Navegando por Autor "Vieira, Lucélia Gonçalves"

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Artigo
Ontogeny of the appendicular skeleton in Melanosuchus niger (Crocodylia: Alligatoridae).
(National Library of Medicine, 2016-08) Vieira, Lucélia Gonçalves; Santos, André Luiz Quaqliatto; Lima, Fabiano Campos; de Mendonça, Sônia Helena Santesso Teixeira; Menezes, Lorena Tannus; Sebben, Antônio
The objective of the present study was to analyze chondrogenesis and the ossification pattern of the limbs of Melanosuchus niger in order to contribute with possible discussions on homology and the fusion pattern of autopodial elements and phylogeny. In the Reserva Extrativista do Lago Cuniã, Rondônia, Brazil, six nests were marked and two eggs removed from each nest at 24-hour intervals until hatching. Embryos were cleared using KOH; bone tissue was stained with alizarin red S and cartilage with Alcian blue. Routine staining with HE was also performed. In the pectoral girdle, the scapula showed ossification centers before the coracoid process. In the pelvic girdle, the ilium and the ischium were condensed as a single cartilage, although ossification took place through two separate centers, forming distinct elements in the adult. The pubis developed from an independent cartilaginous center with free end, which reflects its function in breathing. In the initial stages, the stylopodium and the zeugopodium developed from the condensation of a Y-shaped cartilage in the limbs, and differentiation of the primary axis and digital arch were observed. The greatest changes were observed in the mesopodia. In their evolution, Crocodylia underwent a vast reduction in the number of autopodial elements as a consequence of fusions and ossification of some elements. This study shows that the chondrogenesis and ossification sequences are dissociated. Moreover, the differences between M. niger and other species show clear variation in the patterns for these events in Alligatoridae.
Artigo
Skeletogenesis of the pelvic girdle and members in embryos of Caiman yacare (Crocodylia: Alligatoridae)
(Scientific Research and Essays, 2013-12) Lima, Fabiano Campos; Santos, André Luiz Quagliatto; Vieira, Lucélia Gonçalves; Mendonça, Sônia Helena Santesso Teixeira de; De Simone, Simone Borges Salgueiro; Martins, Clarissa de Araújo; Coutinho, Marcos Eduardo
Caiman yacare embryos were collected and subjected to the bone cleared and Alizarin staining to analyze the ontogenic patterns of the skeletal ossification of the pelvic girdle and members. Ossification of C. yacare pelvis begins at 36 days of incubation. The femur, tibia and fibula present simultaneous stain retention at 30 days. It has four tarsal bones, the calcaneus, the talus, distal III and distal IV. Their ossification starts with the calcaneus from the 40th day of incubation, followed by the talus. At 54 days, the distal tarsal IV is conspicuous, as is the outline of the distal III. Each foot has five metatarsi (MT) and 13 phalanges (phalangeal formula 2:3:4:4). Ossification of the metatarsi begins at 36 days and follows the sequence MTI=MTII=MTIII=MTIV>MTV. The first phalanges begin the ossification process on the 36th day and continue up to the last day of incubation. The sequence of ossification of the proximal phalanges is PPI=PPII=PPIII>PPIV, while that of the medial phalanges is MPII> MPpIII>MDpIII>MPpIV>MDpIV and that of the distal phalanges is DPI>DPII>DPIII>DPIV, and the ontogenic pattern of the bones of the pelvic girdle and members of C. yacare differs from that of other reptiles, albeit with a few similarities. INTRODUCTION Vertebrates have a unique skeleton that is composed of a set of plastic structures that are able to grow, adapt and repair themselves due to the wide morphological and architectural diversity of the skeletal tissue (White et al., 2003; Hildebrand and Goslow, 2006). This trait is conservative to the point that its general pattern displays in the tetrapods lineages. Its evolutionary pattern also enables this structure to respond to the particular habits of each species (Withers, 1992). In some reptiles, the ossification patterns are well known. Several anatomical studies of the skeletons of reptiles have been conducted, as demonstrated by the.