Electron microscopic data for the presence of post-meiotic gene expression in isolated ram sperm chromatin.

A whole mount electron microscopic technique facilitated a direct visualization of transcripts in ram spermatozoa in run-on experiments. The localization of transcripts in sperm chromatin by spreading enabled identification of regions where transcription complexes, presumably pre-mRNA species, were seen related to chromatin. In another series of experiments the localization of polymerase II was demonstrated using a specific antibody against the conservative tail domain of the polymerase II molecule, followed by protein A-gold visualization on spread chromatin and on thin sections from mature spermatozoa. Incorporation of bio-UTP in transcripts was visualized by streptavidin-gold on spreading and on thin sections. The data suggest that transcription occurs at the periphery of the mature spermatozoa.

Electron microscopic demonstration of transcription of ram sperm chromatin.

Transcription of ram sperm chromatin was examined by two electron microscopic techniques, namely spreading and thin sections. Labelling by Streptavidin-gold particles permits identification of transcription complexes, that have previously incorporated biotinylated uridine triphosphate. This supports previous electron microscopic data for randomly distributed transcription complexes and the presence of polymerase II molecules, documented by means of specific antibody using immunoelectron microscopy. Labelling of transcripts with biotin permits exact visualization of the transcription process, as well as identification of regions, where transcription occurs.

[Ultrastructural changes in the uterine epithelium and in the immunocompetent cells of the lymph nodes draining the uterus during pregnancy in swine]. / Ultrastrukturni promeni na matochniia epitel i imunokompetentnite kletki na drenirashtite matkata limfni vuzli prez bremennostta pri svine.

The studies were carried out with both nonpregnant sows aged 1-2 years and pregnant sows from the 30th to the 40th day and on the 60th, 90th, and 100th day of gestation. Three types of cells were found in the epithelium covering the uterus of nonpregnant sows--with kinocilia and microvilli at the apical pole, with microvilli only, and with no microvilli and kinocilia. During pregnancy the ultrastructure of the epithelium were subjected to essential changes which consisted chiefly in increasing the compactness of microvilli, the amount of lysosomes at the apical part, and the basal deposition of fatty globules in some of the cells. The basal membrane on which the epithelial cells lay became considerably thicker. The draining lymph nodes showed a clear trend toward increasing the number of lymphocytes and cells of the plasmatic order. The ultrastructure of the plasmatic cells and lymphocytes spoke of enhanced processes of synthesis.

[Histological characteristics of the testis and epididymis of calves during postnatal development]. / Khistologichni osobenosti na semennitsite i nadsemennitsite na teleta pri postnatalnoto im razvitie.

A histologic investigation was carried out of the testis and epididymis of a total of 42 calves of the Black-and-white grouped in 14 test groups. The animals were currently castrated after the age of 2 months and were raised in the open. Material for investigation was taken on the 1st and 15th day, and once in every following month up to the completion of 12 months of age. It was found that up to the 3rd month there was no lumen in the testicular tubules, but only differentiating Sertoli cells and gonocytes were seen. Spermatogonia and spermatocytes were first observed at the age of 4 months, and prespermatids and sporadic spermatids--in the 8th month. Single spermatozoa in the phase of final shaping appeared in the 10th month, and completed spermatogenesis--in the 11th month. The histogenesis of the wall of the tubules of the epididymis completed earlier as compared to the histogenesis process in the testis--by the age of 8 months. Later on there were morphologically in the epididymis some proliferation and folding of the tubules with widening of the lumen, whereupon the amount of the surrounding connective tissue relatively decreased.

[Localization of alkaline and acid phosphatases in the testes and epididymis of calves during postnatal development]. / Lokalizatsiia na alkalnata i kiselata fosfataza v semennitsite i nadsemennitsite na teleta pri postnatalnoto im razvitie.

A histochemical investigation was carried out after Gomori's method on the activity and localization of the alkaline and acid phosphatase in the testis and epididymis of 28 calves of the Black-and-white breed as dependent on their age--from the first day following birth to the age of 12 months, divided into 14 test groups. It was found that both enzymes had analogous localization in the testis as well as in the various portions of the epididymis, however, the activity of the alkaline phosphatase was higher as compared to that of the acid phosphatase. While in the interstitium of the testis and epididymis on the 1st, 15th, and 30th day following birth the alkaline phosphatase had low activity the acid phosphatase on the same dates was found in the epididymis only.