ABSTRACT Freshwater algae are rich sources of structurally biologically active metabolites, such as fatty acids, steroids, carotenoids and polysaccharides. Among these metabolites, lectins stand out. Lectins are proteins or glycoproteins of non-immune origin which bind to carbohydrates or glycoconjugates, without changing ligand structure. Many studies have reported on the use of Spirogyra spp. as effective bioindicators of heavy metals; however, reports on Spirogyra molecular bioprospecting are quite limited. Therefore, this study aimed to detect, isolate, purify and characterize a lectin present in the freshwater green algae Spirogyra. Presence of the lectin protein in the extract was detected by hemagglutination assays. Subsequently, the protein extract was subjected to a sugar inhibition assay to identify the lectin-specific carbohydrate. Following this, the extract was applied to a guar gum column to afford the pure lectin. The lectin was inhibited by N-acetyl-glucosamine and N-acetyl-beta-D-mannose, but more strongly by D-galactose. The apparent molecular mass of the purified lectin was evaluated by Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE). Electrophoretic analysis revealed a single protein band with an apparent molecular mass of 56 kDa. Thus, it could be concluded that a lectin was purified from Spirogyra spp.

A tartaruga Kinosternon scorpioides (Linnaeus, 1766), com nome popular de jurará, é uma espécie bastante variável, e muitos nomes diferentes são atribuídos às suas populações, de acordo com sua localização geográfica. Atualmente, quatro subespécies foram validadas como K. scorpioides surgindo desde o extremo Sul do Panamá e norte da América do Sul, podendo ser encontradas ainda no Equador, no norte do Peru, sul da Bolívia, norte da Argentina, leste da Guiana e no Brasil. Desde modo, foi realizado um estudo ultrassonográfico e radiológico, a fim de descrever a morfologia e o desenvolvimento dos ovos de K. scorpioides em cativeiro, utilizando-se 20 fêmeas, no período de setembro de 2005 a agosto de 2006. No primeiro mês, o ciclo ovariano foi caracterizado pela ausência de folículos vitelogênicos, atrésicos ou presença de ovos em ovidutos. De outubro de 2005 a março de 2006 a varredura ultrassonográfica permitiu determinar o crescimento vitelogênico dos folículos, os quais foram observados com um formato que variou de ovóide a esférico, envolvidos por um conteúdo ecogênico, uma camada não-ecogência de albumina e uma casca de elevada ecogenicidade. Ovos presentes em ovidutos foram identificados por radiografias apenas 180 dias após início do experimento, quando a casca tornou-se suficientemente mineralizada para impressionar o filme radiográfico. Um transdutor linear de 7,5 MHz promoveu imagens com resolução e penetração adequada para visibilização de folículos. Exames ultrassonográficos sucessivos em fêmeas K. scorpioides permitiram determinar os estágios iniciais de desenvolvimento de folículos vitelogênicos e o exame radiográfico mostrou-se como técnica simples para avaliar a presença de ovos em ovidutos, permitindo fazer inferências sobre desenvolvimento de ovos em jurarás, a partir dos 6 meses de pós-observação por ultrassonografia.

Kinosternon scorpioides (Linnaeus, 1766), with its common name of jurará, is a quite variable species of turtles, and many different names have been applied to populations throughout its range. Currently, however, four subspecies are considered valid as K. scorpioides arises from southern Panama over most of northern South America and is found in Ecuador, northern Peru, southern Bolivia, northern Argentina, eastern Guyana and Brazil. Thus, an ultrasonographic and radiographic study was performed in order to describe the morphology and development of eggs of 20 female jurará mud turtles K. scorpioides, from September 2005 to August 2006. In the first month, the ovarian cycle was characterized by absence of vitellogenic follicles, atresic follicles or oviduct eggs. From October 2005 to March 2006 on, ultrasonographic scanning allowed to establish the growing vitellogenic follicles. Vitellogenic follicles were observed with spherical to ovoid shapes, with a surrounding echogenic yolk, a nonechogenic albumin layer, and a high echogenic shell. The oviduct eggs were identified by radiography just 180 days after beginning the experiment, when the shell became enough mineralized to impress the radiographic film. This experiment allowed to obtain by means of the 7.5 MHz linear probe images with adequate resolution and penetration for visualization of follicles. Successive ultrasonographic examinations of 20 K. scorpioides females allowed to access initial stages of vitellogenic follicles and oviduct eggs, and radiographic examination revealed to be an easy technique to assess oviduct eggs and to allow evaluation of egg development in jurarás, from 6 months on.