Activity of the germinal epithelium in the ovary of a pregnant harvest mouse

1944 ◽  
Vol 89 (2) ◽  
pp. 135-138 ◽  
Author(s):  
Kenneth L. Duke
Keyword(s):  
Germinal Epithelium ◽  
Harvest Mouse

Binucleate Spermiogenesis in the Mouse

1972 ◽  
Vol 30 ◽  
pp. 112-113
Author(s):  
John J. Wolosewick
Keyword(s):  
Electron Microscopy ◽  
Phosphate Buffer ◽  
Seminiferous Epithelium ◽  
Mouse Testis ◽  
Germinal Epithelium ◽  
Intercellular Bridges ◽  
Adult Mice ◽  
Cervical Dislocation ◽  
Human And Mouse

Classically, the male germinal epithelium is depicted as synchronously developing uninucleate spermatids conjoined by intercellular bridges. Recently, binucleate and multinucleate spermatids from human and mouse testis have been reported. The present paper describes certain developmental events in one type of binucleate spermatid in the seminiferous epithelium of the mouse.Testes of adult mice (ABP Jax) were removed from the animals after cervical dislocation and placed into 2.5% glutaraldehyde/Millonig's phosphate buffer (pH 7.2). Testicular capsules were gently split and separated, exposing the tubules. After 15 minutes the tissue was carefully cut into cubes (approx. 1mm), fixed for an additional 45 minutes and processed for electron microscopy.

Ultrastructural Study of Human Testicular Biopsies in Infertility

1976 ◽  
Vol 34 ◽  
pp. 156-157
Author(s):  
Shirley Siew ◽  
Philip Troen ◽  
Howard R. Nankin
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Basement Membrane ◽  
Leydig Cells ◽  
Clinical Evidence ◽  
Young Male ◽  
Germinal Epithelium ◽  
Transmission Electron ◽  
Age Range ◽  
Male Subjects

Testicular biopsies were obtained from six young male subjects (age range 24-33) who complained of infertility and who had clinical evidence of oligospermia. This was confirmed on histological examination which showed a broad spectrum from profound hypospermatogenesis to relatively normal appearing germinal epithelium. Thickening of the tubular walls was noted in half of the cases and slight peritubular fibrosis in one. The Leydig cells were reported as normal or unremarkable.Transmission electron microscopy showed that the thickening of the supporting tissue of the germinal epithelium was caused more by an increase in the thickness of the layers of the lamina propria than of the tubular wall itself. The changes in the basement membrane of the tubular wall consisted mostly of a greater degree of infolding into the tubule and some reduplication which gave rise to a multilayered appearance.

Notes on the Habits of the Long-Tailed Harvest Mouse

1936 ◽  
Vol 17 (3) ◽  
pp. 274 ◽  
Author(s):  
Clarence F. Smith
Keyword(s):  
Harvest Mouse

CYCLIC CHANGES IN THE GONAD OF THE AMERICAN OYSTER, CRASSOSTREA VIRGINICA (GMELIN)

1964 ◽  
Vol 42 (2) ◽  
pp. 305-321 ◽  
Author(s):  
Austina V. Kennedy ◽  
Helen I. Battle
Keyword(s):  
Crassostrea Virginica ◽  
Gonadal Development ◽  
Germinal Epithelium ◽  
Nuclear Area ◽  
Seasonal Growth ◽  
Body Width ◽  
Visceral Mass ◽  
Current Season ◽  
Primary Oocyte ◽  
Cyclic Changes

Cyclic changes in the gonad of Crassostrea virginica (Gmelin), a dioecious, oviparous lamellibranch, are described as they occurred toward the most northerly limit of the range, Malpeque Bay, P.E.I., Canada, during 1961 and 1962. The gonad, composed of right and left gonadal lobes lying immediately beneath the mantle, consists of extensively branched follicles comprising the outer margin of the visceral mass. The follicles open into peripherally located ducts which lead into paired gonoducts terminating in the suprabranchial chamber. During the fall and winter the germinal epithelium is in an indifferent or inactive state. The sex for the current season is distinguishable when proliferation commences in May. Maximum gonadal development occurs in late June or early July as determined by comparison of gonadal width to body width in mid-transverse sections. Primary oocytes are initially distinguishable from oogonia by the presence of a distinct nucleolus, and later by an amphinucleolus consisting of a plasmosome and a karyosome. Seasonal growth of the primary oocyte was followed by a planimetry method using measurements of total area and nuclear area from prepared sections. The spindle for the first meiotic division is established immediately on rupture of the oocyte from the follicular wall. Spermatogenesis and spermiogenesis are completed within the follicle. Following spawning, amoebocytes infiltrate the follicles and interfollicular connective tissue to phagocytize unspawned gametes. By late October the follicles of both male and female consist of a low germinal epithelium and a few unresorbed gametes, and remain inactive until proliferation the following spring.

Attempts to stimulate proliferation of the germinal epithelium of the ovary

1942 ◽  
Vol 82 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Kathryn F. Stein ◽  
Edgar Allen
Keyword(s):  
Germinal Epithelium

OBSERVATIONS ON CADMIUM DAMAGE AND REPAIR IN RAT TESTES AND THE EFFECTS ON THE PITUITARY GONADOTROPHS

1962 ◽  
Vol 24 (4) ◽  
pp. 453-NP ◽  
Author(s):  
M. ALLANSON ◽  
R. DEANESLY
Keyword(s):  
Subcutaneous Injection ◽  
Cadmium Chloride ◽  
Cytological Study ◽  
Interstitial Cells ◽  
Germinal Epithelium ◽  
Seminiferous Tubules ◽  
Interstitial Tissue ◽  
Long Term Effects ◽  
Single Subcutaneous Injection

SUMMARY Cadmium chloride, in a single subcutaneous injection, can destroy spermatogenic and interstitial cells in the rat testis (Pařízek, 1957) and produce changes in the pituitary. The interstitial tissue is restored by ingrowths from the tunica and full androgen secretion returns before there is any regeneration of germinal epithelium. A cytological study has been made of the peripheral and central pituitary gonadotrophs; the latter revert almost to normal as the interstitial tissue regenerates, whereas the former retain characteristic castration features, unless there is also regeneration of the germinal epithelium. This seems to indicate that in the normal testis there is a hormone contribution from the seminiferous tubules as well as from the interstitial cells. The long-term effects of cadmium on the testis depend on the dose. Early stages of tubule restoration have been studied, but after administration of 0·9 mg., actual proliferation of the germinal epithelium was rarely found—only in four out of twenty rats, 113 or 142 days after injection.

Estrogen target cells in gonads of the chicken embryo during sexual differentiation

Development ◽  
1980 ◽  
Vol 55 (1) ◽  
pp. 331-342
Author(s):  
Jean-Marie Gasc
Keyword(s):  
Steroid Hormones ◽  
Sexual Differentiation ◽  
Binding Sites ◽  
Chicken Embryo ◽  
Physiological Role ◽  
Germinal Epithelium ◽  
Target Cells ◽  
Nuclear Labelling ◽  
The Right ◽  
Sites Of Action

Estrogen target cells were searched for in the differentiating gonads of the chicken embryo in order (1) to establish at the cellular level that steroid hormones can play a physiological role in gonadal sexual differentiation, and (2) to localize their sites of action. An autoradiographic technique carried out with frozen sections was employed to demonstrate the presence of binding sites for radiolabelled hormone in the nuclei of the target cells. Target cells for [3H]estradiol are found similarly in gonads of both male and female embryos from 5½ (stage 27 of H and H) to 7 days of incubation. Estrogen target cells are observed in the germinal epithelium of the left but not the right gonad, and in the medulla of both the right and left gonads. In the medulla, numerous cells inside the cords are a target for estradiol. The germ cells, difficult to identify unmistakably in the experimental conditions, do not seem to be a target for estrogen hormones. A 100-fold excess of unlabelled estradiol abolishes the nuclear labelling, which is only slightly reduced after a similar excess of unlabelled dihydrotestosterone. It is concluded that the nuclear binding sites have a limited capacity for steroid hormones and are specific for estrogen hormones. The lack of clear and consistent nuclear labelling after [3H]dihydrotestosterone injection confirms the specificity of the [3H]estradiol nuclear labelling. At day 10 of incubation, only the undifferentiated remnant of the germinal epithelium in the left testis still displays labelled cells after [3H]estradiol injection. These observations confirm the determinative role currently ascribed to the estrogen hormones in the cortical differentiation, but they also emphasize that this role extends to the medulla of both gonads. In light of this presence of estrogen receptor sites in the medullary cords as well as in the germinal epithelium, one can assign the estrogen hormones more specific and diversified roles than currently believed. These roles also appear very precocious in the process of gonadal differentiation. Finally, the absence of target cells for estrogen hormones in the germinal epithelium of the right gonad accounts for the lack of cortical differentiation on the right side.

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