Influence of photoperiod and exogenous melatonin on testis morpho-physiology of sexually mature guinea fowl (Numida meleagris).

The biological effects of simulated photoperiod and melatonin on the control of reproduction of guinea fowls (Numida meleagris) are not well understood. Herein, thirty (30) sexually mature guinea fowl cocks were randomly assigned to 1-6 groups (n = 5) and subjected to different photoperiodic regimes in the presence or absence of exogenous melatonin (Mel; 1 mg/kgBW/day, i/m) for eight weeks. Testes of the euthanized cocks were processed for gross morphology, histological, histochemical, and oxidative stress markers. Testosterone concentration was determined in serum samples using the enzyme-linked immunosorbent assay (ELISA) technique. We observed an increase in testicular size in the Mel and Non-Mel groups under long-day (LD) photoperiods, and in the Non-Mel group under short-day (SD) photoperiod. Conversely, the testicular size was drastically reduced in the Mel group for SD. Seminiferous tubules in the Mel and Non-Mel groups of the SD showed cytomorphological changes, including degenerated cells, focal vacuolations, and depletion of germinal epithelium. However, the germinal epithelium appeared to be complete and active in both the Mel and Non-Mel groups for the LD. In all groups, the testes showed positive staining for PAS with varying intensities. There was a significant difference in PAS-staining intensity between different photoperiodic regimes and exogenous melatonin. The study observed the interaction between photoperiods and exogenous melatonin on glutathione reductase (GSH), malondialdehyde (MDA), and serum testosterone. Overall, the results indicated that a long-day (LD) photoperiod, combined with exogenous melatonin, enhanced reproductive activity in male guinea fowl by increasing testicular size and serum testosterone concentration.

The ultrastructural features of the infundibulum of the green iguana, Iguana iguana.

The purpose of this study is to describe, in detail, the ultrastructure of the infundibulum of the sexually mature and active female green iguana, Iguana iguana. The infundibulum of five iguanas was remarkably distinct from the uterus, and was also clearly demarcated into cranial (expanded v-shaped) and caudal (tubular) divisions. Tissue samples obtained from five portions (three from the cranial division and two from the caudal division) of the infundibulum were processed conventionally for light and electron microscopy. The epithelial lining of the most anterior, middle, and posterior, parts of the cranial division displayed nonciliated cells predominantly, and occasionally ciliated cells. The numerous secretory granules in nonciliated type 1 cell found in the fimbrial aspect of the infundibulum were homogenous and deeply electron-dense, but those in the other two regions were variants of this cell type because they contained variably electron-dense secretory granules. Two main types of nonciliated cells (type 2 and its variant, type 3, as well as type 4) occurred in the epithelial lining of the caudal division of the infundibulum, but they, clearly, showed no dense secretory granules. Whereas the nonciliated type 2 cell and its variant (type 3 cell) contained large glycogen deposits, the type 4 cell lacked these deposits but its apical part contained large lipid-like droplets and, remarkably, blebbed into the duct lumen. The nonciliated cells lining the mucosal tubular glands contained highly electron-dense secretory granules, which were similar to those found in the nonciliated type 1 cell in the epithelial lining of the fimbrial part of the cranial division of the infundibulum.

Changes in testicular histomorphometry and ultrastructure of Leydig cells in adult male Japanese quail exposed to di (n-butyl) phthalate (DBP) during the prepubertal period.

Phthalate esters, such as di(n-butyl) phthalate, (DBP), are synthetic chemical pollutants commonly used as plasticizers in the manufacture of plastics. In the present study, we investigated the effects of DBP in the testes of adult male quails (Coturnix cortunix japonica) exposed by oral gavage to variable doses of DBP (0 [control], 1, 10, 50, 200, and 400 mg/kgbw-d), for 30 days during the prepubertal period, using histo-morphometric and ultrastructural techniques. Generally, significant decreases in seminiferous tubular diameter (STD) and epithelial height (SEH) were observed predominantly at the highest DBP doses (200 and 400 mg/kg), as compared to medium (50 mg/kg), and lowest doses (1 and 10 mg/kg) as well as the control group. Ultrastructurally, apparent dose-specific degenerative changes were observed in the Leydig cells. The lowest DBP doses (1 and 10 mg/kg) did not produce significant effects on Leydig cell ultrastructure, whereas, at the highest doses (200 and 400 mg/kg), the Leydig cells were remarkably conspicuous in the interstitium and appeared foamy. There was a preponderance of electron-lucent lipid droplets which crowded out the normal organelles of the cell, as well as increases in the number of dense bodies in the cytoplasm. The smooth endoplasmic reticulum (sER) was less obvious, compacted, and wedged between the abundant lipid droplets and mitochondria. Taken together, these findings indicate that pre-pubertal exposure of precocious quail birds to DBP, produced parameter-specific histometric tubular changes, as well as dose-dependent cyto-structural derangement of the Leydig cells; which consequently may lead to overt reproductive impairments in the adult bird in the environment.

Spermiogenesis in the cattle egret (Bubulcus ibis).

Avian species comprise more than half of all vertebrates yet there is a dearth of information regarding spermatid development in this class of animals. This report of spermiogenesis in the cattle egret, Bubulcus ibis, is the first in the order Pelecaniformes. Five sexually mature and reproductively active male cattle egrets were captured in the wild, humanely euthanized, the reproductive organs dissected out, and tissues from the testes routinely prepared for transmission electron microscopy. Twelve steps of spermatid development, using the step-wise system, were determined. Acrosomogenesis in the egret results in a relatively short, solid, bullet-shaped acrosome that ends bluntly anteriorly and flat posteriorly or basally. The nucleus displays remarkable morphological changes, with the anterior end of the mature spermatid becoming flat, lacking a rostrum and an endonuclear canal. A perforatorium does not develop. It is noteworthy that a longitudinal, but not a circular, manchette develops during spermiogenesis in this bird. The proximal centriole is attached to the nucleus, at the implantation fossa, by means of well-formed, electron dense struts of material. An amorphous fibrous sheath develops in the principal piece. The interesting development and peculiar features of the acrosome and nucleus, as well as the absence of the perforatorium and circular manchette in the spermatozoon of the cattle egret, may be of phylogenetic significance.

Sperm structure of the cattle egret (Bubulcus ibis).

It remains a major concern that sperm structure has continued to be poorly investigated and reported in avian species. To our knowledge, sperm structure in the order Pelecaniforme has not been reported. Although McFarlane (1963; Proceedings of the XIII International Ornithological Congress; Ithaca, NY; American Ornithologists' Union) reported the study of spermatozoa in two genera and two species of the family Ardeidae, he did not provide an account, or the names of the species examined. The present report on the sperm structure of the cattle egret, Bubulcus ibis, is, thus, the first in the order Pelecaniformes (this bird has been placed variably under the order Ciconiiformes, or the order Pelecaniformes). Five sexually mature and reproductively active male cattle egrets were obtained from the wild, humanely euthanized, the reproductive organs dissected out, and tissues from the ducti deferentia were prepared for transmission electron microscopy. The sperm structure of this bird is generally similar to that described for most non-passerine birds. However, the acrosome is a short, conical or bullet-shaped, blunt-ending organelle that lacks a perforatorium. The base of the acrosome is flat and makes contact with the nucleus along, a correspondingly flat plane. The nucleus, thus, ends anteriorly in a flat plane devoid of a concavity or a rostrum, and an endonuclear canal. The acrosomal and nuclear features of this bird are, therefore, main deviations from the situation in the non-passerine clade of birds.

Spermatid differentiation, with particular reference to acrosomogenesis, in the passeridan bird, Carib grackle (Quiscalus lugubris).

Only a few studies on the development of the passerine spermatozoon are available, yet species variations in the conformation as well as structure of the generally helical acrosome have been reported. This study of spermiogenesis in the Carib grackle (Quiscalus lugubris) intended to provide a deeper understanding of the development of the sperm, and in particular to investigate the bi-partite nature and development of the acrosome as well as its relationship with the nucleus, in the absence of a perforatorium that is found in most non-passerine birds. The acrosomal vesicle already displays a bi-partite nature in the acrosomal granule within the Golgi complex, and the attachment of the dense granule (future acrosomal core) within the crest part (future acrosomal crest) establishes polarity as it approaches and attaches to the nucleus. Thereafter, they develop variably. The acrosomal crest leads the elongation and spiraling of the acrosome, and the core portion contributes significantly to the formation of the keel of the crest part. The rounded, core-bearing part of the base of the acrosome progressively indents and fits into the concavity, thus formed, at the anterior part of the nucleus. The possible homology of the acrosomal complex (including the perforatorium) and the nucleus between non-passerine and passerine birds was discussed. The centriolar complex comprises both the proximal and distal centrioles in all spermatids and spermatozoa. The mitochondria undergo a number of morphological changes, including size and electron-density, from the round spermatid through to the mature spermatid; changes that are probably influenced by their functional states in the different evolving phases of the spermatids.

Structural features of the spermatozoon of a passeridan bird, the Carib grackle, Quiscalus lugubris.

The spermatozoon of the Carib grackle, Quiscalus lugubris, a member of the family Icteridae, is generally similar in organization to the passerine-type of spermatozoon, in being highly elongated and displaying a helical structure of the acrosome, nucleus and principal piece of the tail. There are subtle variations in acrosomal structural features between this organelle in the grackle and that in some of the very few passerine species of birds in which the spermatozoon has been studied. The proximal centriole is present, and, thus, the Carib grackle is the third passeridan bird in which this organelle, hitherto regarded as absent in passerine birds, has been described in the spermatozoon. The spermatozoon of this bird also possesses a granular helix, which feature has been found variably even in the scanty available reports on passerine spermatozoa. It is advocated that the spermatozoon be studied in many more species of this large clade of birds. This report provides a basis for the study of spermiogenesis in the Carib grackle, with the aim of exposing, inter alia, a number of developmental features and processes of certain organelles that have received attention, recently, in the spermatozoa of passerine birds.

The effects on steroidogenesis and histopathology of adult male Japanese quails (Coturnix coturnix japonica) testis following pre-pubertal exposure to di(n-butyl) phthalate (DBP).

In the present study, we have investigated the effects of 30-day dietary (pre-pubertal) exposure to different doses (0 (control), 1, 10, 50, 200 and 400 mg/kg bodyweight/day) of di(n-butyl) phthalate (DBP) on Leydig cells of adult male Japanese quails by quantifying the transcript levels for P450 side-chain cleavage (p450scc), P450c17 (CYP17), and 3ß- and 17ß-hydroxysteroid dehydrogenase (hsd) using quantitative (real-time) polymerase chain reaction (qRT-PCR). In addition, the plasma testosterone levels were analysed using radioimmunoassay (RIA) and testis was examined for evidence of gross pathology and histopathology. Our data showed that pre-pubertal exposure to DBP produced alterations in testicular architecture as evident by poorly developed or mis-shaped testis, and altered spermatogenesis due to tubular degeneration and atrophy of seminiferous tubules especially in the high DBP dose (200 and 400 mg/kg) treated groups. In addition, DBP altered several key enzymes involved in testicular steroidogenesis pathways in an apparent dose-dependent manner. For example, biphasic effects of DBP were observed for P450scc and 3ß-hsd mRNA, that were generally increasing at low dose 10 mg/kg, and thereafter, an apparent dose-dependent decrease between 50 and 400mg/kg. The steroidogenic acute regulatory (StAR) protein was at the lowest detectable limits and therefore not quantifiable. These effects did not parallel the non-significant changes observed for plasma testosterone levels. The present data is consistent with previous reports showing that DBP modulates Leydig cell steroidogenesis in several species, with a potential negative effect on reproduction in those avian species that are vulnerable to endocrine disrupting chemicals.

Spermiogenesis in birds.

Current knowledge on avian spermiogenesis, including strengths and weaknesses, has been reviewed. Information on avian spermiogenesis considerably lags behind that in mammals because of the paucity of reports in birds. Spermiogenesis in passerine birds has received even much less attention than in non-passerine birds. Mechanisms underlying morphogenesis of the acrosome and nucleus, and roles of microtubular assemblies are poorly understood. The proximal centriole found in non-passerine birds, but hitherto considered to be absent in passerine birds, has recently been described in spermatids and mature spermatozoa of 2 passeridan species, including the Masked weaver for which new and detailed spermiogenetic information is provided in this review. A great deal more studies on spermiogenesis, and spermatogenesis generally, in various avian species are required to considerably enhance knowledge of this phenomenon, contribute to comparative spermatology, provide a basis for appropriate applied studies, and contribute to understanding of phylogeny in this vast order of vertebrates.

An immunohistochemical study of the presence and distribution of neuronal and glial markers in simple testicular cysts in the ostrich (Struthio camelus).

Simple testicular cysts are rare in birds and mammals. However, the condition has recently been reported in the ostrich (Struthio camelus), an economically important farmed bird. The innervation of normal and cryptorchid testes, unlike the simple testicular cysts of birds and mammals, has received considerable attention. This study, therefore, immunohistochemically demonstrates the presence and the general distribution pattern of neuronal and glial markers in the simple intratesticular cyst, and its associated structures, of fourteen adult ostriches using antibodies to neurofilament protein, S-100, neuron-specific enolase and protein gene product 9.5. The LSAB+ Kit(DakoCytomation, Denmark) immunostaining protocol was used in this study. The normal seminiferous peritubular tissue showed few or no immunoreactive nerve fibres. A greater density of neurofilament protein, S-100, neuron-specific enolase and protein gene product 9.5 immunopositive nerve fibres were observed in the tunica albuginea adjacent to the cyst, as well as in the peritubular connective tissue of cystic seminiferous tubules. In addition, the tunica adventitia of blood vessels within the interstitial space of the cystic seminiferous tubules displayed neurofilament protein, S-100 and protein gene product 9.5 immunoreactive nerve fibres of varying intensity and pattern. Protein gene product 9.5 immunostaining was also observed in the multinucleated giant cells of both the normal and the cystic seminiferous tubules. The cystic portion of the testis appears to have a richer innervation than the normal portion of the same testis. The richer innervation of simple testicular cysts in the ostrich is similar to that observed in the cryptorchid testis of mammals.

Components and development of the centriolar complex during and beyond spermiogenesis in a passeridan bird, the Masked weaver (Ploceus velatus).

The fate of the proximal centriole in passeridan birds is an area of controversy and relative lack of knowledge in avian spermatogenesis and spermatology. This study examines, for the first time, spatiotemporal changes in the centriolar complex in various phases of spermiogenesis in a passerine bird, the Masked weaver (Ploceus velatus). It also describes the configuration of the centriolar complex and the relationship between it and the granular body in both intra- and extra-testicular spermatozoa. It is shown that the proximal centriole is retained and attaches, at its free end, to the granular body of spermatids in every step of spermiogenesis, as well as in mature intra-testicular and post-testicular spermatozoa, including those in the lumen of the seminal glomus. As the centriolar complex, along with its attached granular body, approaches the nucleus in the early spermatid, the proximal centriole articulates with the distal centriole at an acute angle of about 45°, and thereafter, both centrioles, still maintaining this conformation, implant, by means of their articulating proximal ends, at the implantation fossa of the nucleus. In the mature spermatid and spermatozoon, the granular body winds itself helically around the centriolar complex in the neck/midpiece region of the cell, and, thus, becomes the granular helix. The significance of this observation must await future studies, including possible phylogenetic re-evaluation and classification of birds.

The ductuli efferentes testis of the greater cane rat ( Thryonomys swinderianus).

The structure of the efferent ducts of animals is known to vary from one species to another, it even varies between segments of the ducts in the same species. In the grasscutter or greater cane rat ( Thryonomys swinderianus), there are three segments of the efferent duct, based on their content of non-ciliated or principal cell types. Type I non-ciliated cell is present exclusively in the long proximal part of the duct, and exhibits a well-developed subapical endocytic apparatus as well as numerous oval or pleomorphic dense bodies. The type II non-ciliated cell predominates in the middle part of the duct, displays a poorly developed subapical endocytic apparatus but contains large, numerous vacuoles and dense bodies, all of which fill about two-thirds of the cell height. The type III non-ciliated cell, found in the epithelium of the terminal part of the duct, is poorly endowed with a subapical endocytic apparatus and contains no conspicuous endocytic vesicles or vacuoles. Only a few, small, dense bodies are present, if at all. The efferent duct of the cane rat is thus similar to that of man, the bull, goat and dog, in containing three varieties or types of non-ciliated cells. This report is the first to describe multiple non-ciliated cells in the epithelium of the efferent ducts of a rodent and, indeed, of a mammal smaller than the dog.

Morphological changes in the efferent ducts during the main phases of the reproductive cycle of birds.

The changes that take place in the efferent ducts during the major phases of the reproductive cycle of birds were studied morphologically using standard histological, morphometric, and ultrastructural methods in prepuberal, sexually mature and sexually active, and sexually mature but sexually inactive domestic fowl (Gallus domesticus), drake (Anas platyrhynchos), and guinea fowl (Numida meleagris). Profound structural and dimensional changes occurred in both segments (proximal and distal) of the efferent ducts and, in particular, in the nonciliated (Type I) cell of the proximal duct of sexually mature but inactive birds. The subapical tubulovacuolar system was markedly atrophic in nonciliated (Types I and II) cells and the numerous round dense globules of Type I cells that normally occurred in sexually active birds were replaced by fewer and more pleomorphic bodies containing lipofuscin granules in sexually resting birds. Lipid droplets, few and extremely large in inactive drakes but numerous and smaller in size in guinea fowls and domestic fowls, occurred in the Type I cell at both infra- and supranuclear levels of resting but not in prepuberal or sexually active birds. Ciliated cells in both segments of the ducts exhibited fewer and less profound phase-dependent changes ultrastructurally. Generally, the Type I cells of the proximal efferent duct appeared to be more sensitive to androgen deprivation than the Type II cell of the distal efferent duct or ciliated cells in both ducts. These morphologically phase-dependent features of the efferent ducts of birds may be used, together with or independent of testicular changes, in the determination of the status of the testis and epididymis of a male bird with regard to the reproductive cycle, especially in seasonally breeding species.