PCR-RFLP molecular confirmation of color dilution alopecia in dogs in Brazil

Color dilution alopecia (CDA) is a dermatopathy observed exclusively in animals having a diluted coat color. In dogs, color dilution occurs as a result of a single-nucleotide variation (SNV) c.-22G > A in the melanophilin gene. We standardized a PCR–restriction-fragment length polymorphism (PCR-RFLP) technique to identify this mutation and determine its frequency in dogs in Brazil. The standardized PCR-RFLP technique could efficiently identify the SNV c.-22G > A in the melanophilin gene, with mutated allele frequencies of 0.1, 0.1, and 0.0875 in Dachshund, Miniature Pinscher, and Yorkshire Terrier breeds, respectively, with no statistical difference among the breeds (p = 0.252). The mutation was identified in 2 homozygous Dachshund dogs with alopecia, confirming the clinical characteristic of CDA. The standardization of a simpler and more accessible molecular technique for recognition of the SNV c.-22G > A in the melanophilin gene allows identification of heterozygous (phenotypically normal) dogs that can be excluded from reproduction, to avoid the birth of dogs with diluted coat color and consequently CDA.     

Native leguminous plants for mineland revegetation in the eastern Amazon: seed characteristics and germination

New Forests - For the effective use of native plants for mineland revegetation, an understanding of seed dormancy break and germination requirements, and seed storage tolerance is indispensable. In...     

Potential impact of future climate change on sugarcane under dryland conditions in Mexico

Assessments of impacts of future climate change on widely grown sugarcane varieties can guide decision‐making and help ensure the economic stability of numerous rural households. This study assessed the potential impact of future climatic change on sugarcane grown under dryland conditions in Mexico and identified key climate factors influencing yield. The Agricultural Land Management Alternatives with Numerical Assessment Criteria (ALMANAC) model was used to simulate sugarcane growth and yield under current and future climate conditions. Management, soil and climate data from farm sites in Jalisco (Pacific Mexico) and San Luis Potosi (Northeastern Mexico) were used to simulate baseline yields. Baseline climate was developed with 30‐year historical data from weather stations close to the sites. Future climate for three decadal periods (2021–2050) was constructed by adding forecasted climate values from downscaled outputs of global circulation models to baseline values. Climate change impacts were assessed by comparing baseline yields with those in future decades under the A2 scenario. Results indicate positive impacts of future climate change on sugarcane yields in the two regions, with increases of 1%–13% (0.6–8.0 Mg/ha). As seen in the multiple correlation analysis, evapotranspiration explains 77% of the future sugarcane yield in the Pacific Region, while evapotranspiration and number of water and temperature stress days account for 97% of the future yield in the Northeastern Region. The midsummer drought (canicula) in the Pacific Region is expected to be more intense and will reduce above‐ground biomass by 5%–13% (0.5–1.7 Mg/ha) in July–August. Harvest may be advanced by 1–2 months in the two regions to achieve increases in yield and avoid early flowering that could cause sucrose loss of 0.49 Mg ha^?1 month^?1. Integrating the simulation of pest and diseases under climate change in crop modelling may help fine‐tune yield forecasting.     

Virulence and genotypes of white spot syndrome virus infecting Pacific white shrimp Litopenaeus vannamei in north‐western Mexico

White spot syndrome virus (WSSV) has caused substantial global economic impact on aquaculture, and it has been determined that strains can vary in virulence. In this study, the effect of viral load was evaluated by infecting Litopenaeus vannamei with 10‐fold serial dilution of tissue infected with strain WSSV Mx‐H, and the virulence of four WSSV strains from north‐western Mexico was assessed along with their variable number of tandem repeat (VNTR) genotypes in ORF75, ORF94 and ORF125. The LD₅₀ of the Mx‐H strain was a dilution dose of 10^?7.5; the mortality titre was 10^9.2 LD₅₀ per gram. In shrimp injected with 10^2.5 to 10^6.5 LD₅₀, no significant virulence differences were evident. Using mortality data, the four WSSV strains grouped into three virulence levels. The Mx‐F strain (intermediate virulence) and the Mx‐C strain (high virulence) showed more genetic differences than those observed between the Mx‐G (low‐virulence) and Mx‐H (high‐virulence) strains, in ORF94 and ORF125. The application of high‐viral‐load inocula proved useful in determining the different virulence phenotypes of the WSSV strains from the Eastern Pacific.     

Insect larvae as feed ingredient selectively increase arachidonic acid content in farmed gilthead sea bream (Sparus aurata L.)

This work is aimed at obtaining farmed fish designed to contain targeted PUFAs. To this end, an experiment was conducted with farmed specimens of gilthead sea bream (Sparus aurata L.), which were fed meal containing different percentages of common green bottle fly (Lucilia sericata Meigen) larvae, cultured on appropriate substrates, and then the fatty acid profiles in fish muscles were determined. Results indicate that arachidonic acid content in fish muscle is significantly increased when replacing different proportions of fishmeal by larvae from L. sericata, which contains arachidonic acid up to 10.6% of total fatty acids. Thus, larvae seem to be a suitable vector for introducing target PUFA in fish muscle and it could also contribute to reduce the use of wild fish stocks for fishmeal production.     

Effect of supplementation with urea,blood meal,and rumen-protected methionine on growth performance of Holstein heifers grazing kikuyu pasture

Supplements with corn grain, molasses cane, and different nitrogen sources were evaluated in 16 growing Hosltein heifers [227 ± 33 kg body weight (BW)] grazing kikuyu (Pennisetum clandestinum) pasture in a 10-ha sward (rotational grazing with electric fences) during 90 days in the summer season. The nitrogen sources were urea (U); urea and blood meal (U + BM); and urea, blood meal, and rumen-protected methionine (U + BM + RPM). Heifers were randomly assigned to four experimental supplements defined as follows: control (no supplementation), U, U + BM, and U + BM + RPM. Two kilograms (as fed) of supplement was offered daily. The final BW of heifers fed U + BM + RPM was higher (P < 0.05) than heifers not supplemented. The total and average daily weight gain of heifers supplemented with U + BM + RPM were higher than heifers not supplemented or supplemented with U and U + BM (P < 0.05). The average daily gain of heifers supplemented with U and U + BM were higher than heifers not supplemented (P < 0.05). Grass intake was not affected by supplementation, but total dry matter intake was increased by supplements with U, U + BM, and U + BM + RPM (P < 0.05). Feed conversion was improved by U + BM + RPM (P < 0.05). Total tract digestion was not affected by supplements. Blood urea nitrogen concentrations of heifers supplemented with U, U + BM, and U + BM + RPM were higher than heifers not supplemented (P < 0.05). It is concluded that supplements with U + BM + RPM improved growth performance and feed conversion in heifers grazing kikuyu pasture.     

Development of a Fusarium oxysporum f. sp. melonis functional GFP fluorescence tool to assist melon resistance breeding programmes

Fusarium wilt, caused by Fusarium oxysporum f. sp. melonis (Fom), is one of the most widespread and devastating melon diseases. This vascular disease is caused by the colonization of melon xylem vessels by any of the four Fom races reported (r0, r1, r2 and r1,2, subdivided into r1,2w and r1,2y). The macroscopic evaluation of disease symptoms (disease rating, DR) at several days post‐inoculation (dpi) with Fom spores has been the traditional method to determine the resistance of melon accessions to this fungal pathogen. In this study, one isolate from each Fom race was transformed by Agrobacterium tumefaciens to constitutively express the green fluorescent protein (GFP). Fom‐GFP transformants, as virulent as the corresponding wildtype races, were selected to develop an inoculation assay based on the non‐invasive evaluation of the fluorescence emitted by Fom‐GFP. It was determined that melon root neck was the appropriate area to follow Fom‐GFP and a fluorescence signal rating (FSR) was established in parallel to DR determination. This method allowed the evaluation of GFP signal in the root neck of inoculated melon seedlings at 11–15 dpi. The GFP signal was scored in 62 melon accessions/breeding lines inoculated with different Fom‐GFP, followed by evaluation of the macroscopic DR in the aerial part of melon seedlings at 20–28 dpi. Correlation analysis demonstrated a direct and significant relationship between FSR and DR. This method has shown to be an effective and reliable tool that can assist Fom resistance breeding programmes in melon.     

AVES POLYOMAVIRUS 1 IN ARA CHLOROPTERA AND ECLECTUS RORATUS WITH DISCLOSURE OF FULL GENOMIC SEQUENCES

Aves polyomavirus 1 (APyV) is the causative agent of acute disease in birds and causes high mortality rates in nestlings. Infections have been reported worldwide in a significant number of caged bird species, such as parrots, caiques, budgerigars, lovebirds, and macaws. However, the number of complete viral sequences available in public databases is scarce, especially those with associated clinical histories. In this study, the clinical, pathological, epidemiological, and molecular characteristics of 2 APyV strains detected in Portugal are described. In the autumn of 2015, a 2-month-old female green-winged macaw (Ara chloroptera) from a small breeder died with signs of dehydration, weight loss, and depression, raising the suspicion of polyomavirus infection. Histopathological analysis revealed lesions compatible with APyV infection, and the presence of polyomavirus in several organs was confirmed by polymerase chain reaction. From the cohabitants tested (n = 14), 1 eclectus parrot (Eclectus roratus), which was more than 1-year-old, was also APyV DNA-positive. The full genomic sequences of the 2 strains were obtained and found identical, suggesting a single introduction in the premises and the occurrence of subsequent infections by the same virus. When compared with sequences of other APyVs available in public databases, high nucleotide similarity percentages were obtained, confirming the close genetic relationship among polyomaviruses worldwide. Interestingly, strain APV7, detected in a white-bellied parrot in 2008 in Japan, was the closest strain to those isolated in this report. Attempts to isolate the virus in eggs and cell lines failed. Phylogenetic analysis was performed by the Bayesian method to determine the phylogenetic classification of the macaw and parrot strains. Both clustered into group V, together with other strains from different bird species with no host or spatial-temporal relationships being observed.