Characterization of lacrimal gland lesions and possible pathogenic mechanisms of keratoconjunctivitis sicca in dogs with leishmaniosis

In a previous study, it was found that 2.8% of dogs with leishmaniosis had keratoconjunctivitis sicca (KCS). The aim of this study was to characterize the lesions present in the lacrimal glands of dogs with leishmaniosis and to determine the presence of the parasite by means of immunohistochemistry. The inflammatory infiltrate was described as granulomatous or pyogranulomatous and was located around the ductal component of the glands. Immunoperoxidase staining localized the parasites following the same pattern. Samples from eyes that had clinical signs compatible with KCS presented inflammatory infiltrate and parasite more commonly than those from eyes without clinical signs. One of the mechanisms of KCS in dogs with leishmaniosis may be the inflammatory infiltrate located around the ducts of lacrimal glands, producing retrograde accumulation and retention of secretion. Meibomian gland was the most commonly affected by the infiltrate, highlighting the possibility of a qualitative KCS in these dogs.     

The effect on newborn chicks of oral inoculation of reovirus isolated from chickens with tenosynovitis

Reovirus strain 176, isolated from chickens with tenosynovitis, was highly pathogenic following oral inoculation of 1-day-old specific-pathogen-free chicks. Disseminated lesions including hepatic necrosis, splenic lymphostromal cell hyperplasia, and bursal atrophy occurred on day 3 postinoculation (PI), followed by myocarditis on day 6 PI and by pericarditis and tenosynovitis on day 9 PI. Reovirus was isolated from the liver as early as day 1 PI, whereas significant neutralizing antibody was detected on day 13 PI. Mortality occurred from day 4 to day 7 PI, and the death of birds was associated with the severity of hepatic necrosis. The occurrence of tenosynovitis in virus-inoculated birds was subclinical.     

Heteroduplex mobility assay for genotyping infectious bursal disease virus

A heteroduplex mobility assay (HMA) was developed to genotype infectious bursal disease virus (IBDV). This method analyzed 390-base pair (bp) polymerase chain reaction (PCR) products, encompassing the hypervariable region of the VP2 gene. IBDV strains from the United States and other countries were analyzed. The HMA was able to differentiate standard, antigenic variants and very virulent strains of IBDV. Minor differences between different strains from the same subtype were also detected. Close relationships between field IBDV with vaccines prepared with Delaware E strain were determined by HMA. The results obtained by HMA were confirmed by restriction fragment length polymorphism (RFLP) and phylogenetic analysis of nucleotide sequences. The HMA proved to be a useful technique to rapidly genotype different field strains of IBDV and should prove to be a useful tool in epidemiologic studies.     

Reproduction,condition and abundance of the Mediterranean bluefish (Pomatomus saltatrix) in the context of sea warming

This study evaluates the link between sea warming and three important aspects of the population dynamics of bluefish, Pomatomus saltatrix, in the north‐western (NW) Mediterranean: condition (health measures), reproduction and abundance (as reflected in catch per unit effort, CPUE). We compared the bluefish populations from two areas with different thermal regimes: the Gulf of Roses and the Ebre Delta. First, in order to compare the condition and reproduction parameters of the two populations, specimens were collected from the commercial catch landed in two ports located in these areas. Several indicators of fish condition and reproduction such as hepatosomatic index, gonadosomatic index, maturation timing, length‐at‐first maturity, fecundity, egg quality and atresia (ovarian follicle resorption) were analysed and compared between study areas. Second, time series analyses of sea surface temperatures (SST) and monthly bluefish CPUEs in the two study areas were assessed using Box–Jenkins transfer function models. Our results indicate that bluefish benefit from sea warming in the NW Mediterranean, particularly in the northernmost zone, as evidenced by increasing fish condition in these waters. Sea warming may favour the changes in spawning phenology and the northward expansion of this species. This study provides evidence that a marine fish species that is able to expand or is forced to shift its distribution as a result of sea warming may take advantage of other environmental conditions of new habitats, contributing to the enhancement of the population's productivity in these areas.     

Understanding the relationships between genetic and phenotypic structures of a collection of elite durum wheat accessions

A collection of 191 durum wheat accessions representing Mediterranean Basin genetic diversity was grown in nine different environments in four countries, with productivities ranging from 0.99 to 6.78 t ha⁻¹. The population breeding structure comprised eight genetic subpopulations (GSPs) using data derived from 97 evenly distributed SSR markers. The phenotypic structure was assessed: (i) from the mean values of six agronomic traits across environments (multivariate), and (ii) from data representing each trait in each environment (univariate). Mean daily maximum temperature from emergence to heading was significantly (P < 0.05) and negatively associated to yield, accounting for 59% of yield variations. Significant but weak relationships were obtained between the genetic similarities among accessions and their overall agronomic performance (r = 0.15, P < 0.001), plant height (r = 0.12, P < 0.001), spike–peduncle length (r = 0.06, P < 0.01) and thousand kernel weight (r = 0.03, P < 0.05), suggesting a very low possibility of prediction of the agronomic performance based on random SSR markers. The percentage of variability (measured by sum of squares) explained by the environment varied between 76.3 and 98.5% depending on the trait, while that explained by genotypes ranged between 0.4 and 12.6%, and that explained by the GE interaction ranged from 1.1 to 12.5%. The clustering of the accessions based on multivariate phenotypic data offered the best explanation of genotypic differences, accounting for 30.3% (for yield) to 75.1% (for kernel weight) of the observed variation. The genotype × environment interaction was best explained by the phenotypic univariate clustering procedure, which explained from 28.5% (for kernel weight) to 74.9% (for days to heading) of variation. The only accessions that clustered both in the genetic dissimilarities tree and the tree obtained using Euclidean distances based on standardized phenotypic data across environments were those closely related to the CIMMYT hallmark founder ‘Altar 84’, the ICARDA accessions adapted to continental-dryland areas, and the landraces, suggesting that genetic proximity corresponded to agronomic performance in only a few cases.