Development Of Accessory Glands Research Articles

Oncogenic signaling in the adult Drosophila prostate-like accessory gland leads to activation of a conserved pro-tumorigenic program, in the absence of proliferation.

Drosophila models for tumorigenesis and metastasis have revealed conserved mechanisms of signaling that are also involved in mammalian cancer. Many of these models use the proliferating tissues of the larval stages of Drosophila development, when tissues are highly mitotically active, or stem cells are abundant. Fewer Drosophila tumorigenesis models use adult animals to initiate tumor formation when many tissues are largely terminally differentiated and postmitotic. The Drosophila accessory glands are prostate-like tissues and a model for some aspects of prostate tumorigenesis using this tissue has been explored. In this model, oncogenic signaling was induced during the proliferative stage of accessory gland development, raising the question of how oncogenic activity would impact the terminally differentiated and postmitotic adult tissue. Here, we show that oncogenic signaling in the adult Drosophila accessory gland leads to activation of a conserved pro-tumorigenic program, similar to that observed in mitotic larval tissues, but in the absence of proliferation. Oncogenic signaling in the adult postmitotic gland leads to tissue hyperplasia with nuclear anaplasia and aneuploidy through endoreduplication, which increases polyploidy and occasionally results in non-mitotic neoplastic-like extrusions. We compare gene expression changes in our Drosophila model with that of endocycling prostate cancer cells induced by chemotherapy, which potentially mediate tumor recurrence after treatment. Similar signaling pathways are activated in the Drosophila gland and endocycling cancer cells, suggesting the adult accessory glands provide a useful model for aspects of prostate cancer progression that do not involve cellular proliferation.

Cell cycle variants during Drosophila male accessory gland development.

The Drosophila melanogaster male accessory gland (AG) is a functional analog of the mammalian prostate and seminal vesicles containing two secretory epithelial cell types, termed main and secondary cells. This tissue is responsible for making and secreting seminal fluid proteins and other molecules that contribute to successful reproduction. The cells of this tissue are binucleate and polyploid, due to variant cell cycles that include endomitosis and endocycling during metamorphosis. Here, we provide evidence of additional cell cycle variants in this tissue. We show that main cells of the gland are connected by ring canals that form after the penultimate mitosis, and we describe an additional post-eclosion endocycle required for gland maturation that is dependent on juvenile hormone signaling. We present evidence that the main cells of the D. melanogaster AG undergo a unique cell cycle reprogramming throughout organ development that results in step-wise cell cycle truncations culminating in cells containing two octoploid nuclei with under-replicated heterochromatin in the mature gland. We propose this tissue as a model to study developmental and hormonal temporal control of cell cycle variants in terminally differentiating tissues.

Myofilaments promote wing expansion and maintain genitalia morphology in the American cockroach, Periplaneta americana.

Insects are the most widely distributed and successful animals on the planet. A large number of insects are capable of flight with functional wings. Wing expansion is an important process for insects to achieve functional wings after eclosion and healthy genital morphology is crucial for adult reproduction. Myofilaments are functional units that constitute sarcomeres and trigger muscle contraction. Here, we identified four myofilament proteins, including Myosin, Paramyosin, Tropomyosin and Troponin T, from the wing pads of nymphs in the American cockroach, Periplaneta americana. RNAi-mediated knockdown of Myosin, Paramyosin, Tropomyosin and Troponin T in the early stage of final instar nymphs caused a severely curly wing phenotype in the imaginal moult, especially in the Paramyosin and Troponin T knockdown groups, indicating that these myofilament proteins are involved in controlling wing expansion behaviours during the nymph-adult transition. In addition, the knockdown resulted in abnormal external genitalia, caused ovulation failure, and affected male accessory gland development. Interestingly, the expression of myofilament genes was induced by methoprene, a juvenile hormone (JH) analogue, and decreased by the depletion of the JH receptor gene Met. Altogether, we have determined that myofilament genes play an important role in promoting wing expansion and maintaining adult genitalia morphology, and their expression is induced by JH signalling. Our data reveal a novel mechanism by which wing expansion is regulated by myofilaments and the functions of myofilaments are involved in maintaining genitalia morphology.

The lncRNA male-specific abdominal plays a critical role in Drosophila accessory gland development and male fertility.

Although thousands of long non-coding RNAs (lncRNA) have been identified in the genomes of higher eukaryotes, the precise function of most of them is still unclear. Here, we show that a >65 kb, male-specific, lncRNA, called male-specific abdominal (msa) is required for the development of the secondary cells of the Drosophila male accessory gland (AG). msa is transcribed from within the Drosophila bithorax complex and shares much of its sequence with another lncRNA, the iab-8 lncRNA, which is involved in the development of the central nervous system (CNS). Both lncRNAs perform much of their functions via a shared miRNA embedded within their sequences. Loss of msa, or of the miRNA it contains, causes defects in secondary cell morphology and reduces male fertility. Although both lncRNAs express the same miRNA, the phenotype in the secondary cells and the CNS seem to reflect misregulation of different targets in the two tissues.

Functional male accessory glands and fertility in Drosophila require novel ecdysone receptor.

In many insects, the accessory gland, a secretory tissue of the male reproductive system, is essential for male fertility. Male accessory gland is the major source of proteinaceous secretions, collectively called as seminal proteins (or accessory gland proteins), which upon transfer, manipulate the physiology and behavior of mated females. Insect hormones such as ecdysteroids and juvenoids play a key role in accessory gland development and protein synthesis but little is known about underlying molecular players and their mechanism of action. Therefore, in the present study, we examined the roles of hormone-dependent transcription factors (Nuclear Receptors), in accessory gland development, function and male fertility of a genetically tractable insect model, Drosophila melanogaster. First, we carried out an RNAi screen involving 19 hormone receptors, individually and specifically, in a male reproductive tissue (accessory gland) for their requirement in Drosophila male fertility. Subsequently, by using independent RNAi/ dominant negative forms, we show that Ecdysone Receptor (EcR) is essential for male fertility due to its requirement in the normal development of accessory glands in Drosophila: EcR depleted glands fail to make seminal proteins and have dying cells. Further, our data point to a novel ecdysone receptor that does not include Ultraspiracle but is probably comprised of EcR isoforms in Drosophila male accessory glands. Our data suggest that this novel ecdysone receptor might act downstream of homeodomain transcription factor paired (prd) in the male accessory gland. Overall, the study suggests novel ecdysone receptor as an important player in the hormonal regulation of seminal protein production and insect male fertility.

Effects of male age on the mating behavior of both sexes in the sorghum plant bug, Stenotus rubrovittatus (Hemiptera: Miridae)

In the sorghum plant bug Stenotus rubrovittatus (Matsumura) (Hemiptera: Miridae), mating behavior consists of male courtship and female mating receptivity. Previous studies have found that female age is correlated with ovary development and that mature females with developed ovaries are more receptive to male courtship. Thus, we examined whether male age affects the mating behavior of both sexes and male accessory gland development. Unmated males 0–9 days after emergence and 3-day-old virgin females receptive to male courtship were studied. Immediately after emergence, only 20 % of the males courted females (n = 25). At 3 days old, 68 % of the males courted females (n = 25), the most active age. In contrast, more than 75 % of the courted females were receptive to the male courtship regardless of male age. These results indicate that only male courtship behavior is affected by male age, although it is not enhanced in proportion to male age. Male accessory glands developed with male age. However, no clear relationship was detected between male courtship behavior and accessory gland development. In S. rubrovittatus, it is difficult to explain male courtship behavior solely from male age and accessory gland development.

Temperature-Dependent Reproductive Development ofLygus hesperus(Hemiptera: Miridae)

Recent studies to elucidate relationships between the western tarnished plant bug, Lygus hesperus Knight, and injury to cotton (Gossypium spp.) have identified important differences in feeding behaviors among adults of different gender and reproductive states. These findings suggest a need for improved knowledge of L. hesperus temperature-dependent reproductive development. We used nonlinear biophysical development rate models to describe the reproductive development of adult L. hesperus held under constant temperatures from 12.8 to 35.0°C. In addition, abdominal coloration was measured as a nondestructive indicator of reproductive maturity. The nonlinear models indicated most stages of ovary, seminal vesicle, and medial accessory gland development were subject to mild high-temperature inhibition, except for the stage of filled seminal vesicles. Development of filled seminal vesicles was subject to minor low-temperature inhibition and severe high-temperature inhibition. Estimated development times reflected extensive interindividual variation, especially at low temperatures. This variation suggests the opportunity to select for more rapid or more consistent reproductive development under the conditions of laboratory culture. Although presence of a dark aqua coloration of the ventral abdominal cuticle was statistically associated with reproductive maturity, especially in female L. hesperus, color-based predictions of reproductive maturity were often inaccurate for bugs reared at temperatures above or below 26.7°C. Therefore, use of abdominal coloration as an indicator of reproductive development in ecological studies seems inappropriate. The results provide mathematical descriptions of L. hesperus temperature-dependent reproductive development which should facilitate improved planning and interpretation of studies involving manipulation of adult reproductive status.

The Homeodomain Protein Defective Proventriculus Is Essential for Male Accessory Gland Development to Enhance Fecundity in Drosophila

The Drosophila male accessory gland has functions similar to those of the mammalian prostate gland and the seminal vesicle, and secretes accessory gland proteins into the seminal fluid. Each of the two lobes of the accessory gland is composed of two types of binucleate cell: about 1,000 main cells and 40 secondary cells. A well-known accessory gland protein, sex peptide, is secreted from the main cells and induces female postmating response to increase progeny production, whereas little is known about physiological significance of the secondary cells. The homeodomain transcriptional repressor Defective proventriculus (Dve) is strongly expressed in adult secondary cells, and its mutation resulted in loss of secondary cells, mononucleation of main cells, and reduced size of the accessory gland. dve mutant males had low fecundity despite the presence of sex peptide, and failed to induce the female postmating responses of increased egg laying and reduced sexual receptivity. RNAi-mediated dve knockdown males also had low fecundity with normally binucleate main cells. We provide the first evidence that secondary cells are crucial for male fecundity, and also that Dve activity is required for survival of the secondary cells. These findings provide new insights into a mechanism of fertility/fecundity.

Morphological Characters of Diapause in Lygus hesperus Knight (Hemiptera: Miridae)

Development of management tactics that reduce reliance on conventional pesticides for control of the western tarnished plant bug, Lygus hesperus Knight, will require improved understanding of Lygus ecology. One poorly characterized aspect of Lygus ecology is the induction of adult diapause. Although photoperiod is a key regulator of diapause, previous research has reported inconsistent results, likely because of the different criteria used to distinguish diapause. To establish standardized criteria, we reared L. hesperus under photoperiods of 10- and 14-h and a constant temperature of 26.6°C. Adults were dissected at ages of 3, 7, 10, 14, and 17 days to evaluate associations among characteristics of the fat body and reproductive organs. Whereas most characters examined were at least weakly associated with others, we concluded that seminal vesicle condition, presence of a fatty sheath on the testis, and fat body color were not reliable indicators of L. hesperus physiological status. The most appropriate criteria for distinguishing diapause appeared to be hypertrophied fat bodies combined with undeveloped medial accessory glands (for males) or undeveloped ovaries (for females) in adults that were at least 10 days old. We also evaluated less stringent criteria, permitting some development of accessory glands or ovaries to accommodate the delayed reproductive development observed in some specimens reared under the 10-h photoperiod. The descriptions and illustrations of the morphological characters, combined with our suggested sets of criteria, should permit a more standardized assessment of L. hesperus physiological status, and thereby facilitate meaningful comparisons of research by different investigators.

Atypical Fetal Prostate Development is Associated with Ipsilateral Hypoplasia of the Wolffian Ducts in the ACI Rat

AbstractSerial section reconstruction images of the male ACI rat urogenital sinus shown from a dorso‐cranial view. The image in the lower right illustrates the normal late gestation appearance of the accessory gland development, compared to the Wolffian duct ipsilateral abnormality observed in 25% of the male offspring (upper left). See Potok et al., Anatomical Record 239:747–753.

Structure of the male reproductive system of Anoecia (Anoecia) corni Fabricius, 1775 (Hemiptera, Aphidoidea), a representative of the family Anoeciidae

AbstractThe structure of the male reproductive system of Anoecia (Anoecia) corni Fabricius, 1775, is discussed. On the basis of histological sections and whole mount preparations, the following elements in the structure of the male reproductive system have been examined: the structure of testis and the stage of spermatogenesis; the connection of testis and vasa deferentia; the position and the histological structure of the wall of vasa deferentia; and the development of accessory glands and the ejaculatory duct as well as the structure of the external genitalia. These characters are discussed with reference to the higher classification of Aphidoidea and the taxonomic position of Anoeciidae.

Anatomical investigations of the male reproductive system of five species of Calaphidinae (Hemiptera, Aphidoidea)

AbstractThe structure of the male reproductive system of 5 species of Calaphidinae Clethrobius comes, Euceraphis betulae, Myzocallis (Lineomyzocallis) walshii, Tuberculatus (Tuberculoides) annulatus and Tuberculatus (Tuberculoides) neglectus is discussed. C. comes and E. betulae feed on birches (Betula), whereas M. (L.) walshii, T. (T.) annulatus, and T. (T.) neglectus are associated with oaks (Quercus). On the basis of histological sections and whole mount preparations the following elements in the structure of the male reproductive system have been examined: the number of testis follicles and the stage of spermatogenesis, the connection of follicles and vasa deferentia, the position of the proximal part of vasa deferentia as well as the development of accessory glands and the ejaculatory duct. In males of studied species the characters of the reproductive system have been observed: each testis holds 3 or 4 follicles, strongly elongated and arranged in a rosette. Vasa deferentia run separately along their length, only in the proximal part their walls cling together. Accessory glands are strongly elongated, sometimes asymmetric (T.(T.) annulatus) whereas the ejaculatory duct is usually reduced (in exception C. comes). These characters were then used to supplement morphological data in order to interpret developmental trends in the Calaphidinae.

Development of the accessory glands in the genital tract of female Teleogryllus commodus WALKER (Insecta, Orthoptera)

The development of the female accessory glands in Teleogryllus commodus was studied by detailed morphometric and stereological analyses. In addition, a microsurgical method was developed to quantify the gland secretion. The morphometric results yield evidence that the glands are subject to a significant growth during peak differentiation, starting immediately after the adult moult. The gland growth is exclusively caused by a hypertrophy of single gland cells with respective volume gains between 400 and 700%. According to the stereological results, the volume of mitochondria per cell is marked by an up to fourfold increase during peak differentiation. Other cell structures (rER, sER) are characterized by a similar propagation behavior. The nucleus and nucleolus grow simultaneously with the cell, indicating high production of site-specific macromolecules. Infolds of the basal cell membrane cause a progressive enlargement of the basal cell surface ensuring an increased uptake of secretory precursors from the hemolymph. Quantitative studies show that the total production of secretion increases with proceeding age and can be correlated with a rising egg-laying activity, starting on the eighth day of adult's life. This underlines the main function of the secretion as a lubricant for a facilitated transport of the eggs through the ovipositor.

Age and seasonal changes in the morphomethric development of accessory glands of the West African Dwarf goat

The effects of age and season of birth on the morphometric characteristics of the Vesicular, Cowper's and Ampulla glands were studies in 32 indigenous West Africa Dwarf (WAD) goats aged 1 – 12 months and 12 adults aged >12 months, in Ibadan. While the vesicular and Cowper's glands weight were highly significantly (p KEY WORDS: Age, Season, Growth, Accessory, Glands. [Global Jnl Agric Res Vol.1(2) 2002: 83-88]

Peripubertal exposure to the antiandrogenic fungicide, vinclozolin, delays puberty, inhibits the development of androgen-dependent tissues, and alters androgen receptor function in the male rat.

Vinclozolin is a well-characterized antiandrogenic fungicide. It produces adverse effects when administered during sexual differentiation, and it alters reproductive function in adult male rats by acting as an androgen-antagonist. Two active metabolites of vinclozolin, M1 and M2, compete with natural androgens for the rat and human androgen receptors (ARs), an effect that blocks androgen-induced gene expression in vivo and in vitro. In addition to their effects during perinatal life, androgens play a key role in pubertal maturation in young males. In this regard, the present study was designed to examine the effects of peripubertal oral administration of vinclozolin (0, 10, 30, or 100 mg kg-1 day-1) on morphological landmarks of puberty, hormone levels, and sex accessory gland development in male rats. In addition, as binding of the M1 and M2 to AR alter the subcellular distribution of AR by inhibiting AR-DNA binding, we examined the effects of vinclozolin on AR distribution in the target cells after in vivo treatment. We also examined serum levels of vinclozolin, M1, and M2 in the treated males so that these could be related to the effects on the reproductive tract and AR distribution. Vinclozolin treatment delayed pubertal maturation (at 30 and 100 mg kg-1 day-1) and retarded sex accessory gland and epididymal growth. Serum luteinizing hormone (LH; significant at all dosage levels) and testosterone and 5 alpha-androstane, 3 alpha, 17 beta-diol (at 100 mg kg-1 day-1) levels were increased. Testis size and sperm production, however, were unaffected. It was apparent that these effects were concurrent with subtle alterations in the subcellular distribution of AR. In control animals, most AR were in the high salt cell fraction, apparently bound to the natural ligand and DNA. Vinclozolin treatment reduced the amount of AR in the high salt (bound to DNA) fraction and it increased AR levels in the low salt (inactive, not bound to DNA) fraction. M1 and M2 were found in the serum of animals from the two highest dosage groups, but they were present at levels well below their K1 values. In summary, these results suggest that when the vinclozolin metabolites occupy a small percentage of AR in the cell, this prevents maximal AR-DNA binding and alters in vivo androgen-dependent gene expression and protein synthesis, which in turn results in obvious alterations of morphological development and serum hormone levels. It is noteworthy that similar exposures during prenatal life result in a high incidence of malformations in male rats.

A polypeptide from the brain and corpus cardiacum of male Rhodnius prolixus which stimulates in vitro protein synthesis in the transparent accessory reproductive gland

The transparent accessory reproductive gland of male Rhodnius prolixus produces spermatophore proteins. Regulation of the synthesis of these proteins involves both the corpus allatum and the brain. In vitro studies reported here demonstrate for the first time a polypeptide factor from the brain and corpus cardiacum which directly stimulates protein synthesis in the transparent accessory reproductive gland. The demonstration of a polypeptide factor from the brain extends regulation of accessory gland development in R. prolixus and possibly other male insects to include the neuroendocrine centres of the brain and corpus cardiacum.

Effects of aromatizable androgens on aggressive behaviour among rats (rattus norvegicus).

Three experiments were used to tests the applicability of the aromatization hypothesis of androgen action to aggressive behaviour among Norway rats. In Expt 1, administration of testosterone propionate was highly effective in restoring aggressive behaviour to castrated rats while 17 beta-hydroxy-5 alpha-androstan-3-one was of intermediate effectiveness. Of the steriods tested in Expt 2, androstenedione and testosterone were highly effective, 17 beta, 19-dihydroxyandrost-4-en-3-one was of intermediate effectiveness and cholesterol was ineffective. The results of Expt 3 indicated that treatment with testosterone or oestradiol both resulted in increased aggression while treatment with (5 alpha,17 beta)-17,19-bis(acetyloxy)-andostan-3-one diacetate (5 alpha-19-hydroxytestosterone) was without effect. Androgens which were aromatizable and could be 5 alpha reduced, i.e. testosterone, testosterone propionate and androstenedione, were highly effective in restoring aggressive behaviour; however, two other steroids, 5 alpha,19-hydroxytestosterone which is 5 alpha reduced, and 19-hydroxytestosterone, which can be aromatized, were respectively of low or medium effectiveness on behaviour. However, oestradiol, which did not maintain sexual development of accessory glands, was highly effective in the restoration of aggressive behaviour. Since the behaviourally active steroids in the present experiments were not only those predicted by the aromatization hypothesis, it is proposed that several steroids are capable of activating aggressive behaviour and that the aromatization hypothesis does not adequately explain the hormonal basis of aggressive behaviour among Norway rats.

The Influence of Diet on the Maturation of the Reproductive System of the Apple Maggot, Rhagoletis pomonella1,2

Reproductive behavior of both sexes of the apple maggot was shown to be correlated with ovarian and accessory gland development, and changes in the fat body. A protein free diet resulted in a drastic reduction in ovarian and accessory gland development after day 5 in females. Spermatogenesis was independent of diet and little protein was required for male accessory gland development. Mating behavior in the male was apparently not affected by diet.

Male sexual maturation of the tsetse fliesglossina morsitanswestwood andg. austeniNewstead (Dipt., Glossinidae) in relation to blood feeding

AbstractThe effect of blood feeding on male sexual maturation in the tsetse fliesGlossina morsitansWestwood andG. austeniNewstead was studied by comparing copulation and insemination performance of unfed and fed males during the first five days of adult life. These species differed conspicuously, both in the course of maturation and in the influence of blood feeding on it.G. morsitansmales copulated before they could inseminate, and even fed flies did not all inseminate until day 3; unfed flies showed retarded insemination performance by day 2, before copulation performance declined.G. austenimales were less sexually responsive at first, but they nearly always inseminated when they did copulate, even on day 1. Unfed flies showed less increase in copulation performance by day 4, but no decline. Accessory glands were larger inG. austenithanG. morsitansat emergence, and in unfed flies of both species they ceased to grow after day 3. Both accessory gland size and copulation duration (beyond a minimum duration) were related to insemination success in a general way, though copulation duration was quite variable. Vertebrate blood apparently provides male tsetse with specific nutrients or stimuli which promote sexual performance, in addition to basic energy and water requirements. Feeding probably affects insemination inG. morsitansthrough accessory gland development, allowing more complete spermatophore formation and sperm transfer, but its mode of action onG. austenisexual responsiveness is not evident.

The influence of the social environment on sexual maturation in male mice.

Summary. Albino male mice were reared from weaning in the presence of an adult female, in the presence of an adult male, or in the absence of an adult. At 36, 48, 60 and 78 days of age, males in samples from each rearing condition were killed to assess their reproductive state. The testicular development of young males was most rapid when they were reared in the presence of an adult female. By 78 days of age, this advantage was lost when the males were compared to those reared without an adult present. In contrast to the effect of an adult female, the presence of an adult male had an inhibitory effect on testicular and accessory gland development. The inhibition was most pronounced at 78 days of age. The inhibition of sexual maturation found in this experiment contrasts with an earlier finding that the presence of males accelerates female development. This dual rôle of the male may be an important factor in the dynamics of rodent populations by increasing the availability of mature females and reducing the reproductive capabilities of potential competitors for these females.