Histochemical evaluation of glycoconjugates in the male reproductive tract with lectin-horseradish peroxidase conjugates: I. Staining of principal cells and spermatozoa in the mouse

Several glycoconjugates are thought to bind spermatozoa as they pass through reproductive ducts. Paraffin sections of testis, ductuli efferentes, epididymis, and vas deferens of male mice were stained with ten different lectin-horseradish peroxidase conjugates to localize possible sites of synthesis and secretion of such glycoconjugates, based on the carbohydrate moieties in their constituent oligosaccharide side chains. Principal (columnar) cells lining the efferent ducts, germinal epithelium, and developing and maturing spermatozoa were examined with light microscopy. Staining of the Golgi and apical zones of cells was interpreted as evidence for synthesis and secretion of glycoconjugates. Principal cells synthesized and secreted glycoconjugates with sugar moieties as follows: sialic acid, all regions of the efferent ducts examined; the terminal disaccharide D-galactose- (beta 1----3) -N-acetyl-D-galactosamine, all regions of ducts except epididymis I; terminal alpha-D-galactosamine, some cells in epididymis III-V; N-acetyl-D-galactosamine, ductuli efferentes, epididymis I, II, and some cells in epididymis III-V; alpha-L-fucose, ductuli efferentes, vas deferens, and all regions of the epididymis except IV; N-glycosidic side chains, ductuli efferentes, vas deferens, and epididymis I, IV, and V. All of these sugar residues as well as N-acetyl-D-glucosamine were associated with the acrosomes and tails of spermatozoa throughout the ducts except for alpha-N-acetyl-D-galactosamine in epididymis I, and all occurred during one or more stages of spermiogenesis. The synthesis and secretion of glycoconjugates that bind to spermatozoa appear to involve more regions of the primary reproductive structures than was believed previously.     

Epididymal protease inhibitor (EPPIN) is differentially expressed in the male rat reproductive tract and immunolocalized in maturing spermatozoa

EPPIN (epididymal protease inhibitor; SPINLW1), an antimicrobial cysteine‐rich protein containing both Kunitz and whey acidic protein (WAP)‐type four disulfide core protease inhibitor consensus sequences, is a target for male contraception because of its critical role in sperm motility. Here, we characterized EPPIN's expression and cellular distribution in rat tissues and its in vivo regulation by androgens in the epididymis. EPPIN (mRNA and protein) was abundantly expressed in the rat testis and epididymis; we also found that the vas deferens, seminal vesicles, and brain were novel sites of EPPIN expression. PCR studies demonstrated that in addition to Sertoli cells, spermatogenic cells expressed Eppin mRNA. EPPIN was immunolocalized in Sertoli cells and spermatogenic cells (pachytene spermatocytes and round and elongated spermatids) and in epithelial cells and spermatozoa from efferent ductules and epididymis. EPPIN staining was observed on the middle and principal pieces of the flagellum of testicular spermatozoa. Epididymal spermatozoa had more intense EPPIN staining on the flagellum, and the EPPIN staining became apparent on the head and neck regions. This suggested that the EPPIN found on maturing spermatozoa was secreted primarily by the epithelial cells of the epididymis. Surgical castration down‐regulated EPPIN expression levels (mRNA and protein) in the caput and cauda epididymis, an effect reversed by testosterone replacement. Altogether, our data suggested that EPPIN expression in rats is more widespread than in humans and mice, and is androgen‐dependent in the epididymis. This species could be used as an experimental model to further study EPPIN's role in male fertility. Mol. Reprod. Dev. 79: 832–842, 2012. © 2012 Wiley Periodicals, Inc.     

Quantitative changes ofRicinus communis agglutinin I andHelix pomatia lectin binding sites in the acrosome of rat spermatozoa during epididymal transit

Summary During passage through the epididymis, spermatozoa undergo a number of changes which result in their acquisition of fertility and motility. Some of the changes that occur include loss of the cytoplasmic droplet and changes in sperm morphology, metabolism and properties of the nucleus and plasma membrane. Changes have also been reported in the acrosomic system of mammalian spermatozoa during their transit through the epididymis. In the present study, the quantitative changes of the glycoconjugate content in the acrosome of rat spermatozoa were examined during their passage through the epididymis using lectin-colloidal gold cytochemistry. Various regions of the epididymis (initial segment, caput, corpus and cauda epididymidis) were fixed by perfusion with 1% or 2% glutaraldehyde buffered in sodium cacodylate (0.1M), dehydrated in ethanol and embedded without osmication in Lowicryl K4M. Lectin-colloidal gold labeling was performed on thin sections usingRicinus communis agglutinin I (RCA I) orHelix pomatia lectin (HPL) to detectd-galactose-andN-acetyl-d-galactosamine-containing glycoconjugates, respectively. The labeling density over the acrosome of the acrosomic system was evaluated as the number of gold particles per m² of profile area using a Zeiss MOP-3 image analyzer. The overall mean labeling densities over the acrosome of spermatozoa for each lectin was estimated from 4 rats and over the four distinct epididymal regions. The mean labeling density of the acrosome with RCA I and HPL showed a similar pattern along the epididymis, although RCA I revealed approximately twice as many gold particles per epididymal region. In either case, there was a significant decrease in the labeling density of the acrosome of spermatozoa between the initial segment or caput epididymidis and cauda epididymidis (p<0.01). A similar decrease was also noted between the initial segment and corpus epididymidis (p<0.01). No change was found between the initial segment and caput epididymidis. Controls showed a virtual absence of labeling. These results suggest that in addition to a multitude of changes occurring to spermatozoa during epididymal transit, there are also significant quantitative changes in the glycoconjugate content within the acrosome.     

Lactate dehydrogenase activity of rat epididymis and spermatozoa: effect of constant light

During its passage through the epididymis, the gamete undergoes a process of "maturation" leading to the acquisition of its fertilizing ability. The epididymis displays regional variations in the morphology and metabolic properties of its epithelium which are relevant for the progressive development of mature sperm characteristics. The epididymis has spontaneous peristaltic contractions and receives sympathetic innervation that is modulated by melatonin, a hormone synthesized and released by the pineal gland. Constant lighting disrupts melatonin synthesis and secretion. We have studied the effect of constant light on lactate dehydrogenase (LDH; EC 1.1.1.27) and its isozyme C4 activities and protein content in whole epididymis, epididymal tissue and in spermatozoa from caput and cauda segments. Animals were exposed from birth to an illumination schedule of 14 h light:10 h dark (group L:D). At 60 days of age one group of animals was submitted to constant light over 50 days (group L:L). In order to test the fertilizing ability, the rats of each group were mated with soliciting estrous females. The percentage of pregnancies in females mated with males maintained in L:L was remarkably lower than those in females mated with males maintained in the L:D photoperiod (44% and 88% respectively). Constant light increased protein concentration and LDH activity in caput as well as in cauda of total epididymis. On the contrary, in epididymal tissue, the protein content decreased in both epididymal sections compared with controls. When enzymatic activity was expressed in Units per spermatozoa, constant light induced a significant reduction of total LDH and LDHC4 in caput and cauda spermatozoa while LDH activity of epididymal tissue was not affected. In spite of the decrease in LDH per sperm cell when rats were exposed to constant light, in total epididymis (epididymis tissue plus sperm cells content) and in spermatozoa, values of enzyme activities expressed per weight unit were higher than those of controls. This is explained by the increase in the amount of stored spermatozoa, both in caput and cauda, produced by exposure of animals to constant light. Our results confirm that in rats, chronic exposure to constant light promotes a reduction of fertilizing ability and indicates that continuous lighting reduces the total LDH and LDHC4 activities, possibly due to moderate aging of spermatozoa within the duct by lengthening of the sperm transit through the epididymis.     

Sperm morphological abnormalities appearing in the male rabbit reproductive tract

The role of the excurrent duct system in producing and/or eliminating morphologically abnormal spermatozoa may modify the semen parameters and interfere with sperm fertilizing capacity. To study this process, changes in the morphology of spermatozoa during their transit through the reproductive tract in sexually mature rabbits were investigated. The incidence of head, midpiece and tail abnormalities as well as of multiple defects in a single spermatozoon, and the position of the cytoplasmic droplet along the sperm midpiece were evaluated in samples from the testis, 6 regions of the epididymis and the vas deferens. Spermatozoa were characterized by rapid migration of the cytoplasmic droplet when passing from the proximal to the distal caput of the epididymis, and spermatozoa with no droplet predominated in the distal epididymis and vas deferens. In passing from the testis to the proximal caput of the epididymis, the incidence of spermatozoa with an abnormal midpiece and those with multiple defects decreased significantly. The proportion of spermatozoa with abnormal heads was also lower in the testis, but no statistically significant differences were found, whereas there was no change in the proportion of those with abnormal tails. These results indicate that there must be a mechanism for the disposal of defective spermatozoa. No evidence of spermiophagy by luminal macrophages was observed in the extracts, although a few spermatozoa exhibited signs of degeneration, suggesting, that although intraepithelial phagocytosis has not been clearly demonstrated in the nonexperimental rabbit, sperm cells may undergo a form of autolysis within the lumen of the duct.     

Identification of antigen in rat spermatogenic cells interacting with an anti-human sperm monoclonal antibody

A monoclonal antibody (MAb) raised against human sperm protein, designated YWK-II, was used to determine the distribution of antigens in rat spermatozoa and rat testicular germ cells. By an indirect immunofluorescent method, the antibody localized over the rat spermatozoal head, except for the postacrosomal region. In paraffin sections of adult and immature rat testis, germ cells, at every developmental stage, and Sertoli cells stained, while interstitial cells and peritubular myoid cells remained unstained. When cocultures of Sertoli and germ cells were tested, only the germ cells stained intensely. Sertoli cells and peritubular myoid cells in cultures did not stain. In the epididymal sections, strong staining occurred with spermatozoa in the lumen and epididymal epithelial cells, with moderate staining in the myoid layers of epididymis. To determine the sperm antigen interacting with the YWK-II antibody, rat spermatozoa proteins were prepared and analyzed by an immunoblot technique. The monoclonal antibody interacted with a single protein, with an estimated molecular weight of 115,000, present in the cauda epididymal spermatozoa. Among the proteins of the caput epididymal spermatozoa, however, the antibody interacted with a major and a minor band with molecular weights of 115,000 and 88,000, respectively. On the other hand, with proteins prepared from the membrane fraction of adult and immature rat testis, the antibody reacted with two bands with estimated molecular weights of 88,000 and 115,000. In the lysate prepared from germ cells dissociated from Sertoli-germ cell cocultures, the antibody recognized only the 88,000 protein. The present results show that the YWK-II MAb interacts with two proteins with different molecular weights. The amount of the interacting proteins in spermatozoa varied with their location within the epididymis.     

Dicarbonyl L-Xylulose Reductase (DCXR), a “Moonlighting Protein” in the Bovine Epididymis

During maturation and the acquisition of their fertilization potential, male germ cells are subjected to various sequential modifications that occur in the epididymis. Protein addition, reorganization or withdrawal, comprise some of these modifications. Dicarbonyl L-xylulose reductase (DCXR), a multifunctional protein involved in various enzymatic and protein interaction processes in different physiological systems, is one of the proteins added to spermatozoa in the epididymis. DCXR is a well-conserved protein with multiple characteristics including enzymatic activities and mediation of cell-cell interaction. In this study, we characterized the DCXR gene and protein expression in the bovine epididymis. Dicarbonyl L-xylulose reductase mRNA is differentially expressed in the caput, corpus, and cauda epididymide epithelial cells with a higher level observed in the cauda region. Tissue protein expression follows the same pattern as the corresponding mRNA expression with a cytoplasmic and apical distribution in the corpus and cauda epithelial cells, respectively. The protein can also be found with a nuclear localization in cauda epididymidis epithelial cells. Dicarbonyl L-xylulose reductase is secreted in the epididymis luminal compartment in the soluble fraction and is associated with microvesicular elements named epididymosomes. In spermatozoa, the DCXR protein was found in the cytoplasmic and membranous fractions. Expression of the DCXR protein is higher on caput spermatozoa but finally shows a weak detection in semen. These data describe DCXR in the bovine epididymis and reveal that its behavior differs from that found in humans. It seems that, in this model, the DCXR protein might have a questionable involvement in the fertilization process.     

Immunolocalization of a 25-kilodalton protein in mouse testis and epididymis.

We have recently observed that a polyclonal antibody raised against a mouse epididymal luminal fluid protein (MEP 9) recognizes a 25-kDa antigen in mouse testis and epididymis [Rankin et al., Biol Reprod 1992; 46:747-766]. This antigen was localized by light and electron microscopic immunohistochemistry. The immunoreactivity in the testis was found in the residual cytoplasm of the elongated spermatids, in the residual bodies, and in the cytoplasmic droplets of spermatozoa. In the epididymis, the epithelial principal cells were stained from the distal caput to the distal cauda. Immunogold labeling in the principal cells showed diffuse distribution without preferential accumulation in either the endocytic or the secretory apparatus of the cells. In the epididymal lumen, the immunoreactivity was restricted to the sperm cytoplasmic droplets. No membrane-specific labeling was observed in luminal spermatozoa, cytoplasmic droplets, or isolated sperm plasma membranes. Three weeks after hemicastration or severance of the efferent ducts, a normal distribution of the immunoreactive sites was found in the epididymis. Immunoreactivity, was also detected in the epididymal epithelium of immature mice as well as in that of XXSxr male mice having no spermatozoa in the epididymis. These results suggest that the immunoreactivity seen in the principal cells originates from synthesis rather than endocytosis of the testicular protein from disrupted cytoplasmic droplets. Furthermore, these results suggest that the 25-kDa protein is synthesized independently by both testis and epididymis.     

Excretion of radiolabeled estradiol metabolites in the slow loris (Nycticebus coucang)

The excretion pattern of estradiol was studied in the slow loris Nycticebus coucang) and the ring-tailed lemur (Lemur catta) in order to compare steroid excretion in two representative prosimian species. Daily urinary estrone conjugate measurements in the female loris provided little information when applied over prolonged periods. As a result of these negative data, a metabolic study was performed to determine if estrogen excretion patterns in the slow loris differed from those in the lemur, where urinary assays proved a useful tool in characterizing reproductive cycles. Radio-labeled estradiol was injected intravenously, and serial urine and fecal collections were analyzed for radiolabeled metabolites. The results of these studies demonstrate that more than 92% of the radiolabel was excreted in the feces of the loris, in contrast to only 16% excreted in the feces of the lemur.     

Ultrastructure of the spermatozoon of <Emphasis Type="Italic">Talpa romana</Emphasis> (Mammalia,Lipotyphla)

In this study, we used SEM and TEM to investigate the ultrastructure of spermatozoa from the cauda epididymis of Talpa romana. For comparison, we also analysed spermatozoa from the cauda epididymis of T. europaea captured in the same area. The male gamete of T. romana has a flattened head with an elliptic profile, consisting of a large acrosome and a nuclear region separated by a thin subacrosomal space. At the tip of the nucleus, the subacrosomal space ends in a finger-shaped projection. The tail includes a connecting piece, middle piece, principal piece and end piece. The male gametes of T. romana are substantially similar to those of T. europaea. A comparison with other species of insectivores permits extension of the similarity of sperm features to Scalopus aquaticus and Condylura cristata. Many spermatozoa from the cauda epididymis of T. romana and T. europaea have the tail bent at the annulus, and this is always associated with remnants of cytoplasmic droplets. This morphology is considered to be a common phenomenon.     

Maturation of spermatozoa in the epididymis of the Chinese hamster

Chinese hamster spermatozoa gain their ability to move when they descend from the testis to the distal part of the caput epididymis, but it is not until they enter the corpus epididymis that they become capable of fertilizing eggs. The maturation of the spermatozoa proceeds as they further descend the tract and perhaps continues even in the vas deferens. During transit between the distal caput and proximal cauda epididymides, small membrane-limited vesicles (and tubules) appear on the plasma membrane over the acrosomes of the spermatozoa. The number of vesicles appearing on the sperm brane reaches a maximum when the spermatozoa are in the proximal cauda epididymis. It declines sharply in the distal cauda epididymis. Spermatozoa in the vas deferens are free of the vesicles. The origin, chemical nature, and functional role of the vesicles that appear on the sperm surface during epididymal transit must be the subject of further investigation.     

Association study and expression analysis of CD9 as candidate gene for boar sperm quality and fertility traits

Cluster-of-differentiation antigen 9 (CD9) gene expressed in the male germ line stem cells is crucial for sperm-egg fusion, and was therefore selected as candidate gene for boar semen quality. The association of CD9 with boar sperm quality and fertility trait was analyzed using a total of 340 boars both from purebred Pietrain and Pietrain×Hampshire crosses. A single nucleotide polymorphism (g.358A>T) in intron 6 was significantly associated with sperm motility (MOT) (P<0.001), plasma droplet rate (PDR) (P<0.001) and abnormal spermatozoa rate (ASR) (P<0.01). Boars were divided into two groups with group 1 (G-I) boars having a higher SCON and SMOT, lower SVOL (sperm volume) and group 2 (G-II) having a lower SCON and SMOT, higher SVOL. The mRNA and protein expression levels were evaluated in reproductive, non-reproductive tissues and spermatozoa from G-I and G-II animals by using quantitative real-time PCR and western blotting. When both reproductive and non-reproductive tissues were examined, highest mRNA was expressed in prostate gland, then in the body of the epididymis, vas deferens and tail of the epididymis. In case of reproductive tissues, CD9 expression was higher in tissues and spermatozoa collected from G-I boars than those collected from G-II boars. The mRNA expression was significantly different (P<0.05) in body of epididymis from G-I and G-II boars. The CD9 protein expression results from western blot were coincided with the results of qRT-PCR. Moreover, CD9 protein localization in Leydig cells, Sertoli cells, epithelial cells and spermatozoa was remarkable which indicated the important role of CD9 in spermatogenesis process. By using mRNA and protein expression profiles, it could be shown that CD9 plays a crucial role during sperm development, especially within the epididymis where the maturation of the sperm, a key process for the sperm quality and motility takes place. These results will improve the understanding of the functions of the CD9 in spermatogenesis within the reproductive tracts and will shed light on CD9 as a candidate gene in the selection of good sperm quality boars.     

Human sperm proteins from testicular and epididymal origin that participate in fertilization: modulation of sperm binding to zona-free hamster oocytes, using monoclonal antibodies.

In order to identify human sperm surface proteins involved in the gamete recognition process, mouse monoclonal antibodies were directed against human spermatozoa and screened with live spermatozoa by enzyme-linked immunosorbent assay (ELISA). Immunoperoxidase staining of human testis showed the early presence of four corresponding proteins on germinal cells, while six were detected primarily in testis fluid. The presence of 17 proteins was evidenced in the epididymis. Eight were detected with a decreasing gradient from the beginning to the end of the organ, including vasa efferentia for three of them. The other nine were observed in only one defined segment, usually the caput epididymis, which was found to be the most active region. Comparison of spermatozoa patterns from testis, vasa efferentia, and the three regions of epididymis pointed out a progressive coating. By contrast, three antibodies displayed a migration of spermatozoa surface domains in the course of epididymal transit. Six antibodies were found to inhibit human spermatozoa adherence to zona-free hamster oocytes, while nine promoted it. Molecular weights of antigens corresponding to nine of the antibodies ranged from 11 to 215 kDa. No correlation could be established with previously described human proteins. These observations emphasize the role of epididymis in human sperm maturation.     

Immunocytochemical localization of DJ-1 in human male reproductive tissue

DJ-1 was identified as an activated ras-dependent oncogene product, and was also found to be an infertility-related protein (contraception-associated protein 1; CAP 1) that was reduced in rat spermatozoa treated with ornidazole, one of the endocrine disrupting substances that causes reversible infertility in rats. CAP 1 is present in spermatozoa but is not detectable in the epididymal fluid of fertile rats and appears to be shed from sperm during treatment with ornidazole. To determine the functions of DJ-1 in the human reproductive system as a target protein of endocrine active substances, we identified the localization of DJ-1 in human testis, epididymis, ejaculated spermatozoa, and seminal plasma. DJ-1 was present in cells existing in the seminiferous tubules and Leydig cells. Some strong expressions were observed in Leydig cells and Sertoli cells, suggesting a relation with spermatogenesis via androgen receptor (AR). In ejaculated spermatozoa, DJ-1 existed on the surface of the posterior part of head and the anterior part of the midpiece. DJ-1 was also present on sperm flagella when the antibody penetrated the plasma membrane, suggesting that there are two putative roles in fertilization, one is binding to the egg, and the other is flagella movement. In contrast to previous findings, we detected DJ-1 in seminal plasma of fertile men. These results demonstrate that DJ-1 in human seminal plasma is not only from spermatozoa but also from the testis and epididymis. It is suggested that DJ-1 may play an important and as yet uncharacterized role in spermatogenesis and fertilization in humans.     

Direct injection of foreign DNA into mouse testis as a possible in vivo gene transfer system via epididymal spermatozoa.

We have attempted to transfect testicular spermatozoa with plasmid DNA by direct injection into testes to obtain transgenic animals [this technique was thus termed "testis-mediated gene transfer (TMGT)"]. When injected males were mated with superovulated females 2 and 3 days after injection, (i) high efficiencies (more than 50%) of gene transmission were achieved in the mid-gestational F0 fetuses, (ii) the copy number of plasmid DNA in the fetuses was estimated to be less than 1 copy per diploid cell, and (iii) overt gene expression was not found in these fetuses. These findings suggest the possibility that plasmid DNA introduced into a testis is rapidly transported to the epididymis and then incorporated by epididymal spermatozoa. The purpose of this study was to elucidate the mechanism of TMGT by introducing trypan blue (TB) or Hoechst 33342 directly into testis. We found that TB is transported to the ducts of the caput epididymis via rete testis within 1 min after testis injection, and TB reached the corpus and cauda epididymis within 2-4 days after injection. Staining of spermatozoa isolated from any portion of epididymis was observed 4 days after injection of a solution containing Hoechst 33342. Injection of enhanced green fluorescent protein (EGFP) expression vector/liposome complex into testis resulted in transfection of epithelial cells of epididymal ducts facing the lumen, although the transfection efficiency appeared to be low. In vivo electroporation toward the caput epididymis immediately after injection of EGFP expression vector into a testis greatly improved the uptake of foreign DNA by the epididymal epithelial cells. PCR analysis using spermatozoa isolated from corpus and cauda epididymis 4 days after injection of a DNA/liposome complex into testis revealed exogenous DNA in these spermatozoa even after treatment with DNase I. These findings indicate that exogenous DNA introduced into tesits is rapidly transported to epididymal ducts via the rete testis and efferent ducts, and then incorporated by epithelial cells of epididymis and epididymal spermatozoa.     

Intra-acrosomal 155,000 dalton protein increases the antigenicity during mouse sperm maturation in the epididymis: A study using a monoclonal antibody MC101

We found an intra-acrosomal antigen of about 155,000 daltons (155 kDa) in a survey using the monoclonal antibody MC101 raised against mouse cauda epididymal spermatozoa. Morphological studies by means of indirect immunofluorescence and immunogold electron microscopy localized the antigen to the cortex region of the anterior acrosome. Avidin biotin complex immunocytochemistry initially demonstrated a faint signal at the anterior acrosome in the testis spermatozoa that increased in intensity as the sperm moved toward the distal epididymis. This incremental immunoreactivity was also confirmed by immunoblotting following one-dimensional SDS-PAGE. The 155 kDa protein band was immunostained, and it was much more intense in the cauda epididymal than in the caput and corpus epididymal spermatozoa. Only a trace or no immunostain was evident in the caput or testis spermatozoa. The antigen localization did not change during passage through the epididymis, being confined at the cortex region of the anterior acrosome. The epididymal epithelial cells were not immunostained. These findings suggested that the 155 kDa protein is biochemically modified, further implying that the biochemical alteration of intra-acrosomal material is involved in sperm maturation in the epididymis. © 1995 wiley-Liss, Inc.     

Exudativory in the Bengal slow loris (Nycticebus bengalensis) in Trishna Wildlife Sanctuary,Tripura, northeast India

In this study we estimated the extent of exudativory in Nycticebus bengalensis and examined whether exudates can be considered as fallback foods. This study was carried out in Trishna Wildlife Sanctuary, northeastern India, in winter (December–February) and summer (March and April). We estimated time–activity budget using instantaneous sampling and used continuous focal animal sampling to record all instances and durations of feeding, over a total of 177 hr. Feeding accounted for 22.3±2.2% of the activity budget, with no seasonal difference. Bengal slow lorises fed on exudates, nectar, fruit, bark, invertebrates and avian eggs. In addition to scraping they also obtained exudates by gouging holes into the bark of trees. In winter, lorises almost exclusively fed on exudates (94.3% of winter feeding time). In summer, exudates (67.3%) and nectar from one species (22.3%) dominated the diet. This study identifies the Bengal slow loris as the most exudativorous loris. Exudates rather than being a staple fallback food, seem to be a preferred, patchily distributed and common food in the diet of the Bengal slow loris. Exudativory in this species is characterized by high selectivity among species and seasonal variation, which may be related to variations in productivity of exudates and their chemical composition. An understanding of these factors is necessary for predicting the response of this species to human disturbance such as logging. This study also underscores the importance of protecting some of the common species such as Terminalia belerica on which the loris feeds during periods of scarcity. Am. J. Primatol. 72:113–121, 2010. © 2009 Wiley‐Liss, Inc.     

Effects of X-irradiation on the kinetics of abnormal sperm production and sperm loss in the mouse

Exposure of male mice to 6 Gy of X-rays resulted in a very rapid and extensive sloughing of the germinal epithelium as shown by the accumulation of non-sperm cells within the lumen of the epididymis. These cells were identified as stage 1 and 2 round spermatids. After accumulating in the caput, they progressed through the epididymis over the weeks of sampling and, by Week 9 after irradiation, they had completely disappeared from the organ. It is suggested that the precocious loss of round spermatids is responsible for the induction of oligospermy within the testis and the caput epididymidis. Similar sperm losses from the cauda epididymidis were not observed. Radiation also enhanced the frequency of misshapen spermatozoa normally found in this strain. From kinetic considerations, it is suggested that the generation of abnormal spermatozoa may be biphasic with an early component comprising maturing spermatids and a late contingent composed of affected spermatocytes. Return to the pre-irradiation level of abnormal frequency was not observed within the time frame of this study (10 weeks), perhaps indicating residual damage. The synchrony that existed among the various organs in terms of both sperm loss and the generation of abnormal spermatozoa may be the result of a rapid dispersion of gametes from the testis and not due to local responses as would be expected if sperm flow were affected by the irradiation. The distribution of abnormal sperm types was different in the testis from that in the epididymis, presumably because of a testicular spermatophagic mechanism specific for the removal of certain deformities. It is concluded that the kinetics of spermatogenesis, of spermiogenesis, and of sperm transport in the mouse is not affected by exposure to 6 Gy of X-rays.     

Morphology of the reproductive tract and acquisition of sexual maturity in males of Potamotrygon magdalenae (Elasmobranchii: Potamotrygonidae)

The purpose of this study was to describe the structure of the reproductive tract of males of Potamotrygon magdalenae before, during, and after they acquire sexual maturity, and to establish the first maturity scale for males within the family Potamotrygonidae. The male reproductive tract of P. magdalenae is composed of testes, efferent ducts, epididymides, deferent ducts, seminal vesicles, Leydig, alkaline, and clasper glands, and claspers, all of which are paired and functional. Four sexual maturity stages were established: immature, maturing, reproductively active, and resting. The degree of claspers calcification is also a good indicator of sexual maturity in this species. The testes are lobulated, each lobe contains numerous spermatocysts which are organized in zones and are displaced radially from germinal papillae to the spermatozoa zone where individual spermatozoa are conveyed to the efferent ducts. The epididymis can be regionalized in head, body, and tail; these regions are distinguished by external pigmentation and by the epithelium lining configuration. The tail of the epididymis is connected with the deferent duct and this, in turn, with the seminal vesicle. The spermatozoa are organized in spermatozeugmata which begin to form in the deferent duct; this latter organ is attached laterally at the Leydig gland that is composed by simple glandular units. Irregular and vesicular secretions can be found in the genital ducts. These secretions might be associated with the maturation of the spermatozoa and formation of spermatozeugmata. The male reproductive tract of P. magdalenae is similar to other elasmobranchs; however, two types of primary spermatogonia, an epididymis internally regionalized, and the presence and structure of spermatozeugmata are specific features not yet described in freshwater stingrays. Most of the year, the males were reproductively active, however, few resting adult males occurred during one of the months of the lowest waters. J. Morphol. 276:273–289, 2015. © 2014 Wiley Periodicals, Inc.