Profiles of sex steroids, fecundity and spawning of a migratory characiform fish from the Paraguay–Paraná basin: a comparative study in a three-river system

This study investigated for the first time the reproductive biology of Prochilodus lineatus in a system of rivers in southeastern Brasil, relating it to the role of tributary rivers in the reproductive success of this important commercial fish in the Upper Paraná River basin, where a cascade of hydroelectric dams were deployed. Specimens were caught bimonthly in three river sites: (S1) Grande River, downstream from the Porto Colômbia dam; (S2) Pardo River; and (S3) Mogi Guaçu River. Sex steroid plasma levels, fecundity, follicular atresia, oocyte diameter and gonadosomatic index (GSI) were compared among sites. In S1, fish exhibited changes in the reproductive parameters: lower GSI, oocyte diameter and fecundity and higher follicular atresia index, when compared to S2 and S3. Frequency of maturing fish was higher in S3 and spawning was only registered in S3. In sites S2 and S3, plasma concentrations of testosterone and 17β-estradiol in females and testosterone in males showed wide variations following gonadal maturation. Fish from S1 showed few significant variations in sex steroid concentrations throughout the gonadal cycle. These results indicate that P. lineatus does not reproduce in Grande River (S1), but probably uses the Pardo River (S2) as a migratory route towards the Mogi Guaçu River (S3) where they complete gonadal maturation and spawning. Our findings contribute for understanding the reproductive biology of P. lineatus and to highlight the importance of tributaries in impounded rivers as a favourable environment for migration and spawning of fish.     

Experimental infection of pregnant gilts with Leptospira interrogans serovar mozdok.

Three pregnant gilts were experimentally infected with leptospires of the serovar mozdok, isolated from an aborted pig fetus from a Portuguese pig farm with abortion problems. All the gilts aborted dead or dying piglets on days 105 or 106 of pregnancy. Serovar mozdok was isolated from 12 of the 22 piglets in the three litters. Histological examination of the livers and kidneys of the gilts at the end of the experiment revealed evidence of disease, and leptospires were isolated from their kidneys. Their serological responses up to 42 days after inoculation were monitored by means of a microscopic agglutination test, using 21 antigens from 18 serogroups. Cross reactions to heterologous antigens belonging to the Grippotyphosa, Australis, Icterohaemorrhagiae and Cynopteri groups were observed in all of them.     

Note: Flight capacity,parasitism and emergence of five<Emphasis Type="Italic">Trichogramma</Emphasis> (Hymenoptera: Trichogrammatidae) species from forest areas in Brazil

The flight and parasitism capacities and emergence rate of fiveTrichogramma species [T. acacioi (Brun),T. bruni (Nagaraja),T. demoraesi (Nagaraja),T. maxacalii (Voegelé & Pointel) andT. soaresi (Nagaraja)] were compared. The flight capacity of these parasitoids was assessed in test units. A tube was placed inside each test unit with a piece of card with 300Anagasta kuehniella (Zeller) (Lepidoptera: Pyralidae) eggs parasitized by one of theTrichogramma species. The emerged adults inside the test units were classified according to their position as flyers, non-flyers and walkers. Cards withA. kuehniella eggs, parasitized by one of theTrichogramma species, were assessed to determine the parasitism rate and emergence of these natural enemies. The data were submitted to analysis of variance and the means compared by the Scott-Knott test at 5% probability.Trichogramma maxacalii exhibited better flight capacity than the other species, in addition to good parasitism rate and high percentage of emergence. http://www.phytoparasitica.org posting May 10, 2007.     

Biochemical and histological hepatic changes of Nile tilapia Oreochromis niloticus exposed to carbaryl

The purpose of this study was to evaluate biochemical and morphological responses induced by carbaryl in the liver of Nile tilapia (Oreochromis niloticus) exposed during 21 days to sublethal concentrations (0.25 and 0.5 mg L⁻¹), testing also recover for 14 days in clean water, after 14 days exposure. The activities of the following enzymes were measured: superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), glutathione reductase (GR), and reduced (GSH) and oxidized glutathione (GSSG). Globally, our data showed that exposure to carbaryl decreased the SOD, CAT, GR, and GST activities, except for the SOD and GST activities after 14 days exposure to 0.25 mg L⁻¹. In contrast, after 14 days exposure the GR activity of the hepatic tissue from carbaryl-treated fish showed significant elevation in relation to the control. When fish were left to recover, a positive response was seen in the GSH and GSSG contents. The results of the recovery group suggest that the toxicity produced by carbaryl is reversible to some extent within 15 days. The liver histological analysis showed differences between fish concerning the cellular vacuolization degree (VD) of the hepatocytes. In fish exposed to carbaryl it was observed an increasing hepatocellular basophilia. No other histological alterations were observed when fish was exposed to carbaryl, except a few necrotic foci at day 7. The sections stained with PAS reaction showed that the vacuolization was always not due to glycogen deposits, thus suggesting lipid accumulation. The combined increased basophilia and glycogen depletion is a common, although non-specific, liver response to many toxicants. In short, this work shows a relation between histological and biochemical changes in liver and carbaryl exposure. The effects of carbaryl were observed at different concentrations.     

Prospecting for pig single nucleotide polymorphisms in the human genome: have we struck gold?

Gene‐to‐gene variation in the frequency of single nucleotide polymorphisms (SNPs) has been observed in humans, mice, rats, primates and pigs, but a relationship across species in this variation has not been described. Here, the frequency of porcine coding SNPs (cSNPs) identified by in silico methods, and the frequency of murine cSNPs, were compared with the frequency of human cSNPs across homologous genes. From 150 000 porcine expressed sequence tag (EST) sequences, a total of 452 SNP‐containing sequence clusters were found, totalling 1394 putative SNPs. All the clustered porcine EST annotations and SNP data have been made publicly available at http://sputnik.btk.fi/project?name=swine . Human and murine cSNPs were identified from dbSNP and were characterized as either validated or total number of cSNPs (validated plus non‐validated) for comparison purposes. The correlation between in silico pig cSNP and validated human cSNP densities was found to be 0.77 (p < 0.00001) for a set of 25 homologous genes, while a correlation of 0.48 (p < 0.0005) was found for a primarily random sample of 50 homologous human and mouse genes. This is the first evidence of conserved gene‐to‐gene variability in cSNP frequency across species and indicates that site‐directed screening of porcine genes that are homologous to cSNP‐rich human genes may rapidly advance cSNP discovery in pigs.     

Structural and ultrastructural characteristics of interrenal gland and chromaffin cell of matrinxã, Brycon cephalus Gunther 1869 (Teleostei-Characidae)

This work presents the structure and ultrastructure of the interrenal gland and chromaffin cells, as well as the morphology of the head kidney of Brycon cephalus. The head kidney is composed of fused bilateral lobes located anterior to the swim bladder and ventrolateral to the spinal column. The parenchyma revealed lympho-haematopoietic tissue, melano-macrophage centres, interrenal gland and chromaffin cells. The interrenal gland consisted of cords or strands of cells grouped around the posterior cardinal vein and their branches. Chromaffin cells are found in small groups, closely associated with the interrenal gland and/or under the endothelium of the posterior cardinal vein. So far, the ultrastructural analysis has revealed only one interrenal cell type which contained abundant smooth endoplasmic reticulum and numerous mitochondria with tubulo-vesicular cristae, characteristic of steroid-producing cells. Two types of chromaffin cells were observed. The first type was characterized by the presence of vesicles with round, strongly electron-dense granules, which were eccentrically located. Such cells were interpreted as noradrenaline cells. Meanwhile, cells which contained smaller vesicles and electron-lucent granules, with a small halo separating the granule from the vesicular limiting membrane, were identified as adrenaline cells.     

Acute bacterial cystitis does not cause deoxyribonucleic acid damage detectable by the alkaline comet assay in urothelial cells of dogs

Considering the high incidence of dogs with acute bacterial cystitis (BC) and the relationship among inflammation, genotoxicity, and carcinogenesis, we conducted a case-control study comparing the frequency of deoxyribonucleic acid (DNA) lesions assessed by the comet assay between disease-free animals (13 males and 13 females) and cytology-confirmed cases of acute BC (12 males and 12 females), which was mainly caused by Staphylococcus sp. (40%) and Escherichia coli (35%). The results show no increase in DNA damage in cells obtained by bladder washings and no influence of age, sex, and breed due to acute BC. In conclusion, DNA damage was seemingly not associated with the infection by specific bacteria.     

Effect of Proofing Time and Wheat Flour Strength on Bleaching,Sensory Characteristics,and Volume of French Breads with Added Soybean Lipoxygenase

Soybean lipoxygenase addition in wheat bread doughs is widely used to improve the crumb color and rheology but little is known about the variability of the activity of lipoxygenase under diverse breadmaking conditions. Thus the objective of this study was to evaluate how soybean lipoxygenase can affect bleaching, volume, and sensory characteristics of French breads when proofing time and wheat flour strength varies. A 3-factor Box-Behnken design was used in this study containing one block and three independent variables or factors designated by exogenous lipoxygenase activity (x₁ = 0–71 unit/μg of protein), wheat flour deformation energy (x₂ = 231–258 × 10^–4 J), and proofing time (x₃ = 2–6 hr). Breads were randomly prepared and all assays were repeated three times. Specific volume (from 5.8 ± 0.4 to 9.9 ± 0.4 cm³/g), sensory quality (from 5.2 ± 0.8 to 8.3 ± 0.6), and yellow hue (from 12.6 ± 0.5 to 16.2 ± 0.3) significantly changed (P < 0.01) among the treatments. Specific volume of the breads increased with higher values of wheat flour strength and proofing time (ŷ_vs = 7.5 + 0.9 x₂ + 1.2 x₃ +0.5 x₂x₃). Sensory quality improved at higher values of wheat flour strength and shorter proofing time (ŷ_sq = 7.8 + 0.7 x₂ – 0.2 x₃ – 0.4 x₂² – 0.6x₃² + 0.5 x₂x₃), while lower and more desirable values of yellow hue were achieved at longer proofing time, higher activity of lipoxygenase, and using stronger wheat flours (ŷ_b = 13.7 – 1.2 x₁ – 0.5 x₂ – 0.2 x₃ + 1.0 x₁² – 0.3 x₁x₂). All regression models showed a good fitness to the experimental data (lack-of-fit P > 0.05) and the difference between predicted and observed values were also not significant (P < 0.05). Our results suggested that proofing time and wheat flour strength have a greater effect on volume and sensory quality of French breads than soybean lipoxygenase. However, the bleaching effect of this enzyme showed positive interaction with proofing time and wheat flour strength, suggesting its application even when strong wheat flours are used for the manufacture of French breads.     

Herd-of-origin effect on the post-weaning performance of centrally tested Nellore beef cattle

The objective of a performance test station is to evaluate the performance of potential breeding bulls earlier in order to decrease the generation interval and increase genetic gain as well. This study evaluates the herd-of-origin influence on end-of-test weight (ETW), average daily weight gain during testing (ADG), average daily weight gain during the adjustment period (ADG_adj), rib eye area (REA), marbling (MARB), subcutaneous fat thickness (SFT), conformation (C), early finishing (EF), muscling (M), navel (N) and temperament (T) scores, and scrotal circumference (SC) of Nellore cattle that underwent a performance test. We evaluated 664 animals that participated in the performance tests conducted at the Center for Performance CRV Lagoa between 2007 and 2012. Components of variance for each trait were estimated by an animal model (model 1), using the restricted maximum likelihood method. An alternative animal model (model 2) included, in addition to the fixed effects present in S1, the non-correlated random effect of herd-year (HY). A significant HY effect was observed on ETW, REA, SFT, ADG_adj, C, and C_w (p?相似文献