Role for C-tail residues in delta opioid receptor downregulation

The delta opioid receptor, a member of the G-protein-coupled receptor superfamily, was used as a model system to characterize opioid receptor downregulation. Metabolic labeling followed by immunoprecipitation resulted in the isolation of the epitope-tagged mouse delta opioid receptor as a approximately 60-kDa protein. Prolonged agonist treatment with 100 nM d-Ala2, d-Leu5-enkephalin (DADLE) caused significant (approximately 60%) reduction in the level of receptor. The delta opioid receptor contains a number of phosphorylatable residues in the C tail. Point mutations of the majority of Ser/Thr sequences did not affect the level of downregulation, whereas mutation of Thr353 to Ala did. In order to test if phosphorylation at this site is involved in receptor downregulation, we generated a Thr353Glu mutant that would mimic the phosphorylated Thr at this site. This mutant exhibited a significantly higher extent of downregulation than the Thr353Ala mutant. In order to critically evaluate the requirement of Thr353 in receptor downregulation, we examined the downregulation of wildtype rat delta receptor (which does not contain Ala353) and an Ala353Thr point-mutant rat delta receptor. The wild-type receptor exhibited poor agonist-mediated downregulation, whereas Ala353Thr mutant exhibited increased downregulation. These results and results from additional studies with rat/mouse chimeric receptors support a role for phosphorylation of sites within the C tail in efficient downregulation of delta opioid receptors.     

A paradox survival – report of a repaired syn vivo perforation in a nautiloid phragmocone

The nautiloid Trocholites depressus (Eichwald, 1840) from the Lasnamägi regional stage (Darrivillian, Middle Ordovician) of Vaike Pakri Island (North-West Estonia) is the only known ectocochleate cephalopod that survived and healed a perforation of the phragmocone. Two chambers of the specimen were broken during its lifetime. The injury is located on the venter of the conch directly above the peristomal opening of the body chamber. It is reconstructed that the peristomal mantle tissue carried out an initial sealing of the injured chambers. The complete calcified sealing and compensation of the irregular shell surface started late with the overgrowth of the septa of the preceding whorl. The position and diameter of the siphuncle were not disturbed by the regeneration showing that these characters allowed a low phenotypic variability. Despite the trauma in the midlife growth history of this specimen, it appears to have reached maturity.     

Predictable changes in trophic community structure along a spatial disturbance gradient in streams

1. We assessed insect and resource standing stocks along a spatial gradient of flood disturbance in 19 sub-alpine Swedish streams to test the prediction that change in trophic structure arises from the joint action of disturbance, which affect basal resources, and resource-control, which ties the response of the consumers to the response of the resources.
2. Trophic structure, quantified as scores of non-metric multidimensional scaling based on the biomass of insect trophic groups, changed predictably along the disturbance gradient. In early summer, predators and algae feeders decreased relative to suspension feeders with increasing disturbance; in autumn, algae feeders decreased relative to leaf feeders with increasing disturbance.
3. Across the disturbance gradient, the biomass of algae-, deposit- and leaf-feeders was principally controlled by the availability of the respective resource (algae, fine detritus and coarse detritus), while disturbance only had subsidiary effects on algae feeders in early summer.
4. Overall, patterns in trophic-group biomass along the disturbance gradient were more likely to reflect indirect effects of disturbance via impact on the resources, which reverberated to the consumers because of resource-control, rather than direct effects. In contrast with the view that stream communities are the result of stochastic colonization following disturbance events, in the study streams the trophic structure of insect assemblages is predictable and partly organized by resource-control across a broad range of disturbance conditions.     

Patterns of inbreeding depression in a population of Brassica cretica (Brassicaceae): evidence from family-level analyses

In this investigation, we have collected family-structured data from a partly self-compatible, outcrossing population of Brassica cretica to estimate and compare the effects of one-generation selfing on different types of characters. Inbreeding not only depressed characters that should be positively correlated with fitness irrespective of habitat, e.g. germinability, leaf number and inflorescence size, but also resulted in later flowering, smaller and more asymmetric flowers, and an increased production of basal branches. Population-level estimates of inbreeding depression were similar in magnitude to estimates reported in other wild plant species. There was a tendency for direct components of fitness to exhibit a stronger response to inbreeding than other characters, but only when the differences between selfed and outbred offspring were measured in standard deviation units. Family-level estimates of inbreeding depression were weakly correlated across characters. Given these and other observations, we hypothesize that the genetic basis of inbreeding depression varies across the life cycle and that changes in local inbreeding will lead to shifts in the mean phenotypes of B. cretica populations. However, judging from data on current levels of population divergence, quite large changes in inbreeding will be required to influence large-scale patterns of variation in this species.  © 2002 The Linnean Society of London. Biological Journal of the Linnean Society , 2002, 76 , 317–325.     

Do increases in agricultural yield spare land for nature?

Feeding a rapidly expanding human population will require a large increase in the supply of agricultural products during the coming decades. This may lead to the transformation of many landscapes from natural vegetation cover to agricultural land use, unless increases in crop yields reduce the need for new farmland. Here, we assess the evidence that past increases in agricultural yield have spared land for wild nature. We investigated the relationship between the change in the combined energy yield of the 23 most energetically important food crops over the period 1979–1999 and the change in per capita cropland area for 124 countries over the same period. Per capita area of the 23 staple crops tended to decrease in developing countries where large yield increases occurred. However, this was counteracted by a tendency for the area used to grow crops other than staples to increase in the countries where staple crop yields increased. There remained a weak tendency in developing countries for the per capita area of all cropland to decline as staple crop yield increased, a pattern that was most evident in developing countries with the highest per capita food supplies. In developed countries, there was no evidence that higher staple crop yields were associated with decreases in per capita cropland area. This may be because high agricultural subsidies in developed countries override any land-sparing pattern that might otherwise occur. Declines in the area of natural forest were smaller in countries where the yield of staple crops increased most, when the negative effects of human population increases on forest area were controlled for. Our results show that land-sparing is a weak process that occurs under a limited set of circumstances, but that it can have positive outcomes for the conservation of wild nature.     

Ethnozoology in Brazil: current status and perspectives

Ancient connections between animals and human are seen in cultures throughout the world in multiple forms of interaction with the local fauna that form the core of Ethnozoology. Historically, ethnozoological publications grew out of studies undertaken in academic areas such as zoology, human ecology, sociology and anthropology - reflecting the interdisciplinary character of this discipline. The rich fauna and cultural diversity found in Brazil, with many different species of animals being used for an extremely wide diversity of purposes by Amerindian societies (as well as the descendents of the original European colonists and African slaves), presents an excellent backdrop for examining the relationships that exist between humans and other animals. This work presents a historical view of ethnozoological research in Brazil and examines its evolution, tendencies, and future perspectives. In summary, literature researches indicated that ethnozoology experienced significant advances in recent years in Brazil, although from a qualitative point of view improvement is still needed in terms of methodological procedures, taxonomic precision, and the use of quantitative techniques. A wide range of methodologies and theories are available in different areas of learning that can be put to good use in ethnozoological approaches if the right questions are asked. The challenges to studying ethnozoology in Brazil are not insignificant, and the tendencies described in the present study may aid in defining research strategies that will maintain the quantitative growth observed in the recent years but likewise foster needed qualitative improvements.     

Biomarkers from individual carbonate phases of an Oligocene cold‐seep deposit,Washington State,USA

An Oligocene cold‐seep limestone (Lincoln Creek Formation, Washington State, USA) was studied for its lipid biomarker inventory. Biomarker analysis on minute amounts of sample (tens of mg) and complementary ¹³C_carbonate analyses allowed us to link biogeochemical processes with individual, closely intertwined carbonate phases. The ancient seep deposit exhibits four major carbonate phases, according to the paragenetic sequence of (I) micrite, (II) yellow aragonite, (III) clear aragonite and (IV) equant calcite spar. For the micrite, varying but significant amounts of archaea‐derived isoprenoids clearly indicate that the precipitation of this phase was induced by the microbial anaerobic oxidation of methane (AOM). However, water column‐derived lipids present in this carbonate phase reflect the incorporation of organic matter from background sediment cemented by authigenic micrite. Yellow aragonite made up only a minor rock component (<10% vol.), but contained a major portion of lipid biomarkers indicative of AOM. Along with low δ¹³C_carbonate values (less than ?30‰ Pee Dee Belemnite), this points to an intimate spatial association of AOM consortia with the precipitation of yellow aragonite. Clear aragonite showed similar δ¹³C_carbonate values but much lower, if any, contents of AOM biomarkers. This suggests that AOM‐derived carbonate ions diffused over a greater distance to the site of precipitation compared with yellow aragonite. The latest phase, equant calcite spar, did not yield appreciable biomarkers, but showed a notable ¹³C_carbonate‐enrichment that is most likely caused by methanogenesis that prevailed in the sediments after AOM activity had ceased. A comparison of the ancient seep carbonates with modern counterparts from Hydrate Ridge (offshore Oregon, USA) revealed a remarkable coincidence of the respective mineral phases and their biomarker patterns. This suggests that the mechanisms of carbonate formation and the associated biogeochemical processes remained unchanged over geological times. □Biomarkers, carbonates, cold seeps, Hydrate Ridge, isotopes, Oligocene, Washington.     

A revision of West Palaearctic species of the Micropsectra atrofasciata species group (Diptera: Chironomidae)

Phylogenetic relations among selected Micropsectra (Diptera: Chironomidae) species are inferred using mitochondrial COII gene sequences and morphological characters. Both maximum parsimony and Bayesian analyses indicate a monophyletic atrofasciata species group. However, some species morphologically similar to M. atrofasciata (Kieffer) in the adult male, i.e. M. appendica sp. nov. and M. logani (Johannsen), are placed outside the atrofasciata group in the gene trees. The phylogenetic hypotheses based on parsimony analyses of the combined molecular and morphological data sets weakly support a monophyletic atrofasciata group including M. appendica sp. nov. and M. logani if third positions in the COII gene sequences are excluded. In the taxonomic part of this study, adult males, pupae and larvae of Micropsectra aristata Pinder, M. atrofasciata, M. bavarica sp. nov., M. klinki sp. nov., M. logani, M. pallidula (Meigen) and M. schrankelae sp. nov. , and adult males and pupae of M. appendica sp. nov. and M. sofiae sp. nov. as well as adult males of M. andalusiaca Marcuzzi, M. calcifontis sp. nov., M. freyi Storå, M. longicrista sp. nov., M. robusta sp. nov. , and M. zernyi Marcuzzi are described and diagnosed. Micropsectra bidentata (Goetghebuer), M. jokaquarta Sasa & Ogata, M. miki Marcuzzi, M. pallida Goetghebuer, M. subnitens Goetghebuer, M. suecica (Kieffer) and M. shouharasima Sasa are new junior synonyms of M. atrofasciata; Micropsectra groenlandica Andersen and M. utonaitertia Sasa are new junior synonyms of M. logani; Micropsectra candida Chaudhuri & Datta, M. franzi Goetghebuer and M. viridiscutellata Goetghebuer are new junior synonyms of M. pallidula. Comments on the ecology, distribution and systematics of each species are provided. Keys to all known life stages are presented, as well as an annotated list of species morphologically similar to species in the atrofasciata group and nomina dubia in the atrofasciata group. Chironomus mimulus Holmgren is transferred to the genus Micropsectra. © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society, 2006, 146 , 165–225.     

Phylogenetic relationships of nonbiting midges in the subfamily Tanypodinae (Diptera: Chironomidae) inferred from morphology

The nonbiting midge subfamily Tanypodinae represents one of the most diverse lineages of Chironomidae. Despite the wide distribution and high diversity of tanypodine chironomids, the evolutionary history of the subfamily remains poorly understood. Here, we present the first phylogenetic analysis of the subfamily Tanypodinae based on morphological data. Cladistic analyses were conducted using 86 morphological characters from 115 species belonging to 54 tanypodine genera, including the eight currently recognised tribes: Anatopyniini, Clinotanypodini, Coelopyniini, Macropelopiini, Natarsiini, Pentaneurini, Procladiini and Tanypodini. We use characters from fourth‐instar larvae, pupae and adults of both sexes. We examine the effects of implied weighting by reanalysing the data with varying values of concavity constant (k). Our analysis supports the monophyly of Tanypodinae with Podonominae as its sister group. All previously proposed tribes are recovered as monophyletic assemblages under a wide range of weighting factors. Under these conditions, the genus Fittkauimyia is the sister group of the remaining Macropelopiini and is erected as a new monobasic tribe, Fittkauimyiini trib.n . The tribe Pentaneurini is recovered as monophyletic with some internal relationships resolved. The genus Paramerina, recovered as sister of Reomyia + Zavrelimyia, is formally synonymised with Zavrelimyia syn.n. , based on morphological similarity in all three life stages and treated as a subgenus of the latter. Finally, the recently suggested synonymies of Gressittius and Guassutanypus with Alotanypus and the establishment of the subgenera Conchapelopia (Helopelopia), Macropelopia (Bethbilbeckia), Monopelopia (Cantopelopia), Thienemannimyia (Hayesomyia) and Zavrelimyia (Reomyia and Schineriella) are investigated. Our results support all proposed changes, except for the subgenus‐level status of Helopelopia and Cantopelopia. We suggest re‐establishment of Helopelopia as a genus, but refrain from promoting genus‐level status of Cantopelopia at present because the apparent sister‐relationship between Monopelopia + Nilotanypus likely is due to wing vein reduction caused by miniaturisation. This published work has been registered in ZooBank, http://zoobank.org/urn:lsid:zoobank.org:pub:DF012C17‐AFB3‐4904‐83DC‐30DD94D0B376 .