Four‐dimensional analysis of early pelvic girdle development in Rana temporaria

A key event in vertebrate evolution is the linkage of the appendicular to the axial skeleton. The present study investigates the developmental dynamics of pelvic girdle morphogenesis in Rana temporaria up until metamorphosis, with respect to its functional and spatio‐temporal organization. The main questions to be addressed are: initial location and the number of elements contributing to pelvic girdle formation, mechanism of bridging between the pelvic anlage and the sacrum and arthrogenesis. Serial histological sections of specimens from Gosner Stages 30 to 41 were bright‐field microscopically examined and 3D‐reconstructed. 3D‐models were merged to 4D‐animations illustrating the complex developmental dynamics through time. The results reveal the initial formation of a single mesenchymal condensation located close to the appendicular skeleton, but far from the axial skeleton. In addition, our analysis detects a thin connective tissue strand in R. temporaria guiding the elongation of the ilium towards the sacrum. The 4D‐visualization allows novel insight into the ilio‐sacral bridging process and the reorientation of the pelvis. J. Morphol., 2011. © 2010 Wiley‐Liss, Inc.     

The ultrastructure of the eyes in the veliger-larvae of Aporrhais sp. and Bittium reticulatum (Mollusca,Caenogastropoda)

Summary The cerebrally innervated larval eyes of Aporrhais sp. and Bittium reticulatum are investigated by means of transmission electron microscopy. Each organ consists of a pigmented cup containing an acellular lens. The cornea overlaps the anterior portion of the eye. The retina is composed of sensory cells and supportive cells. The sensory cells of Aporrhais sp. bear one cilium and in Bittium reticulatum two cilia, the ciliary membrane being folded into numerous finger-shaped evaginations. The supportive cells contain the pigment granules and most of them bear one or two cilia, the plasmalemma of which is likewise folded. It is supposed that: (a) these cilia have a transportive function for lens material and (b) that the ciliary photoreceptor of Aporrhais sp. and Bittium reticulatum is a functional adaptation to a relatively long larval period.Abbreviations bb basal body - bp basal plate - c cilium - cc corneal cell - cm ciliary membranes - cw ciliary whorl - gd Golgi dictyosomes - gm granular material - l lens - m mitochondrion - mt microtubules - mv microvilli - mvb multivesicular body - n nucleus - pb pigment border - pg pigment granule - rer rough endoplasmic reticulum - sc sensory cell - sj septate junctions - spc supportive cell     

Endocranial capacity of Western Australian aboriginal crania: comparisons and association with stature and latitude

The endocranial capacities (ECCs) of 73 Western Australian Aboriginal crania were estimated. Using water-standardised mustard seed, ECCs were (in cm3) males--means 1,239, S.D. 92.3; females--means 1,118, S.D. 77.5. The male and female mean values were smaller than those previously published for Australia as a whole; sexual dimorphism (9.7%) was also slightly lower. Comparison of the Western Australian Aboriginal sample with a large Danish sample (Pakkenberg and Voigt, 1964; Holloway, 1980) permitted analysis of factors underlying sex and population differences in ECC. In both samples about 40% of the mean sex differences in ECC could be related to stature differences; for each sex almost 2/3 of the differences between the Western Australian and Danish means appear to be associated with differences in stature and latitude. Allometric adjustments are also involved.     

Proposed follow up programme after curative resection for lower third oesophageal cancer

Cyclins are indispensable elements of the cell cycle and derangement of their function can lead to cancer formation. Recent studies have also revealed more mechanisms through which cyclins can express their oncogenic potential. This review focuses on the aberrant expression of G1/S cyclins and especially cyclin D and cyclin E; the pathways through which they lead to tumour formation and their involvement in different types of cancer. These elements indicate the mechanisms that could act as targets for cancer therapy.     

Untersuchungen über die Biologie von Ustilago violacea (Pers.) Fuck

Ohne ZusammenfassungUnter Mitwirkung von V. Kocher.Die Fortsetzung dieser Untersuchungen wurde durch einen Beitrag der Stiftung zur Förderung der wissenschaftlichen Forschung an der Bernischen Hochschule ermöglicht, der dem einen von uns (Blumer) zugesprochen wurde. Es sei dafür auch an dieser Stelle der beste Dank ausgesprochen.