Stereology and computer assisted three-dimensional reconstruction as tools to study probiotic effects of Aeromonas hydrophila on the digestive tract of germ-free Artemia franciscana nauplii

Aims: Validation of stereology and three‐dimensional reconstruction for monitoring the probiotic effect of Aeromonas hydrophila on the gut development of germ‐free Artemia franciscana nauplii. Methods and Results: Germ‐free Artemia nauplii were cultured using Baker’s yeast and dead Aer. hydrophila. Live Aer. hydrophila were added on the first day to the treatment group. The gut length and volume were monitored on days two and four using stereology and three‐dimensional reconstruction. Both methods showed comparable results. Stereology was least labour intensive to estimate volumes, while three‐dimensional reconstructions rendered architectural and topographical data of the gut. Moreover, a positive effect of probiotic bacterium, Aer. hydrophila is likely. Conclusion: Slight increment in the growth of the digestive tract of A. franciscana nauplii exerted by probiotic bacteria could be detected using stereology and three‐dimensional reconstruction. Significance and Impact of the Study: The gnotobiotic Artemia rearing system is unique to investigate the effects of micro‐organisms on the development of nauplii. However, in the base of this model system, only survival counts and length measurements exist as monitoring tools. Therefore, additional tools such as stereology and three‐dimensional reconstruction are prerequisite to obtain more powerful analysis.     

The coeloms in a late brachiolaria larva of the asterinid sea star Parvulastra exigua: deriving an asteroid coelomic model

Morris, V.B., Selvakumaraswamy, P., Whan, R., and Byrne, M. 2011. The coeloms in a late brachiolaria larva of the asterinid sea star Parvulastra exigua: deriving an asteroid coelomic model. —Acta Zoologica (Stockholm) 92 : 266–275. The coeloms and their interconnexions in a late pre‐metamorphic brachiolaria larva of a sea star are described from the series of images in the frontal, transverse and sagittal planes obtained by confocal laser scanning microscopy. A larval, brachial coelom connects with the coeloms of the adult rudiment that lie posteriorly. The connexion is through the anterior coelom, which lies over the head of the archenteron, to the right anterior coelom and then to the left posterior coelom through the ventral horn of the left posterior coelom. The right posterior coelom is a separate coelom. The hydrocoele is on the larval left side separated from other coeloms except for a connexion to the anterior coelom. On the larval right side, the anterior coelom and right anterior coelom connect with the pore canal that opens to the exterior at the hydropore. From these coeloms, we derived an asteroid coelomic model comprising the larval left and right coeloms linked over the head of the archenteron by a common anterior coelom. The asymmetry of the hydrocoele and the left posterior coelom on the left side linked through the common anterior coelom to the right side, with the external opening, translates into the oral and aboral coeloms of the adult stage. The coelomic model has application in the search for morphological homology between the echinoderm classes and the deuterostome phyla.     

Three-dimensional structure of basal body triplet revealed by electron cryo-tomography

Basal bodies and centrioles play central roles in microtubule (MT)‐organizing centres within many eukaryotes. They share a barrel‐shaped cylindrical structure composed of nine MT triplet blades. Here, we report the structure of the basal body triplet at 33 Å resolution obtained by electron cryo‐tomography and 3D subtomogram averaging. By fitting the atomic structure of tubulin into the EM density, we built a pseudo‐atomic model of the tubulin protofilaments at the core of the triplet. The 3D density map reveals additional densities that represent non‐tubulin proteins attached to the triplet, including a large inner circular structure in the basal body lumen, which functions as a scaffold to stabilize the entire basal body barrel. We found clear longitudinal structural variations along the basal body, suggesting a sequential and coordinated assembly mechanism. We propose a model in which δ‐tubulin and other components participate in the assembly of the basal body.     

鞘翅目形态结构的三维重建与功能之间关系探讨的有效方法评估

本文简要介绍了计算机三维重建技术在鞘翅目形态学研究中的应用,并对所涉及到的成像设备及相关技术做了简要的介绍和评估。同时,本文也对计算机三维重建技术的未来发展方向做了初步的展望。     

三维重建技术与生物陶瓷相结合在下颌骨连续性缺损个体化修复中的应用

目的探讨三维重建技术与生物陶瓷相结合,制作下颌骨连续性缺损的个体化修复假体的可能性。方法（1）应用三维重建技术获得下颌骨连续性缺损的三维重建模型;（2）完成下颌骨连续性缺损的个体化修复假体的生物陶瓷置换。结果应用三维重建技术,能够准确地获得与下颌骨连续性缺损相匹配的个体化生物陶瓷修复体。结论三维重建技术与生物陶瓷相结合可以完成下颌骨连续性缺损的个体化修复,这种技术可以满足下颌骨连续性缺损的外形和功能重建的需要。