Origin and population structure of Brazilian hair sheep breeds.

Brazilian hair sheep constitute a genetic diversity hotspot. These animals are found in the harsh environments of the Brazilian Northwest (semi-arid) region. Genotypes (50K SNP chip) from seven Brazilian sheep breeds (five hair and two coarse wool types) and 87 worldwide breeds were used to test for population structure, admixture and genetic diversity. Moreover, phylogenetic trees evaluating migration events between genetic groups were built. Brazilian Somali, a fat-tailed breed, had a close relationship with East African breeds and clustered distinctly from other Brazilian breeds. Brazilian Blackbelly and Barbados Blackbelly had a close relationship. The Morada Nova breed did not show close relationships with European or African breeds, revealing a single migration event from an Algerian hair breed. Brazilian Fat-tail and Morada Nova share a common ancestor, but the former showed introgressions from Brazilian Somali and Afrikaner breeds, explaining the fat-tail phenotype. The Santa Inês breed received a substantial contribution from Brazilian Bergamasca and showed an admixed origin with recent introgressions from other breeds, mainly from Suffolk. Furthermore, Brazilian Somali and Brazilian Fat-tail are the most endangered sheep genetic resources in Brazil and should be the focus for ex situ conservation programs. In conclusion, Brazilian hair sheep show an African origin and are characterized by diverse genetic composition, reinforcing the need for conservation of these genetic resources, and at the same time, this highly diverse group has variability that can be used in breeding programs.

Ultrastructure and morphogenesis of the wing scales in Heliconius erato phyllis (Lepidoptera: Nymphalidae): what silvery/brownish surfaces can tell us about the development of color patterning?

Usually the literature on Heliconius show three types of scales, classified based on the correlation between color and ultrastructure: type I - white and yellow, type II - black, and type III - orange and red. The ultrastructure of the scales located at the silvery/brownish surfaces of males/females is for the first time described in this paper. Besides, we describe the ontogeny of pigmentation, the scale morphogenesis and the maturation timing of scales fated to different colors in Heliconius erato phyllis. The silvery/brownish surfaces showed ultrastructurally similar scales to the type I, II and III. The ontogeny of pigmentation follows the sequence red, black, silvery/brownish and yellow. The maturation of yellow-fated scales, however, occurred simultaneously with the red-fated scales, before the pigmentation becomes visible. In spite of the scales at the silvery/brownish surfaces being ultrastructurally similar to the yellow, red and black scales, they mature after them; this suggests that the maturation timing does not show a relationship with the scale ultrastructure, with the deposition timing of the yellow pigment. The analysis of H. erato phyllis scale morphogenesis, as well as the scales ultrastructure and maturation timing, provided new findings into the developmental architecture of color pattern in Heliconius.

Sexual Size Dimorphism in the Color Pattern Elements of Two Mimetic Heliconius Butterflies.

Sexual dichromatism and sexual dimorphism of body size are reasonably well studied in butterflies. Sexual size dimorphism of color pattern elements, however, is much less explored. The object of this study is Heliconius, a genus of butterflies well known for the coevolution between mate color preferences and mimicry. Given the sexual role of wing coloration, we investigated the existence of sexual size dimorphism in the wing color elements of a mimetic pair-Heliconius erato phyllis Fabricius and Heliconius besckei Ménétriés-and analyzed the allometric patterns of these traits. Correlation between size of elements in the dorsal and ventral wing surfaces were also estimated. In both species, three out of four elements were larger in males, but the non-dimorphic element was not the same. With regard to the allometric patterns, our most important finding was that smaller males of one species have proportionally larger yellow bars. This is the first study specifically concerning quantitative sexual dimorphism in the coloration of this well-known genus of butterflies and it opens new prospects to investigate sex-related natural selection and sexual selection of color pattern elements.

Effects of amphetamine on immune-mediated lung inflammatory response in rats.

OBJECTIVE: The present study analyzed the effects of acute amphetamine (AMPH) treatment on immune-mediated lung inflammatory response in rats. METHODS: There were four experiments. In the first and second experiments, rats were treated with AMPH (1 mg/kg) or 0.9% NaCl, and locomotor activity (experiment 1) and serum AMPH concentrations (experiment 2) were measured 1 or 12 h after treatment. In the third experiment, rats which were immunized with ovalbumin (OVA) were treated 14 days later with 0.9% NaCl or AMPH (1 mg/kg). Twelve hours after these treatments, all animals were submitted to challenge by 1% OVA inhalation being analyzed afterwards for bronchoalveolar lavage fluid (BAL), peripheral blood and bone marrow cellularity. In the fourth and final experiment, rats were treated and studied as for experiment 3, except that half of the animals within each group were previously treated with metyrapone prior to the OVA challenge. RESULTS: In the non-immunized rats, AMPH treatment induced an increase in locomotor activity synchronized to high serum AMPH concentrations 1 h after, but not 12 h after treatment. In OVA-challenged rats, AMPH treatment decreased the total number of inflammatory cells, recovered in both BAL and peripheral blood and increased the total number of bone marrow cells. These effects, observed 1 day after OVA challenge, were abrogated by previous metyrapone treatment. CONCLUSION: AMPH treatment changed HPA-axis responsiveness to the stress condition imposed by the OVA challenge decreasing lung and blood leukocytes cellularity most probably via corticosterone actions on bone marrow activity.

Cytogenetics of eight Neotropical species of Chauliognathus Henzt, 1830: implications on the ancestral karyotype in Cantharidae (Coleoptera).

Meiotic chromosomes of eight Neotropical species of the genus Chauliognathus occurring in Southern Brazil were analysed from testis cells. The meioformula of all the species was n = 6 + X (with six pairs of autosomes and one X chromosome). This meioformula is also present in C. scriptus plus two other species of other genera of Cantharidae, suggesting an evolutionary tendency towards the compaction of the karyotype starting from the ancestral Polyphagan meioformula n = 9 + Xy(p). The presence of an XO sex chromosome mechanism in all cantharid species studied to date indicates that the reduction of the number of autosomes was probably paralleled by the loss of the small typical Polyphagan yp heterosome. Thus the meioformula n = 6 + X seems to be an apomorphy for Cantharidae and may have evolved soon after the separation of the ancestral cantharid from the other families of Polyphaga.

Melatonin modulates allergic lung inflammation.

Asthma is an inflammatory lung disease characterized by cell migration, bronchoconstriction and hyperresponsiveness, and can be induced, as an experimental model, by ovalbumin sensitization followed by a challenge. In addition to the well-known immunostimulatory effects of melatonin, research has identified some of its anti-inflammatory properties. In this study, we evaluated the influence of pinealectomy and melatonin administration on cell migration in an experimental model of allergic airway inflammation. We evaluated, in pinealectomized rats treated or not with melatonin, cell migration into the bronchoalveolar fluid, the number of cells and their proliferative activity in the bone marrow, and plasma corticosterone levels. Pinealectomy reduces, 24 hr after the challenge, the total cell number count in the lung and bone marrow cell proliferation, without changing the number of cells in the bone marrow or in the peripheral blood. This fact suggests that melatonin is important in the control of cell recruitment from the bone marrow and the migration of those cells to the lung. Melatonin administration to pinealectomized rats seems to restore the ability of cells to migrate from the bone marrow to the bronchoalveolar fluid. So, the development of specific inhibitors of melatonin would benefit patients with asthma.

Rejection and immunosuppression in kidney transplantation.

Seventeen out of 85 renal allograft patients suffered 23 episodes of rejection. Of these 22 (96%) were associated with a significant increase in DNA synthesis in the peripheral blood and in 12 instances (55%) the DNA increase occurred before biochemical or clinical evidence. The prognostic value depends on the frequency of sampling and in all patients measured daily the DNA increase was predictive with a mean value of 7 days before other signs. Nine patients experienced 12 rejection episodes that resulted in the loss of their graft. All these cases of irreversible rejection were characterized by a significant elevation in DNA synthesis within 36 days of transplant. In 57 patients with good function 46 suffered 120 episodes of infection. DNA synthesis was increased in 12.5% of these. Thus an increase in DNA synthesis is 8 x more likely to be due to rejection than infection. The level of DNA and RNA synthesis may prove a useful guide for monitoring the level of immunosuppression in these patients.

Congenital malformations, twinning and associated variables in a Brazilian population.

A sample of 6052 newborn children (4968 whites, 1084 Blacks) issued from parents with a generally low socioeconomic level, was studied in relation to congenital anomalies and twinning rates. The observed frequency of major malformations was 1.3% and of minor defects 2.0%. The twinning rate was 1.4%. Race differences were generally nonsignificant in these variables. These results are in agreement with those obtained in some other Brazilian series, but discrepancies were also observed. A total of 13% of the malformations observed proved to be familial, polydactyly being the most common anomaly encountered in this class. The frequency of malformations different from those present in the propositi is higher in their sibships than the general prevalence of defective children found among the sibs of normal babies (13% and 4% respectively). Age, gestation length and exposure of the mothers to noxious agents during pregnancy were not significantly different when the parents of normal and malformed children were compared. On the other hand, as expected, the parents of twins are significantly older than those of single-born, and the gestation length was much reduced in pregnancies resulting in multiple births.