Nick Anthony’s research while affiliated with University of Arkansas at Fayetteville and other places

Bones play an essential role being responsible for the support of body mass, protection of internal organs, and providing musculature attachment sites while also serving as a reservoir for eggshell mineralization during the production phase. Targeted genetic selection has contributed to body morphometry and performance potential and could be inadvertently associated with undesirable effects on bone stability. In this study, bone parameters were compared between a contemporary and heritage line for the effect of strain and dietary regimen. A total of 320 White Leghorn laying hens (69 weeks of age) of two different strains were distributed into a 2 × 2 factorial arrangement creating 4 experimental treatment groups: 1). 2016 hen on 1940 diet, 2). 2016 hen on 2016 diet, 3). 1940 hen on 1940 diet, and 4). 1940 hen on 2016 diet with 8 replicates per treatment. Keel bones were assessed for deviations and or fractures. Significant differences (P ≥ 0.05) were observed for both deviations and/or fractures with the 2016 strain having more when compared to the 1940 strain. Humerus and tibia bones were analyzed for bone mineral density, breaking strength, and bone ash. Humerus and tibia weights which included both pre (with meat attached) and post weights (without meat attached) had significant differences (P ≤ 0.05) in the pre-weight in the 2016 hens, however no significant differences in the post weights. Results suggest that genetics played a role in the differences observed with the bone parameters measured and nutrition had few adverse effects.

This study identified and evaluated differences between microbiome compositions of the ileum and ceca of 1940 and 2016 white leghorn genetic strains fed representative contemporary diets from those times. Ileal and cecal samples were collected at 69 weeks of age. Alpha and beta diversity metrics were generated, and the Analysis of Composition of Microbiomes (ANCOM) was utilized to determine significantly different taxa. Ileum and ceca alpha diversity were significantly different (p = 0.001; Q = 0.001); however, no differences between genetic lineage were observed (p > 0.05; Q > 0.05). Beta diversity between the ileum and ceca and the genetic lines was significantly different (p = 0.001; Q = 0.001). The ANCOM of the ileum showed significant differences between Proteobacteria and Actinobacteriota phyla (p ˂ 0.05) and significant differences between Pseudomonas, Rhizobiaceae, Leuconostoc, and Aeriscardovia genera (p ˂ 0.05). For ceca ANCOM, Proteobacteria, Firmicutes, Actinobacteriota, and Euryarchaeota phyla were significantly different (p ˂ 0.05), with Firmicutes having the highest relative abundance across all groups, and there were significant differences in genera Pseudomonas, Leuconostoc, Alloprevotella, and Aeri scardovia, with Alloprevotella having the highest relative abundance. The results suggest that genetic makeup in conjunction with the nutritional composition influences the cecal and ileal microbiota of corresponding hens.

This study was conducted to identify and evaluate the differences between the microbiome composition of the ileum and ceca of 1940 and 2016 genetic strains of white leghorns fed representative contemporary diets from those times. Ileal and cecal samples were aseptically collected from both genetic lines at 69 weeks of age. The genomic DNA of the ileal and cecal contents were extracted and the V4 region of the 16S rDNA was sequenced on an Illumina Miseq. Microbiota data were filtered and aligned using the QIIME2 2020.2 pipeline. Alpha and beta diversity metrics were generated and the Analysis of Composition of Microbiomes (ANCOM) was utilized to determine significantly different taxa. Data were considered significant at P ≤ 0.05 for main effects and Q ≤ 0.05 for pairwise differences. Alpha diversity of the ileum and ceca were significantly different (P = 0.001; Q = 0.001; however, no differences between genetic lineage were observed (P > 0.05; Q > 0.05). The beta diversity between the ileum and ceca, as well as between the genetic lines (1940 vs. 2016) were significantly different from one another (P = 0.001; Q = 0.001). Using ANCOM, Proteobacteria and Actinobacteriota were significantly different than other phyla (P ˂ 0.05) with a higher relative abundance of Proteobacteria being observed among treatment groups 2 and 3, while Actinobacteriota had higher relative abundance in treatment groups 1 and 4. Among the significantly different genera in the ileum, Pseudomonas , Rhizobiaceae , Leuconostoc , and Aeriscardovia were different (P ˂ 0.05) with treatment groups 1 and 4 having a higher relative abundance of Aeriscardovia , while treatment groups 2 and 3 had higher relative abundance in both Pseudomonas and Leuconostoc . In the ceca, Proteobacteria , Firmicutes , Actinobacteriota , and Euryarchaeota were significantly different phyla (P ˂ 0.05) with Firmicutes having the highest relative abundance across all treatment groups. Among the significantly different genera ( Pseudomonas , Leuconostoc , Alloprevotella , and Aeriscardovia ), Alloprevotella had the highest relative abundance across all treatment groups 1 and 2, while Leuconostoc and Pseudomonas had the highest relative abundance in treatment group 4. Results from this study suggest that genetic makeup in conjunction with the nutritional composition of laying hens influences the cecal and ileal microbiota of corresponding hens.

Unlike PIWI-interacting RNA (piRNA) in other species that mostly target transposable elements (TEs), >80% of piRNAs in adult mammalian testes lack obvious targets. However, mammalian piRNA sequences and piRNA-producing loci evolve more rapidly than the rest of the genome for unknown reasons. Here, through comparative studies of chickens, ducks, mice, and humans, as well as long-read nanopore sequencing on diverse chicken breeds, we find that piRNA loci across amniotes experience: (1) a high local mutation rate of structural variations (SVs, mutations ≥ 50 bp in size); (2) positive selection to suppress young and actively mobilizing TEs commencing at the pachytene stage of meiosis during germ cell development; and (3) negative selection to purge deleterious SV hotspots. Our results indicate that genetic instability at pachytene piRNA loci, while producing certain pathogenic SVs, also protects genome integrity against TE mobilization by driving the formation of rapid-evolving piRNA sequences.

The chicken continues to hold its position as a leading model organism within many areas of research, as well as a being major source of protein for human consumption. The First Report on Chicken Genes and Chromosomes [Schmid et al., 2000], which was published in 2000, was the brainchild of the late, and sadly missed, Prof Michael Schmid of the University of Würzburg. It was a publication bringing together updates on the latest research and resources in chicken genomics and cytogenetics. The success of this First report led to the subsequent publication of the Second [Schmid et al., 2005] and Third [Schmid et al., 2015] reports proving popular references for the research community. It is now our pleasure to be able to introduce publication of the Fourth report. Being seven years since the last report, this publication captures the many advances that have taken place during that time. This includes presentation of the detailed genomic resources that are now available, largely due to increasing capabilities of sequencing technologies and which herald the pangenomic age, allowing for a much richer and more complete knowledge of the avian genome. Ongoing cytogenetic work also allows for examination of chromosomes, specific elements within chromosomes and the evolutionary history and comparison of karyotypes. We also examine chicken research efforts with a much more ‘global’ outlook with a greater impact on food security and the impact of climate change, and highlight the efforts of international consortia, such as the Chicken Diversity Consortium. We dedicate this Report to Michael.