An assessment of the fertilizing ability of spermatozoa in the epididymis of the marmoset monkey (Callithrix jacchus)

The fertilizing ability of spermatozoa from different regions of the epididymis of the marmoset monkey, Callithrix jacchus , was assessed by determining their rate of fusion with zonaless hamster ova in vitro. This technique tests for functional competence and was validated using epididymal spermatozoa of the hamster whose fertility have been measured previously by in vivo fertilization experiments. The results suggest that some marmoset spermatozoa first acquire the ability to fertilize in the distal caput and proximal corpus epididymidis although the majority become fertile on reaching the proximal cauda region. Acquisition of fertilizing capacity was associated with a change in the degree and character of sperm motility. However, it is considered that modifications to the sperm plasmalemma which allow capacitation and the acrosome reaction to occur are of primary importance for sperm fertility. The development of sperm fertilizing ability in the marmoset is discussed in relation to that in other primates.     

Collection and analysis of semen from the common marmoset (Callithrix jacchus)

The authors examined the seminal characteristics of 16 male common marmosets (Callithrix jacchus) to provide baseline data for future studies of the reproductive biology of this species. Semen samples were collected by electroejaculation. There was considerable inter- and intra-male variation in all seminal characteristics. The median seminal volume was 30 microliters (range 8 to 85 microliters), and the median total sperm count was 5.1 x 10(6) sperm (range, 0.1 to 43 x 10(6]. The median progressive sperm motility was 48% (range, 10% to 76%), and 49% of the sperm exhibited normal morphology (range, 24% to 81%). Three types of sperm head abnormalities and eight types of tail defects were noted. Tail defects were common (median, 50%; range, 17% to 76%), whereas head defects were relatively rare (median, 4.5%; range, 0% to 24%). The results indicate that semen samples can be routinely collected from this species, but considerable inter- and intra-male variation can be expected. It is therefore important to examine several semen samples from each male marmoset to obtain an accurate seminal picture.     

Ultrastructure of adult and juvenile marmoset (Callithrix jacchus) Sertoli cells in vivo and in vitro.

The morphologic differentiation of Sertoli cells isolated from adult and juvenile marmosets and cultured on different extracellular matrices was evaluated by light and electron microscopy and compared to cells in vivo. Both cell types could be maintained in culture for at least 6 days. The degree of cellular differentiation, shape, ultrastructural appearance, and polarity seemed to benefit from laminin-coated substrata, compared with collagen-, fibronectin-, serum-, and heparan sulfate-coated substrata. With the former two substrates, a difference in behavior between juvenile and adult cells was evident. Whereas juvenile cells displayed a lesser degree of differentiation, adult cells exhibited identical morphologic characteristics in culture and in vivo. Cyclicity of morphologic features was not found, neither in vivo nor in vitro. The results indicate that: (1) laminin plays a unique role for marmoset Sertoli cell differentiation in vitro compared with other extracellular components; (2) a greater similarity between cells in vivo and in vitro is evident with adult Sertoli cells; and (3) the adult marmoset monkey could provide a primate model for mature Sertoli cells in culture, since there is a close similarity to human adult Sertoli cells in vitro and in vivo.     

Morphological and histochemical effects of 2,3,7,8-tetrachlorodibenzo-p dioxin (TCDD) on marmoset (Callithrix jacchus) testes

The testes of marmosets (Callithrix jacchus), which had been treated with a single dose of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (0.3 microgram to 10 micrograms/l kg body weight (BW)) were studied after 7 days using morphological and histochemical techniques. Light microscopic and electron microscopic examination revealed decreased intercellular contact in the germinal epithelium, as indicated first by enlarged intercellular spaces between the Sertoli's cells and between the Sertoli's cells and neighboring germ cells (i.e., spermatogonia and preleptotene spermatocytes), particularly in the basic compartment of the germinal epithelium. Second, decreased intercellular contact was indicated by the accumulation of premature spermatids and spermatocytes in the tubular lumen after TCDD treatment. The Sertoli's cells exhibited an increased amount of lipids, phagolysosomes, and vacuoles in their cytoplasm. Spermatids were frequently affected by TCDD, particularly during early spermiogenesis. These alterations included vacuolization of the cytoplasm and the development of additional germinal vesicles. This special effect on spermiogenesis became even more evident quantitatively by determination and counting of tubular stages in semithin sections. Tubular determination on the basis of the appearance of spermatids revealed that the ratio of tubular stages I to III became lower and that of stages V to VII became higher, dose dependently, indicating a maturation stop at the beginning of spermiogenesis caused by TCDD treatment. After TCDD treatment, Leydig's cells were morphologically unaffected, but histochemical investigations revealed decreased activity of 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD). The sensitivity of the applied methods was different in view of the level of unaffection. The effect of Leydig's cells, as indicated by the decreased activity of 3 beta-HSD, had already been found at a dose of 1 microgram/kg BW TCDD, whereas clear-cut morphological and morphometrical effects were seen at 3 micrograms/kg BW for the first time. Moreover, with the special effect on spermiogenesis in marmoset monkeys, the findings demonstrate that the toxicity of TCDD on testicular morphology is species specific.     

Continuous light environment has no effect on the circadian testosterone rhythm, spermatogenesis or fertility of the marmoset (Callithrix jacchus)

Maintenance of adult male marmosets in continuous light for 60 days had no effect on the circadian rhythmicity of plasma testosterone levels, spermatogenesis or fertility. The results indicate that photoperiodicity is not the environmental determinant that regulates reproduction in male marmosets.     

Abundant occurrence of basal radial glia in the subventricular zone of embryonic neocortex of a lissencephalic primate, the common marmoset Callithrix jacchus

Subventricular zone (SVZ) progenitors are a hallmark of the developing neocortex. Recent studies described a novel type of SVZ progenitor that retains a basal process at mitosis, sustains expression of radial glial markers, and is capable of self-renewal. These progenitors, referred to here as basal radial glia (bRG), occur at high relative abundance in the SVZ of gyrencephalic primates (human) and nonprimates (ferret) but not lissencephalic rodents (mouse). Here, we analyzed the occurrence of bRG cells in the embryonic neocortex of the common marmoset Callithrix jacchus, a near-lissencephalic primate. bRG cells, expressing Pax6, Sox2 (but not Tbr2), glutamate aspartate transporter, and glial fibrillary acidic protein and retaining a basal process at mitosis, occur at similar relative abundance in the marmoset SVZ as in human and ferret. The proportion of progenitors in M-phase was lower in embryonic marmoset than developing ferret neocortex, raising the possibility of a longer cell cycle. Fitting the gyrification indices of 26 anthropoid species to an evolutionary model suggested that the marmoset evolved from a gyrencephalic ancestor. Our results suggest that a high relative abundance of bRG cells may be necessary, but is not sufficient, for gyrencephaly and that the marmoset's lissencephaly evolved secondarily by changing progenitor parameters other than progenitor type.     

Diurnal and annual variations in plasma androgen levels in the adult male marmoset (callithrix jacchus)

Diurnal and annual variations in plasma androgen levels were studied in adult male marmosets. A distinct diurnal pattern, characterized by low androgen levels during the lights-on period and high levels during the lights-off period was observed (n=7). In contrast to this, no definite circannual pattern in androgen levels was observed (n=6).     

Ultrastructure of paracriny/steroidogenesis in principal cells of the marmoset epididymis

The ultrastructural features of the principal cell in the epididymal epithelium of the marmosets are distinguished by an intercellular exchange of substances contained within cytoplasmic vesicles and the presence of paracrystalline bodies. The possibility of the exchange of substances constituting paracriny and the paracrystalline inclusion having a role in steroidogenic activity is discussed.     

Functional response properties of neurons in the dorsomedial visual area of New World monkeys (Callithrix jacchus)

The dorsomedial visual area (DM), a subdivision of extrastriatecortex located near the dorsal midline, is characterized byheavy myelination and a relative emphasis on peripheral vision.To date, DM remains the least understood of the three primarytargets of projections from the striate cortex (V1) in New Worldmonkeys. Here, we characterize the responses of DM neurons inanaesthetized marmosets to drifting sine wave gratings. Most(82.4%) cells showed bidirectional sensitivity, with only 6.9%being strongly direction selective. The distribution of orientationsensitivity was bimodal, with a distinct population (correspondingto over half of the sample) formed by neurons with very narrowselectivity. When compared with a sample of V1 units representinga comparable range of eccentricities, DM cells revealed a preferencefor much lower spatial frequencies, and higher speeds. End inhibitionwas extremely rare, and the responses of many cells summatedover distances as large as 30°. Our results suggest cleardifferences between DM and the two other main targets of V1projections, the second (V2) and middle temporal (MT) areas,with cells in DM emphasizing aspects of visual information thatare likely to be relevant for motor control.     

Cortical input to the frontal pole of the marmoset monkey

We used fluorescent tracers to map the pattern of cortical afferents to frontal area 10 in marmosets. Dense projections originated in several subdivisions of orbitofrontal cortex, in the medial frontal cortex (particularly areas 14 and 32), and in the dorsolateral frontal cortex (particularly areas 8Ad and 9). Major projections also stemmed, in variable proportions depending on location of the injection site, from both the inferior and superior temporal sensory association areas, suggesting a degree of audiovisual convergence. Other temporal projections included the superior temporal polysensory cortex, temporal pole, and parabelt auditory cortex. Medial area 10 received additional projections from retrosplenial, rostral calcarine, and parahippocampal areas, while lateral area 10 received small projections from the ventral somatosensory and premotor areas. There were no afferents from posterior parietal or occipital areas. Most frontal connections were balanced in terms of laminar origin, giving few indications of an anatomical hierarchy. The pattern of frontopolar afferents suggests an interface between high-order representations of the sensory world and internally generated states, including working memory, which may subserve ongoing evaluation of the consequences of decisions as well as other cognitive functions. The results also suggest the existence of functional differences between subregions of area 10.     

Biological action of estrogen on the epididymis of prepubertal rhesus monkey

An estrogen binding protein has been demonstrated in the cytosol of the epididymis and caudal lobe of prostate of immature rhesus monkey. Scatchard plot analyses were linear, suggesting a single class of high affinity binding sites for the synthetic estrogen, R-2858 (Moxestrol) with a Kd of 5.88 X 10(-10) mol/l and a concentration of binding sites of 17.0 +/- 4.4 fmol/mg cytosol protein in the epididymis. In the prostate, the concentration of binding sites was 19.7 +/- 3.6 fmol/mg cytosol protein with a Kd of 5.42 X 10(-10) mol/l. In immature castrated monkeys, administration of estradiol dipropionate caused a significant increase in the weight, total protein and sialic acid content of the epididymis. This biological action of estrogen on the epididymis is presumably mediated via estrogen receptor.     

Ultrastructural and histochemical observations on the principal cells of monkey epididymis

A correlative ultrastructural and histochemical study of the epididymal principal cells was carried out on six normal mature macaque monkeys with known reproductive histories. The outstanding cytologic feature of the principal cells was the abundance of infranuclear electron-dense granules (0.2-0.5 micronsm). These cellular inclusions are found in close proximity with large clusters of small mitochondria and to the subepithelial and periductular capillaries surrounding the basal epithelium. Histochemical tests revealed that these granules do not contain acid phosphatase, are not lipid, but do contain mucopolysaccharides and glycoprotein moieties. This intriguing morphological characteristic of the infranuclear region of the principal cells is similar throughout the entire length of the epididymis and appears to be unique in the monkey. The close relationship of these secretion type granules to mitochondria and their proximity to basal epithelial capillaries is in agreement with the concept of epididymal secretion and a possible endocrine function of the mammalian epididymis must be considered.     

Non-human leukocyte antigen antibodies reactive with endothelial cells could be involved in early loss of renal allografts

Preformed donor-specific human leukocyte antigen (HLA) antibodies have been associated with allograft dysfunction and failure. However, recipients of HLA-identical kidneys can develop acute humoral rejection, implicating putative pathogenic antibodies that are directed against non-HLA antigens. We investigated the presence of endothelial cell-reactive antibodies in 11 patients who experienced early loss of their transplanted kidneys owing to humoral rejection and 1 loss from renal venal thrombosis. We examined the potential efficacy of intravenous immunoglobulin to block the binding of these antibodies, as previously suggested for anti-HLA antibodies.     

Vasectomy-dependent dysregulation of a local renin-angiotensin system in the epididymis of the cynomolgus monkey (Macaca fascicularis)

The mammalian epididymis is a fundamental organ for sperm cell maturation; it allows mammals to acquire their fertilizing ability. We have previously shown that during obstruction in cases of vasectomy, gene expression profiles were modified in human and cynomolgus monkey epididymides. Paracrine factors thus appear to be key elements in local gene expression along the epididymis. Local renin-angiotensin systems (RAS) have been described in many other organs as paracrine regulators of gene expression. This work demonstrates the presence of a local RAS in the epididymis of the cynomolgus monkey and investigates the vasectomy-dependent changes occurring in this system. After unilateral vasectomy in 4 monkeys (two for 3 days and two others for 7 days), the presence of two major components of the RAS (ie, angiotensinogen [ANG] and the type 1 receptor to angiotensin II [AT-I]) was evaluated in the vasectomized and the normal controlateral epididymides of each monkey. We also show by in situ hybridization that the principal cells of the epididymis express ANG and AT-I mRNAs and immunohistochemistry permitted to verify the co-localization of the AT-I protein and mRNA. Quantitative comparisons of individual variations in the mRNA and protein profiles for ANG and AT-I revealed that vasectomy altered the RAS expression profiles in an individual manner, thus confirming its role as a local system. This study provides a good basis for further investigation of the possible implications of the RAS in the physiology of the epididymis. Furthermore, the individual dependent modifications are in accordance with the very fluctuating results obtained in the fertility status of human patients undergoing a vasectomy reversal. The variations observed in the RAS expression profiles may be a good model to study the causes of the overall epididymal gene expression dysregulation that follows vasectomy and potentially affects fertility.     

Characterization and androgen dependence of specific proteins in the epididymis of adult rhesus monkey (Macaca mulatta)

The androgen dependence and regional distribution of specific epididymal proteins have been investigated in the adult rhesus monkey (Macaca mulatta). The protein pattern of the epididymal cytosol was studied in intact, castrated, and testosterone-treated castrated monkeys by polyacrylamide gel electrophoresis (PAGE) and electrofocusing. At least five distinct protein components of the epididymal cytosol were androgen-sensitive. The PAGE of cytosol from various portions of the epididymis showed that whereas four protein components were uniformly distributed in the caput, corpus, and caudal segments, one of the androgen-dependent proteins was found to be associated with the caudal portion of the epididymis. Electrofocusing of epididymal cytosol also confirmed the presence of five androgen-dependent proteins in the adult monkey. The isoelectric points of these proteins were shown to range between 5.6 and 6.5, and the molecular weights were found to range between 15,000 and 61,000.     

Preaponeurotic endoscopic repair (REPA) indication in men could be controversial

Hernia - To evaluate the outcomes of REPA and establish if any differences in complications and evolution are present between males and females. A retrospective study including consecutive patients...     

Noninvasive measures of bone bending rigidity in the monkey (M. nemestrina).

The in vivo bending rigidity and bone mineral content of monkey ulnae and tibiae were measured. Bending rigidity in the anteroposterior plane was measured by an impedance probe technique. Forced vibrations of the bones were induced with an electromechanical shaker, and force and velocity at the driving point were determined. The responses over the range of 100-250 Hz were utilized to compute the bending rigidity. Bone mineral content in the cross section was determined by a photon absorption technique. Seventeen male monkeys (Macaca nemestrina) weighing 6-14 kg were evaluated. Repeatability of the rigidity measures was 4%. Bone mineral content was measured with a precision of 3.5%. Bending rigidity was correlated with the mineral content of the cross section, r = 0.899. Two monkeys were evaluated during prolonged hypodynamic restraint. Restraint produced regional losses of bone most obviously in the proximal tibia. Local bone mineral content declines 17 to 24% and the average bending rigidity declines 12 to 22%. Changes in bones leading to a reduction in mineral content and stiffness are discussed.     

Are eosinophil leucocytes involved in the oestrogenic response of the postnatal rat epididymis?

The effects of oestrogens and androgens, alone or in combination, on several epididymal parameters have been studied in 15-day-old rats after neonatal treatment. Oestrogens induced several responses, such as increased growth of the fibromuscular stroma and eosinophil leucocyte accumulation, whereas the proliferative activity of the epithelium was decreased significantly. Otherwise, the density of intra-epithelial leucocytes was not modified. Different oestrogen-induced responses, such as the increase in volume of the fibromuscular stroma and eosinophil leucocyte accumulation were inhibited by treatment with testosterone, whereas dihydrotestosterone had no appreciable effect. This study raises the possibility that eosinophils are mediators of some of the oestrogenic responses in the early postnatal rat epididymis.