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Journal ArticleDOI

The ultrastructure of the spermatheca in the red spotted newt

01 Dec 1970-Journal of Morphology (Wiley Subscription Services, Inc., A Wiley Company)-Vol. 132, Iss: 4, pp 397-423
TL;DR: Each outpocketing, or tubule, when studied in thin section with the electron microscope showed a wall consisting of two components, a continuous inner or lining layer of epithelial cells and an outer covering layer of myoepithelial cells.
Abstract: Sperm from the male spermatophore in the red spotted newt are held indefinitely in convoluted, tubular outpocketings of the female cloaca called, collectively, a spermatheca. Each outpocketing, or tubule, when studied in thin section with the electron microscope showed a wall consisting of two components, a continuous inner or lining layer of epithelial cells and an outer covering layer of myoepithelial cells. The myoepithelial layer is penetrated by occasional openings or intercellular spaces through which the epithelial cells make contact with a basal lamina that bounds the tubule. The myoepithelial cells resemble smooth muscle cells displaying filaments (mean diameter = 75 A ± 1 S.E.) that are probably constituted of actin, dense bodies and prominent caveolae. They are sparsely supplied with mitochondria, ribosomes, Golgi complexes and, sometimes, particles of glycogen. Typically the epithelial cells contain secretion granules, numerous mitochondria and ribosomes. They contain some fibers similar to those of the myoepithelial cells but with mean diameters that are significantly larger (90 A ± 2 S.E.). Occasional profiles of Golgi complexes are evident and glycogen particles are abundant throughout the cytosomes of spermathecal tubules from adult animals bearing sperm. Secretory granules and glycogen are extremely rare or lacking in the spermathecae of efts that have not attained sexual maturity and in animals with ablated or involuted ovaries. In such animals large electron-lucid vesicles appear at or near luminal borders. Glycogen is absent and secretory granules show signs of dissolution in the spermathecal cells of gravid females induced to ovulate by the injection of chorionic gonadotropin. It is indicated that the epithelial cells provide nourishment for the sperm while they are retained within the spermathecal tubules, that the discharge of sperm from the spermatheca is facilitated by the contraction of the myoepithelial cells and that gonadal hormones act in the regulation of spermathecal function.
Citations
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Book ChapterDOI
01 Jan 1984
TL;DR: Among urodeles, the necessary conditions for sperm competition, internal fertilization, multiple mating by females and sperm storage are widespread, and several recent studies provide evidence that it has been very important in the evolution of urodele sexual behavior.
Abstract: The chapter describes sperm competition as a major factor in the sexual behavior of many species. This is clearly a major factor that has led to the evolution in males of a variety of behavior patterns, morphological features and physiological processes that serve to reduce its impact, such as mate-guarding and sexual dimorphism. The potential for sperm competition may have shaped the evolution of anuran sexual behavior. In particular, amplexus, by which males sequester and guard females has evolved as an adaptation that prevents sperm competition. Among urodeles, the necessary conditions for sperm competition, internal fertilization, multiple mating by females and sperm storage are widespread, and several recent studies provide evidence that it has been very important in the evolution of urodele sexual behavior. A female strategy that incorporates multiple mating and sperm competition imposes a strong selection on how much males invest in sperm production and in the way that males allocate sperm to individual matings. This also leads to a diverse array of behavioral patterns and other adaptations.

100 citations

Journal ArticleDOI
Paul A. Verrell1
TL;DR: Experimental manipulation of the ambient sex ratio in an observation aquarium showed that the number of females available to a male did not influence his ‘decision’ whether to perform hula display or-attempt amplexus, while in the presence of other males, a courting male showed a greater tendency to adopt the amplexu mode of courtship.
Abstract: This paper extends previously published observations of the sexual behavior of the redspotted newt. In encounters between single males and females, the male either performs a brief lateral, or ‘hula’, display or clasps the female and holds her in amplexus for as long as 3 h. Experimental manipulation of the ambient sex ratio in an observation aquarium showed that the number of females available to a male did not influence his ‘decision’ whether to perform hula display or-attempt amplexus. In the presence of other males, a courting male showed a greater tendency to adopt the amplexus mode of courtship. Males interfered with one another's attempts to court and inseminate females. Unpaired males tried to displace those engaged in amplexus, but were seldom successful. During the spermatophore deposition and transfer stage of both courtship modes, unpaired males mimicked female behavior, apparently in order to obtain inseminations. Hula courtships were the most vulnerable to this type of competition; multiple insemination of the female was occasionally observed. The various costs and benefits associated with the various sexual strategies of male newts are discussed, together with some relevant ecological data. Similarly complex behavior in some other animals is also considered.

67 citations

Journal ArticleDOI
TL;DR: Evidence is presented which suggests that free fructose and glucose are produced by the oviduct, possibly to be utilized for sperm metabolism at the time of ovulation and sperm release.
Abstract: The sperm storage receptacles in the oviduct of the garter snake, Thamnophis sirtalis, were studied using histological, histochemical, and electron microscopic techniques. The receptacles are located in the posterior infundibulum and are readily distinguished from other structures within the oviduct. The luminal epithelium consists of secretory cells and ciliated cells. The latter cell type also lines the ducts leading to the receptacles. The distribution of lipids, carbohydrates, and several enzymes (succinic dehydrogenase, acid and alkaline phosphatases, nonspecific esterase, lipase, sorbitol dehydrogenase) in the infundibulum is described. At the electron microscopic level sperm heads are seen to be closely associated with the surface of receptacle cells, often indenting the luminal plasma membrane. The possibility of a “Sertoli cell-like” relationship is discussed. Formation of cytoplasmic vacuoles in receptacle cells is temporally associated with ovulation and may be part of a mechanism for sperm release from receptacle cells. No contractile elements were observed immediately around the receptacles. Evidence is presented which suggests that free fructose and glucose are produced by the oviduct, possibly to be utilized for sperm metabolism at the time of ovulation and sperm release.

66 citations

Book ChapterDOI
01 Jan 2000
TL;DR: An analysis of the microenvironment in the female reproductive tract during sperm storage along with the elucidation of the molecules that raise the osmolality in the epididymis is surely where future research might most profitably be directed.
Abstract: Publisher Summary Sperm storage involves the retention of viable spermatozoa within the reproductive tract for prolonged periods. Sperm-storing species are seasonal breeders that have become adapted to retain the male gamete for extended time intervals. Usually, prevailing environmental conditions are not conducive to the establishment of pregnancy at the time sperm are produced. Other reasons for storing sperm may be social conditions that do not allow the sexes to meet in order to copulate at a time most opportune for pregnancy to ensue immediately. Sperm storage typically occurs in females whose gametogenic cycle is not in synchrony with that of the male; however, the term can equally be applied to the male that retains gametes beyond the cessation of spermatogenesis. Furthermore, for sperm storage to be established in the female, it must be demonstrated that conception does not depend upon reinsemination at a time closer to ovulation, a scenario often made possible by concurrent sperm retention in the male of the species. An analysis of the microenvironment in the female reproductive tract during sperm storage along with the elucidation of the molecules that raise the osmolality in the epididymis is surely where future research might most profitably be directed. Such knowledge could have far-reaching applications to the short-term preservation of sperm of human and agricultural animal species as an alternative to cryopreservation or even to long-term cryobanking of such sperm by the provision, in the freezing medium, of molecules that may be less toxic to sperm than those currently used as cryoprotectants.

61 citations

References
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Journal ArticleDOI
TL;DR: The stain reported here differs from previous alkaline lead stains in that the chelating agent, citrate, is in sufficient excess to sequester all lead present, and is less likely to contaminate sections.
Abstract: Aqueous solutions of lead salts (1, 2) and saturated solutions of lead hydroxide (1) have been used as stains to enhance the electron-scattering properties of components of biological materials examined in the electron microscope. Saturated solutions of lead hydroxide (1), while staining more intensely than either lead acetate or monobasic lead acetate (l , 2), form insoluble lead carbonate upon exposure to air. The avoidance of such precipitates which contaminate surfaces of sections during staining has been the stimulus for the development of elaborate procedures for exclusion of air or carbon dioxide (3, 4). Several modifications of Watson's lead hydroxide stain (1) have recently appeared (5-7). All utilize relatively high pH (approximately 12) and one contains small amounts of tartrate (6), a relatively weak complexing agent (8), in addition to lead. These modified lead stains are less liable to contaminate the surface of the section with precipitated stain products. The stain reported here differs from previous alkaline lead stains in that the chelating agent, citrate, is in sufficient excess to sequester all lead present. Lead citrate, soluble in high concentrations in basic solutions, is a chelate compound with an apparent association constant (log Ka) between ligand and lead ion of 6.5 (9). Tissue binding sites, presumably organophosphates, and other anionic species present in biological components following fixation, dehydration, and plastic embedding apparently have a greater affinity for this cation than lead citrate inasmuch as cellular and extracellular structures in the section sequester lead from the staining solution. Alkaline lead citrate solutions are less likely to contaminate sections, as no precipitates form when droplets of fresh staining solution are exposed to air for periods of up to 30 minutes. The resultant staining of the sections is of high intensity in sections of Aralditeor Epon-embedded material. Cytoplasmic membranes, ribosomes, glycogen, and nuclear material are stained (Figs. 1 to 3). STAIN SOLUTION: Lead citrate is prepared by

24,137 citations

Journal ArticleDOI
TL;DR: Epoxy embedding methods of Glauert and Kushida have been modified so as to yield rapid, reproducible, and convenientembedding methods for electron microscopy.
Abstract: Epoxy embedding methods of Glauert and Kushida have been modified so as to yield rapid, reproducible, and convenient embedding methods for electron microscopy. The sections are robust and tissue damage is less than with methacrylate embedding.

9,741 citations

Journal ArticleDOI
TL;DR: More rapid than previous techniques, this method gives blocks which do not fracture unduly on trimming and provides sections of soft tissues at 1 μ for phase contrast microscopy, as well as ultrathin sections which cut as easily with glass knives as sections of methacrylate.
Abstract: Fixed tissue is dehydrated with tertiary butyl alcohol overnight. The following day it is cleared in toluene, infiltrated and embedded in Araldite resin-hardener-accelerator mixture without dibutyl...

3,197 citations

Book
01 Jan 2002
TL;DR: The easiest way of discovering the latest morphological, nomenclature and the most recent views on the homologies of anuran structures is to compare the relevant sections in the two books.
Abstract: AbstractSALAMANDER is a name not unknown to folklore, mythology or even slang. Henceforward it must be more than a nominal acquaintance of every zoologist, without distinction of creed or class, for Dr. Francis has given us a book with a much wider appeal than its title would suggest. In his preface the author says that: “Its intention is to provide a general account of the anatomy and morphology of a tailed Amphibian?the Salamander, which shall, within limits, be comparable with the work of Ecker and Gaupp on its ecaudate relative?the Frog”. There can be no doubt of his successful achievement of this object, and the two works are not only comparable but also complementary; the easiest way of discovering the latest morphological, nomenclature and the most recent views on the homologies of anuran structures is to compare the relevant sections in the two books.The Anatomy of the Salamander By Dr. Eric T. B. Francis. With an Historical Introduction by Prof. F. J. Cole. Pp. xxxi + 381 + 26 plates. (Oxford: Clarendon Press; London: Oxford University Press, 1934.) 25s. net.

332 citations

Journal ArticleDOI
TL;DR: It is concluded that rat submaxillary gland MEC are similar to visceral smooth muscle cells and could efficiently serve as an adjunctive mechanism in the egestive phase of secretion.

123 citations