RESUMO
BACKGROUND: Placental characters vary among Xenarthra, one of four supraordinal clades of Eutheria. Armadillos are known for villous, haemochorial placentas similar to humans. Only the nine-banded armadillo has been well studied so far. METHODS: Placentas of three species of armadillos were investigated by means of histology, immunohistochemistry including proliferation marker, and transmission and scanning electron microscopy. RESULTS: The gross anatomy differed: Euphractus sexcinctus and Chaetophractus villosus had extended, zonary placentas, whereas Chaetophractus vellerosus had a disk. All taxa had complex villous areas within the maternal blood sinuses of the endometrium. Immunohistochemistry indicated the validity of former interpretations that the endothelium of the sinuses was largely intact. Tips of the villi and the columns entering the maternal tissue possessed trophoblast cell clusters with proliferation activity. Elsewhere, the feto-maternal barrier was syncytial haemochorial with fetal vessels near the surface. CONCLUSIONS: Differences among armadillos occurred in regard to the extension of the placenta, whereas the fine structure was similar. Parallels to the human suggest that armadillos are likely to be useful animal models for human placentation.
Assuntos
Animais Selvagens/anatomia & histologia , Tatus/anatomia & histologia , Placenta/anatomia & histologia , Animais , Animais Selvagens/metabolismo , Argentina , Tatus/metabolismo , Biomarcadores/metabolismo , Brasil , Proliferação de Células , Membrana Corioalantoide/anatomia & histologia , Membrana Corioalantoide/citologia , Membrana Corioalantoide/metabolismo , Feminino , Imuno-Histoquímica , Placenta/citologia , Placenta/metabolismo , Placentação , Gravidez , Proteínas da Gravidez/metabolismo , Especificidade da Espécie , Trofoblastos/citologia , Trofoblastos/metabolismo , Xenarthra/anatomia & histologia , Xenarthra/metabolismoRESUMO
The X-ray structure of the tetragonal form of apo acyl-CoA-binding protein (ACBP) from the Harderian gland of the South American armadillo Chaetophractus villosus has been solved. ACBP is a carrier for activated long-chain fatty acids and has been associated with many aspects of lipid metabolism. Its secondary structure is highly similar to that of the corresponding form of bovine ACBP and exhibits the unique flattened alpha-helical bundle (up-down-down-up) motif reported for animal, yeast and insect ACBPs. Conformational differences are located in loops and turns, although these structural differences do not suffice to account for features that could be related to the unusual biochemistry and lipid metabolism of the Harderian gland.
Assuntos
Tatus/metabolismo , Inibidor da Ligação a Diazepam/química , Animais , Bovinos , Cristalização , Cristalografia por Raios X , Glândula de Harder/química , Glândula de Harder/metabolismo , Modelos Moleculares , Conformação ProteicaRESUMO
The anatomical, histological, histochemical and ultrastructural characteristics of the lacrimal gland (LG) and nictitans gland (NG) of the armadillo Chaetophractus villosus were described. The histochemical and histological features of both glands in male and female adult animals were compared. The tissues were processed with conventional techniques for light and transmission electron microscopy. Fixed specimens were submitted to a battery of tests for glycans, glycosaminglycans, glycoconjugates, proteins, and lipids. The LG of the armadillo may be considered within the set of glandulae lacrimales superior in which primates, carnivores, perisodactyls and artiodactyls are included. The localization of the NG was similar to that of other mammals. Lacrimal and NG were histologically and histochemically identical. The secretory endpieces consisted of three cell types: (1) Mucous cells (MC) with different types of mucous secretory granules with neutral and sialic acid-containing glycoconjugates (GCs). (2)Seromucous cells (SMC) showing a variety of moderately electron dense secretory granules with flocculent material with carboxylated acidic, neutral, and sialic acid-containing GCs. Intercellular canaliculi with junctional complexes and basolateral intercellular spaces were frequent. (3) Serous cells (SC) with electron dense secretory granules. Histochemically, they showed the strongest reaction for proteins and neutral, weakly acid and carboxylated acidic GCs. The epithelium of the intra- and inter-lobular excretory ducts showed secretory activity, junctional complexes, and wide basolateral intercellular spaces with lateral folds. The endpieces and ducts were surrounded by myoepithelial cells. The stroma was characterized by fenestrated endothelium, unmyelinated axons, and abundant plasma cells. MC, SMC, and the duct system were richly innervated by hypolemmal nerve terminals.
Assuntos
Tatus/anatomia & histologia , Aparelho Lacrimal/ultraestrutura , Membrana Nictitante/ultraestrutura , Animais , Tatus/metabolismo , Feminino , Aparelho Lacrimal/metabolismo , Masculino , Microscopia Eletrônica , Membrana Nictitante/metabolismo , Vesículas Secretórias/ultraestruturaRESUMO
Similar to those of other species, the Harderian glands of armadillo produce an abundant lipid secretion, most of which is composed of 1-alkyl-2,3-diacylglycerol. Biosynthesis of this component is apparently performed with the participation of one cytosolic pool of acyl-CoA and another of free fatty acids. The acyl-CoA-binding protein (ACBP) is present at a concentration at least 7-fold that of the heart-type fatty acid-binding protein (H-FABP), though lower than that in other armadillo organs such as liver and brain. The ACBP complete amino acid sequence was determined by Edman degradation of peptides generated by cleavage of the protein with cyanogen bromide, endopeptidase Glu-C, and trypsin. ACBP consists of 86 residues and has a calculated molecular mass of 9783 Da, taking into account that an acetyl group is blocking the N-terminus. Identity percentages between armadillo Harderian gland ACBP and other known ACBPs show that the protein belongs to the liver-specific ACBP isoform (L-ACBP). The fact that the ACBP concentration is higher than that of FABP suggests that the Harderian gland is able to store acyl-CoA amounts in ACBP larger than those of fatty acids in H-FABP for 1-alkyl-2,3-diacylglycerol synthesis.
Assuntos
Tatus/metabolismo , Proteínas de Transporte/química , Glândula de Harder/química , Metabolismo dos Lipídeos , Proteínas de Neoplasias , Proteínas Supressoras de Tumor , Sequência de Aminoácidos , Animais , Proteínas de Transporte/isolamento & purificação , Proteínas de Transporte/fisiologia , Cromatografia em Gel , Cromatografia em Camada Fina , Citosol/química , Inibidor da Ligação a Diazepam , Diglicerídeos/biossíntese , Proteína 7 de Ligação a Ácidos Graxos , Proteínas de Ligação a Ácido Graxo , Feminino , Glândula de Harder/metabolismo , Humanos , Mamíferos/metabolismo , Dados de Sequência Molecular , Especificidade de Órgãos , Alinhamento de Sequência , Especificidade da EspécieRESUMO
Conventional carbohydrate histochemistry and the binding patterns of 21 lectins were analysed to characterise the glycoconjugate content in the components of the vomeronasal organ of the armadillo Chaetophractus villosus. The mucomicrovillous complex of the sensory epithelium bound most of the lectins studied. No reaction was observed with Con A, PSA, S-Con A and SBA, and the sustentacular cells were-stained with UEA-I, DSL, LEL, STL and Con A. The vomeronasal receptor neurons were labelled with S-WGA, WGA, PNA, UEA-I, STL, Con A, S-Con A, ECL and RCA120. The basal cell layer reacted with S-WGA, WGA, LCA, UEA-I, DSL, LEL, STL, Con A, JAC and VVA. The nonsensory epithelium exhibited a differential staining in relation to the different components. The mucociliary complex stained with ECL, DBA, JAC, RCA120, STL, LCA, PHA-E, PHA-L, LEL, BSL-I and VVA. However, SJA and UEA-I stained the mucus complex lining a subpopulation of columnar cells. The cytoplasm and cell membranes of columnar cells was labelled with DBA, DSL and LCA. The apical region of these cells exhibited moderate reactivity with LEL and SJA. None of the lectins bound specifically to secretory granules of the nonsecretory cells. Basal cells of the nonsensory epithelium were labelled with DSL, LEL, LCA, BSL-I and STL. The vomeronasal glands showed a positive reaction with WGA, DSL, LEL, LCA, DBA, PNA, RCA120 and SBA. Subpopulations of acinar cells were observed with ECL, S-WGA, Con A, S-Con A and DBA. PNA and RCA120 stained the cells lining the glandular ducts. In comparison with previous results obtained in the olfactory mucosa of the same group of armadillos, the carbohydrate composition of the vomeronasal organ sensory epithelium differed from the olfactory sensory epithelium. This is probably related to the different nature of molecules involved in the perireceptor processes.
Assuntos
Tatus/metabolismo , Glicoconjugados/análise , Órgão Vomeronasal/química , Animais , Sítios de Ligação , Feminino , Histocitoquímica/métodos , Lectinas/metabolismo , Masculino , Mucosa/química , Mucosa Olfatória/químicaRESUMO
Conventional histochemistry and the binding patterns of 22 biotinylated lectins were examined for characterisation of glycoconjugates in the components of the olfactory mucosa of the armadillo Chaetophractus villosus. The mucous lining the olfactory epithelium showed binding sites for DSL, WGA, STL, LEL, PHA-E and JAC. Only the basilar processes of the supporting cells stained for Con-A and S-Con A. The olfactory receptor neurons stained with LEL, LCA, Con A, S-Con A, JAC and PNA. The layer of basal cells did not react with any of the lectins studied. Bowman's glands in the lamina propria showed subpopulations of acinar cells reacting with SBA, S-WGA, WGA, STL, Con A, PSA, PNA, SJA, VVA, JAC and S-Con A, but in our optical studies with lectins we were unable to differentiate between mucous and serous cells in the way that is possible on electron microscopy. The ducts of Bowman's glands were labelled with S-WGA, STL, LEL, PHA-E, BSL-I and JAC. This histochemical study on the glycoconjugates of the olfactory mucosa in the order Xenarthra provides a basis for further experimental investigations.
Assuntos
Tatus/metabolismo , Glicoconjugados/análise , Mucosa Olfatória/química , Acetilglucosamina/análise , Animais , Feminino , Fucose/análise , Galactose/análise , Histocitoquímica , Lectinas , Masculino , Manose/análiseRESUMO
The fatty acid-binding protein (FABP) from armadillo liver was purified to homogeneity by a procedure involving gel filtration and two anion exchange chromatography steps. The purified protein proved to have a pI between 5.0 and 5.2 and migrated by sodium dodecyl sulfate-polyacrilamyde gel electrophoresis as a single entity of approximately 14 kDa. The armadillo FABP cross-reacted with antiserum against rat liver FABP but not against rat intestinal FABP. The same as other members of the family, it has a blocked N-terminus. Amino acid sequencing of peptides obtained by cyanogen bromide cleavage and in-gel tryptic digestion shows that the armadillo, despite being one of the less evolved mammals, has a liver FABP of the same type as that of highly evolved mammals.
Assuntos
Tatus/metabolismo , Proteínas de Transporte/isolamento & purificação , Ácidos Graxos/metabolismo , Fígado/metabolismo , Proteína P2 de Mielina/isolamento & purificação , Proteínas de Neoplasias , Proteínas do Tecido Nervoso , Proteínas Supressoras de Tumor , Sequência de Aminoácidos , Aminoácidos/análise , Animais , Tatus/genética , Proteínas de Transporte/química , Proteínas de Transporte/genética , Reações Cruzadas , Citosol/metabolismo , Evolução Molecular , Proteína 7 de Ligação a Ácidos Graxos , Proteínas de Ligação a Ácido Graxo , Humanos , Imunoquímica , Ponto Isoelétrico , Dados de Sequência Molecular , Peso Molecular , Proteína P2 de Mielina/química , Proteína P2 de Mielina/genética , Filogenia , Ratos , Homologia de Sequência de AminoácidosAssuntos
Tatus/metabolismo , Metabolismo Energético , Xenarthra/metabolismo , Animais , Temperatura Corporal , Peso Corporal , Feminino , MasculinoRESUMO
Slices of adrenal glands from fetal newborn and adult armadillo dasypus novemcintus synthesized in vitro 3-ketosteroids including cortisol and corticosterone from endogenous aubstrale or added progesterone. ACTH astimulated steroidogenesis. Steroid aynthesis tended to increase with advancing age no qualitative changes were found. Similarly testes from fetal armadillos converted labeled progesterone do 17a hydroxyprogesterone, androstenedione and testosterone.