P element-induced, X-linked lethal mutations causing melanotic tumors in Drosophila melanogaster

Call number: LD2668 .T4 BIOL 1987 W37Master of ScienceBiolog

Assembly of hundreds of novel bacterial genomes from the chicken caecum

BACKGROUND: Chickens are a highly important source of protein for a large proportion of the human population. The caecal microbiota plays a crucial role in chicken nutrition through the production of short-chain fatty acids, nitrogen recycling, and amino acid production. In this study, we sequence DNA from caecal content samples taken from 24 chickens belonging to either a fast or a slower growing breed consuming either a vegetable-only diet or a diet containing fish meal. RESULTS: We utilise 1.6 T of Illumina data to construct 469 draft metagenome-assembled bacterial genomes, including 460 novel strains, 283 novel species, and 42 novel genera. We compare our genomes to data from 9 European Union countries and show that these genomes are abundant within European chicken flocks. We also compare the abundance of our genomes, and the carbohydrate active enzymes they produce, between our chicken groups and demonstrate that there are both breed- and diet-specific microbiomes, as well as an overlapping core microbiome. CONCLUSIONS: This data will form the basis for future studies examining the composition and function of the chicken caecal microbiota

Evidence of longer life; a cohort of 39 labrador retrievers.

A panel of veterinary and academic experts reviewed current available evidence on age at death for Labrador and reached a consensus that their average/typical lifespan was 12 years of age (Adams and others, 2016). A prospective cohort study that described the longevity of 39 pedigree adult neutered Labradors, showed that 89.7% lived to meet/exceed this typical lifespan. The study showed that maintenance of lean body mass and reduced accumulation of body fat were associated with attaining a longer than average lifespan whilst gender and age at neutering were not associated with longevity (Adams and others 2016)

Evidence of longer life; a cohort of 39 labrador retrievers.

A panel of veterinary and academic experts reviewed current available evidence on age at death for Labrador and reached a consensus that their average/typical lifespan was 12 years of age (Adams and others, 2016). A prospective cohort study that described the longevity of 39 pedigree adult neutered Labradors, showed that 89.7% lived to meet/exceed this typical lifespan. The study showed that maintenance of lean body mass and reduced accumulation of body fat were associated with attaining a longer than average lifespan whilst gender and age at neutering were not associated with longevity (Adams and others 2016)

Accuracy of Genomic EBV Using an Evenly Spaced, Low-density SNP Panel in Broiler Chickens

Whole-genome or genomic selection is based on associations of large number of markers across the genome with phenotype but will require use of small SNP panels to be cost effective in chickens. The potential loss of accuracy of genotyping selection candidates with an evenly-spaced low-density marker panel and imputation of high-density SNP genotypes was evaluated in a commercial broiler chicken line. Several methods were used to estimate marker effects. The loss in accuracy was less than 5% for different methods and traits. Thus, genomic selection using evenly-spaced low-density marker panels is a cost-effective choice for implementation of genomic selection

Investigating volatile semiochemical production from Bos taurus and Bos indicus as a novel phenotype for breeding host resistance to ixodid ticks

Ticks and tick-borne diseases cause significant loss in livestock production with about 80% world's cattle at risk. The cost of chemical control is high and there is an ever-increasing tick resistance to chemical acaricides. Genetic selection as alternative long-term control strategy is constrained by laborious phenotyping using tick counts or scores. This study explored the use of host volatile semiochemicals that may be attractants or repellents to ticks as a phenotype for new tick resistance, with potential to be used as a proxy in selection programmes. Approximately 100 young cattle composed of Bos indicus and Bos taurus were artificially infested with 2,500 African blue tick, Rhipicephalus decoloratus larvae, with daily female tick (4.5 mm) counts taken from day 20 post-infestation. Volatile organic compounds were sampled from cattle before and after tick infestation by dynamic headspace collection, analysed by high-resolution gas chromatography (GC) and subjected to multivariate statistical analysis. Using 6-day repeated measure analysis, three pre-infestation GC peaks (BI938 - unknown, BI966 - 6-methyl-5-hepten-2-one and BI995 – hexyl acetate) and one post-infestation GC peak (AI933 – benzaldehyde / (E)-2-heptenal) were associated with tick resistance (P < 0.01 and P < 0.05 respectively). The high correlation coefficients (r = 0.66) between repeated records with all volatile compounds support the potential predictive value for volatile compounds in selective breeding programmes for tick resistance in cattle

Parental methyl-enhanced diet and in ovo corticosterone affect first generation Japanese quail (Coturnix coturnix japonica) development, behaviour and stress response.

Abstract The role of maternal investment in avian offspring has considerable life history implications on production traits and therefore potential for the poultry industry. A first generation (G1) of Japanese quail (Coturnix japonica) were bred from a 2 × 2 factorial design. Parents were fed either a control or methyl-enhanced (HiBET) diet, and their eggs were treated with a vehicle or corticosterone injection during day 5 of incubation. A subset of G1 birds were subjected to an open field trial (OFT) and capture-restraint stress protocol. Significant effects of HiBET diet were found on parental egg and liver weights, G1 hatch, liver and female reproductive tract weights, egg productivity, latency to leave the OFT central zone, male baseline 11-dehydrocorticosterone, and female androstenedione plasma concentrations. In ovo treatment significantly affected latency to return to the OFT, male baseline testosterone and androstenedione, and change in androstenedione plasma concentration. Diet by treatment interactions were significant for G1 liver weight and male baseline plasma concentrations of corticosterone. These novel findings suggest significant positive effects on reproduction, growth, precociousness, and hypothalamic–pituitary–adrenal axis function from enhanced methyl diets, and are important in understanding how in ovo stressors (representing maternal stress), affect the first offspring generation