Parrots are considered the third most popular pet species, after dogs and cats, in the United States of America. Popular birds include budgerigars, lovebirds and cockatiels and are known for their ...plumage and vocal learning abilities. Plumage colour variation remains the main driving force behind breeder selection. Despite the birds' popularity, only two molecular genetic tests-bird sexing and pathogen screening-are commercially available to breeders. For a limited number of species, parentage verification tests are available, but are mainly used in conservation and not for breeding purposes. No plumage colour genotyping test is available for any of the species. Due to the fact that there isn't any commercial plumage genotype screening or parentage verification tests available, breeders mate close relatives to ensure recessive colour alleles are passed to the next generation. This, in turn, leads to inbreeding depression and decreased fertility, lower hatchability and smaller clutch sizes, all important traits in commercial breeding systems. This review highlights the research carried out in the field of pet parrot genomics and points out the areas where future research can make a vital contribution to understanding how parrot breeding can be improved to breed healthy, genetically diverse birds.
Parrots have remarkable plumage coloration that result in part from a unique ability to produce pigments called psittacofulvins that yield yellow to red feather colors. Little is known about the ...evolution of psittacofulvin-based pigmentation. Widespread color mutations of captive-bred parrots provide perfect opportunities to study the genetic basis of this trait. An earlier study on
budgerigars, which do not possess psittacofulvins, reveals the involvement of an uncharacterized polyketide synthase (MuPKS) in yellow psittacofulvin synthesis. The
phenotype had repeatedly appeared in different parrot species, similar to independent experimental replications allowing the study of convergent evolution and molecular mechanism of psittacofulvin-based pigmentation. Here, we investigated the genetic basis of the
phenotypes in two species of
parrots, Fischer's lovebird (
) and Yellow-collared lovebird (
). Using whole-genome data, we identified a single genomic region with size <2 Mb to be strongly associated with the color difference between
and wild-type (WT) birds in both species. Surprisingly, we discovered that the mutation associated with the
phenotype was identical to the previously described substitution causing the functional change of MuPKS in budgerigars. Together with the evidence of shared
-associated haplotypes and signatures of a selective sweep in this genomic region in both species, we demonstrated both
mutation and interspecific introgression play a role in the evolution of this trait in different
species. The convergent substitution in the same gene in both lovebirds and budgerigars also indicates a strong evolutionary constraint on psittacofulvin-based coloration.
Lovebirds (genus Agapornis of family Psittaculidae) are a group of small, colourful parrot species endemic to sub-Saharan Africa and Madagascar, two-thirds of which are considered to have declining ...populations. Effective conservation efforts are hampered by a lack of information, particularly for species occurring in regions that have received little research attention. We combined expert knowledge with a review of the primary and grey literature to identify key knowledge gaps and priority conservation actions for this group of birds. Published studies were found to be largely concentrated on lovebird populations in southern Africa and, to a lesser extent in East Africa, and therefore mostly concern members of the 'white eye-ring' clade. Some species, such as the Black-collared Lovebird Agapornis swindernianus, remain very poorly studied, with a lack of even basic information such as georeferenced occurrence records. Several lovebird species were historically taken from the wild in large numbers for the international pet trade, leading to population declines. Although trade in wild lovebirds has been much reduced compared with historical levels, considerable numbers are still captured for local and international trade without any monitoring of the wild populations. Habitat change continues to drive declines in the population and range of some species, particularly those considered habitat specialists, such as the Nyasa Lovebird A. lilianae and the Black-cheeked Lovebird A. nigrigenis. However, changing habitat has also driven range expansions and, in combination with trade, has created numerous novel contact zones between formerly allopatric species, such as between Fischer's Lovebird A. fischeri and Yellow-collared Lovebird A. personatus. Hybridisation has been widely reported, particularly in East Africa, and studies on the implications of this for conservation, building on recent advances in genetic tools, are urgently needed. We call for more targeted research on lovebirds to inform assessments of their population trends, to understand the drivers of these trends, and to highlight opportunities to leverage existing data and new research tools to advance knowledge to support conservation in this group of birds.
In animal breeding, a species sex can influence the value of the animal. For example, in the horse breeding industry, mares are preferred as polo horses, while in wildlife breeding males with larger ...horns are more valuable. Therefore, the economic advantages of knowing the unborn fetus' sex are important to successful animal management. Ultrasonography is used to determine the sex of unborn fetuses, but this method places additional stress on the animal and require specialized equipment and expertise. Conversely, molecular-based sexing techniques require less invasive sampling and can determine sex more reliably. Although in humans, various studies have evaluated the use of cell-free fetal DNA (cffDNA) for prenatal sexing, very few animal studies have been published in this field. Several factors can affect the sensitivity of cffDNA-based sex determination, for example the gestational age. These factors are often not optimized and validated when establishing a protocol for prenatal sexing. In this review, we summarize the current literature on cffDNA in animals. We discuss the diagnostic applications and limitations in the use thereof in animal husbandry and wildlife management. Lastly, the feasibility of implementing diagnostic tests is evaluated and solutions are given to the current drawbacks of the technology.
•Cell-free fetal DNA (cffDNA) is a non-invasive source of the entire fetal genome.•Despite this cffDNA is rarely used in non-invasive prenatal testing (NIPT) in animals.•Several challenges still exist in developing routine NIPT for animals.•The biggest challenges are the practical implementation and affordability of the tests.
In aviculture, lovebirds are considered one of the most popular birds to keep. This African parakeet is known for its range of plumage colors and ease to tame. Plumage variation is the most important ...price-determining trait of these birds, and also the main selection criterion for breeders. Currently, no genetic screening tests for traits of economic importance or to confirm pedigree data are available for any of the nine lovebird species. As a starting point to develop these tests, the de novo genome of Agapornis roseicollis (rosy-faced lovebird) was sequenced, assembled, and annotated. Sequencing was done on the Illumina HiSeq 2000 platform and the assembly was performed using SOAPdenovo v2.04. The genome was found to be 1.1 Gb in size and 16,044 genes were identified and annotated. This compared well with other previously sequenced avian genomes, such as the chicken, zebra finch, and budgerigar. To assess genome completeness, the number of benchmarking universal single-copy orthologs were identified in the genome. This was compared to other previously assembled avian genomes and the results indicated that the genome will be useful in the development of genetic screening tests to aid lovebird breeders in selecting breeding pairs.
The multi-drug resistance (mdr-1) gene mutation is a phenomenon well known to current veterinary practitioners. The mutation causes a predisposition for, amongst other phenomena, macrocyclic ...lactone-induced neurotoxicosis in affected canines, a condition that can be fatal. Various herding dog breeds can be heterozygous or homozygous for the mutation, and prevalence differs only slightly in dog populations between geographical regions. This report provides prevalence data of the canine mdr-1 mutation in 306 South African dogs.
Canine degenerative myelopathy (DM) is a progressive disease process that is diagnosed late in life and mainly affects the pelvic limbs. Factors that make an ante-mortem definitive diagnosis of DM ...include: an insidious onset and clinical manifestation that mimics other disease processes of the pelvic limbs (hip dysplasia, cranial cruciate ligament rupture, etc.) or there may even be concurrent disease processes, old-age onset and lack of reliable diagnostic methods. Until recently, South African dog owners had to submit samples to laboratories overseas for genetic testing in order to confirm an affected dog (homozygous A/A) and to aid in the ante-mortem diagnosis of DM. Only affected dogs have been confirmed to manifest the clinical signs of DM. This study aimed to verify whether genetic testing by a local genetic laboratory was possible in order to detect a missense mutation of the superoxide dismutase gene (SOD1) that is implicated in causing the clinical signs of DM. The study also aimed to detect and map the inheritance of this disease process in a local Boxer dog population where the pedigree of the sampled population was known. Venous blood collected from Boxer dogs using a simple random sampling technique. The samples were genotyped for the SOD1:c.118GA polymorphism. Carrier and affected Boxer dogs were detected. A pedigree that demonstrated the significance of inheriting a carrier or affected state in the population was mapped. The present study concludes that genotyping of the missense mutation in Boxer dogs is possible in South Africa. There are carrier and affected Boxer dogs in the local population, making DM a plausible diagnosis in aged dogs presenting with pelvic limb pathology.
The multi-drug resistance (mdr-1) gene mutation is a phenomenon well known to current veterinary practitioners. The mutation causes a predisposition for, amongst other phenomena, macrocyclic ...lactone-induced neurotoxicosis in affected canines, a condition that can be fatal. Various herding dog breeds can be heterozygous or homozygous for the mutation, and prevalence differs only slightly in dog populations between geographical regions. This report provides prevalence data of the canine mdr-1 mutation in 306 South African dogs.
L-2 hydroxyglutaric aciduria is an autosomal recessive error of metabolism that manifests as an encephalopathy. The most common presenting signs are seizures, tremors, ataxia and/ or dementia. Some ...affected dogs show only subtle behavioural changes. Amongst canines, the condition has been best described in Staffordshire Bull Terriers. Although this is the first reported case in South Africa, at least three other affected dogs have been indentified by polmerase chain reaction (PCR) in this country. Affected dogs have normal haematology, serum biochemistry and routine urine analysis. This report discusses the advantages and limitations of the three main diagnostic modalities, namely: magnetic resonance imaging, urine gas chromatography-mass spectrometry and genetic testing. The aim of this report is to increase awareness of the condition, assist diagnosis in encephalopathic dogs and improve detection of carriers amongst breeding stock.
The multi-drug resistance (mdr-1) gene mutation is a phenomenon well known to current veterinary practitioners. The mutation causes a predisposition for, amongst other phenomena, macrocyclic ...lactone-induced neurotoxicosis in affected canines, a condition that can be fatal. Various herding dog breeds can be heterozygous or homozygous for the mutation, and prevalence differs only slightly in dog populations between geographical regions. This report provides prevalence data of the canine mdr-1 mutation in 306 South African dogs.
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