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PubMed1998

Response to photoperiod during diapause development in the spider mite Tetranychus urticae.

To study the question whether photoperiodic time measurement in the spider mite Tetranychus urticae is based on a qualitative or quantitative principle, the duration of diapause development was determined in individual females at various constant photoperiods at 19 degrees C. Diapause duration at all four long-night treatments fluctuated around 64.5 days, varying from 62.2 at LD 12:12h to 66.4 at LD 10:14h. The within-treatment variation in diapause duration of the long-night groups appeared to be significantly correlated to the nightlength of the photoperiods used; the longer the nightlength, the higher the within-treatment variation. Frequency distributions of females completing diapause under the two regimes with nightlengths near the critical nightlength were skewed to the right. Mean diapause durations at these regimes, LD 13:11h and LD 14:10h, were 25.4 and 11.9 days, respectively. Mites completed diapause rapidly and synchronously under the three short-night photoperiods tested; within two weeks after transfer from cold storage at 4 degrees C to the diapause terminating regimes at 19 degrees C all females started reproduction. Mean diapause durations were 8.1, 6.4 and 6.5 days for the short-night treatments LD 15:9h, LD 17:7h and LD 19:5h, respectively. The coefficients of variation of diapause duration (variability within groups relative to the mean) of the short-night and the long-night groups varied from 18 to 42%; the coefficients of the two intermediate groups were 69and 81%. There was a clear difference in diapause duration between long-night and short-night groups, but no significant difference was present in this characteristic between different long-night groups on the one hand and only a small difference between different short-night groups on the other. These results support the hypothesis that photoperiodic time measurement in the spider mite is based on a qualitative principle; photoperiods are classified as either 'long' or 'short' in relation to a 'critical' photoperiod. However, around the critical nightlength, intermediate responses were observed which might hint at the quantitative nature of the underlying mechanism. Therefore, although most results are in agreement with the hypothesis of a qualitative mechanism, it cannot be excluded that photoperiodic time measurement in the spider mite is based on a quantitative principle.

Journal Article↗

PubMed1988

Painless cauterization of spider veins with the use of iontophoretic local anesthesia.

Treatment of small vascular abnormalities of the skin is painful, and injections of local anesthetic agents distort the operating field. Iontophoresis of salt-free, 4% lidocaine, with and without epinephrine, delivered to the skin from a receptacle with a semipermeable membrane, and with the use of a current-controlled electrical system, resulted in effective anesthesia of the skin for cauterization of "spider" veins. Fourteen subjects received 32 treatments. Sixteen paired areas of spider veins were anesthetized with iontophoresis of lidocaine and with lidocaine plus epinephrine 1/50,000. The duration of anesthesia with lidocaine averaged 14 minutes; relief of pain was complete in 9/16 treatments, adequate in 6/16, and inadequate in 1/16. Lidocaine plus epinephrine supplied anesthesia for 56 minutes; relief of pain was total in 14/16 treatments and adequate in the remaining two. Thus iontophoresis with the use of selected local anesthetic and iontophoretic equipment provides adequate conditions for cauterization of spider veins, a procedure poorly served by conventional local anesthesia.

Anesthesia, Local↗

PubMed1999

High temperatures eliminate Wolbachia, a cytoplasmic incompatibility inducing endosymbiont, from the two-spotted spider mite.

Wolbachia can induce cytoplasmic incompatibility (CI) in the arrhenotokous two-spotted spider mite between uninfected females and infected males. Cytoplasmic incompatibility is expressed through a male-biased sex ratio and a low hatchability, and can be suppressed by removing Wolbachia from spider mites reared on a diet with antibiotics. Here we investigated whether heat-treatment can elimate Wolbachia from infected mites. Using a PCR assay with a Wolbachia-specific primer pair (ftsZ), and by standard crosses, we were able to show that 71 per cent of the mites had lost the Wolbachia infection after rearing the infected population at 32+/-0.5 degrees C for four generations. The infection could be completely removed when mites were reared at 32+/-0.5 degrees C for six generations. Curing through high temperatures could be one of the reasons why mixed infected/uninfected populations occur in the field. An additional consequence of rearing mites at 32+/-0.5 degrees C was the shortened development time. The effect of environmental temperature on the abundance of Wolbachia and possible behavioural consequences for the spider mite are discussed.

Administration, Oral↗

PubMed2003

Exudate from sporulating cultures of Hirsutella thompsonii inhibit oviposition by the two-spotted spider mite Tetranychus urticae.

The acaricidal mycopathogen Hirsutella thompsonii has been found to secrete metabolites that are active against female Tetranychus urticae. Specifically, the rose-colored exudate produced on sporulating cultures of Mexican HtM120I strain sterilized female spider mites in a dose-dependent fashion. Topical application of the exudate resulted in a 100% reduction in mite fecundity over the initial six days of experimentation. Depending upon the exudate dosage, mites partially recovered within 3 and 6 d post-treatment and produced a limited number of eggs. The spider mite active HtM120I exudate contained less detectable HtA toxin than the HtM120I broth filtrate, and it was innocuous when injected into the greater wax moth Galleria mellonella L. larvae. Broth filtrates of HtM120I cultures, although toxic to assayed G. mellonella larvae, did not inhibit mite oviposition to the degree or duration of the exudate preparations. These findings suggest that the factor responsible for suppressing oviposition in female spider mites is linked to the sporulation process and is distinct from the well-characterized HtA produced by vegetative cells.

Animals↗

PubMed2006

Homology of arthropod anterior appendages revealed by Hox gene expression in a sea spider.

Arthropod head segments offer a paradigm for understanding the diversification of form during evolution, as a variety of morphologically diverse appendages have arisen from them. There has been long-running controversy, however, concerning which head appendages are homologous among arthropods, and from which ancestral arrangement they have been derived. This controversy has recently been rekindled by the proposition that the probable ancestral arrangement, with appendages on the first head segment, has not been lost in all extant arthropods as previously thought, but has been retained in the pycnogonids, or sea spiders. This proposal was based on the neuroanatomical analysis of larvae from the sea spider Anoplodactylus sp., and suggested that the most anterior pair of appendages, the chelifores, are innervated from the first part of the brain, the protocerebrum. Our examination of Hox gene expression in another sea spider, Endeis spinosa, refutes this hypothesis. The anterior boundaries of Hox gene expression domains place the chelifore appendages as clearly belonging to the second head segment, innervated from the second part of the brain, the deutocerebrum. The deutocerebrum must have been secondarily displaced towards the protocerebrum in pycnogonid ancestors. As anterior-most appendages are also deutocerebral in the other two arthropod groups, the Euchelicerata and the Mandibulata, we conclude that the protocerebral appendages have been lost in all extant arthropods.

Animals↗

PubMed2003

Comparison of potassium titanyl phosphate vascular laser and hyfrecator in the treatment of vascular spiders and cherry angiomas.

Patients with vascular spiders and angiomas, especially on exposed sites, demonstrate considerable psychological morbidity and therefore request treatment. Traditionally, electrosurgical modalities have been used to treat such lesions, but more recently lasers have been introduced. This open study assesses the efficacy of these two treatment modalities, scoring patients' preference and psychological morbidity before and after treatment. All patients had two vascular spiders or angiomas. One lesion was randomized for treatment with the hyfrecator, whilst the other lesion was treated with the potassium titanyl phosphate (KTP) vascular laser. The end-point of the study was either clearance of lesions or a maximum of three treatments at 2-month intervals. In this first comparative study, we demonstrate that both therapeutic modalities were effective in treating these lesions and in significantly reducing the post-treatment psychological morbidity score. However, on average, only one treatment with the KTP laser was required to achieve clearance compared with two treatments with the hyfrecator. This would result in less clinic visits. In addition, patients favoured the KTP laser because of the lack of side-effects. Both the KTP vascular laser and the hyfrecator were able to clear vascular spiders and angiomas, but the KTP laser was superior as fewer treatment episodes were required and patients preferred this treatment modality because of the lack of side-effects.

Adolescent↗

PubMed1999

Group founding and breeding structure in the subsocial spider stegodyphus lineatus (Eresidae)

Co-operative behaviour may evolve by enhancing the genetic similarity of group members. Increased group similarity is thought to be the basis for the 'subsocial route' of social evolution in the spider family Eresidae. Two processes may promote the similarity of individuals within populations or breeding groups, namely philopatry in stable environments and founder events in a stochastic environment. We show that both processes led to genetic differentiation within and among populations of the subsocial spider Stegodyphus lineatus. Within populations we distinguished between the genetic structure caused by random mating and philopatry in old breeding groups and that caused by newly founded groups consisting of sibs. Such sib-groups suggest that new breeding groups are established primarily by single females. The different gene coancestries among breeding groups resulted in high variances among single-locus data. The results imply that sex-specific dispersal behaviour (random male mating-dispersal or female group founding) had different impacts on the population structure. This type of population structure, where within-population philopatry and founder events may lead to differential proliferation of breeding groups, is very similar to that presumed for social spiders, and is also one that could provide the conditions for interdemic selection.

Journal Article↗

PubMed1983

Spider leg autotomy induced by prey venom injection: An adaptive response to "pain"?

Field observations showed orb-weaving spiders (Argiope spp.) to undergo leg autotomy if they are stung in a leg by venomous insect prey (Phymata fasciata). The response occurs within seconds, before the venom can take lethal action by spread to the body of the spiders. Autotomy is induced also by honeybee venom and wasp venom, as well as by several venom components (serotonin, histamine, phospholipase A(2), melittin) known to be responsible for the pain characteristically elicited by venom injection in humans. The sensing mechanism by which spiders detect injected harmful chemicals such as venoms therefore may be fundamentally similar to the one in humans that is coupled with the perception of pain.

Journal Article↗

PubMed2004

Differential timing of spider mite-induced direct and indirect defenses in tomato plants.

Through a combined metabolomics and transcriptomics approach we analyzed the events that took place during the first 5 d of infesting intact tomato (Lycopersicon esculentum) plants with spider mites (Tetranychus urticae). Although the spider mites had caused little visible damage to the leaves after 1 d, they had already induced direct defense responses. For example, proteinase inhibitor activity had doubled and the transcription of genes involved in jasmonate-, salicylate-, and ethylene-regulated defenses had been activated. On day four, proteinase inhibitor activity and particularly transcript levels of salicylate-regulated genes were still maintained. In addition, genes involved in phospholipid metabolism were up-regulated on day one and those in the secondary metabolism on day four. Although transcriptional up-regulation of the enzymes involved in the biosynthesis of monoterpenes and diterpenes already occurred on day one, a significant increase in the emission of volatile terpenoids was delayed until day four. This increase in volatile production coincided with the increased olfactory preference of predatory mites (Phytoseiulus persimilis) for infested plants. Our results indicate that tomato activates its indirect defenses (volatile production) to complement the direct defense response against spider mites.

Acyclic Monoterpenes↗

PubMed2004

Combined transcript and metabolite analysis reveals genes involved in spider mite induced volatile formation in cucumber plants.

Many plants have an indirect defense against herbivores by emitting volatiles that attract carnivorous enemies of the herbivores. In cucumber (Cucumis sativus) the production of carnivore attractants can be induced by herbivory or jasmonic acid spraying. From the leaves of cucumber plants with and without spider mite infestation, two subtractive cDNA libraries were made that were enriched in cDNA fragments up- or down-regulated by spider mite infestation. A total of 713 randomly selected clones from these libraries were used to make a cDNA microarray. Subsequently, cucumber plants were sprayed with jasmonic acid, mechanically damaged, infested with spider mites, or left untreated (control). Leaf samples were taken at a range of different time points, and induced volatile compounds and mRNA (from the same leaves) were collected. cDNAs prepared from the mRNA were hybridized to the clones on the microarray. The resulting gene expression profiles were analyzed in combination with volatile production data in order to gain insight in the possible involvement of the studied genes in the synthesis of those volatiles. The clones on the microarray and the induced cucumber volatiles could be grouped into a number of clusters in which specific biosynthetic genes clustered with the product of that pathway. For example, lipoxygenase cDNA clones clustered with the volatile (Z)-3-hexenyl acetate and the volatile sesquiterpene (E,E)- alpha-farnesene clustered with an up-regulated sesquiterpene synthase fragment. This fragment was used to screen a cDNA library which resulted in the cloning of the cucumber (E,E)-alpha-farnesene and (E)-beta-caryophyllene synthases. The use of combined global gene expression analysis and metabolite analysis for the discovery of genes involved in specific biosynthetic processes is discussed.

Amino Acid Sequence↗

PubMedDate not supplied

Cerebrospinal fluid indices in cryptococcal and tuberculous meningitis: the spider web coagulum and its diagnostic significance.

The differentiation between a chronic cryptococcal meningitis and a chronic tuberculous meningitis may cause problems for the clinician only if standard microbiological methods are not applied to the diagnosis of both infections. In a male non-AIDS patient (50 y), 11 years after a suggested diagnosis of "tuberculous meningitis", meningoencephalitis with hydrocephalus was diagnosed and treated accordingly without success. Mycobacterium tuberculosis was never found. Because fibrin fibres of a spider web coagulum in the CSF resembled Aspergillus mycelium, the patient was then treated with amphotericin B + flucytosine. Finally, a mycological examination led to the true diagnosis: (1) In the CSF, resembling Aspergillus hyphae were found to be spider web coagulum fibres. (2) Cryptococcal meningoencephalitis based on the detection of Cryptococcus neoformans in CSF and its antigen in serum and CSF. - At post-mortem, cryptococcal meningoencephalitis was established as cause of death. Residual signs of tuberculosis could not be detected in the brain and the meninges. Common clinical similarities of cryptococcal and tuberculous meningitis and the possibility of a double infection are discussed. A comparison of the presence of Cr. neoformans in the meninges of non-AIDS and AIDS patients is made. The formation of spider web coagulum in the CSF is discussed. Proposals for the diagnosis, therapy and prophylaxis of cryptococcal meningitis are made.

Cryptococcosis↗

PubMed1973

Isolation of a new simian foamy virus from a spider monkey brain culture.

A syncytium-forming (foamy) virus was isolated from a spider monkey brain cell culture. Cytopathic effect was observed both in the brain culture and in human embryonic kidney cells. Neutralizing antibody was present in the sera of the spider monkey from whom the isolation was made. The virus was inhibited by 5-bromo-2-deoxyuridine (20 mug/ml), contained a ribonucleic acid-dependent deoxyribonucleic acid polymerase, and had an infectivity peak at 1.15 g/cm(3) in a sucrose density gradient. The virus passed through a 220-nm but not a 100-nm membrane filter, was chloroform sensitive, and was inactivated at 56 C in 30 min. Hemagglutinating and hemadsorption activity was not noted with a variety of erythrocytes. The virion was spherical, formed in the cytoplasm, and was 105 to 115 nm in diameter. Ring-shaped nucleoids, 45 to 50 nm in diameter, were associated with tubular profiles. The virus was not neutralized by sera prepared against known viruses, including simian foamy virus types 1 through 7, Mason-Pfizer monkey virus, and bovine syncytial and measles viruses. Sera from a rabbit hyperimmunized with the isolate and sera from 19 spider monkeys had neutralizing antibody to the isolate; however, these sera did not cross-react with simian foamy virus types 1 through 7. Neutralizing antibody to the isolate was not detected in sera from 16 humans, 9 rhesus monkeys, and 10 chimpanzees.

Animals↗

PubMed2004

Construction and characterization of bacterial artificial chromosome library of black-handed spider monkey (Ateles geoffroyi).

The large-insert genomic DNA library is a critical resource for genome-wide genetic dissection of target species. We constructed a high-redundancy bacterial artificial chromosome (BAC) library of a New World monkey species, the black-handed spider monkey (Ateles geoffroyi). A total of 193 152 BAC clones were generated in this library. The average insert size of the BAC clones was estimated to be 184.6 kb with the small inserts (50-100 kb) accounting for less than 3% and the non-recombinant clones only 1.2%. Assuming a similar genome size with humans, the spider monkey BAC library has about 11x genome coverage. In addition, by end sequencing of randomly selected BAC clones, we generated 367 sequence tags for the library. When blasted against human genome, they showed a good correlation between the number of hit clones and the size of the chromosomes, an indication of unbiased chromosomal distribution of the library. This black-handed spider monkey BAC library would serve as a valuable resource in comparative genomic study and large-scale genome sequencing of nonhuman primates.

Animals↗

PubMed1983

Detachable stainless-steel spider. A new device for vessel occlusion.

A new device for transcatheter vessel occlusion consists of a stainless-steel spider which can be screwed onto a threaded guide wire. Since the spider can be retrieved after it is extruded from the catheter, accurate placement is possible. The device was tested in the aorta and pulmonary artery of dogs. The spider blocked the movement of steel coils and wool streamers and occluded the vessel. This device is particularly useful for occlusion of large arteriovenous fistulas in the lungs.

Animals↗

PubMed1986

Locomotion and feeding postures of spider and howling monkeys: field study and evolutionary interpretation.

Field observations demonstrate clear differences in locomotion and feeding postures between spider monkeys (Ateles) and howling monkeys (Alouatta). When feeding, Ateles employs sitting postures approximately half the time, and a variety of suspensory postures using the tail the other half. Ateles moves quadrupedally during 52% of locomotion, by tail-arm suspension 25%, and various mixed support-suspensory modes the remainder. Tail-arm suspension is practiced more rapidly on thinner supports, and on more negatively inclined supports than is quadrupedal movement. Howlers do not locomote by tail-arm suspension: movement is almost entirely quadrupedal and is slower than that of spider monkeys. The positional behavior of spider monkeys fits closely recent views of major adaptive changes in hominoid evolution emphasizing brachiation and speed during travel. Howler locomotion and also tissue composition appear related to diet and digestive mechanisms.

Alouatta↗

PubMed2005

The male genital system of the cellar spider Pholcus phalangioides (Fuesslin, 1775) (Pholcidae, Araneae): development of spermatozoa and seminal secretion.

BACKGROUND: Most arthropods pass through several molting stages (instars) before reaching sexual maturity. In spiders, very little is known about the male genital system, its development and seminal secretions. For example, it is unknown whether spermatozoa exist prior to-, or only after the final molt. Likewise, it is unclear whether sperm are produced throughout male adulthood or only once in a lifetime, as is whether seminal secretions contain factors capable of manipulating female behavior. In order to shed light on these aspects of the reproductive biology of spiders, we investigated the male genital system of the common cellar spider Pholcus phalangioides, with special emphasis on its development and seminal secretions. RESULTS: Testes already display all stages of spermatogenesis in subadult males (about four weeks before the final molt). Their vasa deferentia possess proximally a very voluminous lumen containing dense seminal fluid and few spermatozoa, whereas the distal part is seemingly devoid of contents. Spermatoza of P. phalangioides are typical cleistospermia with individual secretion sheaths. In male stages approximately two weeks prior to the final molt, the lumina of the testes are wider and filled with a dense secretion. The wide, proximal portion of the vasa deferentia is filled with secretion and a large number of spermatozoa, and the narrow distal part also contains secretion. In adult males, the wide lumina of the testes are packed with spermatozoa and secretions. The latter are produced by the somatic cells that bear microvilli and contain many vesicles. The lumina of the vasa deferentia are narrow and filled with spermatozoa and secretions. We could identify a dense matrix of secretion consisting of mucosubstances and at least three types of secretion droplets, likely consisting of proteinaceous substances. CONCLUSION: This study reveals that spermatogenesis begins weeks before maturity and takes place continuously in the long-lived males of P. phalangioides. Possible functions of the various types of secretion in the seminal fluid and previously investigated female secretions are discussed in the light of sexual selection.

Journal Article↗

PubMed2002

[Study on construct and expression of synthetic genes encoding spider dragline silk in Escherichia coli].

Dragline spider silk produced from Nephilia clavipes major ampullate is a natural fibrous protein with specific mechanical properties such as high tensile strength and elasticity. Synthetic gene monomer encoding recombinant spider silk protein, based on the known repetitive protein sequence and partial cDNA sequence of dragline silk, was constructed and expressed. DNA monomer sequences were multimerized to encode high molecular weight synthetic spider silks using a "head-to-tail" construction strategy. Multimer was cloned into pET30a(+), a prokaryotic high potency expression vector, and induced with IPTG. The protein from 8-unit repeat was produced in Escherichia coli at levels up to 20 mg/L. The protein was easily purified with high recovery by using an metal ion affinity chromatography and purity was over 90%. The results of SDS-PAGE and Western blot suggested that the mass of the expression product was about 37 kD. This value and amino acid analysis were consistent with those of theoretic calculation.

Amino Acid Sequence↗

PubMed2005

[Study on the conditions of high density fermentation for the engineering bacterial strain with RGD spider silk protein gene].

Spider silk becomes the protein fibroin with excellent character in the natural world because of its unique mechanical properties. The genetic engineering technique is an effective method to procure the spider silk protein. In order to obtain RGD-spider silk protein gene recombinant engineering strain pNSR-16 on a regular scale, we determine the optimal conditions of the growth and expression of pNSR-16 through culture in laboratory, and based on these, study the fed-batch high density culture. We control the flow of carbon-nitrogen, the dissolved oxygen concentration and the cell specific growth rate, which make the final cell density and concentration of recombinant protein of total protein arrive at OD600 57.15 and 20.8%, respectively.

Animals↗