Pathology and ultrastructure of Hz-2V infection in the agonadal female corn earworm,Helicoverpa zea

The pathology and ultrastructure of the reproductive tract of Hz-2V-infected female corn earworm moths, Helicoverpa zea, were studied. The identity of malformed reproductive tissues found in virus-infected moths was determined by examining these tissues in moths that were infected with the virus at different life stages. Malformation of reproductive tissues in the progeny of virus-infected female moths was first observed by 3 days post-pupation (dpp), indicating that virus replication had altered the differentiation of these tissues very early on in their development. The ultrastructure of the grossly malformed agonadal reproductive tissues from insects aged 3-10dpp revealed the absence of the cuticular lining found in the oviducts of normal moths, and the proliferation of epithelial cells in these infected oviduct tissues. In addition, large quantities of virus were found aggregated into a large mass in the lumen of the malformed cervix bursa of 10dpp agonadal female pharate adult moths. Prior to eclosion, the virus in the cervix bursa was observed separated into spherical masses, which are thought to exude through the ductus bursa and collect over the vulva, forming a viral "waxy plug" that is likely to play an important role in virus transmission.     

Physiological control of pheromone production in Choristoneura fumiferana and C. rosaceana

The diel periodicity of calling behavior and pheromone production are synchronous in virgin females of both Choristoneura fumiferana and C. rosaceana (Lepidoptera: Tortricidae). Newly emerged females decapitated prior to scotophase produced no or very little pheromone 24 h later. However, injection of PBAN or Br-SEG homogenates, obtained from donors of the same or the other species, stimulated pheromone production to normal levels. Transection of the ventral nerve cord (VNC) or extirpation of the terminal abdominal ganglion (TAG) did not affect pheromone production in control females. Similarly, injections of PBAN or Br-SEG homogenates into decapitated females reactivated pheromone production to normal levels, whether or not the VNC was intact or the TAG present. Furthermore, octopamine was not effective in stimulating pheromone production in decapitated females. Taken together, these results indicate that the regulation of pheromone production is not neurally mediated in either Choristoneura species. However, there was no evidence that hemolymph collected from pheromone-producing females contained pheromonotropic activity. Similarly, isolated glands incubated with PBAN did not produce pheromone. The presence of the bursa copulatrix was required to produce pheromone in both tortricids as production was not restored in decapitated bursa-less females injected with PBAN or a Br-SEG homogenate. However, an extract of the bursa copulatrix did not elicit pheromonotropic activity in decapitated females or incubated glands of either species. The bursa copulatrix is only involved in pheromone production of some species of tortricids but our results do not support the current explanation for such interspecific differences. We postulate that the relative importance of a bursa factor may be related to the evolution of different desaturation systems used for pheromone biosynthesis in the Tortricidae. Arch.     

Regulation of reproductive behaviour and egg maturation in the tobacco hawk moth, Manduca sexta

ABSTRACT. The virgin female tobacco hawk moth, Manduca sexta, flies during the early scotophase in an LD 16:8 cycle at 24C then begins 'calling' within 2h. Mating lasts 3–4 h. Oviposition occurs in the succeeding scotophases if a tobacco plant is present. The switch from virgin 'calling' behaviour to mated ovipositional behaviour is mediated by the presence of sperm and/or associated testicular fluids in the bursa copulatrix. The corpora allata, which are necessary for egg maturation in this species, are activated via the NCC I and II around the time of eclosion. Feeding increases the activity of the corpora allata in the virgin female (as judged by the number of eggs matured in 4 days) but mating brings about a further stimulation of the activity of the corpora allata. The stretching of the bursa copulatrix by the insertion of the spermatophore during mating is probably the trigger for this response. Continued neural input from the bursa copulatrix to the brain is necessary to maintain the increased activity of the corpora allata.     

Function of multiple sperm-storage organs in female damselflies (Ischnura senegalensis): difference in amount of ejaculate stored, sperm loss, and priority in fertilization

We studied changes in the number of sperm within two kinds of female sperm-storage organ in the damselfly Ischnura senegalensis (Odonata: Coenagrionidae): the bursa copulatrix and the spermatheca. We counted the number of sperm within each storage organ and tested their viability after a single copulation in female damselflies kept for seven days with and without oviposition. We also counted sperm and tested their viability in females that underwent an interrupted second copulation after the sperm-removal stage, and after subsequent oviposition. Our results showed that the bursa copulatrix and spermatheca have different sperm storage roles. Immediately after copulation, most eggs appear to have been fertilized with bursal sperm, which were positioned near the fertilization point. By seven days after copulation, a greater proportion of spermathecal sperm were used for fertilization, as the number of bursal sperm had decreased. We hypothesize that female damselflies use the spermatheca for long-term storage and the bursa copulatrix for short-term storage: bursal sperm are more likely to be used for fertilization but may have a higher risk of mortality due to sperm removal by a competing male and/or sperm expelling by the female, whereas spermathecal sperm are safer but will be used for fertilization only after their release from the spermatheca.     

Functional morphology of the sperm-containing chambers of the sea slug Okenia polycerelloides in the context of sexual selection

Sea slugs are interesting models to study post-copulatory sexual selection in simultaneous hermaphrodites due to the enormous variation of their reproductive systems. However, the knowledge of the functional morphology of their reproductive system is limited to few species, and it is rarely discussed in the context of sexual selection theory. In this study, we investigated the functional morphology of the sperm-containing chambers (i.e., ampulla, seminal receptacle, and bursa copulatrix) of the reproductive system of Okenia polycerelloides (Ortea & Bouchet, 1983), based on light, confocal, and electron microscopy. Although the morphology of the ampulla is similar to other species, indicating that it is a site for autosperm storage, we found some sperm facing the ampullar epithelium, a feature commonly regarded as characteristic of the seminal receptacle of sea slugs. The seminal receptacle of O. polycerelloides showed secretory activity and contained sperm with distribution and orientation suggestive of stratification of allosperm from distinct mating events, a feature that would affect sperm competition. The bursa copulatrix had epithelial cells with secretory and absorptive characteristics, and contained degraded sperm and yolk granules within its lumen. Comparative analyses of the contents of each organ demonstrated that sperm digestion occurs in the bursa copulatrix and affects sperm heads first, changing their morphology from slender and curved to shorter and ellipsoid before complete lysis. Although digestion and absorption of surplus sperm are currently the main hypothesized functions for the bursa copulatrix, its role in cryptic female choice should not be ruled out. The close structural connection between the seminal receptacle and bursa copulatrix, as well as their muscular walls, would enable control over the fate of the sperm received in each mating event, that is, storage or digestion.     

Angiotensin I-converting enzyme (ACE) activity of the tomato moth, Lacanobia oleracea: changes in levels of activity during development and after copulation suggest roles during metamorphosis and reproduction

Angiotensin I-converting enzyme (ACE) is a dipeptidyl carboxypeptidase that removes C-terminal dipeptides from relatively short oligopeptides, usually smaller than 15 amino acids. In mammals, the enzyme has several important roles in the metabolism of vasoactive peptides, but its physiological role in insects is not fully understood. We now report the properties of an ACE in a lepidopteran species (the tomato moth, Lacanobia oleracea) and suggest new physiological roles for the enzyme in this insect. ACE activity increases four-fold during the last stadium and in early pupae, a rise which, in its timing, is similar to what has been observed previously in the transition of larva to pupa in Drosophila melanogaster. This suggests that the increase in ACE activity might be of general importance for peptide metabolism during metamorphosis in holometabolous insects. High levels of ACE activity were found in the haemolymph of sixth stadium larvae and adult insects, and in the reproductive tissues of both male and female adults. Almost all of the ACE activity in the reproductive tissues was found in the accessory glands of the male and the spermatheca and bursa copulatrix of the female. The decline in accessory gland ACE in mated males and the concomitant rise in ACE activity in the spermatheca and bursa copulatrix of the female suggested the transfer of ACE from the male to the female during copulation. Using several convenient peptides as substrates, we have shown that the spermatophore/bursa copulatrix taken from mated female insects possess an aminopeptidase, a carboxypeptidase and a dipeptidase, in addition to high levels of ACE. These peptidases might be involved in the breakdown of proteins to peptides and eventually to amino acids in the spermatophore. Evidence for such a proteolytic pathway and its role in providing substrates for the TCA cycle has been obtained previously in a study of reproduction in Bombyx mori.     

Role of Nosema bombycis infected male silk moths in the venereal transmission of pebrine disease in Bombyx mori (Lep., Bombycidae)

Abstract: The role of male moths of silkworm in the spread of pebrine spores (disease) has been studied using appropriate crossings and examining the multiplication of spores in the testis. Sections of infected testis reveal the presence of spores in the peritoneal sheath, spermatids but not in the sperm. A large number of spores was observed in the bursa copulatrix of the uninfected female moth mated with an infected male moth. This is a first record of venereal transmission of pebrine spores in silkworms. Venereally transmitted spores do not contribute to transovarial transmission, but give a false positive indication during mother-moth examination. An alternative method for mother-moth testing has also been discussed.     

The anatomy of fertilization in the yellow dung fly Scathophaga stercoraria

Female yellow dung flies, Scathophaga stercoraria, can influence the traffic of sperm stored in their spermathecae to the site of fertilization in the bursa copulatrix. However, the anatomical mechanisms employed are largely unknown. We investigated the anatomy of the female genital tract, seeking structures involved in sperm transfer and egg fertilization. We found a membranous structure descending from the ends of the spermathecal and accessory gland ducts into the bursa copulatrix. We call this the prolatus. Sperm accumulate in the prolatus during oviposition. When an egg is in the bursa the egg micropyle, rather than being aligned towards the dorsal openings of the spermathecal ducts, lies on the opposite, ventral side. We also confirm the presence, and suggest a function for, a cuticularized pouch on the ventral wall of the anterior bursa copulatrix. This pouch, plus a previously undescribed chamber, may be homologous to the ventral receptacle/fertilization chamber found in other dipterans. Further, we describe a translucent cap, apparently transversed by channels, covering the micropyle. Sperm were observed to aggregate on and in the micropyle cap, which appears to attract and hold sperm. We interpret the prolatus as a structure that allows an ovipositing female to transfer a few sperm onto the ventral bursal wall and thus, indirectly, onto the micropyle cap. Such anatomy potentially gives the female a large degree of control over sperm traffic from storage to the site of fertilization.     

斑衣蜡蝉雌性生殖系统超微结构

【目的】明确斑衣蜡蝉Lycorma delicatula雌成虫生殖系统整体形态及超微结构特征,为蜡蝉总科昆虫分类及系统发育探讨提供更多形态学证据。【方法】采用光学显微镜与透射电子显微镜,观察斑衣蜡蝉雌成虫生殖系统整体形态和各主要器官的超微结构。【结果】斑衣蜡蝉雌成虫生殖系统主要包括1对卵巢、1个中输卵管、1个交配囊、1个交配囊管、1个前阴道、1个后阴道、1个受精囊、1个受精管和2根受精囊附腺。卵巢为端滋式,由14根卵巢小管组成,卵室由固有膜、滤泡细胞和卵细胞组成,卵巢小管中的滋养细胞清晰可见;中输卵管位于前阴道基部,由中输卵管腔、上皮细胞、肌肉鞘和基膜组成;交配囊膨大呈圆球状,囊壁由上皮细胞、肌肉层和基膜组成;交配囊管呈圆柱状,连接交配囊和后阴道,由肌肉鞘、上皮细胞层和管腔组成;前、后阴道超微结构相似,主要由肌肉鞘、基膜、上皮细胞和管腔组成,但后阴道上皮细胞细胞核周围存在分泌颗粒,且管腔内有大量微绒毛,而前阴道壁内包含有大量囊泡结构;受精管从中输卵管末端延伸至受精囊,由基膜、厚层肌肉鞘和管腔组成;受精囊为受精管近末端略膨大的囊状结构,由肌肉鞘、基膜、上皮细胞和囊腔构成;雌性受精囊附腺着生于受精囊末端,为均匀的螺旋管状,主要由肌肉层、上皮细胞层和附腺中心管腔组成。【结论】斑衣蜡蝉雌性生殖系统与已报道的蜡蝉总科其他类群的雌性生殖系统结构相似,但卵巢小管数目有差异;蝉亚目中不同总科雌成虫雌性附腺与受精囊附腺的形态特征存在明显区别;斑衣蜡蝉雌性生殖系统超微结构与叶蝉总科和沫蝉总科昆虫也存在部分差异。这些差异是否可以作为头喙亚目高级阶元的划分依据仍有待于进一步研究。     

Embryo transfer rederivation of C.B-17/Icr-Prkdc(scid) mice experimentally infected with mouse parvovirus 1

We determined whether embryos derived from C.B-17/Icr-Prkdc(scid) (SCID) mice infected with mouse parvovirus (MPV) 1b and mated to MPV-naive B6C3F1 mice would transmit virus to naive recipient female mice and rederived progeny. Viral DNA was detected by quantitative PCR (qPCR) in lymphoid tissues, gonad, sperm, and feces of all MPV1b-inoculated SCID mice. Viral DNA was detected in 1 of 16 aliquots of embryos from infected male SCID mice and in 12 of 18 aliquots of embryos from infected female SCID mice. All recipient female mice implanted with embryos from infected SCID male mice and their progeny were negative by serology and qPCR. In contrast, 3 of 5 recipient female mice implanted with embryos from infected SCID female mice and 14 of 15 progeny mice from these recipients were seropositive by multiplex fluorescent immunoassay (MFI) for MPV capsid antigen (rVP2). All of these mice were negative by MFI for parvovirus nonstructural protein antigen (rNS1) and by qPCR, with the exception of 1 recipient female mouse that displayed weak rNS1 seroreactivity and low levels of MPV DNA in lymphoid tissues. Seroreactivity to rVP2 declined over time in all progeny mice from infected SCID female mice until all were seronegative by 20 wk of age, consistent with maternal antibody transfer. Given that the high levels of MPV contamination detected in our experimentally infected SCID mice are unlikely in naturally infected immunocompetent mice, these data indicate that embryo transfer rederivation is effective for the eradication of MPV from infected colonies.     

Stimulation of sex pheromone production by proteinaceous extracts of the bursa copulatrix in the redbanded leafroller moth

Pheromone biosynthesis in the redbanded leafroller moth, Argyrotaenia velutinana, was stimulated by homogenates of the bursa copulatrix. Although pheromonotropic activity was also extractable from the ovary, the activity of pheromone biosynthesis activating neuropeptide (PBAN) or bursa extracts was not impaired in isolated abdomens by removal of the ovary. Response to the bursa extracts was dependent on the dose administered and the time of incubation. Amounts of pheromone present in adult females of different ages appeared to be correlated with the extractable amount of pheromonotropic activity from their bursa copulatrix. Decapitation did not result in the suppression of burse factor production. Homogenates of the bursa elicited similar effects in both isolated gland and isolated abdomen incubations, but the brain neuropeptide, PBAN, was less active in the former than in the latter. Bursa extracts stimulated pheromone production in isolated abdomen incubations deprived of the bursa copulatrix, but PBAN did not. Loss of activity of bursa homogenates after treatment with either pronase E or carboxypeptidase Y indicated that the pheromonotropic factor is a proteinaceous substance. The mechanism through which pheromone production is regulated in redbanded leafroller moths is discussed. © 1992 Wiley-Liss, Inc.     

Ultrastructure of the reproductive system of the house dust mitesDermatophagoides farinae andD. pteronyssinus (Acari,Pyroglyphidae) with remarks on spermatogenesis and oogenesis

Several parts of the reproductive system of both sexes ofDermatophagoides farinae andD. pteronyssinus are investigated and compared by light-, scanning electron-, and transmission electron microscopy. New techniques have been employed for scanning of the internal structures of these mites. The male reproductive system consists of unpaired testis, paired vasa deferentia, an accessory gland, ejaculatory duct, and copulatory organ. The female reproductive system consists of bursa copulatrix, ductus bursae, receptaculum seminis, paired ducti receptaculi, ovaries, oviducts, one chorion gland, ovipositor, and oviporus. Testis as well as ovaries are characterized by syncytia of nutritional function. The specifics of spermatogenesis are discussed in connection with sperm transfer. Similarities between the construction of the ovaries and oogenesis in astigmatic mites and telotrophic meroistic ovaries in insects are discussed.     

Ultrastructure and function of long and short sperm in Cicadidae (Hemiptera)

The cicada, Graptopsaltria nigrofuscata, produces two distinct sizes of sperm, as determined by either nuclear volume of early spermatids or nuclear length of mature sperm. Between both sperm, there is no difference in location of the acrosome and flagellum during spermiogenesis. The acrosome is covered by an anteacrosomal bleb, which is inserted in a common mass, spermatodesm, derived from cyst cells. Both kinds of sperm linked to the spermatodesm form sperm bundles, respectively. During copulation, the sperm bundles are transported from the vesicula seminalis of the male to the bursa copulatrix of the female. Morphometric analyses of the nuclear length revealed that the two kinds of sperm reach the bursa copulatrix in the same condition as that found in the vesicula seminalis. Once transferred inside the latter, the sperm bundles disintegrated to individual sperm within a few hours, and the tail components, such as the axoneme and mitochondrial derivatives, become separated from each other over time. The tail completely splits from the sperm nucleus 24 h after copulation. Fertile sperm accumulate in the spermatheca, the final storage organ, where only long sperm survived for any length of time. Fertilized eggs examined by vital staining contain only sperm with long nuclei.     

原位杂交检测人工感染鸭体内鸭瘟病毒的复制

鸭瘟(Duck plague,DP)是由鸭瘟病毒(Duck plague virus,DPV)引起的鸭、鹅和天鹅的一种急性败血性传染病,发病率和死亡率甚高,是养鸭业的一大危害[1-2].     

Reproduction in the freshwater gastropod,Helisoma: involvement of prostaglandin in egg production

Summary

The introduction of nanogram quantities of prostaglandin E₂ (PGE₂) into the female genital opening of mated animals was found to increase both the number of egg masses produced and the number of eggs per mass. The intrahaemocoelic administration of a thousand-fold higher concentration of PGE₂ was without effect, suggesting an indirect role of prostaglandin(s) in the regulation of egg production.

Prostaglandin (PG) synthetase activity in both the bursa copulatrix and ovotestis varied with the reproductive status. High PG synthetase activity was present in virgin animals, and lower activity was found in mated animals.

Prostaglandins produced by the bursa copulatrix are proposed here to be involved in the production of a matedness factor, which acts upon the brain to initiate or modulate egg production. PG produced by the ovotestis may be involved in ovulation. A model is proposed for the involvement of PG in the regulation of reproduction in Helisoma.     

Evidence for lock-and-key mechanisms in the internal genitalia of the Apamea moths (Lepidoptera, Noctuidae)

Abstract. Fifty of the fifty-six species of the genus Apamea known from North America and three Palaearctic species were analysed for lock-and-key characters in their internal genitalia, mainly in the male vesica and the female bursa copulatrix. There were an average of 4.5 such characters per species, structurally corresponding in the two sexes. Anatomically they form a postcopulatory but prezygotic isolation mechanism. In some closely related species, the internal genitalia are very similar, but these species have a precopulatory isolation mechanism in the presence or absence of male abdominal coremata. Closely related species did not have more lock-and-key characters than unrelated species, which is taken to indicate absence of character displacement. The anatomical distribution of the lock-and-key characters was examined and the organs of eight species are illustrated.
The lock-and-key hypothesis has been abandoned by several earlier authors but mainly on consideration of external genitalia. In Apamea the invariable functional correspondence between sexes in the sperm transferring organs, and the overall species-specifity of characters but non-existence of interspecific differences under a precopulatory mechanism indicate that (a) lock-and-keys are functioning and (b) they act as isolation mechanisms. Alternative hypotheses of genitalic evolution are reviewed.     

Laboratory experiments on infection rates of Amblyospora dyxenoides (Microsporida: Amblyosporidae) in the mosquito Culex annulirostris

Laboratory observations were made of the microsporidian parasite Amblyospora dyxenoides in its natural mosquito host, Culex annulirostris. There were no differences in the numbers of eggs laid and in the proportions which hatched between infected and uninfected females, indicating that the parasite did not affect fecundity. Unlike other species of Amblyospora which have been studied the development of binucleate spores in adult mosquitoes increase with age of the host in both sexes and in females it proceeds independently of egg development and blood feeding. The same trend is apparent for adult mosquitoes which acquired the infection in the larval stage by horizontal transmission from the intermediate copepod host as well as for mosquitoes which acquired oenocytic infections by transovarial transmission. There was considerable variation in the proportion of mosquitoes which became infected after exposure to A. dyxenoides infected copepods. Infections in larval progeny of female mosquitoes infected via spores produced in copepods ranged from 0 to 100% in individual batches and averaged 45.6% with meiospore infections, 19.3% with oenocytic infections, with the remaining 35.7% being uninfected. Similar variability was observed in the progeny of infected female mosquitoes in the second generation after exposure to infected copepods. During experiments in which the microsporidium was maintained in C. annulirostris through 9 successive transovarially transmitted cycles (by selectively rearing the progeny of females infected with binucleate spores after an initial exposure to infected copepods) the proportion of infected progeny with oenocytic infections increased from 25 to around 50% whereas the incidence of meiospore infections declined from 50 to 10%.(ABSTRACT TRUNCATED AT 250 WORDS)     

A Male-Associated DNA Sequence in a Dioecious Plant, Cannabis sativa L.

Male-associated DNA sequences were analyzed in a dioecious plant,Cannabis sativa L. (family: Moraceae), which is known to havesex chromosomes. DNA was isolated from male and female plantsand subjected to random amplification of polymorphic DNA. Twoout of 15 primers yielded fragments of 500 and 730 bp whichwere detected in all male plants but not in any of the femaleplants tested. These two DNA fragments were cloned and usedas probes in gel blot analysis of genomic DNA. When the maleand female DNAs were allowed to hybridize with the 500-bp probe,no differences in patterns were observed between male and femaleplants. By contrast, when these DNAs were allowed to hybridizewith the 730-bp probe, much more intense bands specific to maleplants were detected, in addition to less intense bands thatwere common to both sexes. The 730-bp DNA fragment was namedMADCl (male-associated DNA sequence in Cannabis sativa). Thesequence of MADCl did not include a long open reading frameand it exhibited no significant similarity to previously reportedsequences. (Received May 8, 1995; Accepted September 18, 1995)