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71.
Aim To investigate biogeographical patterns of cleptoparasitic Exaerete bee species and their orchid bee hosts.
Location Neotropical region, from Central America to southern Brazil.
Methods Correlations between relative frequencies of cleptoparasitic Exaerete species and their host Eulaema species were employed to investigate the geographical association between such species pairs.
Results Our data support the current proposition that the Eulaema meriana / Eulaema flavescens complex is the main host for Exaerete frontalis . Contrary to current belief, however, Eulaema nigrita apparently is not the only and, in some regions, not the most important host for Exaerete smaragdina .
Main conclusions Current knowledge on cleptoparasite host associations among orchid bees is based on fortuitous observations, and in some instances generalizations from such observations are not corroborated by the frequencies and distributions of the bees involved. Our data suggest that cleptoparasitic pressure, rather than other features of the forest environment, may be responsible for the low abundance of E. nigrita in the Amazonian forests. 相似文献
Location Neotropical region, from Central America to southern Brazil.
Methods Correlations between relative frequencies of cleptoparasitic Exaerete species and their host Eulaema species were employed to investigate the geographical association between such species pairs.
Results Our data support the current proposition that the Eulaema meriana / Eulaema flavescens complex is the main host for Exaerete frontalis . Contrary to current belief, however, Eulaema nigrita apparently is not the only and, in some regions, not the most important host for Exaerete smaragdina .
Main conclusions Current knowledge on cleptoparasite host associations among orchid bees is based on fortuitous observations, and in some instances generalizations from such observations are not corroborated by the frequencies and distributions of the bees involved. Our data suggest that cleptoparasitic pressure, rather than other features of the forest environment, may be responsible for the low abundance of E. nigrita in the Amazonian forests. 相似文献
72.
Tettamanti G Grimaldi A Casartelli M Ambrosetti E Ponti B Congiu T Ferrarese R Rivas-Pena ML Pennacchio F Eguileor Md 《Cell and tissue research》2007,330(2):345-359
We have analyzed midgut development during the fifth larval instar in the tobacco budworm Heliothis virescens. In prepupae, the midgut formed during larval instars undergoes a complete renewal process. This drastic remodeling of the
alimentary canal involves the destruction of the old cells by programmed cell-death mechanisms (autophagy and apoptosis).
Massive proliferation and differentiation of regenerative stem cells take place at the end of the fifth instar and give rise
to a new fully functioning epithelium that is capable of digesting and absorbing nutrients and that is maintained throughout
the subsequent pupal stage. Midgut replacement in H. virescens is achieved by a balance between this active proliferation process and cell-death mechanisms and is different from similar
processes characterized in other insects.
This work was supported by FAR 2006 (University of Insubria) to G.T., by a MIUR-FIRB-COFIN grant (no. RBNE01YXA8/2004077251),
and by the Centro Grandi Attrezzature (University of Insubria). 相似文献
73.
Velentzas AD Nezis IP Stravopodis DJ Papassideri IS Margaritis LH 《Cell and tissue research》2007,327(2):399-414
We describe the features of programmed cell death occurring in the egg chambers of Drosophila virilis during mid-oogenesis and late oogenesis. During mid-oogenesis, the spontaneously degenerating egg chambers exhibit typical
characteristics of apoptotic cell death. As revealed by propidium iodide, rhodamine-conjugated phalloidin staining, and the
TUNEL assay, respectively, the nurse cells contain condensed chromatin, altered actin cytoskeleton, and fragmented DNA. In
vitro caspase activity assays and immunostaining procedures demonstrate that the atretic egg chambers possess high levels
of caspase activity. Features of autophagic cell death are also observed during D. virilis mid-oogenesis, as shown by monodansylcadaverine staining, together with an ultrastructural examination by transmission electron
microscopy. During the late stages of oogenesis in D. virilis, once again, the two mechanisms, viz., nurse cell cluster apoptosis and autophagy, operate together, manifesting features
of cell death similar to those detailed above. Moreover, an altered form of cytochrome c seems to be released from the mitochondria
in the nurse cells proximal to the oocyte. We propose that apoptosis and autophagy function synergistically during oogenesis
in D. virilis in order to achieve a more efficient elimination of the degenerated nurse cells and abnormal egg chambers.
The present study was co-financed within Op. Education by the European Social Fund and by National Resources via a grant (HRAKLEITOS
70/3/7164) to Professor L.H. Margaritis. 相似文献
74.
In honeybees (Apis mellifera), the biogenic amine octopamine has been shown to play a role in associative and non-associative learning and in the division
of labour in the hive. Immunohistochemical studies indicate that the ventral unpaired median (VUM) neurones in the suboesophageal
ganglion (SOG) are putatively octopaminergic and therefore might be involved in the octopaminergic modulation of behaviour.
In contrast to our knowledge about the behavioural effects of octopamine, only one neurone (VUMmx1) has been related to a
behavioural effect (the reward function during olfactory learning). In this study, we have investigated suboesophageal VUM
neurones with fluorescent dye-tracing techniques and intracellular recordings combined with intracellular staining. Ten different
VUM neurones have been found including six VUM neurones innervating neuropile regions of the brain and the SOG exclusively
(central VUM neurones) and four VUM neurones with axons in peripheral nerves (peripheral VUM neurones). The central VUM neurones
innervate the antennal lobes, the protocerebral lobes (including the lateral horn) and the mushroom body calyces. Of these,
a novel mandibular VUM neurone, VUMmd1, exhibits the same branching pattern in the brain as VUMmx1 and responds to sucrose
and odours in a similar way. The peripheral VUM neurones innervate the antennal and the mandibular nerves. In addition, we
describe one labial unpaired median neurone with a dorsal cell body, DUMlb1. The possible homology between the honeybee VUM
neurones and the unpaired median neurones in other insects is discussed.
This work was supported by the DFG ME 365/24-2. 相似文献
75.
Neuropeptides are a diverse widespread class of signaling substances in the nervous system. As a basis for the analysis of peptidergic neurotransmission in the insect olfactory system, we have studied the distribution of neuropeptides in the antennal lobe of the moth Heliothis virescens. Immunocytochemical experiments with antisera recognizing A-type allatostatins (AST-As), Manduca sexta allatotropin (Mas-AT), FMRFamide-related peptides (FaRPs), and tachykinin-related peptides (TKRPs) have shown that members of all four peptide families are present in local interneurons of the antennal lobe. Whereas antisera against AST-As, Mas-AT, and FaRPs give similar staining patterns characterized by dense meshworks of processes confined to the core of all antennal-lobe glomeruli, TKRPs are present only in neurons with blebby processes distributed throughout each glomerulus. In addition to local neurons, a pair of centrifugal neurons with cell bodies in the lateral subesophageal ganglion, arborizations in the antennal lobe, and projections in the inner antenno-cerebral tracts exhibits tachykinin immunostaining. Double-label immunofluorescence has detected the co-localization of AST-As, Mas-AT, and FaRPs in certain local interneurons, whereas TKRPs occurs in a distinct population. MALDI-TOF mass spectrometry has revealed nearly 50 mass peaks in the antennal lobe. Seven of these masses (four AST-As, two N-terminally extended FLRFamides, and Mas-AT) match known moth neuropeptides. The data thus show that local interneurons of the moth antennal lobe are highly differentiated with respect to their neuropeptide content. The antennal lobe therefore represents an ideal preparation for the future analysis of peptide signaling in insect brain. 相似文献
76.
A nicotinic acetylcholine receptor (nAChR) subunit gene, Mdalpha2, was isolated and characterized from the house fly, Musca domestica. This is the first nAChR family member cloned from house flies. Mdalpha2 had a cDNA of 2,607 bp, which included a 696 bp 5'-untranslated region (UTR), an open reading frame of 1,692 bp, and a 219 bp 3'-UTR. Its deduced amino acid sequence possesses the typical characteristics of nAChRs. Mdalpha2 genomic sequence was 11.2 kb in length in the aabys strain and 10.9 kb in the OCR strain, including eight exons and seven introns. Based on the deduced amino acid sequence, Mdalpha2 had the closest phylogenetic relationship to the Drosophila melanogaster Dalpha2 and Anopheles gambiae Agamalpha2, and a similar genomic structure to Dalpha2. Quantitative real-time PCR analysis showed that Mdalpha2 is expressed in the head and the thorax at 150- and 8.5-fold higher levels than in the abdomen. Linkage analysis of a Mdalpha2 polymorphism indicates this gene is on autosome 2. The importance of these results in understanding the diversity and phylogenetic relationships of insect nAChRs, the physiology of nAChRs in the house fly, and the utility of nAChR sequences in resistance detection/monitoring is discussed. 相似文献
77.
This paper describes a rare case of a male moth in Baltic amber in an excellent position for establishing a species. The moth represents the second species of the genus Baltimartyria Skalski, 1995, described herein as Baltimartyria rasnitsynisp. n. The detection of this new species prompts research on the systematic position of the genus within the family Micropterigidae. The genus was found to provide none of the apomorphic characters that would allow placement in one of the monophyletic lineages within the family. The genus is provisionally assigned to the "southern sabatincoid group", a weakly supported assemblage of Southern Hemisphere genera. The sister genus has still to be determined. Baltimartyria is the first North Hemisphere representative in this group. Some general aspects of historical biogeography relevant for the group are briefly discussed. 相似文献
78.
A comparison of the geographical distribution patterns of 647 species of Chrysomelidae in Central Europe revealed 13 types of distribution: (1) widely distributed, (2) southern, (3) southeastern, (4) southwestern, (5) northern, (6) eastern, (7) south east quarter, (8) south west quarter, (9) fragmented, (10) montane, (11) subalpine & alpine, (12) scattered, (13) unusual, and irregular patterns produced by insufficient data. Some of these distributions are trivial (e. g. northern, eastern, etc., alpine) but others are surprising. Some cannot be explained, e. g. the remarkable gaps in the distribution of Chrysolina limbata (Fabricius, 1775) and in Aphthona nonstriata (Goeze, 1777). Although our 63.000 records are necessarily tentative, we found that the distribution maps from these data reflect in many cases the common knowledge on the occurrence of leaf beetles in specific areas. 相似文献
79.
Lepidopterans display biological rhythms associated with egg laying, eclosion and flight activity but the photoreceptors that mediate these behavioural patterns are largely unknown. To further our progress in identifying candidate light-input channels for the lepidopteran circadian system, we have developed polyclonal antibodies against ultraviolet (UV)-, blue- and extraretinal long-wavelength (LW)-sensitive opsins and examined opsin immunoreactivity in the adult optic lobes of four hawkmoths, Manduca sexta, Acherontia atropos, Agrius convolvuli and Hippotion celerio. Outside the retina, UV and blue opsin protein expression is restricted to the adult stemmata, with no apparent expression elsewhere in the brain. Melatonin, which is known to have a seasonal influence on reproduction and behaviour, is expressed with opsins in adult stemmata together with visual arrestin and chaoptin. By contrast, the LW opsin protein is not expressed in the retina or stemmata but rather exhibits a distinct and widespread distribution in dorsal and ventral neurons of the optic lobes. The lamina, medulla, lobula and lobula plate, accessory medulla and adjacent neurons innervating this structure also exhibit strong LW opsin immunoreactivity. Together with the adult stemmata, these neurons appear to be functional photoreceptors, as visual arrestin, chaoptin and melatonin are also co-expressed with LW opsin. These findings are the first to suggest a role for three spectrally distinct classes of opsin in the extraretinal detection of changes in ambient light and to show melatonin-mediated neuroendocrine output in the entrainment of sphingid moth circadian and/or photoperiodic rhythms.This work was partially supported by the Canadian Institute for Advanced Research (A.D.B.) and the National Science Foundation (grant nos. IBN-0082700 and IBN-0346765; A.D.B.). 相似文献
80.
Hernández-Martínez S Li Y Lanz-Mendoza H Rodríguez MH Noriega FG 《Cell and tissue research》2005,321(1):105-113
Confocal laser-scanning microscopy was used to carry out a comparative study of the immunostaining for three families of neuropeptides, viz., allatostatin-A (AS-A), allatostatin-C (AS-C) and allatotropin (AT), in adult female mosquitoes of Aedes aegypti and Anopheles albimanus. The specific patterns of immunostaining for each of the three peptides were similar in both species. The antisera raised against AT, AS-A, and AS-C revealed intense immunoreactivity in the cells of each protocerebral lobe of the brain and stained cells in each of the ventral ganglia and neuronal projections innervating various thoracic and abdominal tissues. Only the AS-A antiserum labeled immunoreactive endocrine cells in the midgut. The distribution of the peptides supports the concept that they play multiple regulatory roles in both species.This work was supported by NIH grant AI 45545 to F.G.N. and CONACyT G-37186-M to M.H.R. 相似文献