Island in the maritime Antarctic. Net photosynthesis (P _n ) and dark respiration rates of two colonies (A and B) were measured with a portable infrared gas analyzer. Colony A showed small P _n compared with its dark respiration rates throughout the growing season. Colony B showed much higher net photosynthetic rates, but the dark respiration rates of the two colonies did not differ significantly. Net photosynthetic rate determined at light saturation was almost constant over a wide temperature range, from 5° to 15°C, while the dark respiration was strongly affected by temperature. To assess the impact of warming on the carbon balance of the moss, cumulative carbon gain of the moss was calculated using a simulation model for the main part of the growing season. The results suggest that climatic warming may cause a reduction of carbon gain in some relatively photosynthetically inactive moss colonies. Received: April 13, 2001 / Accepted: November 5, 2001     

Some notes on the vértesszöllös occipital

An examination of the Vértessz?ll?s occipital bone indicates the need for takings its condition and preservation as well as certain aspects of its morphology into account prior to a metric assessment of its features. This analysis confirms the presence of extrasutural bones on the lambdoidal suture as well as some distortion in the sagittal curvature of this region. The advisability of using the endocranial sutures as well as other data for defining lambda in cases such as this is discussed, and a procedure for determining the position of opisthion is indicated. A metric and morphological analysis is used to support the claim that the specimen can be considered a large late representative of Homo erectus in Europe.     

Fly on the wall – attachment structures in lower Diptera

Pretarsal attachment structures of representatives of the megadiverse Diptera are examined and documented, mainly using scanning electron microscopy. The focus is on the basal ‘nematoceran’ lineages. The diversity in structures is much higher than suggested by brief summarizing accounts in earlier studies. Both hairy and smooth attachment structures occur. A well‐developed, pad‐like empodium with its ventral surface covered with adhesive hairs is arguably a groundplan feature of Diptera. Very often this pad is combined with the presence of hairy pulvilli. However, smooth pulvilli occur in two of the examined groups. A smooth arolium is present in Tipulomorpha and likely an autapomorphy of this clade, suggesting that it was acquired secondarily. Evolutionary transformations are interpreted based on recently published dipteran phylogenies.     

Effects of Bacillus thuringiensisδ-endotoxin-fed Helicoverpa armigera on the survival and development of the parasitoid Campoletis chlorideae

With the deployment of transgenic crops expressing δ‐endotoxins from Bacillus thuringiensis (Bt) for pest management, there is a need to generate information on the interaction of crop pests with their natural enemies that are important for regulation of pest populations. Therefore, we studied the effects of the Bt δ‐endotoxins Cry1Ab and Cry1Ac on the survival and development of the parasitoid Campoletis chlorideae Uchida (Hymenoptera: Ichneumonidae) reared on Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) larvae fed on Bt toxin‐intoxicated artificial diet. The H. armigera larvae fed on artificial diet impregnated with Cry1Ab and Cry1Ac at LC₅₀ (effective concentration to kill 50% of the neonate H. armigera larvae) and ED₅₀ (effective concentration to cause a 50% reduction in larval weight) levels before and after parasitization resulted in a significant reduction in cocoon formation and adult emergence of C. chlorideae. Larval period of the parasitoid was prolonged by 2 days when fed on Bt‐intoxicated larvae. No adverse effects were observed on female fecundity. The observed effects appeared to be indirect in nature, because no Bt proteins were detected through enzyme‐linked immunosorbent assay in the C. chlorideae larvae, cocoons, or adults fed on Cry1Ab‐ or Cry1Ac‐treated H. armigera larvae. The effects of Bt toxin proteins on C. chlorideae were due to early mortality of H. armigera larvae, that is, before completion of parasitoid larval development.