Transfer RNATyr of melanoma tissues and cells: relevance to melanin synthesis?

The tRNA present in swine melanoma tumor tissue and normal gray skin tissue were compared by aminoacylation of the unfractionated tRNA preparations. Of the seventeen amino acids studied, seven showed differences in rate of acceptance to tRNAs from normal and tumor tissues; the tRNAs of two amino acids, tyrosine and glycine, showed dramatic three fold increases in melanoma tumor. As melanin biosynthesis proceeds from tyrosine oxidation the investigations focused on the increase in tyrosine tRNA. Kinetic analysis of tyrosine aminoacylation to normal and melanoma tRNAs revealed no differences. Analysis of the isoaccepting species of tRNATyr from normal skin and melanoma tumor tissues identified three isoacceptors; tRNATyr, represented the predominant species in normal gray skin, while tRNA2Tyr predominated in melanoma tumor tissue. The tyrosine acceptances by tRNAs from three human melanoma cell lines were analyzed and found to be variable, but isoaccepting species analysis of the tRNATyr of these three cell lines still showed a correlation between the preponderance of tRNA2Tyr and extent of tyrosine acceptance. Additionally the enzymatic activity for the oxidation of tyrosine was found to be related to tyrosine acceptance and tRNA2Tyr predominance..     

Homing and migration of mesenchymal stromal cells: How to improve the efficacy of cell therapy?

Mesenchymal stromal cells(MSCs) are currently being investigated for use in a wide variety of clinical applications. For most of these applications, systemic delivery of the cells is preferred. However, this requires the homing and migration of MSCs to a target tissue. Although MSC hominghas been described, this process does not appear to be highly efficacious because only a few cells reach the target tissue and remain there after systemic administration. This has been ascribed to low expression levels of homing molecules, the loss of expression of such molecules during expansion, and the heterogeneity of MSCs in cultures and MSC culture protocols. To overcome these limitations, different methods to improve the homing capacity of MSCs have been examined. Here, we review the current understanding of MSC homing, with a particular focus on homing to bone marrow. In addition, we summarize the strategies that have been developed to improve this process. A better understanding of MSC biology, MSC migration and homing mechanisms will allow us to prepare MSCs with optimal homing capacities. The efficacy of therapeutic applications is dependent on efficient delivery of the cells and can, therefore, only benefit from better insights into the homing mechanisms.     

Activity of digestive proteinases and carbohydrases in the alimentary tract of the fig leaf roller,Choreutis nemorana Hübner (Lepidoptera: Choreutidae)

.The fig leaf roller or Fig-tree Skeletoniser, Choreutis nemorana (Lep.: Choreutidae), is a destructive pest of fig trees found in some fig-growing areas of Iran. The larvae feed on the upper level of leaves, near the main vein. In this study, digestive carbohydrases including α-glucosidase, β-glucosidase, α-galactosidase, β-galactosidase and proteinases including trypsin, chymotrypsin and elastase were investigated. The results showed that the carbohydrases were present in the alimentary tracts of the pest. Optimum pH for α-glucosidase and β-glucosidase activity was at pH 6.0 and 7.0, respectively. Maximum activity of α-galactosidase and β-galactosidase occurred at pH 6.0. Total proteolitic activity against the substrate azocasein was optimally occurred at pH 10.0. The greatest activity of trypsin, chymotrypsin and elastase was determined at pH 10.0, 11.0 and 11.0, respectively. Zymogram analyses using nitrocellulose membrane revealed two trypsin isoforms in which one of them was completely inhibited by Soybean Kunitz inhibitor and the other was notably inhibited.     

Gap junctions between germ and somatic cells in the testis of the moth,Anagasta küehniella (Insecta: Lepidoptera)

Summary Heterocellular gap junctions were demonstrated in germ cysts of the moth Anagasta küehniella (Lepidoptera). They conjoin peripheral germ cells of a cyst and cells of their envelope. Their morphology differs according to the developmental stage of the germ cell involved. While gap junctional profiles are flat in cysts of gonia, in cysts of early spermatocytes they appear as button-like structures, the germ cell indenting the corresponding cyst cell. In cysts of late spermatocytes and of young spermatids, they are very numerous and often located at the extremity of conical protrusions of the germ cell. On the germ cell side, cytoplasmic microfilaments are associated with the junctional differentiation. Gap junctions are observed as being pinched off from the surface of the spermatids and, correspondingly, gap vesicles are found in the cyst cells. This, together with the fact that gap junctions are not found at later stages of development, suggests that internalization of the gap junctions might take place before elongation of the spermatids. The potential importance of these germsomatic cell gap junctions is evaluated in light of recent physiological findings obtained by other authors on the oocyte-cumulus system and also in relation with some particularities in the development of the male germ cells in Lepidoptera.     

Structure and ultrastructure of the silk glands and spinneret of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae)

This study provides comprehensive documentation of silk production in the pest moth Helicoverpa armigera from gland secretion to extrusion of silk thread. The structure of the silk glands, accessory structures and extrusion apparatus are reported. The general schema of the paired silk glands follows that found for Lepidoptera. Morphology of the duct, silk press, muscle attachments and spigot are presented as a three-dimensional reconstruction and the cuticular crescent-shaped profile of the silk press is demonstrated in both open and closed forms with attendant muscle blocks, allowing advances in our knowledge of how the silk press functions to regulate the extrusion of silk. Growth of the spigot across instars is documented showing a distinctive developmental pattern for this extrusion device. Its shape and structure are related to use and load-bearing activity.     

Anatomy of the neurosecretory cells in the cerebral and subesophageal ganglia of the female European corn borer moth,Ostrinia nubilalis (Hübner) (Lepidoptera: Pyralidae)

The anatomy of the neurosecretory cells in the brain-subesophageal ganglion complex of female European corn borer moth Ostrinia nubilalis (Lepidoptera: Pyralidae) was studied using histological and cobalt backfilling techniques. Histological staining revealed the presence of 2 median and one lateral neurosecretory cell groups in the brain. These brain neurosecretory cells are made up of mainly type A cells with a few type B cells in the median group. Three type C neurosecretory cell clusters occupy the apparent mandibular, maxillary, and labial neuromeres at the ventral median aspect of the subesophageal ganglion. Axonal pathways of the neurosecretory cell groups were delineated by retrograde cobalt filling from the corpora cardiaca. Fibers of the 3 brain neurosecretory cell groups merged to form a distinct axonal tract that exits the brain via the fused nervi corporis cardiaci-1 + 2. Cobalt backfilling from the corpora cardiaca filled 4 groups of cell bodies in the subesophageal ganglion. The presence in the subesophageal ganglion of extensive dendritic arborizations derived from the brain suggests interactions between neurosecretory cell groups in the 2 head ganglia.     

Responses of Adult Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) to Light and Combinations of Attractants and Light

Responses of adult Indianmeal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) to light alone and to a combination of attractant(s) and green/UV lights were studied. When P. interpunctella adults were given a choice between dark areas and areas illuminated with UV, green, or white light, they rested preferentially on surfaces in the illuminated areas. UV light elicited the strongest of the positive phototactic responses. Light traps were not as effective as traps baited with pheromones or food lures in capturing adult moths, and combining green or UV light with these attractants did not significantly increase the trap catches. Gravid females required a period of darkness to realize maximum oviposition, and illumination above 8 lx during the scotophase of a 24-hr light–dark cycle inhibited oviposition.     

Phylogeny,classification and divergence times of pygmy leaf‐mining moths (Lepidoptera: Nepticulidae): the earliest lepidopteran radiation on Angiosperms?

Nepticulidae represent one of the early diverging Lepidoptera lineages, and the family currently comprises over 850 described species. The larvae of the vast majority of the species are leaf miners on Angiosperms and highly monophagous, which has led to persistent ideas on coevolution with their plant hosts. We present here a molecular phylogeny based on eight gene fragments from 355 species, representing 20 out of 22 extant Nepticulidae genera. Using two fossil calibration points, we performed molecular dating to place the origin of the family in the Early Cretaceous, before the main Angiosperm diversification. Based on our results we propose a new classification, abandoning all ranks between family and genus, as well as subgenera to allow for a stable classification. The position of Enteucha Meyrick within Nepticulidae remains somewhat ambiguous, and the species‐rich cosmopolitan genus Stigmella Schrank, with nearly half of all described Nepticulidae, requires further study. Ectoedemia Busck, Zimmermannia Hering, Acalyptris Meyrick, Etainia Beirne, Parafomoria Borkowski, Muhabbetana Koçak & Kemal and Fomoria Beirne appear to have diversified in a relatively short evolutionary period, leading to short branches in the molecular phylogeny and unclear suprageneric relations. Otherwise support values throughout the phylogeny are mostly high and the species groups, genera and higher clades are discussed in respect of their supporting morphological and life‐history characters. Wing venation characters are confirmed to be mostly reliable and relevant for Nepticulidae classification, but some other previously used characters require reinterpretation. The species groups of most genera are recovered, but only partly so in the large genus Stigmella. The molecular dating results are compared with existing knowledge on the timing of the Angiosperm radiation and reveal that the diversification of Nepticulidae could largely have been contemporaneous with their hosts, although some of the genera restricted to a single plant family appear to have begun to diversify before their hosts.     

Classification,nomenclature and identification of lime swallowtail butterflies: A post‐cladistic analysis (Lepidoptera: Papilionidae)

Specimens taxonomically treated in the Fauna Hawaiiensis were associated by cluster analysis, thereby reconstructing assemblages of Hawaiian carabid beetle species (Coleoptera: Carabidae) observed during the late 19th century. Associations among specimens representing 193 species permit concise hypotheses of habitat preferences for many of the 32 carabid species collected during the early period of European scientific exploration (1872–1902), but not observed since. These associations are consistent with data derived from contemporary biological surveys of Hawai'i. Absence of entire clusters of associated species from recent collections suggests actions of common agents leading to extinction or extreme population reduction. The candidate list of threatened and endangered species of the US. Fish and Wildlife Service established prior to 1994 included one Hawaiian carabid species missing since 1902, versus eight other species collected at various times over the past century. Improvements in knowledge of carabid beetle species’ spatial distribution and temporal persistence derived from recent field survey and taxonomic research demonstrate that the types of criteria used to construct that list must be rejected. Future consideration of official conservation status for any Hawaiian carabid beetle species must take into account the status of ecologically associated species, and the limited likelihood that individuals of all extant species can be consistently observed in nature due to their natural relative rarity or their secretive habits within restricted geographic and ecological distributions. Historical specimen associations serve as the best guides for continuing efforts to monitor known faunal members and to rediscover long‐missing species. These associations also serve to link information concerning individual species with particular habitats.     

Regional differences in the apical F-actin cytoskeleton of silk gland cells of Calpodes ethlius (Stöll) (Lepidoptera : Hesperiidae)

Silk glands of the larvae of Calpodes ethlius, Stöll (Lepidoptera : Hesperiidae) were labelled with rhodaminyl-phalloin, which is specific for f-actin. Most f-actin lies below the apical cell surface in bundles oriented in rings around the lumen of the gland. By the fifth larval stadium, the density of bundles differs in the 5 regions of the gland, the greatest density occurring in the narrower anterior regions. The greater bundle density may be correlated with the increased hoop stress where the gland has the smallest diameter. F-actin from the bundles redistributes during larval moults to coat vacuoles in the cytoplasm, except in the 2 most anterior regions where it keeps its arrangement from stage to stage, even through the moult.     

How do insects react to novel inherited symbionts? A microarray analysis of Drosophila melanogaster response to the presence of natural and introduced Spiroplasma

Maternally inherited endosymbionts are found in numerous insect species and have various effects on host ecology. New symbioses are most commonly established following lateral transfer of an existing symbiont from one host species to another. Laboratory study has demonstrated that symbionts commonly perform poorly in novel hosts, with weak vertical transmission and maladaptive pathogenicity being observed in the generations following transfer. This poor performance probably limits symbiont occurrence. We here use microarray technology to test whether poor symbiont performance observed following 1 year of vertical transmission through a new host is associated with alteration in host gene expression or whether it occurs independently of this. We utilize the Drosophila melanogaster--Spiroplasma interaction and test the response of the host in the presence of both natural Spiroplasma infections and novel Spiroplasma infections transinfected previously from other host species. None of the Spiroplasma infections investigated produced upregulation in host haemolymph/fat body-based immune responses, and we therefore rejected the hypothesis that failure to thrive was associated with immune upregulation. One infection was associated with a downregulation of genes associated with egg production compared to uninfected controls, indicative of damage to the host. The Spiroplasma infection showed that the weakest vertical transmission showed no significant disturbance to host gene expression compared to uninfected controls. We conclude that the failure of Spiroplasma in novel host species is associated either with causing harm to their new hosts or through a failure to thrive in the new host that occurs independently of host responses to infection.     

Organization of the lamina ganglionaris of the optic lobe of the butterfly Pararge aegeria (Linné) (Lepidoptera : Satyridae)

The present work reports on a neuroanatomical study of the butterfly Pararge aegeria (Lepidoptera : Satyridae) focusing on the lamina ganglionaris underlying two different regions of the retina of the compound eye: the dorsal rim area and the large dorsal region. No differences between both lamina regions, concerning the structure of the cartridges and the morphology of the identified neurons, could be detected. After passing the basement membrane, the visual cell axons are organized in retinotopic bundles (pseudocartridges), in which the axons of the 9 visual cells (V1 and 5, D2, 4, 6, 8, H3 and 7, B9) are arranged in the same way as in the retina. In the pseudocartridge there are no synaptic contacts. Before entering the lamina cartridge, the bundles rotate 90 °. The cartridges are joined by the fibres of 4 monopolar cells (L1, L2, L3 and L4), which could be identified and located inside the lamina cartridges in serial EM-sections. Golgi impregnations revealed the morphology of these fibres. Thus, the regional specialization of the retina (dorsal rim area and large dorsal region) does not seem to be reflected at the level of the first visual neuropil. Additionally, the cartridges of both lamina regions were investigated qualitatively for synaptic contacts among fibres. In addition to monadic chemical synapses and multiple contact synapses with presynaptic ribbons, cell contacts are also facilitated by invaginations and bridges. These cellular interactions and their functional implications are discussed.     

Enhancement of attraction to sex pheromone of Grapholita molesta (Busck) (Lepidoptera: Tortricidae) by structurally unrelated sex pheromone compounds of Conogethes punctiferalis (Guenée) (Lepidoptera: Crambidae)

Grapholita molesta (Busck) (the oriental fruit moth; OFM) and Conogethes punctiferalis (Guenée) are both fruit and stem borers with overlapping habitats, occurrences, and outbreak cycles. These two species are in different families and they have completely different sex pheromone components. Here, the effects of the sex pheromone components of C. punctiferalis, (E)-10-hexadecenal (E10-16:Ald) and (Z)-10-hexadecenal (Z10-16:Ald) and their mixture, were evaluated on the sexual communication of OFM by examining electrophysiological (EAG) and behavioral responses. We found that a considerably large amount of E10-16:Ald or Z10-16:Ald and a tiny amount of OFM pheromone elicited comparable EAG responses in OFM males, indicating the low antennal olfactory sensitivity of OFM males to the heterospecific pheromone compounds. In two different peach orchard parcels, captures of OFM by their pheromone lures baited in delta traps were increased by at least 1.5 times when OFM pheromone lures were combined with lures that contained 1000 μg of either E10-16:Ald, Z10-16:Ald or their mixture. In two other pear orchard parcels, both E10-16:Ald and Z10-16:Ald increased captures of OFM in Unitraps in a dose-dependent manner with more than a four-fold increase. Therefore, the enhanced attractiveness of OFM lures by the two interspecific pheromones suggests their potential application to improve mass trapping, population monitoring and mating disruption of OFM.     

Oral—parenteral immunization leads to the appearance of IgG auto-anti-idiotypic cells in mucosal tissues

The appearance of plasma cells, specific for antigen or autologous idiotypic antibody, in rabbits immunized systemically, orally, or orally-systemically was determined using immunofluorescence techniques. Oral or parenteral immunizations alone did not lead to the appearance of anti-idiotypic cells in mucosal tissues, although IgA antigen-binding cells were observed in these sites after the oral administration of antigen. However, when rabbits were primed with orally administered antigen, followed by a regimen of concurrent oral—parenteral immunizations, IgG anti-idiotypic plasma cells were demonstrated in mucosal lymphoid tissues.     

Impact of some insecticides and their mixtures on the population of tomato borers,Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) and Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) in tomato crop at Upper Egypt

Impact of some insecticides and their mixtures (Emamectin benzoate, Imidaclopride, Chlorfenapyr, Indoxacarb, Profenofos, Pyridalyl, Methomyl and Teflubenzuron) were evaluated against the tomato borers, Tuta absoluta (Meyrick) and Helicoverpa armigera (Hübner) population in tomato crop at Upper Egypt. Results of LC₅₀ values indicated that Emamectin benzoate was the most toxic compound (LC₅₀ 0.461%) against T. absoluta, larvae. The carbamate insecticide, Methomyl, followed this descending order, showing almost similar toxicity, while Teflubenzuron and Chlorfenapyr were less effective (LC₅₀ 1.054 and 3.165%, respectively). Pyridalyl was found to be the most effective insecticide against larval stage of H. armigera. (LC₅₀ 0.513%). The corresponding toxicities of the other tested insecticides, arranged according to their LC₅₀ values in descending order were as follow: Methomyl, Emamectin benzoate, Profenofos, Imidaclopride, Teflubenzuron, Indoxacarb and Chlorfenapyr. Their LC₅₀ values were ranged between (0.513 and 0.872%). While, their toxicity indexes were ranged between (92.432 and 58.830%, respectively). On the other hand, there were no differences occurred among the treatments. Mean of percent infestation was decreased six weeks after six sprayings, and the per cent reduction in infestation was 79.73, 80.22, 78.41, 80.88, 80.50, 78.30, 79.64 and 78.25% using Emamectin benzoate, Methomyl, Imidaclopride, Pyridalyl, Profenofos, Indoxacarb, Teflubenzuron and Chlorfenapyr, respectively. The efficiency of the tested insecticides was increased with increasing the number of sprays from two to six causing reduction in insect borer infestation ranged between 68.02 and 80.88%, respectively. Generally, the tested insecticides and their mixtures achieved a considerable reduction in T. absoluta and H. armigera population.     

Biogeography,ecology and conservation of Erebia oeme (Hübner) in the Carpathians (Lepidoptera: Nymphalidae: Satyrinae)

The European endemic Erebia oeme (Hübner [1804]) (Lepidoptera: Nymphalidae: Satyrinae) is discovered in the Carpathian Chain, from where it was considered to be absent. The single population found is situated in the southern part of the Romanian Carpathians (Retezat Mountains), where it flies sympatrically and synchronically with Erebia medusa ([Denis & Schiffermüller] 1775). The similar external morphology of these two species probably caused E. oeme to be overlooked in the Carpathians, leading to an unexpected information gap in the otherwise thoroughly studied European continent. The morphology of the Romanian specimens is compared to populations from the rest of the species’ range and to E. medusa. In addition, we tested DNA barcoding as a method to discriminate between these species and confirmed that it represents an effective identification tool for the taxa involved. The habitat of E. oeme, adults of both sexes and their genitalia are illustrated in comparison with E. medusa. Based on the study of several collections, we show that E. oeme is likely to be extremely local in the Carpathians and provide arguments to consider the species as vulnerable in Romania.     

The evolutionary basis of leaf senescence: method to the madness?

Recent studies on the differential expression of genes associated with leaf senescence support the long-standing interpretation of plant senescence as an organized, genetically controlled process. Sequence identities of genes that are differentially expressed in senescing leaves indicate roles in the salvage of nutrients. By considering this salvage function as the selected trait and the degeneration and death of the tissue a pleiotropic consequence of nutrient redistribution, the process of leaf senescence can be reconciled with evolutionary theories on the origins of senescence in animals.