Partial characterization of phagocytic activity in neutrophils of the nine-banded armadillo Dasypus novemcinctus

Though the armadillo is important as a research model in leprosy studies, the activity of armadillo's neutrophils is an aspect of little research. The aim of this study was carried out to partially characterize the chemotaxis, endocytosis and bacteriocidal ability of the neutrophils found in the nine-banded armadillo (Dasypus novemcinctus). Results showed that the chemotactic activity of the neutrophils, evaluated by the movement of the neutrophils through a nitrocellulose membrane (5 microm) in response to a chemo-attractive substance, was greater towards the armadillo serum (5.16+/-1.35 migration index, p<0.05) than towards the formil methionyl leucil phenylalanine (fMLP, 1.43+/-0.18 migration index) or human serum (0.56+/-0.18 migration index). Regarding endocytic capacity of the neutrophils and the monocytes against Escherichia coli was evaluated by a flow cytometry and using opsonized and non-opsonized E. coli-FITC at the following incubation times: 5, 10, 20, 30 and 60 min. The largest percentage of endocytosis by the neutrophils was 92.32+/-0.12% with opsonized bacteria and 77.73+/-14.33% with non-opsonized bacteria at 10 min incubation time, while the largest percentage of endocytosis by monocytes was 89.94+/-1.40% with opsonized bacteria and 73.07+/-15.6% with non-opsonized bacteria at 20 min incubation time. Evaluation of the bacteriocidal capacity of neutrophils using the methyl-thiazol-tetrazolium salts (MTT) reduction color-measurement assay showed an 89.0+/-10% mortality rate of non-opsonized E. coli and 89.0+10% of opsonized E. coli. In conclusion, the armadillo neutrophils show a good phagocytosis and bacteriocidal activity; however, a deficiency in the migration towards the fMLP was observed. This deficiency could be a cause so that the armadillo neutrophils do not respond quickly to invading microorganism.     

Identification of CD3+ T lymphocytes in the green turtle Chelonia mydas

To understand the role of the immune system with respect to disease in reptiles, there is the need to develop tools to assess the host's immune response. An important tool is the development of molecular markers to identify immune cells, and these are limited for reptiles. We developed a technique for the cryopreservation of peripheral blood mononuclear cells and showed that a commercially available anti-CD3 epsilon chain antibody detects a subpopulation of CD3 positive peripheral blood lymphocytes in the marine turtle Chelonia mydas. In the thymus and in skin inoculated with phytohemagglutinin, the same antibody showed the classical staining pattern observed in mammals and birds. For Western blot, the anti-CD3 antibodies identified a 17.6 kDa band in membrane proteins of peripheral blood mononuclear cell compatible in weight to previously described CD3 molecules. This is the first demostration of CD3+ cells in reptiles using specific antibodies.     

Effect of rider experience and evaluator expertise on subjective grading of lameness in sound and unsound sports horses under saddle

The primary objective of this study was to investigate whether rider experience influences the assessment and grading of lameness in horses based on under-saddle gait analysis. Thirteen adult sports horses in active training were included in the study. After a baseline lameness and neurologic examination by the principal investigators, horses were videotaped while being ridden by an experienced and a less experienced rider. A 3-minute video was made for each horse and rider and 26 videos were randomly ordered and compiled on a DVD. Veterinarians with different levels of experience in evaluating lameness and veterinary students viewed the DVD and assigned a lameness score to each horse/rider combination. In a model accounting for the expertise of the evaluator, there was no difference in overall lameness scores between experienced and less experienced riders. This result was consistent for both sound and unsound horses. The overall lameness scores reported by specialists and students, however, differed significantly. The lameness score reported by the study participants while the horse was ridden was significantly associated with the subjective baseline lameness assessment reported by the principal investigators for the same limb when the horse was not under saddle. Additional work is necessary to determine whether riders with even lower skill levels would further alter the balance and motion pattern of the horse and have more influence on subjective grading of lameness.     

Genome-wide association study for age at puberty in young Nelore bulls

Selection for bulls that would reach puberty early reduces the generation interval and increases fertility and herd productivity. Despite its economic importance, there are few QTL associated with age at puberty described in the literature. In this study, a weighted single-step genome-wide association study was performed to detect genomic regions and putative candidate genes related to age at puberty in young Nelore bulls. Several protein-coding genes related to spermatogenesis functions were identified within the genomic regions that explain more than 0.5% of the additive genetic variance for age at puberty in Nelore bulls, such as ADAM11, BRCA1, CSNK2A, CREBBP, MEIOC, NDRG2, NECTIN3, PARP2, PARP9, PRSS21, RAD51C, RNASE4, SLX4, SPA17, TEX14, TIMP2 and TRIP13 gene. Enrichment analysis by DAVID also revealed several GO terms related to spermatogenesis such as DNA replication (GO:0006260), male meiosis I (GO:0007141), double-strand break repair (GO:0006302), base excision repair (GO:0006284), apoptotic process (GO:0006915), cell–cell adhesion (GO: 0098609) and focal adhesion (GO:0005925). The heritability for age at puberty shows that this trait can be improved based on traditional EBV selection. Adding genomic information to the system helps to elucidate genes and molecular mechanisms controlling the sexual precocity and could help to predict sexual precocity in Nelore bulls with greater accuracy at younger age, which would speed up the breeding programme for this breed.     

Brain anatomy of two-toed sloth (Choloepus didactylus,Linnaeus, 1758): A comparative gross anatomical study of extant xenarthrans

The neural system plays an important role in understanding some features of animals. Anatomical complexity correlates with the increase of functional capacity. Xenarthrans include anteaters (Vermilingua), armadillos (Cingulata) and sloths (Folivora). This group is the base of eutherian mammals, and understanding the anatomy of its neural system could provide data for functional and evolutionary interpretations. The gross anatomy of the xenarthran brain is recorded. Four extant families of Pilosa and two families of Cingulata were sampled. Usual dissection procedures were used, and the brains were analysed macroscopically. The brain of two-toed sloth, three-toed sloth, six-banded armadillo, giant anteater and collared anteater are gyrencephalic. Pygmy anteater, nine-banded armadillo, great long-nosed armadillo, southern naked-tailed armadillo and giant armadillo are lissencephalic. In most species, the rhinal fissure presents two segments, rostral and caudal (except in Vermilingua and three-toed sloth). The diencephalon and brainstem present similar anatomy. The cerebellum is wide and presents four lobes (rostral, central, caudal and floccular). Its average volume is 12.16% (Folivora), 14.26% (Vermilingua) and 18.61% (Cingulata). Among these groups, there is a statistical difference between Folivora/Cingulata concerning the cerebellum average. The general pattern of the brain of the xenarthrans is similar to that of other mammals.     

Biological characteristics and pathogenicity of avian Escherichia coli strains.

Fifty avian (chicken) pathogenic Escherichia coli strains (APEC) isolated from individuals suffering from omphalitis, septicaemia and swollen head syndrome, and 30 strains isolated from healthy chickens were studied regarding their biological characteristics such as serogroups, haemolysin, colicin, cytotoxin, toxin and siderophore production, adhesion capacity to in vitro cultivated cells, and absorption of Congo red dye. Serotyping demonstrated that most of the omphalitis and normal strains were untypable, whereas most of the septicaemic strains were either untypable or rough. There was no prevalent serogroup among the pathogenic strains studied. The capacity for adhesion and invasion of in vitro cultured cells (HeLa, HEp-2, KPCC), as well as the agglutination of different types of red blood cells and the LD50 of each strain were also evaluated. No correlation was observed between the biological characteristics and pathogenicity, except that colicin was characteristically produced by swollen head syndrome E. coli strains. No correlation was found between adhesion or haemagglutination patterns and pathogenicity. Only six of the 50 strains revealed invasive capacity and the strain that best invaded the cell lines was the one with the lowest LD50.