Accessory Reproductive Glands Research Articles

The reproductive biology of the Cape mole‐rat, Georychus capensis (Rodentia, Bathyergidae)

Georychus capensis is a seasonal breeder with the reproductive potential of producing two litters during the summer breeding season (August to December). These solitary mole‐rats signal to each other through the soil, by drumming with their hind feet. This drumming is probably important in spacing the burrow systems and in triggering the onset of reproductive behaviour. In a captive male the onset of drumming was accompanied by a rise in urinary testosterone concentrations and the enlargement of testes and accessory reproductive glands. The male appeared to drum with a different frequency to the female. Courtship is initiated by the male and copulation involves brief multiple intromissions. The gestation period is about 44 days and the mean litter size is 5.9 with a maximum of 10 pups. Development of the pups is relatively rapid. Inter‐sibling aggression begins to develop at 35 days, eventually resulting in the pups dispersing when about 60 days old. Body mass increases exponentially from birth to day 60 and the asymptote is reached around day 260. These features are compared with those of other solitary subterranean rodents and with those of the social Bathyergidae (Cryptomys hottentotus, Cryptomys damarensis and Heterocephalus glaber).

Identification and partial characterization of the major secretory protein of the long hyaline gland in the male grasshopper, Melanoplus sanguinipes

In the adult male migratory grasshopper, Melanoplus sanguinipes, the major secretory product of the long hyaline gland (a distinct tubule type of the accessory reproductive gland complex) is an abundant glycoprotein (LHPI) with a native molecular weight of about 72,000 Da. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) of this protein gives rise to a 36,000 Da subunit. Partial peptide mapping of the 36,000 Da subunit, using the agents N- chlorosuccinimide , papain, and staphylococcal V8 protease, shows that this polypeptide is found in a viscous secretion and, to a much lesser extent, in empty spermatophores, both of which are recoverable from between the female's ovipositor valves after mating. Polyclonal antibodies raised against the LHPI 36,000 Da subunit electrophoretically purified from long hyaline glands, cross react with similar molecular weight counterparts in viscous secretion and spermatophore extracts. LHPI is present in 1-day-old adults and accumulates up to levels of about 1 mg in 17-day-old virgins. LHPI is the single most abundant protein in the long hyaline gland accounting for 37–51% of the total protein in virgin males 5–17 days old. An estimated 160 μg was lost from the gland in a single mating on day 7 of which 110 μg was recovered at the completion of mating. Mating on day 5, 6, or 7 resulted in a 1.6–1.8 fold increase in rate of in vivo incorporation of [ 3H]leucine into LHPI measured on day 7. This apparent increase in LHPI synthesis is paralleled by increased accumulation of protein in the gland in mated males.

Growth, carcass traits, boar odor and testicular and endocrine functions of male pigs fed a progestogen, altrenogest.

Crossbred (Chester White X Yorkshire X Duroc) boars were used to evaluate the effects of feeding a progestogen (altrenogest) on body growth, endocrine function (determined during feeding and after withdrawal of altrenogest), carcass composition, boar odor and testicular function (determined after a 30-d withdrawal from altrenogest). Boars from 18 litters were assigned at 12 wk of age to three treatments: 1) 18 control boars; 2) 18 boars fed altrenogest (20 mg/day) for 6 wk from 15 to 21 wk of age, followed by 30 d with no treatment; and 3) 18 boars castrated at 2 wk of age (barrows). Daily gains were greater (P less than .05) in boars fed altrenogest than in barrows through 21 wk of age but were lower (P less than .05) than those of control boars and barrows during the 30-d withdrawal period. Boars fed altrenogest weighed less (P less than .05) than control boars and barrows at 25 wk of age (at slaughter). Both groups of boars were similar in percentage of muscle and had less (P less than .05) backfat than barrows, whereas control boars had the largest (P less than .05) loineye areas. Based on evaluations by a trained sensory panel, intensity of boar odor in fat samples was similar for both groups of boars and was greater (P less than .05) than that for barrows. Weights of accessory reproductive glands and weight and sperm content of testes and epididymides were reduced (P less than .05) in boars fed altrenogest.(ABSTRACT TRUNCATED AT 250 WORDS)

A new non-hormonal antifertility drug DL-204: I. Effects on testes and accessory glands of reproduction in male rats

The effect of DL-204, 2-(3-ethoxyphenyl)-5,6-dihydro-5-triazole (5,1a)-isoquinoline, a non-hormonal post-implantational anti-fertility drug, on tissue weights, nucleic acids and total protein concentrations in the testes, ventral prostate and seminal vesicles were evaluated in immature and sexually mature rats, while changes in DNA synthesis were studied only in the immature rats. Treatment of 21-day-old rats at doses of 5mg and 10mg/kg bw once daily for 15 days had no effect on body weight but reduced the weights of testes and accessory glands of reproduction. The concentration of DNA increased while RNA and protein decreased significantly. Treatment of adult rats with DL-204 at a dose of 10mg/kg bw had no effect on body and testes weights but reduced ventral prostate and seminal vesicle weights. The concentration of RNA and protein decreased significantly, while DNA concentration was not altered. DL-204 treatment resulted in drastic decrease of RNA/DNA ratio, reflecting ribosomal loss and cytoplasmic shrinkage. The effects observed after DL-204 treatment are comparable to post-castration changes. DL-204 may be acting on testes and accessory reproductive organs by blocking androgen biosynthesis and/or by antagonizing the action of androgens. It may be acting directly on the normal function of the hypothalamo-pituitary-gonadal axis.

Seasonal changes in condition, reproduction and fecundity in the wild European rabbit (Oryctolagus cuniculus)

A total of 1248 rabbits (Oryctolagus amiculus) were shot on farmland in Cambridgeshire, UK over a period of three years. This provided pooled estimates of changes in reproductive and body condition and of fecundity during the annual cycle. Both males and females showed a significant annual cycle in reproductive condition as indicated by changes in the size of the gonads and accessory glands of reproduction. No females were pregnant during October, November and December, but males with active spermatogenesis were found during every month of the year. The distribution of pregnancies through the year showed that the reproductive season varied greatly between individuals. Peak fecundity occurred during April, May and June. On average, each female conceived 23.9 and suckled 17.2 young per breeding season. Proportionately more young died during the early stages of the reproductive season. The body weight of adult males, but not of females, varied seasonally. Body condition (kidney fat index) in adults was maximal at the start of the breeding season and minimal at the end.

Biochemical and immunochemical evidence for the origin of the spermatophore material inGlossina morsitans morsitans Westwood

Protein patterns in secretions from fully differentiated male accessory reproductive glands (ARG), spermatophore (Sp) and testes (Te) of the tsetse,Glossina morsitans morsitans Westwood, were determined by isoelectrofocusing. Isoelectrofocusing patterns of total ARG proteins and those of Sp were remarkably similar. At least 27 bands were detected in ARG and Sp. Out of these, 13 were major protein bands and isoelectrofocused in the pl range of 4 and 6.55. About 10 of these 13 were found to be acidic. Ouchterlony immunodiffusion and straight line immunoelectrophoresis showed that male accessory reproductive gland secretory proteins and spermatophore share common immunological characteristics which are different from those of the testes.

Purification and characterization of a proline-rich secretory protein that is a precursor to a structural protein of an insect spermatophore.

The spermatophore or sperm sac of Tenebrio molitor (yellow mealworm beetle) is an acellular structure composed mostly of structural proteins, termed spermatophorins. The proteins are derived from the bean-shaped accessory reproductive glands of the male and are assembled into the multilayered structure within the ejaculatory duct. Homogenates of the secretory plug from this gland were used as immunogens for the production of monoclonal antibodies, including one identified as PL 21.1 which recognizes an antigen in the gland and the spermatophore. With the aid of gel filtration and immunoaffinity chromatography with a PL 21.1, we isolated a glandular secretory protein that is a precursor to a spermatophorin with similar electrophoretic mobility. On native polyacrylamide gels, the antigen from gland homogenates has an apparent molecular mass of 370 kDa. On sodium dodecyl sulfate gels, the antigen from the gland and that from the spermatophore have apparent molecular masses of 23 kDa. According to immunoblots of sodium dodecyl sulfate gels, the 23-kDa glandular antigen is organ-specific and adult-specific. By immunocytochemistry with PL 21.1, we found the antigens to be restricted to secretory vesicles of only one cell type in the gland and to a discrete layer in the outer wall of the spermatophore. The 23-kDa secretory antigen is distinguished by being high in glutamic acid/glutamine (15.4%) and in proline (25.2%).

Structure and function of the ovipositor and associated sensilla of the apple maggot, Rhagoletis pomonella (Walsh) (Diptera : Tephritidae)

The ovipositor of Rhagoletis pomonella (Walsh) (Diptera : Tephritidae) has a dorsal process which terminates distally in a slightly upcurved tip and 2 ventral processes that are joined throughout their length by a membrane up to the region of the cloaca, where the ventral processes are not attached. The surface of the ovipositor contains both hair-like and campaniform mechanosensilla capable of monitoring both cuticular stress and mechanical contact of the ovipositor from the initial through the final steps of penetration of the fruit, egg-laying, copulation, and possibly dragging the ovipositor during deposition of the oviposition deterrent pheromone. Near the tip of the ovipositor are 2 longitudinally aligned grooves, each containing 3 pairs of chemosensilla. In addition, 1 pair of shorter chemosensilla are just distal to and outside the groove. All chemosensilla contain 3 or 4 chemosensitive neurons. During fruit penetration and egg-laying, the ovipositor is protracted, thus placing the chemosensilla in contact with various fruit chemicals. These chemosensilla are responsive to naturally occurring fruit chemicals. The possible role of the ovipositor chemosensilla in monitoring fruit quality, the deposition of the oviposition deterrent pheromone, the presence of chemical contaminants on the ovipositor, and the female's own accessory reproductive gland secretions remains to be established.

Effects of long-term treatment with melatonin or melatonin plus ectopic pituitary transplants on testicular LH/hCG and prolactin receptors in juvenile Syrian hamsters (Mesocricetus auratus).

Juvenile hamsters were injected daily with melatonin and some were also given transplants of 2 pituitaries under the kidney capsule. Weights of the testes and the accessory reproductive glands were reduced after 8 and after 12 weeks of melatonin treatment, but remained unaltered in animals treated with ectopic pituitary transplants. Levels of testicular LH/hCG receptors were significantly reduced by daily melatonin injections for 8 and 12 weeks. The presence of pituitary transplants in melatonin-injected hamsters prevented these reductions, and increased LH/hCG receptors above control levels. These changes in testicular LH/hCG receptors were closely related to alterations in serum prolactin concentration induced by melatonin and pituitary transplants. After 8, but not after 12 weeks of treatment, testicular prolactin receptor levels were reduced by melatonin and maintained by the presence of pituitary transplants. We conclude that: juvenile male hamsters become sensitive to the effects of daily melatonin injections when they reach maturity; daily melatonin injections can reduce the levels of testicular LH/hCG and prolactin receptors; and the effects of melatonin on LH/hCG and prolactin receptors are probably due to suppression of endogenous prolactin release.

Seasonal changes in plasma testosterone concentrations and Leydig cell and accessory gland activity in the Cape horseshoe bat (Rhinolophus capensis).

Male Cape horseshoe bats were studied in the Cape Province of South Africa (33 degrees 17'S, 26 degrees 25'E) between January 1983 and June 1985. The reproductive cycle is characterized by reactivation of the seminiferous tubules in early summer (October) after a 4-month (June to September) period of winter inactivity. Spermiogenesis occurred between January and April, and spermatozoa were released to the epididymides in April and May. Spermiogenesis was associated with Leydig cell activity and increasing plasma testosterone concentrations. At this time components of the reproductive accessory glands became secretorily active or showed increasing secretory activity. During winter Leydig cells were secretorily inactive and plasma testosterone concentrations dropped, but components of the accessory complex remained active. There was a second period of Leydig cell secretory activity and increasing and peak plasma testosterone values in late winter/early summer which may be associated with copulation or the initiation of a new cycle of spermatogenesis.

Courtship Feeding in Katydids (Orthoptera: Tettigoniidae): Investment in Offspring or in Obtaining Fertilizations?

Studies indicate that courtship feeding in insects represents mating effort that evolved to ensure successful insemination. I tested this hypothesis with katydids (Requena verticalis), in which males feed females after mating by producing a sperm-free mass, the spermatophylax, from reproductive accessory glands. Although courtship feeding in this species prevents the female's removing and eating the sperm-containing ampulla before insemination has occurred, the spermatophylax is more than twice the size necessary to transfer a full complement of sperm and to transfer substances preventing female response to male sexual sounds. Thus, I reject the hypothesis that the function of excess maledonated nutrition is mating effort that protects the ejaculate. The size of the spermatophylax probably did not evolve only as a result of intersexual selection by premating female choice for males capable of producing larger contributions. Since feeding on spermatophylax nutrients by females increases egg size, and pos...

Immunochemical ablation of accessory reproductive glands of the male desert locust

Injection of antiserum prepared against accessory reproductive gland (ARG) secretions of the male desert locust, Schistocerca gregaria, disrupted the normal growth and function of the ARG complex in sexually maturing adults. Male locusts were injected with either antiserum or normal guinea-pig serum on days 3, 7 and 10 after adult ecdysis. When the injection of ARG antiserum began as early as day 3 of adult development a marked inhibition of ARG growth was accompanied by the suppression of other characteristics of sexual maturation (yellow body coloration and mating behaviour). Inhibition of ARG growth, while significant, was less pronounced when antiserum injections began on day 7 of adult development, and the injected males did not exhibit normal mating behaviour when placed with virgin females. When single antiserum injections were administered on day 10 of adult development, the males still attained their yellow body coloration by day 19 and copulated normally with virgin females, although their ARGs were only equivalent in size to those 13-day-old males.

A new non-hormonal antifertility drug DL 111-IT: I. Effects on testes and accessory glands of reproduction in male rats

Effect of DL-111, 3-(2-ethylphenyl)-5-(3-methoxyphenyl-1H-1,2,4-triazole, a non-hormonal postimplantational antifertility agent, on testicular and accessory reproductive organ weights and total protein, RNA and DNA concentrations were evaluated in immature and adult rats. Treatment of 21-day-old rats at doses of 2.5 mg and 5 mg/kg body weight decreased body weight, weights of testes and accessory glands of reproduction. RNA and protein concentrations decreased significantly with significant increase increase in DNA concentration in testes, epididymis, ventral prostate and seminal vesicles. DL-111 treatment of adult rats at doses of 5 mg and 10 mg/kg body weight had no effect on body weight, but significantly decreased weights of testes and accessory glands of reproduction. RNA and protein concentrations decreased significantly in all tissues studied while DNA concentration was not altered. RNA/DNA ratio decreased significantly, reflecting ribosomal loss and cytoplasmic shrinkage. These effects of DL-111 are comparable to post-castrational changes in accessory glands of reproduction. We presume that these changes are mediated by blocking the androgen biosynthesis and/or by interfering with normal function of hypothalamo-pituitary-gonadal axis.

A new non-hormonal antifertility drug DL 111-IT: II. Effects on testicular hyaluronidase activity in male rats

Effects of DL-111, [3-(2-ethylphenyl)-5-(3-methoxyphenyl-1H-1,2,4-triazole] a non-hormonal antifertility agent, on testicular hyaluronidase activity, an accurate biochemical marker for testicular function, were evaluated in male rats. Treatment of 21-day-old rats with DL-111 sc for 7 or 15 days resulted in a significant fall in testicular weight and complete suppression of hyaluronidase activity. During the 30-day post-treatment the enzyme activity was restored to normal levels. Treatment of 40-day-old rats for 7 or 15 days also produced a significant decrease in testicular weight and hyaluronidase activity. Simultaneous administration of LH, PMSG or T with DL-111 to 21-day-old rats blocked the inhibitory activity of the drug as the enzyme activity was restored to untreated control levels. Administration of FSH along with DL-111 had no effect on suppressive action of the drug. These results suggest that in male rats DL-111 inhibits testicular activity by reducing LH levels, thereby reducing T levels as observed by reduced weights of testes and accessory glands of reproduction and hyaluronidase activity.

Testicular development and endocrine function in boars fed altrenogest (1986)

Crossbred male pigs were used to evaluate the influence of a synthetic progestogen on reproductive development. Concentrations of luteinizing hormone (LH) and testosterone in blood serum were reduced while boars were being fed altrenogest (15 to 21 wk of age). At 25 wk of age (4 wk after withdrawal from altrenogest), weights of the testes and accessory reproductive glands and testicular content of sperm were reduced in boars that had been fed altrenogest. However, testicular weight and content of sperm had returned to control values following 12 wk after withdrawal from altrenogest. In addition, concentration of LH and testosterone in blood serum were similar for control boars and boars previously fed altrenogest. We conclude that suppression of normal reproductive development of growing boars by altrenogest merely delays the onset of sexual maturation but does not permanently affect testicular function.; Swine Day, Manhattan, KS, November 20, 1986

Morphology and Histochemistry of the Ferret Prostate

The gross anatomy, histology and histochemistry of the ferret prostate is described. The structure and course of the prostatic urethra and the ductus deferentes are also described. The prostate is the only accessory reproductive gland present in the ferret. The prostate consists of tubuloalveolar glands surrounded by fibromuscular connective tissue. Histochemical studies showed that the glandular parenchyma contained large amounts of sialidase-labile sialomucin as well as acid phosphatase and small quantities of alkaline phosphatase and proteins. The findings in this study are discussed in relation to similar studies in other animals and man.

A monoclonal antibody against a structural protein in the spermatophore of Tenebrio molitor (coleoptera)

Monoclonal antibodies were produced against insoluble proteins of spermatophores of Tenebrio molitor. One hybridoma clone produced antibody which recognized two antigens (29.4 and 27.6 kd mol. wt) in the bean-shaped accessory reproductive glands (BAGs) and in the secreted precursor of the insoluble fraction of the spermatophore. At least two molecular weight variants which differed by 1.5–1.7 kd mol. wt daltons are present. Processing accompanies secretion into the BAG lumen, with a reduction of about 4000 daltons in apparent molecular weights. The amount of target antigen during reproductive maturation, its localization and its transport were studied using Western blotting and immunohistochemistry. The monoclonal antibody recognized a protein present in one of the eight secretory cell types (type 3) of the BAG, in the secretory production of this gland, and in discrete layers of the spermatophore ejected from the male. This specific probe, and others currently being produced, will facilitate detailed studies on the process of spermatophore formation.

Reproductive capacity of male laboratory rats

The purpose of this research was to investigate the reproductive capacity (i.e., the ability to successfully transfer an ejaculate and induce a progestational response in the female) of male laboratory rats ( Rattus norvegicus). Males were individually mated to sucessive females in a single session for one ejaculatory series each. There was a marked decline in both the total number of sperm per ejaculate and the number of sperm transported to the uterus with repeated ejaculations. Dimensions of the copulatory plug of the male decreased over successive ejaculations, reflecting a diminished output of the secretions of the reproductive accessory glands. Male copulatory behavior changed over successive ejaculations. Actual fertility appeared somewhat diminished in late ejaculatory series. Such constraints on the reproductive capacity of the male may have implications for the mating strategy employed by wild males in the field.

Annual variations in plasma sex steroid-binding protein and testosterone concentrations in the adult male little brown bat: relation to the asynchronous recrudescence of the testis and accessory reproductive organs.

The annual reproductive cycle of the male little brown bat, in contrast to seasonal reproductive patterns of other mammals, is differentiated by an asynchronous recrudescence of the testis and the accessory reproductive glands. Spermatogenesis occurs during the summer, whereas fully stimulated accessory organs, stored epididymal spermatozoa, and sexual behavior are expressed later during a mating period that extends, albeit interrupted by hibernation, from late summer until early spring. To investigate whether changes in high affinity androgen-binding activity in the circulation are related to the delayed renewal of the accessory organs, plasma sex steroid-binding protein (SBP) and total testosterone (T) levels were measured throughout the year. From these data and determinations of association constants for T binding to SBP and albumin at both hibernating (4 degrees C) and active (40 degrees C) temperatures, estimates of the unbound ("free") and albumin-bound T fractions were made and correlated with changes in the accessory reproductive organs. Plasma SBP concentrations (mean +/- SEM) exhibited wide seasonal fluctuations: they were baseline in May (10 +/- 2 nM) following spring arousal, increased dramatically in June (184 +/- 24 nM), and reached peak levels in early July (262 +/- 29 nM), where they remained until August. In late August they began to fall (104 +/- 23 nM) and then returned to baseline during the hibernation period (October-April). Although total T levels were also elevated in June, it appeared that the unbound ("free") and the unbound plus albumin-bound T fractions did not increase until late July. Since the accessory gland weights did not begin to increase until late July as well, it was concluded that increases in the unbound and albumin-bound T fractions may be an important factor in the recrudescence of the accessories and that increased SBP activity in early summer may play a role in the regression and delayed renewal of these organs. However, what factor(s) maintain the accessory glands, epididymal spermatozoa, and sexual behavior during the breeding and hibernation periods when all T fractions were low are, as yet, undetermined.

Kronborgia pugettensis sp.nov. (Neorhabdocoela: Fecampiidae), an endoparasitic turbellarian infesting the shrimp Heptacarpus kincaidi (Rathbun), with notes on its life-history.

The morphology of Kronborgia pugettensis sp. nov., an endoparasite from the haemocoele of the caridean shrimp Heptacarpus kincaidi is described from specimens collected in the San Juan Island region of the western coast of North America. Members of this species are unisexual as are other members of the genus, but only females were found. An ootype and a type of accessory reproductive gland not known from other Kronborgia spp. are described, but they are probably present in other members of the genus. The life-history is similar to that of other Kronborgia spp. After the female reaches maturity, it emerges from the host and secretes a tubiform cocoon around itself and deposits its egg capsules within it. Embryogenesis lasts about 4 months. A free-swimming larva locates the new host, attaches to its exterior, and secretes a cyst around itself. It then penetrates through the exoskeleton to reach the haemocoele. K. pugettensis is easily distinguished from other members of the genus by the shape of the cocoon, type of host, and geographic distribution. This is the second species of fecampiid described from North America, but several undescribed species are known to exist from their cocoons.