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Query: UMLS:C0276640 (TEM)
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The purpose of the present study was to determine whether Octopus vulgaris spermatozoa are activated by progesterone stimulation. Spermatozoa were collected from the spermatophores in the Needham's sac of the male (MS) and from the spermathecae of oviducal glands of the female (FS). We used transmission (TEM) and scanning (SEM) electron microscopy to study the morphology of untreated, Ca2+ ionophore A23187 and progesterone-treated MS spermatozoa, and untreated FS spermatozoa. We showed that ionophore and progesterone stimulation of MS spermatozoa induce breakdown of the membranes overlapping the acrosomal region, exposing the spiralized acrosome. These modifications resemble the acrosome reaction observed in other species. FS stored in the spermathecae did not show the membranes covering the acrosomal region present in the MS spermatozoa. When ionophore and progesterone treatments were performed in Ca2+-free artificial sea water, no changes were observed, suggesting the role of external calcium in modifying membrane morphology. Lectin studies showed a different fluorescence distribution and membrane arrangement of FS-untreated spermatozoa with respect to the MS, suggesting that spermatozoa transferred in the female genital tract after mating, are stored in a pre-activated state. The plasma membrane of the untreated MS and FS spermatozoa was labelled with Progesterone-BSA-FITC, indicating the presence of plasma membrane progesterone receptor. Taken together these data suggest that progesterone induces an acrosome- like reaction in MS spermatozoa similar to that induced by calcium elevation. In addition progesterone may play a role in the pre-activation of spermatozoa stored in the female tract, further supporting the hypothesized parallelism between cephalopods and vertebrates.
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PMID:Progesterone induces activation in Octopus vulgaris spermatozoa. 1133 51

In the bovine reproductive tract, the uterine tube is the critical site for a series of events required for fertilization and early embryonic development. In previous studies, a defined category of subfertile heifers, repeat-breeder heifers (RBH), has presented peri-oestrual disturbances (deviating hormone patterns and follicular dynamics) and uterine maternal-embryonic asynchrony. The present study aimed to investigate if tubal function was also affected, by determination of differences in the morphology of the tubal lining epithelium of RBH (n = 4) in comparison to controls (n = 6) during standing oestrus, studied by light and electron microscopy (SEM/TEM), and relate this to steroid hormone concentrations and receptor distribution in the target tissues. Tissue distribution of oestrogen receptor alpha (ERalpha) and progesterone receptor B (PRB) was quantified using immunohistochemistry. In particular, secretory cells differed in appearance between RBH and controls. The cells were less lumen protruding, microvilli were fewer and smaller and secretory granules in the apical cytoplasm were more numerous in RBH. Furthermore, the tubal epithelium was conspicuously coated with amorphous material. Morphological differences between categories were not explained hormonally or by steroid receptor distribution, except in two heifers from which uterine tubes were obtained after the luteinizing hormone (LH) surge. The isthmic PRB : ERalpha ratio was twice as high in the RBH than in the control. The deviating ultrastructure found in RBH, before and after the LH surge, might influence the tubal microenvironment with effects on gamete transport and final maturation and early embryonic development. The present study confirms that previously recorded perturbations in reproductive physiology in RBH are also manifested in the uterine tube, mainly by a deviating ultrastructure of the lining epithelium.
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PMID:Deviant peri-oestrual hormone patterns affect the epithelium of the uterine tube in repeat-breeder heifers. 1261 90