Topographical distribution of the gonadotrophs,mammotrophs, somatotrophs and thyrotrophs in the pituitary gland of the baboon (Papio cynocephalus)

The identification and regionalization of four pituitary parenchymal cell types, gonadotrophs, mammotrophs, somatotrophs and thyrotrophs, were studied in the baboon (Papio cynocephalus) hypophysis using immunocytochemistry. The gonadotrophs were homogeneously distributed throughout the entire pars distalis. Both mammotrophs and somatotrophs predominate at the superior and inferior poles of the organ. The medial and anteromedial regions are populated by mammotrophs and thyrotrophs, while the lateral and posterior portions of the pars distalis contain large numbers of somatotrophs.     

Ultrastruktur und polysaccharidanteile der cuticula von Triops cancriformis Bosc. (Crustacea,Notostraca) während der Häutungsvorbereitung

Zusammenfassung Die Cuticula von Triops cancriformis besteht aus Endo-, Exo- und Epicuticula. Die Epicuticula ist aus vier Schichten aufgebaut, die Exocuticula aus 10 und die Endocuticula aus 60–80. Die Schichten der Endocuticula sind aus annähernd oberflächenparallel verlaufenden Mikrofibrillen, die zu Lamellulae zusammentreten, gebildet. Diese Lamellulae atehen senkrecht zur Oberfläche. Die Lamellulae der einzelnen Lagen verlaufen im rechten Winkel zu denen der Nachbarlagen. In Sinnesborsten verläuft so ein Teil der Fibrillen in Längsrichtung, der andere quer zur Längsachse.Polysaccharide finden sich in den Lamellulae, in zwei Schichten der Epicuticula, den Desmosomen und als Glykogengranula in Epidermiszellen.Die Häutung zeigt anscheinend keine Besonderheiten gegenüber anderen Arthropoden.

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Ultrastructure and polysaccharide content of the cuticle of Triops cancriformis Bosc. (Crustacea, Notostraca) during the Molting preparation

Summary The cuticle of Triops cancriformis consists of endo-, exo- and epicuticle. The epicuticle comprises 4 layers, the epocuticle 10 and the endocuticle 60–80 layers. The layers of the endocuticle consist of microfibrils. These microfibrils are almost parallel to the surface of the cuticle and merge into lamellulae. These lamellulae run vertical to the surface. The lamellulae in any one layer are at right angles to the lamellulae in the neighbouring layers. Thus, some of the fibrils in sensory setae are parallel to the longitudinal axis and others are perpendicular to it.Polysaccharides are found in the lamellulae, in two layers of the epicuticle, in the attachment regions and in the glycogen deposits in the epidermis cells.The molting process seems to be similar to the molting process of other arthropoda.

     

Licht- und elektronenmikroskopische untersuchungen zur haftborstenentwicklung bei Tarentola m. mauritanica L. (Reptilia,Gekkonidae)

Zusammenfassung Kurz nach einer Hdutung wird bei Tarentola m. m. bereits die übemächste Epidermisgeneration — und somit auch die der Haftborsten —angelegt. Das geschieht vornehmlich in der Oz- (Oberhäutchenzellen-) und in der Hs-Schicht (clear layer). Zunächst entstehen die Aufspaltungen der Haftborstenenden, indem Keratinfilamentbündel nach einem bestimmten System von den Oz-Zellen aus in die Hs-Zellen einwachsen. Auf these Weise fungieren die Zellen der Hs-Schicht als Matrix der Haftborsten. Nach Abschluß dieses Prozesses werden die eigentlichen Haftborsten gebildet unter gleichzeitigem Auseinanderrücken der Hs- und Oz-Schichten. Die Hs-Schicht behdlt ihre Matrizen-Funktion bis zur anschließenden Häutung bei.

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Light and electron microscope studies of developing setae of Tarentola m. mauritanica (Rept., Gekkonidae)

Summary In Tarentola m. mauritanica the next epidermis generation but one and therefore the adhesive setae of the generation after this begin to develop shortly after a skin has been shed. This development takes place principally in the horny layer (Oz) and the clear layer. First bundles of keratin filaments radiate from the horny layer into the clear layer, thus giving rise to the split distal parts of the adhesive bristles. Thus the cells in the clear layer act as a matrix for the setae. When this stage is complete the formation of the setae proper begins, while the horny layer and the clear layer become separated from each other. The clear layer retains its function as matrix for the setae until the next time a skin is shed.

     

Comparison of the localization of nucleic acid synthesis during bud formation on leaf fragments and on intact undetached leaves ofBegonia rex Putz.

The budding capacity ofBegonia rex leaf fragments is well known; that of undetached leaves has been shown by us only recently after treating the leaves with 6γγ DMAAP. Benzyladenine is as effective as 6γγ DMAAP in stimulating budding. Lower temperatures (17°, 22–12°, 12°) are also capable of inducing bud formation but only after a small cut has been made in a main vein of the undetached leaf. Root formation can also be provoked on undetached leaves which have a cut in the main leaf vein by higher temperatures (24–22°) or by an IAA treatment. Differences in the first stages of bud formation on leaf fragments and on undetached leaves are observed using histochemical and histoautoradiographic techniques.     

The histones of the ciliated protozoan Stylonychia mytilus

Histones were extracted from pure macronuclei, micronuclei and macronucleus anlagen and from chromatin which was isolated from these different nuclear fractions. Analysis of these preparations by polyacrylamide gel electrophoresis showed differences in electrophoretic patterns between the histones of these nuclei.