Insect intestinal mucins and serine proteases associated with the peritrophic matrix from feeding, starved and moulting Mamestra configurata larvae

Insect intestinal mucins (McIIM2-4) expressed in the midgut of feeding, starved and moulting Mamestra configurata larvae were identified. McIIM2 and McIIM4 were associated with the peritrophic matrix (PM). PMs from feeding and starved larvae were translucent and contained organized chitin bundles perpendicular to their long axis, whereas PM from moulting larvae consisted of an inner opaque mass surrounded by an outer translucent sleeve. Serine protease genes (McSP1, McSP2, McSP25 and McSP29) were also expressed in these larvae and several serine proteases were associated with the PM. Serine protease activity was also detected in the midgut of feeding, starved and moulting larvae.

A chitin deacetylase and putative insect intestinal lipases are components of the Mamestra configurata (Lepidoptera: Noctuidae) peritrophic matrix

One- and two-dimensional gel electrophoresis coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to identify cDNA encoding a chitin deacetylase (McCDA1) and three insect intestinal lipases (McIIL1, McIIL2 and McIIL3) associated with the Mamestra configurata (bertha armyworm) peritrophic matrix. Recombinant McCDA1 was active and chitin deacetylase activities were detected in the midgut. McCDA1 and the McIIL genes were expressed exclusively in the midgut; however, McCDA1 and McIIL2 were expressed in all larval stages, whereas McIIL1 was expressed mainly in feeding larvae and McIIL3 primarily during the moult.

Does host plant influence parasitism and parasitoid species composition in Lygus rugulipennis? A molecular approach

Lygus Hahn plant bugs (Hemiptera: Miridae) are serious pests of a wide variety of economically important crops in North America. European Peristenus digoneutis Loan and P. relictus Ruthe (Hymenoptera: Braconidae) are being considered for release in Canada as part of a classical biological control program for Lygus. The attractiveness of different host plants to European Peristenus has not been addressed, but may be an important consideration prior to parasitoid release. Lygus rugulipennis Poppius nymphs were collected in the Northern Temperate Atlantic (NTA) ecoregion on red clover (Trifolium pratense L.; Fabaceae) and chamomile (Matricaria recutita L.; Asteraceae), and in the Western European Broadleaf Forest (WEBF) ecoregion on red clover and alfalfa (Medicago sativa L.; Fabaceae). Parasitism levels and parasitoid species were determined using a multiplex PCR assay for P. digoneutis, P. relictus, and P. pallipes Curtis. Mean parasitism levels in L. rugulipennis were 45-49% in the NTA ecoregion and 25-32% in the WEBF ecoregion. However, in neither ecoregion were parasitism levels and parasitoid species compositions significantly different in nymphs from different host plant species. Furthermore, multiparasitism was low despite the fact that P. digoneutis and P. relictus share the same host species.

Characterization of an intestinal mucin from the peritrophic matrix of the diamondback moth, Plutella xylostella

The peritrophic matrix (PM) of Plutella xylostella larvae was found to contain twelve integral and eighteen loosely associated proteins. An antiserum against Mamestra configurata integral PM proteins cross-reacted with several P. xylostella PM proteins and was used to isolate a partial cDNA encoding an insect intestinal mucin (PxIIM). PxIIM was expressed primarily in the larval midgut. The deduced protein sequence of the partial cDNA contained three potentially glycosylated, mucin-like domains and six cysteine-rich chitin-binding domains (CBDs). An additional chitin-binding domain was proposed to reside at the amino terminus of the protein based on comparison with other IIM. The organization of mucin domains and CBDs exhibited features, including an internal triplet of regularly spaced CBDs and a carboxyl terminal CBD with two additional conserved cysteine residues, that were found to be common to other lepidopteran IIMs.

Male infertility

Infertility affects 13-18% of couples and growing evidence from clinical and epidemiological studies suggests an increasing incidence of male reproductive problems. The pathogenesis of male infertility can be reflected by defective spermatogenesis due to pituitary disorders, testicular cancer, germ cell aplasia, varicocele and environmental factors or to defective sperm transport due to congenital abnormalities or immunological and neurogenic factors. Recent studies suggest an increased incidence of genetic disorders related to male infertility which may affect different levels, interfering with germ cell generation and maturation or leading to the production of non-functional spermatozoa. The identification of genetic causes of male infertility raises the issue of the transmission of defects to the offspring, a situation that is becoming more important given the increasing use of intracytoplasmic sperm injection (ICSI), a procedure in which the natural selection of the spermatozoa is by-passed. Fertilization can occur in vitro using ejaculated, epididymal or testicular spermatozoa, either fresh or frozen-thawed, providing opportunities hitherto not possible for men to be genetic fathers.

Clinical evaluation of three different gonadotrophin-releasing hormone analogues in an IVF programme: a prospective study

The efficacy and safety of short acting buserelin and nafarelin intranasal spray were compared to long acting leuprorelin depot intramuscular or subcutaneous injection in this prospective study of 157 women undergoing controlled ovarian hyperstimulation (COH) for in-vitro fertilisation (IVF). Patients were allocated to three groups to receive buserelin 150 microg nasal spray three times daily (Group B), nafarelin nasal spray 400 microg twice daily (Group N), or leuprorelin depot 3.75 mg once by intramuscular or subcutaneous injection (Group L) for pituitary desensitisation prior to commencing COH with human menopausal gonadotrophins (hMG) according to the Centre's protocol. The mean (+/-S.D.) age (years) (32.6+/-3.8: Group B, 32.1+/-3.3: Group N versus 32.1+/-3.3: Group L); mean (+/-S.D.) total dosage of hMG (ampoules) (37.5+/-16.1: Group B, 39.8+/-14.2: Group N versus 41.9+/-12.6: Group L) and mean daily dosage of hMG (ampoules) (3.1: Group B, 2.8: Group N versus 3.0: Group L) seen were not statistically significantly different. The duration between starting the different gonadotrophin-releasing hormone (GnRHa) and the beginning of the next menstrual period was also not seen to be statistically significantly different between the three groups (Group B: 10+/-5.5, Group N: 9.1+/-4.1 versus Group L: 8.2+/-3, days). The number of abandoned cycles was higher in Group L (17% versus 11.8%: Group B and 11.3%: Group N) but this difference did not reach statistical significance. The clinical pregnancy rates per oocyte retrieval and per embryo transfer procedure were respectively, 31.1, 35% in Group B, 12.8, 14% in Group N versus 20.5, 23.7 in Group L and were not seen to be statistically significantly different even when ongoing pregnancy rates were compared. Apart from a statistically significantly greater incidence of allergic nasal reactions in the nafarelin group (P=0.001), all other side-effects were not shown to be statistically significantly different between the three groups. We conclude that a single dose of leuprorelin depot can be considered to be as an equally effective alternative to multiple doses of buserelin or nafarelin for pituitary desensitisation in women undergoing COH for IVF.

Value of measuring serum FSH in addition to serum estradiol in a coasting programme to prevent severe OHSS

BACKGROUND

Withholding gonadotrophins (coasting) can reduce the risk of severe ovarian hyperstimulation syndrome (OHSS) in patients having assisted reproduction therapy. This requires daily serum estradiol (E(2)) measurements, which occasionally have been seen to decline suddenly and sharply.

METHODS

To increase the sensitivity of the coasting programme we measured serum FSH in parallel with E(2) in patients at risk of developing OHSS.

RESULTS

Out of a total of 1240 cycles, 106 were coasted and in 89 both serum E(2) and FSH were measured at least twice during the coasting period. One case of late severe OHSS was encountered in the study group. The serum FSH declined by a rate of 24.3 +/- 4.5% per day. Serum E(2) level reached a 'safe level' of <10,000 pmol/l when the serum FSH declined to 5 IU/l or less.

CONCLUSION

The results from this study show that measuring serum E(2) and FSH can assist in predicting the point at which serum E(2) has declined to a level safe enough to administer the trigger HCG.

Screening spring wheat for midge resistance in relation to ferulic acid content

The concentration of ferulic acid (FA), the major phenolic acid in the wheat kernel, was found to differ significantly in the mature grain of six wheat cultivars known to have a range of tolerance to the orange wheat blossom midge (Sitodiplosis mosellana). Differences in FA content were correlated with floret infestation level of the cultivars. The wheat cultivars ranked similarly in FA content at the four locations where they were tested, despite a significant effect of environment. Ferulic acid was synthesized mainly during the early stages of grain filling but at different rates among cultivars. Ferulic acid was concentrated primarily in the shorts and bran fractions in an insoluble-bound form. A high correlation was obtained between FA contents as determined by GLC, fluorometry, UV, and colorimetry. The colorimetric procedure was modified as a qualitative, simple, and rapid test for identifying midge-resistant wheat and evaluated in several field trials. The method should provide a rapid tool in the preliminary screening of experimental lines in the development of midge-resistant wheat cultivars.

Effects of tissue extracts on oviduct contraction in the migratory grasshopper, Melanoplus sanguinipes

The isolated oviduct of the migratory grasshopper, Melanoplus sanguinipes, shows a myogenic, rhythmic pattern of contraction. The pattern of contraction can be modified by treatment with hemolymph or extracts from a variety of tissues from animals of differing age, sex, and mated status. Extracts of oviducts and ventral nerve cord (VNC), as well as hemolymph, from both virgin and mated females were almost always stimulating, though their effect on frequency, amplitude and/or tonus varied. In contrast, whereas extracts of spermatheca and brain from mated females were stimulating, extracts of these tissues from virgin females inhibited contraction. All male material tested (long hyaline tubules (LHT), the male accessory gland complex less the LHT, testes, brain, VNC and hemolymph) stimulated oviduct contraction in a dose-dependent manner, usually enhancing at least two of frequency, amplitude and tonus. However, oviposition-stimulating protein, a purified product of the LHT, provoked only an increase in frequency when applied to the oviduct. LHT extract modulated the effects of virgin female tissue extracts, always in a stimulatory manner.

Purification and characterization of an oviposition-stimulating protein of the long hyaline tubules in the male migratory grasshopper, Melanoplus sanguinipes

An oviposition-stimulating protein (OSP) was isolated and purified from the long hyaline tubules of the male accessory gland complex in the migratory grasshopper, Melanoplus sanguinipes. Gel filtration of the native OSP, using Sephadex G-100, indicates its molecular weight to be about 60000Da with the oviposition-stimulating activity while sodium dodecyl sulphate-polyacrylamide gel electrophoresis shows that the OSP comprises two subunits, each with a molecular weight of 30000Da. The purified OSP appears as a single symmetric peak on fast performance liquid chromatography using Mono Q. Isoelectric focusing of the OSP indicates an apparent pI of 5.5. Injection of the OSP induces oviposition in about 70% of ovulated virgin females within 48h. Stimulation of oviposition can be blocked by a polyclonal antibody raised against the OSP 30000Da subunits. Amino acid analysis of the dimer and its subunits shows a comparatively high content of aspartic acid/asparagine (14.8%) as well as leucine (12.2%) and glutamic acid/glutamine (12.0%). The N-terminal 21 amino acid sequence of the OSP shows little similarity to known peptides. Immunoreactivity with the anti-OSP antibody was observed in the viscous secretion, spermatheca, and the egg-pod froth of mated females, confirming transfer of the OSP from male to female during copulation.

Prolongation of life in an experimental model of aging in Drosophila melanogaster

(R)-Deprenyl, the archetypical monoamine oxidase-B inhibitor, has been shown to increase life-span in a number of species. Although many theories for this effect have been suggested, for example, an increase in superoxide dismutase (SOD) activity, the mechanism of action has yet to be elucidated. To investigate this phenomenon, we have examined the effects of (R)-deprenyl, and some aliphatic propargylamines, in an experimental aging model in Drosophila melanogaster. Both wild-type Oregon-R type flies, as well as a SOD knock-out mutant strain were used. Flies obtained from a series of paired mates were divided equally among treatment groups. In all studies, flies were treated for the duration of life following adult emergence. The aging model consists of substitution of sucrose with galactose in the regular food media of the flies. Initial experiments confirmed that such a substitution resulted in a significant (p < 0.01, Breslow test) reduction in mean and maximal life-span of flies, an effect not due to nutrient deprivation. Inclusion of (R)-deprenyl and the aliphatic propargylamines in the media, at average daily doses in the range 0.5-1 ng/fly/day, led to a significant increase in mean and maximal life-span of galactose-treated, but not control flies. This effect was seen in both wild-type and mutant flies.

A physical map of the Mamestra configurata nucleopolyhedrovirus genome and sequence analysis of the polyhedrin gene

The genome structure of a nucleopolyhedrovirus (NPV) isolated from the bertha armyworm, Mamestra configurata Walker (Lepidoptera: Noctuidae) (MacoNPV) was analysed with six restriction endonucleases (REN): BamHI, EcoRI, HindIII, PstI, SmaI and Xhol. More than 70 MacoNPV REN fragments were cloned into plasmids pUC18 and pBluescript SK(+). The physical map with 112 restriction sites for the above REN was constructed using double digests and Southern blot hybridization analysis of the MacoNPV DNA clones. The size of the DNA genome of the MacoNPV-90/2 isolate used for this study was estimated at 156 kbp based on REN fragment sizes. The position of the polyhedrin gene, which has by convention been used as the zero point of the REN maps of NPV, was determined by hybridizing the Autographa californica multicapsid nucleopolyhedrovirus HindIII-V fragment clone, which contains most of the polyhedrin gene, with genomic blots of MacoNPV. The cloned MacoNPV fragments identified as containing the polyhedrin gene were sequenced and an ORF coding for a 246 amino acid polypeptide with 98.7% sequence identity with Panolis flammea nucleopolyhedrovirus (PaflNPV) polyhedrin protein was identified. The putative polyhedrin gene sequence had 97.2% and 91.2% identity with the PaflNPV and Mamestra brassicae multicapsid nucleopolyhedrovirus polyhedrin gene sequences, respectively, and also contained an upstream region identical to the highly conserved 12 bp consensus sequence TGTAAGT-AATTT typical of NPV very late genes.

Juvenile hormone-dependent LHPI and RNA synthesis in Melanoplus sanguinipes long hyaline tubule: events associated with the "insensitive period"

Juvenile hormone (JH) regulation of the synthesis of LHPI, the major secretory protein of the long hyaline tubule in the male accessory reproductive gland (MARG) of Melanoplus sanguinipes, was examined by in vitro radiolabeling and immunoprecipitation. In MARG taken from normal insects JH III immediately stimulates production of immunospecific LHPI. In contrast, JH III does not initially promote synthesis of LHPI in MARG of allatectomized insects. Only after prior exposure to the hormone [for 24 hr when applied in vivo (topically) or 16 hr under in vitro conditions] is LHPI synthesis enhanced by JH III in the MARG of allatectomized insects. These results suggest that in the prolonged absence of JH III the MARG are "switched off," that is, lose their sensitivity to the hormone. Sensitivity is regained during the 24- or 16-hr "lag phase." Use of the translational inhibitor cycloheximide confirmed the existence of the lag phase in JH III-mediated LHPI synthesis. JH III stimulates RNA synthesis in a dose-dependent manner in the long hyaline tubule at concentrations < 64 nM. Above this level, RNA synthesis was depressed. Actinomycin D given simultaneously with JH III inhibited RNA synthesis, but not the synthesis of LHPI in the long hyaline tubule. It is suggested that understanding the nature of the lag phase will facilitate clarification of the mechanism of action of JH in the MARG.

Corpus allatum and corpus cardiacum regulation of long hyaline gland protein synthesis in the male grasshopper, Melanoplus sanguinipes

Rates of accumulation of, and radiolabel incorporation into, the major secretory product of the long hyaline gland, a glycoprotein LHPI, were used to examine the role of the corpus allatum (CA) and corpus cardiacum (CC) in the regulation of protein synthesis in the accessory reproductive gland of the male grasshopper, Melanoplus sanguinipes. Incorporation of [35S]methionine into LHPI in vitro indicated that LHPI was an endogenous long hyaline gland protein, whose in vivo synthesis in allatectomized animals was stimulated by topical application of juvenile hormone (JH) III. This response was not dependent on the presence of the extrinsic lobe of the CC, the CC/brain complex, or on continued feeding and suggests a direct effect of JH on the gland. Severance of the nervi corporis allati I and II reduced accumulation of LHPI but unilateral CA removal did not, perhaps because of a compensatory activation of the remaining CA. Normal postcopulatory stimulation of LHPI accumulation was abolished by allatectomy. These results suggest that the physiological level of JH may regulate LHPI synthesis. Corpus cardiacum effects were small in comparison to those of the CA; they were evident only in cardiacectomized animals that were allatectomized also and exerted over prolonged periods when the animals continued to feed. Endocrine manipulations produced no qualitative changes in long hyaline gland LHPI immunoreactive protein, only quantitative ones.

Juvenile hormone biosynthesis during sexual maturation and after mating in the adult male migratory grasshopper, Melanoplus sanguinipes

Juvenile hormone III is the exclusive juvenile hormone produced by the corpora allata in adult male Melanoplus sanguinipes. For the first 5 days after adult emergence, the rate of juvenile hormone biosynthesis is low, it then increases rapidly to peak on day 7. Between days 7 and 12 the rate declines to that of newly emerged males and then increases again in 14-day insects. In males allowed a single mating on day 7, the rate of juvenile hormone biosynthesis remains elevated at least to day 12.

Changes in the protein concentration and volume of the haemolymph in relation to yolk deposition, ovariectomy, allatectomy, and cautery of the median neurosecretory cells in Melanoplus sanguinipes

The protein concentration and volume of the haemolymph may change with no apparent relation to one another in normal, ovariectomized, allatectomized, and median-neurosecretorycell-cauterized (mNSC-cauterized) females. Therefore, protein levels in the haemolymph are more meaningfully expressed in terms of the total protein content. In normal females, fluctuations in the haemolymph volume tend to parallel changes in the protein concentration during the first and subsequent gonotrophic periods. However, significantly less protein accumulates during the latter periods. The suggestion that these fluctuations partly reflect changes in the vitellogenic requirements of the oocytes is supported by the finding that both the volume and protein concentration increase significantly after ovariectomy.Allatectomy or mNSC cautery prevents the normal accumulation of protein in the haemolymph. In allatectomized females, the slight increase in protein concentration is accompanied by a decline in haemolymph volume. Cautery of the mNSC, provided it is performed within 3 h of emergence, results in a low protein concentration but has no effect on the haemolymph volume. The observations are discussed in terms of the corpora allata and mNSC control of haemolymph protein synthesis.

Histological changes in the ovary in relation to yolk deposition, allatectomy, and destruction of the median neurosecretory cells in Melanoplus sanguinipes

Histological changes in the ovary during periods of yolk deposition suggest that differentiation of the follicular epithelium and oolemma is an essential prerequisite to the pinocytotic uptake of protein into the oocytes. Before vitellogenesis, intercellular spaces form between adjacent follicle cells, and a brush border appears along the oocyte surface. The presence of protein within these spaces and of elementary yolk spheres along the brush border suggests that protein reaches the oocyte by an intercellular route.Accumulation of yolk does not occur after allatectomy or median neurosecretory cell (mNSC) cautery. Allatectomy inhibits the differentiation of the follicle cells and oolemma. In contrast, after mNSC cautery, differentiation occurs but the pinocytotic vesicles pinched off from the oolemma are empty, indicating that the availability of yolk precursors, not the uptake mechanism, has been affected. In addition, the appearance of secretion in the lateral oviducts is prevented by allatectomy, but merely delayed by mNSC cautery. The findings indicate that the corpora allata, but not the mNSC, are the source of a gonadotropin that regulates follicle-cell differentiation and the development of secretion in the lateral oviducts.

Reproductive growth in normal, allatectomized, median-neurosecretory-cell-cauterized, and ovariectomized females of Melanoplus sanguinipes

Changes in the weight of the whole insect, fat body, and ovary during successive gonotrophic cycles have been measured. The effects of ovariectomy, cautery of the median neurosecretory cells (mNSC), or removal of the corpora allata (CA) on the development of the fat body and reproductive system have also been observed.After an initial period of somatic growth, changes in body weight are very largely due to growth of the proximal oocytes and to oviposition. Yolk deposition begins when the oocytes are1.0 mm long and occurs most rapidly during the final stages of their development. Vitellogenesis begins in the penultimate oocytes when the proximal oocytes are 3.0–3.5 mm long. Ovariectomy results in a significant increase in the weight of the fat body. Removal of the CA prevents oocyte development beyond the 1-mm stage and production of secretion in the lateral oviducts. Both effects can be reversed by treating operated insects with juvenile hormone. Cautery of the mNSC, provided it is carried out within 3 h of emergence, also inhibits oocyte growth and delays the appearance of secretion in the lateral oviducts.

Insemination in the migratory grasshopper, Melanoplus sanguinipes (Fabr.)

Insemination in Melanoplus sanguinipes takes place by means of a small, relatively simple, tubular spermatophore which begins to form in the ejaculatory duct almost immediately after a pair is securely coupled. It takes about 5 min to complete the process of forming the spermatophore in the ejaculatory duct, extruding it into the spermathecal duct and ejecting it from the spermathecal duct and aedeagus following sperm transfer. During extrusion the tube penetrates only a short distance into the wide bend of the spermathecal duct at which point the seminal fluid is discharged. The entire spermatophore is then withdrawn and becomes lodged between the valvulae of the female. As many as 14 spermatophores are produced consecutively during a single copulation. The situation in M. sanguinipes is discussed in relation to the information available on other acridids.

Morphology and histology of the cephalic endocrine glands of the damselfly, Coenagrion angulatum Walker (Zygoptera: Odonata)

In Coenagrion angulatum Walk. there is a single group of neurosecretory cells, median in position, on each side of the brain. The A- and B-type cells are intermingled within each group and their axons form a single pair of nerves to the corpora cardiaca. No pattern of secretory activity is discernible in the B cells. The A cells of mature nymphs and newly emerged adults are loaded with fuchsinophilic droplets but the amount of stainable material decreases as sexual maturation proceeds. A corresponding change in the location and amount of fuchsinophilic material takes place in the corpora cardiaca. In the mature nymph and young adult there is much material distributed throughout the gland. During sexual maturation it becomes less in quantity and restricted to a position adjacent to the aorta wall. A pair of stout, strongly fuchsinophilic nerves leaves the anterior end of the corpora cardiaca and passes ventrolaterally. These bypass the corpora allata and enter the thorax. Their point of termination has not been determined in this study. The corpora allata are small, roundish-oval bodies in the mature juvenile and newly emerged adult damselfly. While retaining their general shape they increase in volume several fold as sexual maturation takes place. The ventral glands are large, lobular structures in mature nymphs. Immediately after emergence they shrink and their cells become pycnotic. Generally by the fourth day of adult life they have disappeared. The results of this study are discussed in relation to those of other authors for the Odonata.

Male accessory gland substance: an egg-laying stimulant in Melanoplus sanguinipes (F.) (Orthoptera:Acrididae)

The rate of egg deposition by mature virgin females of the migratory grasshopper, Melanoplus sanguinipes (F.), increased markedly after implantation of accessory glands from mature males. Implants consisting of one-half of a complete set of glands, or of the 10 short hyaline glands alone, were about equally effective in increasing the rate of egg deposition. However, in each case the oviposition rate was less than that of normally mated females of the same age. Implanting only the white glands of the accessory gland complex had a lesser effect on egg-laying and implants of the long hyaline gland or of the seminal vesicle had little or no effect.Our results indicate that the physical act of mating per se or the presence of sperm probably do not provide the primary stimulus to egg-laying. The abdominal location of the implanted accessory gland does, however, suggest that some diffusible chemical substance is responsible for increasing egg deposition in these virgin females.