70 GONADAL DEVELOPMENT IN GUINEA PIG MALES (CAVIA PORCELLUS)

2016 ◽  
Vol 28 (2) ◽  
pp. 164
Author(s):  
F. Oliveira ◽  
A. Santos ◽  
A. A. Neto
Keyword(s):  
Guinea Pig ◽  
Sertoli Cells ◽  
Sexual Differentiation ◽  
Primordial Germ Cells ◽  
Gonadal Development ◽  
Postnatal Period ◽  
Seminiferous Tubules ◽  
Morphological Description ◽  
Hormonal Function ◽  
Gonad Differentiation

Sexual differentiation in mammals is an event that presents many variations between species. Because it is related to hormonal function, any imbalance in the androgens and estrogens production can lead to malformations. Because sexual differentiation occurs in different ways among various animals, the recognition of their peculiarities becomes important in order to correct reproductive handling in different species. Considering that the guinea pig is commonly used as an experimental model in the reproductive area, the goal of this work was to perform a morphological description of gonad differentiation of the male guinea pig during embryonic development. In total, 11 conceptuses with ages 25 (n = 3), 30 (n = 2), 40 (n = 2), 50 (n = 2), and 65 (n = 2) days were used for light microscopy processing. The embryos at 25 days were processed completely. For the others, the gonads were dissected. The samples were dehydrated in alcohol, embedded in paraffin, and 5-µm sections were stained with hematoxylin-eosin. In the guinea pig gonad at 25 days gestation, there was a presence of gonadal cords, formed by condensation of somatic cells, which is characteristic of an undifferentiated gonad. In addition, we observed the presence of mesonephric and paramesonephric ducts in different embryos, indicating that other genital system organs were not formed. For the 30 days of development of guinea pigs, we observed that gonadal cords were differentiated in testicular cords by invasion of mesenchymal and endothelial cells, and also composed of Sertoli cells and primordial germ cells. These cords were among a large amount of testicular mesenchyme at the 40-day group. With 50- and 65-day development samples, the gonad was completely differentiated into testicle, with the presence of spermatogonia and Sertoli cells in the seminiferous tubules, and a large amount of interstitial Leydig cells around the tubules. We conclude that gonadal differentiation in guinea pig males occurs around the middle of pregnancy, between 25 and 30 days and that, before the end of the pregnancy, at 50 days, the testicle presents morphology similar to that found in the postnatal period.

scholarly journals Minireview: Transcriptional Regulation of Gonadal Development and Differentiation

Endocrinology ◽  
2005 ◽  
Vol 146 (3) ◽  
pp. 1035-1042 ◽  
Author(s):  
Susan Y. Park ◽  
J. Larry Jameson
Keyword(s):  
Germ Cells ◽  
Sertoli Cells ◽  
Leydig Cells ◽  
Cell Types ◽  
Gonadal Development ◽  
Targeted Mutagenesis ◽  
Seminiferous Tubules ◽  
Molecular Pathways ◽  
Theca Cells ◽  
Main Cell

The embryonic gonad is undifferentiated in males and females until a critical stage when the sex chromosomes dictate its development as a testis or ovary. This binary developmental process provides a unique opportunity to delineate the molecular pathways that lead to distinctly different tissues. The testis comprises three main cell types: Sertoli cells, Leydig cells, and germ cells. The Sertoli cells and germ cells reside in seminiferous tubules where spermatogenesis occurs. The Leydig cells populate the interstitial compartment and produce testosterone. The ovary also comprises three main cell types: granulosa cells, theca cells, and oocytes. The oocytes are surrounded by granulosa and theca cells in follicles that grow and differentiate during characteristic reproductive cycles. In this review, we summarize the molecular pathways that regulate the distinct differentiation of these cell types in the developing testis and ovary. In particular, we focus on the transcription factors that initiate these cascades. Although most of the early insights into the sex determination pathway were based on human mutations, targeted mutagenesis in mouse models has revealed key roles for genes not anticipated to regulate gonadal development. Defining these molecular pathways provides the foundation for understanding this critical developmental event and provides new insight into the causes of gonadal dysgenesis.

The development of the testis of the Merino ram, with special reference to the orgin of the adult stem cells

1962 ◽  
Vol 13 (3) ◽  
pp. 487 ◽  
Author(s):  
CS Sapsford
Keyword(s):  
Stem Cells ◽  
Basement Membrane ◽  
Germ Cells ◽  
Sertoli Cells ◽  
Adult Stem Cells ◽  
Germ Line ◽  
Primordial Germ Cells ◽  
Seminiferous Tubules ◽  
Stages Of Development ◽  
Striking Change

In the ram, as in other mammals, the sex cords are made up of two types of cell: indifferent cells (derivatives of the coelomic epithelium) and primordial germ cells. In the cords, each type pursues a separate and independent line of development to become respectively the Sertoli cells and the stem cells (type A spermatogonia) of the adult testis. The principal changes taking place in the primordial germ cells (gonocytes) are a reduction in the size and number of the Feulgen-positive particles in the nuclei, the appearance and subsequent fusion of the nucleoli, and, finally, an increase in the size of the nuclei. While these changes are taking place, the cytoplasm increases in volume and inclusions become more numerous. Cells which have undergone all these transformations have been called prospermatogonia. The cells of the germ line are at first more centrally placed in the sex cords than the indifferent cells. Just before spermatogenesis begins, they migrate to the basement membrane of the seminiferous tubules. All germ cells in tubules in which spermatogenesis has been initiated are seen as prospermatogonia. These cells become flattened against the basement membrane, and their nuclei become more oval in shape. They thus become identical with the stem cells of the adult. Little change is evident in the nuclei of the indifferent cells until puberty. Feulgen-positive material is found in the form of coarse granules at earlier stages of development. At puberty, these granules become dispersed to give a much more homogeneous nucleus. Concurrently, nuclei increase in size, and single or double true nucleoli can be identified. During development, increases in cytoplasmic volume take place. Although cell boundaries between indifferent cells cannot be seen in fixed material, phase contrast observations of fresh material have demonstrated that some forms exist as mononucleate units. It could not be determined whether the same was true in the case of Sertoli cells. No striking change in the relative numbers of glandular interstitial cells could be observed at different stages of development.

scholarly journals Duplicated insertion mutation in the microtubule-associated protein Spag5 (astrin/MAP126) and defective proliferation of immature Sertoli cells in rat hypogonadic (hgn/hgn) testes

Reproduction ◽  
2006 ◽  
Vol 132 (1) ◽  
pp. 79-93 ◽  
Author(s):  
Hiroetsu Suzuki ◽  
Mio Yagi ◽  
Katsushi Suzuki
Keyword(s):  
Sertoli Cells ◽  
Recessive Gene ◽  
Postnatal Growth ◽  
Postnatal Period ◽  
Male Rats ◽  
Seminiferous Tubules ◽  
Insertion Mutation ◽  
C Terminus ◽  
Abnormal Mitosis ◽  
Antigen 5

Male rats with hypogonadism (hgn/hgn) experience sterility from testicular dysplasia, which is controlled by a single recessive gene, hgn. The postnatal growth of the seminiferous tubules was severely affected. In this study, we localized thehgnlocus to a 320 kb region on rat chromosome 10 and detected the insertion of a 25 bp duplication into the sixth exon of the sperm-associated antigen 5 (Spag5/astrin/MAP126) gene, which codes for a microtubule-associated protein. This mutation results in a truncatedSpag5protein lacking the primary spindle-targeting domain at the C terminus. Immunological staining with antibodies to markers for Sertoli and germ cells during the early postnatal period indicated that the abnormal mitosis with dispersed chromosomes inhgn/hgntestes occurs in proliferating Sertoli cells. Therefore, apoptotic Sertoli cell death would result from the disorganization of the spindle apparatus caused by defectiveSpag5. These findings suggested that theSpag5is essential for testis development in rats and that thehgn/hgnrat is a unique animal model for studying the function ofSpag5.

Early gonadal development and sexual differentiation in muskellunge (Esox masquinongy)

1997 ◽  
Vol 75 (8) ◽  
pp. 1262-1269 ◽  
Author(s):  
Feng Lin ◽  
Konrad Dabrowski ◽  
Lucy P. M. Timmermans
Keyword(s):  
Cross Section ◽  
Germ Cells ◽  
Sexual Differentiation ◽  
Resting State ◽  
Early Stage ◽  
Primordial Germ Cells ◽  
Gonadal Development ◽  
Mitotic Division ◽  
Early Prophase ◽  
Esox Masquinongy

Primordial germ cells (PGCs) were first identified in muskellunge (Esox masquinongy) of 14 mm total length (TL) 3 weeks post fertilization. At 32 mm TL, gonad strings were complete and formed a typical gonad shape in cross section. Blood vessels were first found in the gonads with Crossmon staining at 46 mm TL. Some of the PGCs underwent mitotic division at this stage. The ovarian sac started to develop in a fish of 82 mm TL, while the germ cells were still considered to be undifferentiated. In a fish of 138 mm TL, female gonads could be clearly identified from the ovarian sac and groups of oogonia, whereas in another type of gonad, the morphology of undifferentiated gonads was maintained. Germ cells became numerous in both sexes at 211 mm TL. Female gonads contained lobes with germ cells, including oogonia, early-prophase oocytes, and large oocytes. Spermatogonia and cells undergoing mitosis were observed in the testis. Ovaries in a fish of 250 mm TL were at the early stage of perinucleolus (early diplotene). Our observations indicate that in muskellunge (i) the PGCs remained in a resting state for up to 8 weeks post fertilization, (ii) gametogenesis occurred earlier in females than in males, (iii) the gonads developed from an undifferentiated stage directly into an ovary or testis, and (iv) the somatic elements in the gonads differentiated prior to the germ cells.

scholarly journals Studies on Postnatal Development of Testis of Guinea Pig (Cavia porcellus)

2021 ◽  
Vol 12 (5) ◽  
pp. 477-484
Author(s):  
S. Rajathi ◽  
◽  
Geetha Ramesh ◽  
T. A. Kannan ◽  
K. Raja ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Sertoli Cells ◽  
Guinea Pigs ◽  
Tunica Albuginea ◽  
Age Groups ◽  
Seminiferous Tubules ◽  
Interstitial Tissue ◽  
Left Testis

The histology and histochemistry of the testis of guinea pig of various postnatal age groups was conducted. A total of 24 guinea pigs of four different postnatal ages with six male animals each were collected from the Department of Laboratory Animal Medicine, Madhavaram Milk Colony, Chennai as per the Ethical committee approval. After collection, animals were euthanized as per CPCSEA norms and testis was dissected out and was cut into small pieces, fixed and processed for paraffin embedding. Sections of 4–5 µm thickness were cut and used for the routine and special histological and histochemical staining techniques. Testes wereencapsulated by tunica vaginalis and tunica albuginea. Septa from the capsule divided the testicular parenchyma into lobules. Each lobule consisted of seminiferous tubules which consisted of spermatogenic cells in stratified layers and sertoli cells. Pre-weaning and weaning group of guinea pigs seminiferous tubules showed wide lumen with only type 1 and type 2 spermatogonia and sertoli cells. Young and adult animals seminiferous tubules showed narrow lumen with type 1 and type 2 spermatogonia, primary spermatocytes in various stages of differentiation, secondary spermatocytes, spermatids (early and late) and sertoli cells. Sertoli cells were large oval shaped cells with lightly stained irregular shaped nucleus. Interstitial tissue contained leydig cells in all ages.Leydig cells appeared as varied in shape. In all the age groups studied, PAS activity was noticed in the capsule and basement membrane. The micrometrical parameters increased as age advanced in both right and left testis.

scholarly journals Developmental expression and spermatogenic stage specificity of transcription factors GATA-1 and GATA-4 and their cofactors FOG-1 and FOG-2 in the mouse testis

2002 ◽  
pp. 397-406 ◽  
Author(s):  
I Ketola ◽  
M Anttonen ◽  
T Vaskivuo ◽  
JS Tapanainen ◽  
J Toppari ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Sertoli Cells ◽  
Gonadal Development ◽  
Developmental Expression ◽  
Seminiferous Tubules ◽  
Testicular Development ◽  
Adult Testis ◽  
Stage Specificity ◽  
And Function

OBJECTIVE: The transcription factors GATA-1 and GATA-4 have been implicated in the regulation of testicular development and function. Their cofactors FOG-1 and FOG-2 are expressed in the gonads, but their cell-specific and developmental expression in the testis remains unresolved. Therefore, we analyzed GATA-1, GATA-4, FOG-1 and FOG-2 expression in detail, from undifferentiated male urogenital ridge to adult testis. METHODS: Immunohistochemistry and in situ hybridization were applied on mouse testicular samples. RESULTS: GATA-4 and FOG-2, but not GATA-1 or FOG-1, were expressed as early as in the male urogenital ridge. FOG-2 expression was localized in the Sertoli cells at embryonal day 12.5 (E12.5), but it diminished with advancing fetal testicular development. In E17.5 testis, FOG-2 was present only in the testicular capsule and a subset of fetal Leydig cells. FOG-1 was expressed from E15.5 Sertoli cells onwards, whereas GATA-1 was not detected during the fetal period at all. In the postnatal testis, FOG-2 was abundantly expressed immediately after birth, but in adult testis its expression was predominantly restricted to stage VII-XII seminiferous tubules. Stage specificity was also found for FOG-1, which, similarly to GATA-1, was abundantly expressed in stage VII-XII tubules during adulthood. CONCLUSIONS: Our results indicate that FOG-2, in addition to GATA-4, has a role in early gonadal development and sexual differentiation, and FOG-1 at later fetal stages, while GATA-1 executes its action postnatally. The findings suggest that, in contrast to the hematopoietic system and the heart, GATA-1 and GATA-4 do not use FOG-1 and FOG-2 respectively as their only cofactors during the early stages of testicular development.

Sex chimaerism, fertility and sex determination in the mouse

Development ◽  
1991 ◽  
Vol 113 (1) ◽  
pp. 311-325 ◽  
Author(s):  
C.E. Patek ◽  
J.B. Kerr ◽  
R.G. Gosden ◽  
K.W. Jones ◽  
K. Hardy ◽  
...  
Keyword(s):  
Sex Determination ◽  
Sertoli Cells ◽  
Leydig Cells ◽  
Sex Chromosome ◽  
Tunica Albuginea ◽  
In Situ Hybridisation ◽  
Ovarian Surface Epithelium ◽  
Surface Epithelium ◽  
Seminiferous Tubules ◽  
Coelomic Epithelium

Adult intraspecific mouse chimaeras, derived by introducing male embryonal stem cells into unsexed host blastocysts, were examined to determine whether gonadal sex was correlated with the sex chromosome composition of particular cell lineages. The fertility of XX in equilibrium XY and XY in equilibrium XY male chimaeras was also compared. The distribution of XX and XY cells in 34 XX in equilibrium XY ovaries, testes and ovotestes was determined by in situ hybridisation using a Y-chromosome-specific probe. Both XX and XY cells were found in all gonadal somatic tissues but Sertoli cells were predominantly XY and granulosa cells predominantly XX. The sex chromosome composition of the tunica albuginea and testicular surface epithelium could not, in general, be fully resolved, owing to diminished hybridisation efficiency in these tissues, but the ovarian surface epithelium (which like the testicular surface epithelium derives from the coelomic epithelium) was predominantly XX. These findings show that the claim that Sertoli cells were exclusively XY, on which some previous models of gonadal sex determination were based, was incorrect, and indicate instead that in the mechanism of Sertoli cell determination there is a step in which XX cells can be recruited. However, it remains to be established whether the sex chromosome constitution of the coelomic epithelium lineage plays a causal role in gonadal sex determination. Male chimaeras with XX in equilibrium XY testes were either sterile or less fertile than chimaeras with testes composed entirely of XY cells. This impaired fertility was associated with the loss of XY germ cells in atrophic seminiferous tubules. Since this progressive lesion was correlated with a high proportion of XX Leydig cells, we suggest that XX Leydig cells are functionally defective, and unable to support spermatogenesis.

scholarly journals Toxicity and Reproductive Parameters Impairment of Cypermethrin in Male Guinea Pig (Cavia porcellus)

2018 ◽  
Vol 6 (2) ◽  
pp. 130 ◽  
Author(s):  
Bertin Narcisse Vemo ◽  
Augustave Kenfack ◽  
Ferdinand Ngoula ◽  
Edouard Akono Nantia ◽  
Claude Cedric Njieudeu Ngaleu ◽  
...  
Keyword(s):  
Body Weight ◽  
Guinea Pig ◽  
Sperm Count ◽  
Prostatic Acid Phosphatase ◽  
Domestic Animals ◽  
Seminiferous Tubules ◽  
Reproductive Parameters ◽  
Serum Concentrations ◽  
Total Protein Level ◽  
Germinal Cells

Cypermethrin is a large spectrum action insecticide, globally employed to control pests in agriculture and some human and domestic animals ectoparasites. This study aimed to evaluate its toxicity and reproduction impairment in male guinea pig. Forty adult male guinea pigs were divided into 4 groups and orally submitted to 0, 92, 137.5 and 275 mg/kg body weight/day for 90 days. The weight of the liver increased significantly, while that of kidneys decreased significantly in treated animals compared to controls. Serum concentrations of creatinine, urea, ALAT, ASAT, total cholesterol, prostatic acid phosphatase increased significantly, while the testicular total protein level decreased significantly in groups given the insecticide relatively to the control. The testes weight, libido, serum level of testosterone, mobility, sperm count and the percentage of spermatozoa with entire plasma membrane decreased significantly in animals exposed to cypermethrin with reference to controls. The percentages of abnormal spermatozoa increased significantly in animals submitted to 137.5 or 275 mg/kg body weight (bw) of cypermethrin compared to control ones. On the testis histological sections of pesticide-treated animals, immature germinal cells were observed in the lumen of seminiferous tubules. Cypermethrin was toxic in male guinea pig and damaged reproductive parameters.

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