Prospective study relating genotype profiles with race performance in racing pigeons.

This is a prospective study to investigate the impact of genotype profiles on race performance in racing pigeons. Genotypes studied included lactate dehydrogenase A (LDHA), dopamine receptor (DRD), myostatin (MSTN), and feather keratin (F-KER), as well as demographic factors such as gender, color, and the mtDNA. This study shows differences within genotypes DRD456 (P = 0.027) and F-KER (P = 0.018). For DRD456, race coefficients were lower (= better performance) for genotype CT. For F-KER, race coefficients were lower for GG, overall, while within the F-KER TT genotype race performance was best at longer distances. After including Queen L mtDNA in the model, both the effects of F-KER and DRD456 remained significant. The effect of Queen L mtDNA alone was significant (P = 0.004) and mainly driven by the effect in short distance races. In addition, birds with the checker color check had a lower race coefficient than birds with the color blue bar (P = 0.0012). Also, this effect was independently significant and remained significant in the multivariate analysis. No differences in race coefficients were seen between genotypes for LDHA and MSTN nor for the demographic factor of gender. While individual factors were related to differences in race performance, and although one could be tempted to favor a bird with DRD4 CCCT-F-KER TT-LDHA AB-checker color for long distance races, further and larger prospective studies including birds unrelated to our family of birds will be needed to confirm our findings and to determine a superior profile including multiple genetic factors.

Arginine to Glutamine Variant in Olfactomedin Like 3 (OLFML3) Is a Candidate for Severe Goniodysgenesis and Glaucoma in the Border Collie Dog Breed.

Goniodysgenesis is a developmental abnormality of the anterior chamber of the eye. It is generally considered to be congenital in dogs (Canis lupus familiaris), and has been associated with glaucoma and blindness. Goniodysgenesis and early-onset glaucoma initially emerged in Border Collies in Australia in the late 1990s and have subsequently been found in this breed in Europe and the USA. The objective of the present study was to determine the genetic basis of goniodysgenesis in Border Collies. Clinical diagnosis was based on results of examinations by veterinary ophthalmologists of affected and unaffected dogs from eleven different countries. Genotyping using the Illumina high density canine single nucleotide variant genotyping chip was used to identify a candidate genetic region. There was a highly significant peak of association over chromosome 17, with a p-value of 2 × 10-13 Expression profiles and evolutionary conservation of candidate genes were assessed using public databases. Whole genome sequences of three dogs with glaucoma, three severely affected by goniodysgenesis and three unaffected dogs identified a missense variant in the olfactomedin like 3 (OLFML3) gene in all six affected animals. This was homozygous for the risk allele in all nine cases with glaucoma and 12 of 14 other severely affected animals. Of 67 reportedly unaffected animals, only one was homozygous for this variant (offspring of parents both with goniodysgenesis who were also homozygous for the variant). Analysis of pedigree information was consistent with an autosomal recessive mode of inheritance for severe goniodysgenesis (potentially leading to glaucoma) in this breed. The identification of a candidate genetic region and putative causative variant will aid breeders to reduce the frequency of goniodysgenesis and the risk of glaucoma in the Border Collie population.

Vertical transmission of avian bornavirus in Psittaciformes: avian bornavirus RNA and anti-avian bornavirus antibodies in eggs, embryos, and hatchlings obtained from infected sun conures (Aratinga solstitialis).

Fertilized eggs were obtained from four pairs of sun conures (Aratinga solstitialis) infected with avian bornavirus (ABV) genotype 2, as determined by the sequence of the P24 gene. ABV RNA could be detected in early embryos of all four pairs. ABV RNA also was detected in brain, liver, and eyes of late-stage embryos of one of the pairs (Pair 4) and in blood of a 2-wk-old hatchling of this pair, demonstrating that vertical transmission can occur. ABV RNA could be detected in the liver but not in the brain or eyes of the late-stage embryos of another pair (Pair 3). Although it could be detected in the undeveloped eggs of the female parent and 8-day-old embryos, bornaviral RNA could not be found in the brain and liver of the late-stage embryos or in feathers and blood of young (5-9-wk-old) hatchlings of a third pair (Pair 2). At 11 wk, ABV RNA could be detected again in feathers and blood of these hatchlings and in the brain of one of the hatchlings of Pair 2 that suddenly died. ABV RNA could however be detected in throat swabs of the 5- and 9-wk-old hatchlings and their parents (Pair 2). Although the continued presence of ABV RNA in feathers and blood below the detection level of the reverse transcription-PCR used cannot be excluded, this result also may be attributable to feeding by the infected parents. Analysis by enzyme-linked immunosorbent assay showed that egg yolks and serum of late-stage embryos contain variable amounts of non-neutralizing anti-ABV-P40, -P10, -P24, and -P16 antibodies, the ratio of which reflected the antibody ratio in the serum of the female parent. Antibodies against the viral glycoprotein, which are considered neutralizing in mammals, and against ABV RNA polymerase were not detected. Whereas 5-wk-old hatchlings of the pair (Pair 2) that produced ABV RNA-free late-stage embryos were free of anti-ABV antibodies, such antibodies could be detected again in the serum of these hatchlings at 9 wk of age, before the age that bornaviral RNA could again be detected in feathers and blood. At 16 wk, these antibodies became abundant. The finding that late-stage embryos, presumably free of ABV RNA, can be obtained from eggs from infected parents suggests that hand- or foster-raising of such birds may be a method to obtain birnavirus-free offspring from some infected birds.

Diagnosis of Avian bornavirus infection in psittaciformes by serum antibody detection and reverse transcription polymerase chain reaction assay using feather calami.

Avian bornavirus (ABV) is the causative agent of proventricular dilatation disease (PDD), a highly devastating and contagious disease of psittacines (parrots and parakeets), which has resulted in the death of many captive birds. Accurate diagnosis of bornavirus infection is therefore important for the identification and isolation of infected birds. The current study showed that nonvascular contour (chest) feather calami provide a ready and minimally invasive source of RNA for the detection of ABV by reverse transcription polymerase chain reaction (RT-PCR). Storage of the feathers at room temperature for at least a month did not affect the results. Serological analysis by enzyme-linked immunosorbent assay (ELISA) showed that identification of anti-bornaviral nucleoprotein P40 antibodies can identify many birds with a past or present infection. The presence of anti-avian bornaviral P24 phosphoprotein and P16 matrix protein antibodies was quite variable, rendering these antibodies less useful for diagnosis of ABV infection. The significance of the present findings is that the use of nonvascular feathers as a source of RNA allows sample collection under conditions where storage of other samples would be difficult. Serum detection by ELISA of anti-P40 antibodies allows the identification of infected birds when RT-PCR fails.