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Luca Racca Andrea Villa Lukardis C. M. Wencker Marco Camaiti Hugues-Alexandre Blain Massimo Delfino 《Journal of morphology》2020,281(7):808-833
The skull osteology of Hierophis viridiflavus is here described and figured in detail on the basis of 18 specimens. The sample includes specimens from the ranges of both H. viridiflavus viridiflavus and H. viridiflavus carbonarius as well as specimens not identified at sub-specific level. The main characters that define H. viridiflavus in comparison to the parapatric congeneric species Hierophis gemonensis are wide maxillary diastema, basioccipital crest well distinct in three lobes and basioccipital process well marked. The foramina of the otoccipital and prootic, and the basioccipital process of the basioccipital are among the most ontogenetically variable characters, as indicated by two juvenile specimens included in the sample. A specimen-level phylogenetic analysis including H. gemonensis and other outgroups (overall 6 species, 26 specimens, 64 skull characters) recovered all H. viridiflavus specimens in one clade, indicating the presence of a clear phylogenetic signal in the applied characters. However, the resolution within the H. viridiflavus clade is poor the monophyly of H. viridiflavus carbonarius was retrieved, but not that of Hierophis v. viridiflavus. Probably due to the relatively high variability, the skull morphology does not support the recently proposed specific status of the two subspecies. 相似文献
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P Ragone F Potente J Slipka V Pesce Delfino 《Bollettino della Società italiana di biologia sperimentale》1991,67(2):175-182
A prominent problem in the morphological study of developing biological structures is shape parametrization with the aim to evaluate transformations in a non subjective way. We carried out an analytical morphometrical study on a series of human embryos, by means of the S.A.M. (Shape Analytical Morphometry) software package. After standardization and normalization of the fronto-facial sagittal profiles, the analytical procedures applied were: 1) Fourier analysis: each profile was considered as an irregular but periodic function obtained by the sum of sinusoids of increasing order. 2) Shape Asymmetry Evaluation: couples of profiles are compared by means of "Janus" procedure; by a parabolic fitting we obtained parameters able to evaluate allometric and isometric differences between the two profiles. The preliminary results of the applied procedures indicated that rate and direction of allometric and isometric growth are not constant during the time. 相似文献
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An easy-to-assemble apparatus for the laser-light excitation of fluorofores in polyacrylamide gels is described. The assemblage is made up of a continuous-wave ion-argon laser with adjustable power output, a beam diffuser, appropriate filters to block excitation light, and a photographic camera. With this setup a minimum 20-fold increase of sensitivity was obtained for fluorofore detection in polyacrylamide gels as compared to the more conventional uv-light excitation using a commercial preparation of Con A-FITC (concanavalin A-fluorescein isothiocyanate) as reference molecule in the gel. The same apparatus, used to analyze the Con A-positive glycoproteins contained in serum Cohn fraction IV separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, showed a number of fluorescent components in a wide range of relative intensities while uv-light excitation showed none. Acrylamide concentration in the gel is critical, since a working limit of between 10 and 12% has been found, above which the diffusion of Con A-FITC in the gel, necessary to label glycoprotein bands, is hampered. The system described here also permits the optimization of detection of minor components not otherwise observable by conventional light excitation, because light power, angle of incidence, and beam divergence can be adapted to analyze specific areas of the sample gel. 相似文献
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Hormonal imprinting takes place at the first encounter of the hormone and receptor, and results in a changed binding capacity and reaction of the cell and its progeny generations. The imprinting effect of three amino acids and their oligopeptides is studied using fluorescent-labelled peptides. Glycine and lysine could provoke positive imprinting (increased binding in the progeny generations) for their own peptides, but alanine could not. Mostly positive imprinting was provoked by glycine and lysine peptides for their own peptides of different chain length. The optimal chain length provoking self-imprinting was four for glycine, two for lysine and three for alanine. Except in this case, alanine was neutral or provoked mostly negative imprinting. After reaching the optimal chain length, there is a decline in binding. Evolutionary conclusions are discussed. 相似文献