Bipedal locomotion in Tropidurus torquatus (Wied, 1820) and Liolaemus lutzae Mertens, 1938

Bipedalism has evolved on numerous occasions in phylogenetically diverse lizard families. In this paper we describe, for the first time, bipedal locomotion on South American lizards, the sand-dweller Liolaemus lutzae and the generalist Tropidurus torquatus. The lizards were videotaped running on a racetrack and the sequences were analyzed frame by frame. The body posture, as a whole, diverged a lot during bipedal locomotion between the two species, even though there was no difference regarding their sprint performance. The locomotor behavior of L. lutzae is, in general, more similar to the one observed on other sand-dweller lizards. Certain particularities are common, such as the digitigrade posture at footfall and throughout stance, trunk angles; and tail posture. In contrast, T. torquatus exhibited high trunk angles and dragged its tail, in a posture compared to basilisks. This body posture could be related to certain characteristics and obstacles of a microhabitat such as the one around lakes and streams (basilisks) and the one with compact shrubby vegetation (T. torquatus)

Bipedal locomotion in Tropidurus torquatus (Wied, 1820) and Liolaemus lutzae Mertens, 1938

Bipedalism has evolved on numerous occasions in phylogenetically diverse lizard families. In this paper we describe, for the first time, bipedal locomotion on South American lizards, the sand-dweller Liolaemus lutzae and the generalist Tropidurus torquatus. The lizards were videotaped running on a racetrack and the sequences were analyzed frame by frame. The body posture, as a whole, diverged a lot during bipedal locomotion between the two species, even though there was no difference regarding their sprint performance. The locomotor behavior of L. lutzae is, in general, more similar to the one observed on other sand-dweller lizards. Certain particularities are common, such as the digitigrade posture at footfall and throughout stance, trunk angles; and tail posture. In contrast, T. torquatus exhibited high trunk angles and dragged its tail, in a posture compared to basilisks. This body posture could be related to certain characteristics and obstacles of a microhabitat such as the one around lakes and streams (basilisks) and the one with compact shrubby vegetation (T. torquatus)

Interferon (IFN) beta treatment induces major histocompatibility complex (MHC) class I expression in the spinal cord and enhances axonal growth and motor function recovery following sciatic nerve crush in mice

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Aims: Major histocompatibility complex (MHC) class I expression by neurones and glia constitutes an important pathway that regulates synaptic plasticity. The upregulation of MHC class I after treatment with interferon beta (IFN beta) accelerates the response to injury. Therefore the present work studied the regenerative outcome after peripheral nerve lesion and treatment with IFN beta, aiming at increasing MHC class I upregulation in the spinal cord. Methods: C57BL/6J mice were subjected to unilateral sciatic nerve crush and treatment with IFN beta. The lumbar spinal cords were processed for immunohistochemistry, in situ hybridization, Western blotting and RT-PCR, while the sciatic nerves were submitted for immunohistochemistry, morphometry and counting of regenerated axons. Motor function recovery was monitored using the walking track test. Results: Increased MHC class I expression in the motor nucleus of IFN beta-treated animals was detected. In the peripheral nerve, IFN beta-treated animals showed increased S100, GAP-43 and p75NTR labelling coupled with a significantly greater number of regenerated axons. No significant differences were found in neurofilament or laminin labelling. The morphological findings, indicating improvements in the regenerative process after IFN treatment were in line with the motor behaviour test applied to the animals during the recovery process. Conclusions: The present data reinforce the role of MHC class I upregulation in the response to injury, and suggest that IFN treatment may be beneficial to motor recovery after axotomy.366515534Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [2005/03159-4, 2009/07443-0, 2006/06673-3