Accessory Secretions Research Articles

Effects of gamma irradiation on the mechanisms of sperm transfer in Trichoplusia ni

The mechanisms involved in the transfer of sperm by unirradiated and irradiated cabbage loopers were studied by live dissection of the female immediately after the initiation of mating. This technique allows for observation of the entire mating and sperm transfer process. Failure of gamma-sterilized (30 krad.) adult male cabbage loopers to transfer sperm to the spermatheca was due to the inability of the irradiated males properly to incorporate sperm into the spermatophore bulb. The time required for mating was significantly longer for gamma-sterilized male moths. The timing of the insertion of the spermatophore, inflating the spermatophore bulb, and the inclusion of sperm into the bulb was altered in irradiated moths. Most irradiated males studied everted their endophallus early and ejaculated into the bursa copulatrix. Since eupyrene sperm have no motility until reaching the spermatheca, they have no way of being utilized for fertilization. A fraction of the apyrene sperm, on the other hand, find their way from the bursa copulatrix to the spermatheca since this type of sperm is motile at the time of ejaculation. Apyrene sperm being anucleate cannot effect fertilization so that radio-sterilization of the cabbage looper is essentially due to lack of sperm utilizable by the female. Irradiated males ejaculated the same number of eupyrene and apyrene bundles as the controls. These studies indicate that the elicitation of the ovipositional response is initiated by one or more of the male accessory secretions which must be incorporated into the spermatophore bulb to be effective.

Cytological and cytochemical studies on the ejaculatory duct and accessory secretion in Musca domestica

The accessory secretion produced in the ejaculatory duct of male adults of Musca domestica was found to be an arginine-rich proteinaceous substance. The synthesis and extracellular storage of the secretion occurs in the anterior region of the duct and apparently coincides with the expression of sexual maturity. Three, and sometimes four, successive matings were required to deplete totally the secretion from the storage area. Renewed synthesis was usually observed within the secretory cells after two successive copulations and continued for more than 24 hr in those ducts which had been depleted by repeated matings. The structure and possible function the accessory secretion serves in the induction of mating refusal behaviour in female flies is discussed.

The Motility and Aerobic Metabolism of Spermatozoa in Laboratory Animals with Special Reference to the Effects of Cold Shock and the Importance of Calcium for the Motility of Hamster Spermatozoa1

The metabolism and motility of epididymal spermatozoa of the hamster, rat, guinea pig, and rabbit have been studied in the presence or absence of male accessory secretions. The metabolic activity of hamster spematozoa was about three times higher than that of rat spermatozoa. In both Ringer’s solution and in 0.85% NaCl solution the motility of hamster epididymal spermatozoa was greatly decreased for about 4 hr and recovered again in the course of incubation at 37 C. This reaction seemed to be specific to hamster spermatozoa and was never observed in rat, guinea pig, and rabbit spermatozoa. The motility and respiration of hamster spermatozoa were depressed by the presence of fresh seminal vesicular fluid. However, the presence of fluids from fresh dorsal prostate or from the seminal vesicle stored at 5 C for 2 days stimulated both respiration and motility. In contrast, the presence of fluid from the ventral prostate depressed both oxygen uptake and motility of spermatozoa. A factor which can sensitize the epididymal spermatozoa to cold shock seemed to be present in the male accessory glands although the location of this factor may differ in different species. Hamster epididymal spermatozoa stopped forward motility immediately after being mixed with calcium-free solutions, although short-wave flagellation continued for a long while. In contrast, progressive motility of long duration was observed in the epididymal spermatozoa of the rat, mouse and rabbit either with or without calcium chloride in the media. The effect of calcium on the motility of hamster spermatozoa is specific to the spermatozoa themselves and is not influenced by accessory secretions. The minimal concentration of calcium chloride for the maintenance of normal motility of hamster spermatozoa was found to be 0.001 M in the medium. The motility of hamster spermatozoa was maintained by the addition of glucose, fructose, fructose-1,6-phosphate, sodium acetate, or even ATP only when calcium chloride and sodium bicarbonate were present in the medium. Calcium chloride had no effect on the oxygen uptake and fructose utilization by hamster spermatozoa, but only the presence of calcium chloride would maintain progressive motility for 12 hr. It appears that there is an intrinsic difference in the mechanism of motility of spermatozoa of the hamster and those of other species although there is little evidence to show a difference in their metabolic patterns.

SPERMATOPHORES AND SPERMATOZOA OF THE SQUID LOLIGO PEALII.

In the squid, spermatozoa are encased in spermatophores formed from male accessory secretions. Spermatophores about 1 cm in length were found to contain between seven and ten million densely packed spermatozoa. The substance of the sphermatophore itself was identified chiefly as a protein-polysaccharide complex, the precise composition differing among the various tunics and membranes; outer layers were classed as mucopolysaccharides, and the inner as mucoproteins. Of special morphological interest is the spiral filament consisting of tightly packed stellate particles in a gelatinous matrix, and of chemical interest the ‘cement’ which appears to be a strongly alkaline substance. A photomicrographic record was made of the spermatophoric reaction, which results in the release of the spermatozoa. Metabolic studies carried out with suspensions of squid spermatozoa have shown that the motility of such spermatozoa can be extended significantly by the addition of glycolys-able sugars. The ability of squid spermatozoa to convert glucose and fructose into lactic acid contrasts markedly with the lack of glycolytic ability which characterizes the spermatozoa of invertebrates with fully external fertilization. The spermatophore fluid of the squid contains a substance which, when added to a suspension of washed spermatozoa, causes a distinct inhibition of sperm motility and respiration; the nature of the factor responsible for this effect is still unknown.

A PHARMACOLOGICALLY ACTIVE AGENT IN THE REPRODUCTIVE SYSTEM OF INSECTS

The opaque accessory secretion from the male reproductive system of insects has been characterized in various ways. It exerts a melanophorotropic effect on the melanocytes in the skin of the frog, Rana pipiens, a property which, among naturally occurring compounds, is shared only by the indolalkylamines. The secretion also increases the rate of beating of the heart of the cockroach Periplaneta americana; its activity in this respect is unaffected by heating or by incubating with the enzyme trypsin, but it is destroyed by the action of the enzymes monoamine oxidase, tyrosinase, and o-diphenol oxidase. The active principle is associated with particles from which it is slowly released into solution. It is tentatively concluded that the material is an o-dihydroxyindolalkylamine.

Androgens in the bovine testis and spermatic vein blood.

BULL testis is the organ from which testosterone was first isolated nearly twenty-five years ago1. Information is still scarce, however, on the hormone content of this gland at various stages of the animal's development, nor is it known at what age androgenic steroids are first secreted by the gonads in appreciable amounts. Hooker2 was able to demonstrate the presence of unidentified androgenic material in the testes of prepuberal calves by bioassay. Recent evidence, derived from the chemical analysis of seminal plasma and accessory secretions, indicates that already at the early age of 4–5 months a source of androgens must be present in bull calves, sufficient to induce specific secretory activity in the male accessory glands3. The present study was intended to supplement these observations by direct determination of androgenic steroids in the testicular tissue and the spermatic vein blood of the bull.

The Migration of Spermatozoa in the Female of Rhodnius Prolixus Stal

ABSTRACT Removal of the opaque accessory glands from a male Rhodnius prevents the normal migration of the spermatozoa in a female which is inseminated by it. The opaque accessory secretion induces rhythmic contractions in the oviducts, probably by acting through a peripheral nervous system. Paralysis of the muscles of the female without interfering with the motility of the spermatozoa prevents the ascent of the spermatozoa. Killing the spermatozoa in the bursa has no effect on their subsequent migration. The central nervous system is not essential for the migration. It is concluded that the migration of spermatozoa in the female of Rhodnius proxlixus is a result of rhythmic contractions set up in the oviduct by the opaque accessory secretion of the male acting through a peripheral nervous system. Evidence in the literature suggests that the mechanism may operate in a number of spermatophore-forming species.

Glycosidases in mammalian sperm and seminal plasma.

PREVIOUS investigations of animal glycosidases have shown that certain enzymes of this group occur in a state of particularly high activity in reproductive organs; for example, β-glucuronidase in the preputial glands of the female rat1, and β-N-acetyl-glucosaminidase and α-mannosidase in the epididymis of the male rat2. Preliminary results indicated high α-mannosidase, and relatively low β-N-acetylglucosaminidase, activity in rat epididymal sperm, whereas the high activity of both enzymes in bull semen was largely confined to the seminal plasma (Conchie, J., and Levvy, G. A., unpublished work). It was the object of the present investigation to extend the study of these enzymes to the sperm, seminal plasma and male accessory secretions of other animals, and also to compare the activity of the three glycosidases mentioned with that of other similar enzymes, namely, β-mannosidase, α- and β-glucosidase, α- and β-galactosidase, β-xylosidase and α-N-acetylglucosaminidase. The substrates used were phenolphthalein glucuronide and the phenol and o- or p-nitrophenol derivatives of other glycosides3. Results are expressed in units, defined as micrograms of aglycone (phenolphthalein, phenol and o- or p-nitrophenol, respectively) liberated under suitable conditions2,3 by 1 ml. semen or accessory gland secretion in 1 hr. at 37° C. Results for sperm are calculated on the original volume of semen. The species investigated include the ram, bull, boar, stallion, rabbit, dog and man.

Carbohydrate and adenosinetriphosphate in sea-urchin semen.

SEA-URCHINS differ from mammals, in which fertilization is internal and the survival of spermatozoa largely depends on extraneous nutrients provided by accessory secretions, in that fertilization takes place after the eggs and sperm have been shed into sea water, which is a poor source of organic nutrients. Furthermore, unlike mammalian spermatozoa which in most species, including man, obtain their metabolic energy through anaerobic and aerobic glycolysis1, sea-urchin spermatozoa depend on a non-glycolytic and strictly aerobic metabolism; sea-urchin semen is devoid of significant amounts of fructose or other fermentable sugars; and the spermatozoa are incapable of glycolysing sugars added in vitro2.

OBSERVATIONS ON THE MOTILITY OF RABBIT SPERMATOZOA IN DILUTE SUSPENSION

1. Rabbit spermatozoa suspended in Baker's solution rapidly lose motility at relatively high dilutions. At a concentration of 0.4 million per ml., the spermatozoa from most ejaculates are completely immotile within 2 or 3 hours. The same phenomenon occurs with chloride-free diluents and is therefore not due to the toxic action of chlorides. 2. This rapid immobilisation may be prevented by suspension in cell-free supernatants from other more concentrated suspensions of rabbit semen and by the accessory secretions from a vasectomised buck. The most effective supernatants are those prepared from suspensions of spermatozoa which have been left overnight before centrifuging. Immobilisation may also be prevented by many other agents, the most effective of which are gum arabic, starch, glycogen, and serum proteins (carbohydrate-containing or carbohydrate-free). Yet, in no case is the action of these substances as effective as more concentrated suspension in Baker's solution. 3. The immobilisation is not prevented by catalase, gelatin, agar, or sodium silicate. It is almost certainly not due to the toxic action of traces of heavy metals and is not affected by the use of water doubly distilled over glass in the preparation of the diluent, or by treating the diluent with activated charcoal. 4. Washing with Baker's solution does not cause immobilisation of spermatozoa suspended at 20 million per ml. at a stage at which the concentration of seminal plasma has been reduced to that equivalent to dilution to 0.4 million per ml. Further washing (six repeated centrifugings of 0.2 ml. semen in 4 ml. of Baker's solution) immobilises them. This confirms the opinion that loss of intracellular, or perhaps rather paracellular, material is a responsible agent in the dilution phenomenon.