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FRANCOIS PALLUAULT BRUNO PIETRZYK EDUARDO DEI-CAS CHRISTIAN SLOMIANNY BENOIT SOULEZ DANIEL CAMUS 《The Journal of eukaryotic microbiology》1991,38(4):407-411
Three-dimensional reconstruction of a binucleate intermediate precyst of Pneumocystis carinii was performed from serial-thin sections using the CATIA (Conception Assistée Tridimensionnelle Inter Active) Dassault system program. The presence of a mitochondrion, complex well-developed endoplasmic structures, and numerous Golgi vesicles was established. A better understanding of the ultrastructure of rabbit-derived P. carinii stages made it possible to formulate hypotheses on the evolution and physiology of the endomembrane system. Thus, the presence of the well-developed endoplasmic saccular structure and more than 230 Golgi vesicles in its vicinity might be implicated in the differentiation of the parasite surface structures and might also be related to nuclear division and individualization of intracystic bodies. 相似文献
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YANN SURGET-GROBA BENOIT HEULIN CLAUDE-PIERRE GUILLAUME MIKLOS PUKY DMITRY SEMENOV VALENTINA ORLOVA LARISSA KUPRIYANOVA IOAN GHIRA BENEDIK SMAJDA 《Biological journal of the Linnean Society. Linnean Society of London》2006,87(1):1-11
The evolution of viviparity in squamates has been the focus of much scientific attention in previous years. In particular, the possibility of the transition from viviparity back to oviparity has been the subject of a vigorous debate. Some studies have suggested this reversal is more frequent than previously thought. However, none of them provide conclusive evidence. We investigated this problem by studying the phylogenetic relationships between oviparous and viviparous lineages of the reproductively bimodal lizard species Zootoca vivipara . Our results show that viviparous populations are not monophyletic, and that several evolutionary transitions in parity mode have occurred. The most parsimonious scenario involves a single origin of viviparity followed by a reversal back to oviparity. This is the first study with a strongly supported phylogenetic framework supporting a transition from viviparity to oviparity. © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 87 , 1–11. 相似文献
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