Katie E Fowler

Reconstruction of gross avian genome structure, organization and evolution suggests that the chicken lineage most closely resembles the dinosaur avian ancestor

BackgroundThe availability of multiple avian genome sequence assemblies greatly improves our ability to define overall genome organization and reconstruct evolutionary changes. In birds, this has previously been impeded by a near intractable karyotype and relied almost exclusively on comparative molecular cytogenetics of only the largest chromosomes. Here, novel whole genome sequence information from 21 avian genome sequences (most newly assembled) made available on an interactive browser (Evolution Highway) was analyzed.ResultsFocusing on the six best-assembled genomes allowed us to assemble a putative karyotype of the dinosaur ancestor for each chromosome. Reconstructing evolutionary events that led to each species’ genome organization, we determined that the fastest rate of change occurred in the zebra finch and budgerigar, consistent with rapid speciation events in the Passeriformes and Psittaciformes. Intra- and interchromosomal changes were explained most parsimoniously by a series of inversions and translocations respectively, with breakpoint reuse being commonplace. Analyzing chicken and zebra finch, we found little evidence to support the hypothesis of an association of evolutionary breakpoint regions with recombination hotspots but some evidence to support the hypothesis that microchromosomes largely represent conserved blocks of synteny in the majority of the 21 species analyzed. All but one species showed the expected number of microchromosomal rearrangements predicted by the haploid chromosome count. Ostrich, however, appeared to retain an overall karyotype structure of 2n = 80 despite undergoing a large number (26) of hitherto un-described interchromosomal changes.ConclusionsResults suggest that mechanisms exist to preserve a static overall avian karyotype/genomic structure, including the microchromosomes, with widespread interchromosomal change occurring rarely (e.g., in ostrich and budgerigar lineages). Of the species analyzed, the chicken lineage appeared to have undergone the fewest changes compared to the dinosaur ancestor.

Genome wide analysis reveals single nucleotide polymorphisms associated with fatness and putative novel copy number variants in three pig breeds

BackgroundObesity, excess fat tissue in the body, can underlie a variety of medical complaints including heart disease, stroke and cancer. The pig is an excellent model organism for the study of various human disorders, including obesity, as well as being the foremost agricultural species. In order to identify genetic variants associated with fatness, we used a selective genomic approach sampling DNA from animals at the extreme ends of the fat and lean spectrum using estimated breeding values derived from a total population size of over 70,000 animals. DNA from 3 breeds (Sire Line Large White, Duroc and a white Pietrain composite line (Titan)) was used to interrogate the Illumina Porcine SNP60 Genotyping Beadchip in order to identify significant associations in terms of single nucleotide polymorphisms (SNPs) and copy number variants (CNVs).ResultsBy sampling animals at each end of the fat/lean EBV (estimate breeding value) spectrum the whole population could be assessed using less than 300 animals, without losing statistical power. Indeed, several significant SNPs (at the 5% genome wide significance level) were discovered, 4 of these linked to genes with ontologies that had previously been correlated with fatness (NTS, FABP6, SST and NR3C2). Quantitative analysis of the data identified putative CNV regions containing genes whose ontology suggested fatness related functions (MCHR1, PPARα, SLC5A1 and SLC5A4).ConclusionsSelective genotyping of EBVs at either end of the phenotypic spectrum proved to be a cost effective means of identifying SNPs and CNVs associated with fatness and with estimated major effects in a large population of animals.

Novel approach for deriving genome wide SNP analysis data from archived blood spots

BackgroundThe ability to transport and store DNA at room temperature in low volumes has the advantage of optimising cost, time and storage space. Blood spots on adapted filter papers are popular for this, with FTA (Flinders Technology Associates) Whatman™TM technology being one of the most recent. Plant material, plasmids, viral particles, bacteria and animal blood have been stored and transported successfully using this technology, however the method of porcine DNA extraction from FTA Whatman™TM cards is a relatively new approach, allowing nucleic acids to be ready for downstream applications such as PCR, whole genome amplification, sequencing and subsequent application to single nucleotide polymorphism microarrays has hitherto been under-explored.FindingsDNA was extracted from FTA Whatman™TM cards (following adaptations of the manufacturer’s instructions), whole genome amplified and subsequently analysed to validate the integrity of the DNA for downstream SNP analysis. DNA was successfully extracted from 288/288 samples and amplified by WGA. Allele dropout post WGA, was observed in less than 2% of samples and there was no clear evidence of amplification bias nor contamination. Acceptable call rates on porcine SNP chips were also achieved using DNA extracted and amplified in this way.ConclusionsDNA extracted from FTA Whatman cards is of a high enough quality and quantity following whole genomic amplification to perform meaningful SNP chip studies.

Time-lapse embryo imaging and morphokinetic profiling: Towards a general characterisation of embryogenesis

In vitro fertilisation is an effective method of assisted reproductive technology in both humans and certain non-human animal species. In most species, specifically, in humans and livestock, high in vitro fertilisation success rates are achieved via the transfer of embryos with the highest implantation and subsequent developmental potential. In order to reduce the risk of multiple gestation, which could be a result of the transfer of several embryos per cycle, restrictive transfer policies and methods to improve single embryo selection have been implemented. A non-invasive alternative to standard microscopic observation of post-fertilisation embryo morphology and development is time-lapse technology; this enables continuous, uninterrupted observation of embryo development from fertilisation to transfer. Today, there are several time-lapse devices that are commercially available for clinical use, and methods in which time-lapse could be used to improve embryology are continually being assessed. Here we review the use of time-lapse technology in the characterisation of embryogenesis and its role in embryo selection. Furthermore, the prospect of using this technology to identify aneuploidy in human embryos, as well as the use of time-lapse to improve embryological procedures in agriculturally important species such as the pig and cow are discussed.

[Avian cytogenetics goes functional] Third report on chicken genes and chromosomes 2015

Opening insights into new technologies in avian genomics The chicken has long been a model organism for genetic and developmental studies. It is now beginning to take its place as a model genome, opening up the fields of phylogenetics and comparative genomics like never before. This report comes at a time of huge technological advances (particularly in sequencing methodologies) and summarizes the current efforts to complete the gaps in the genome. It describes the progress that has been made in genomic annotation, particularly with respect to noncoding RNAs and genetic variants. Reviews of comparative genomics, avian evolution and sex determination are included as well as transcriptomic case studies and developments in epigenetic studies. The Third Report on Chicken Genes and Chromosomes also features the National Avian Research Facility and how it has developed into a resource for the study of avian biology, genetics, infection and disease. In this volume researchers interested in genetics, genomics and evolution will find detailed information that has not been available until now.

Avian cytogenetics goes functional

Chromosomal abnormalities in secondary bovine oocytes matured in vitro up to 48 hours Abstract Chromosomal abnormalities in secondary bovine oocytes matured in vitro up to 48 hours. 21st International Colloquium on Animal Cytogenetics and Gene Mapping Rubessa M., Pauciullo A., Peretti V., Iannuzzi L., Ramunno L., Di Berardino D.Edited by: L. Iannuzzi, A. Perucatti, A. Iannuzzi, A. Pauciullo, V. Genualdo, D. Incarnato, L. Keller (CNRISPAAM, Naples, Italy)Sister Chromatid exchange (SCE) test in river buffalo cells treated with Furocoumarins. / Iannuzzi A.; Perucatti A.; Genualdo V.; Pauciullo A.; Pucciarelli L.; Incarnato D.; Melis R.; Porqueddu C.; Marchetti M.; Iannuzzi L.. In: CHROMOSOME RESEARCH. ISSN 0967-3849. 22(2014), pp. 421-421. Original Citation: Sister Chromatid exchange (SCE) test in river buffalo cells treated with Furocoumarins.Comparative FISH-mapping of TNF, STAT5A and MNTR1A fecundity genes on river buffalo, cattle, sheep and goat. / Iannuzzi A.; Perucatti A.; Pauciullo A.; Genualdo V.; Incarnato D.; Pucciarelli L.; De Lorenzi L.; Parma P.; Iannuzzi L.. In: CHROMOSOME RESEARCH. ISSN 0967-3849. 22(2014), pp. 418-418. Original Citation: Comparative FISH-mapping of TNF, STAT5A and MNTR1A fecundity genes on river buffalo, cattle, sheep and goat.Multicolor FISH with 10 specific painting probes for the rapid identification of the sub-metacentric river buffalo autosomes (Bubalus bubalis, 2n=50) / Pauciullo A.; Perucatti A.; Iannuzzi A.; Incarnato D.; Genualdo V.; Pucciarelli L.; Di Berardino D.; Iannuzzi L.. In: CHROMOSOME RESEARCH. ISSN 0967-3849. 22(2014), pp. 410-410. Original Citation: Multicolor FISH with 10 specific painting probes for the rapid identification of the sub-metacentric river buffalo autosomes (Bubalus bubalis, 2n=50)

The production of pig preimplantation embryos in vitro: Current progress and future prospects

Human assisted reproductive technology procedures are routinely performed in clinics globally, and some of these approaches are now common in other mammals such as cattle. This is currently not the case in pigs. Given that the global population is expected to increase by over two billion people between now and 2050, the demand for meat will also undoubtedly increase. With this in mind, a more sustainable way to produce livestock; increasing productivity and implementing methods that will lead to faster genetic selection, is imperative. The establishment of routine and production scale pig embryo in vitro production could be a solution to this problem. Producers would be able to increase the overall number of offspring born, animal transportation would be more straightforward and in vitro produced embryos could be produced from the gametes of selected elite. Here we review the most recent developments in pig embryology, outline the current barriers and key challenges that exist, and outline research priorities to surmount these difficulties.

Canine recommended breed weight ranges are not a good predictor of an ideal body condition score

Breed-specific ideal bodyweight range information is widely used by dog owners and breeders as a guideline to ensure animals are within a healthy weight range. Body Condition Scoring, a method used by veterinarians to assess an animals overall shape with regard to weight is considered to be an excellent method to determine an animals overall body condition; these values, however, do not always correspond to published weight ranges. Here, the weight, neuter status, age and a nine-point Body Condition Score of a population of 140 purebred dogs were recorded and subsequently analysed to determine whether bodyweight was an effective predictor for Body Condition Scores. This comparison indicated that published recommended, breed-specific body weight ranges are not a good predictor for an ideal BCS and as such, guidelines for owners and breeders need to be systematically reviewed.

Upgrading Molecular Cytogenetics to Study Reproduction and Reproductive Isolation in Mammals, Birds, and Dinosaurs

amazing diversity of life, including over 2,000 species of vascular plants, exotic mammals such as tapirs, giant anteaters, howler monkeys, ocelots, and jaguars, in addition to hundreds of different bird species and thousands of different insects, the choice of Foz is an excellent analogy for the diverse approaches and systems chromosome biologists explore, and that will be emphasized throughout this conference. The 2016 ICC program offers seven sessions, beginning with a session on Chromosome Structure and Nuclear Architecture, highlighting the influences and interactions chromosomes have on the three-dimensional space of the nucleus. Session II will focus on Specialized Chromosomes, such as sex chromosomes and B chromosomes, whose structure and behavior are often distinguished from that of autosomal chromosomes. Population and Evolutionary Chromosome Biology, the third session, covers a synthesis of chromosome biology and The International Chromosome Conferences (ICC) originated from the Oxford Chromosome Conferences, inaugurated by C.D. Darlington and K.R. Lewis in 1964 and held subsequently in England in 1967 and 1970. The Chromosome Conference grew to an international event with its fourth meeting, held in Jerusalem, Israel in 1972, heralding the beginning of 40 years of technological advances that have expanded our understanding of chromosome biology in model and non-traditional biological systems. Having been hosted in Europe and the United States 16 times since then, this year the ICC will be held across the equator in Foz do Iguaçu, Brazil, on July 10–13, 2016. The event will bring scientists from across the globe to a biannual meeting focused on modern advances in chromosome biology, technology and theory. The Iguaçu National Park, a UNESCO World Heritage Centre, includes the Iguaçu Falls and has been chosen as one of the ‘New Natural Seven Wonders of the World’. Home to an Published online: June 2, 2016I.O. Furo a , R. Kretschmer b , R.J. Gunski c , A.D.V. Garnero c , M.A. Ferguson-Smith d , P.C.M. O ́Brien d , E.H.C. de Oliveira e, f a Programa de Pós-Graduação em Genética e Biologia Molecular, PPGBM, Universidade Federal do Pará, Belém, b PPGBM, Universidade Federal do Rio Grande do Sul, Porto Alegre, and c Programa de Pós-Graduação em Ciências Biológicas, Universidade Federal do Pampa, São Gabriel, Brazil; d Department of Veterinary Medicine, University of Cambridge, Cambridge, UK; e Instituto de Ciências Exatas e Naturais, Universidade Federal do Pará, Belém, and f Laboratório de Cultura de Tecidos e Citogenética, SAMAM, Instituto Evandro Chagas, Ananindeua, Brazil

AVIAN ANCESTRAL KARYOTYPE RECONSTRUCTION AND DIFFERENTIAL RATES OF INTER-AND INTRA-CHROMOSOMAL CHANGE IN DIFFERENT LINEAGES

Universidade Estadual Paulista Julio de Mesquita Filho, Instituto de Biociencias, Rio Claro, BrasilThe advent of the next generation sequencing (NGS) made sequencing and scaffolding of an entire animal genome a routine procedure. As the result we face a fast increase in the number of animal genomes available due to the activities of large international genome sequencing initiatives e.g., Genome 10K (G10K) or smaller projects. However, the full informative power of a sequenced genome could only be achieved when it is assembled into chromosomes. Usually, a draft or nearly complete animal chromosome assembly is achieved through three steps: (i) constructing contigs based on read overlaps, (ii) merging contigs into scaffolds using pair-end reads, and (iii) mapping scaffolds on chromosomes with the use of physical or genetic maps. As the cost of mapping techniques is still much higher than sequencing, the genetic and physical maps are not available for the majority of the de novo sequenced genomes. To overcome this problem for assemblies that employ long-insert libraries (5 – 40 Kbp) we recently developed the reference-assisted chromosome assembly (RACA) algorithm (Kim et al., 2013). This method relies on both the raw sequencing data (reads) and comparative information; the latter is obtained from alignments between the target (de novo sequenced), a closely related (reference) and more distantly related (outgroup) genomes. Using RACA followed by the manual FISH or PCR verification steps we are reconstructing the chromosome organisation of 19 bird species sequenced by the G10K community. We use the publically available chicken (Gallus gallus) and zebra finch (Taeniopygia guttata) chromosome assemblies as either reference or outgroup for each reconstruction depending on their phylogenetic relationships with each target species. Initially, we established the optimal RACA parameters for a bird chromosome assembly reconstruction using the duck (Anas platyrhynchos) and budgerigar (Melopsittacus undulatus) super-scaffolds assembled with the support from physical maps. This step allowed us to test the reliability of RACA reconstructions for bird genomes. Due to a higher evolutionary conservation of the bird karyotype compared to the mammalian one, we have achieved ~97% accuracy of scaffold adjacencies in our predicted chromosome fragments compared to the ~93-96% accuracies reported for mammals (Kim et al., 2013). We detected ~4-28% of scaffolds in different target bird genomes that are either chimeric or containing genuine lineage-specific evolutionary breakpoint regions. Some of these scaffolds will be selected for follow up PCR or FISH verifications. All RACA reconstructions will become publicly available from our Evolution Highway comparative chromosome browser http://evolutionhighway.ncsa.uiuc.edu/birds/ and will be further utilised to study connections between the chromosome evolution, adaptation and phenotypic diversity in birds and other vertebrates.Universidade Estadual Paulista, Nucleo de Pesquisa e Conservacao de Cervideos, Faculdade de Ciencias Agrarias e Veterinarias, Jaboticabal, Brasil• Invited speaker abstracts have the prefix “S” • Selected Oral presentations have the prefix “O” • Poster abstracts have the prefix “P” S1: 50th Anniversary of the first Oxford Chromosome Conference and some reflections on chromosome synapsis Malcolm A Ferguson-Smith Department of Veterinary Medicine, University of Cambridge, Cambridge, UK. Cyril Darlington, who organised the first Oxford Chromosome Conference 50 years ago, was one of the great pioneers of cytogenetics. He brought new understanding to the mechanisms of mitosis and meiosis and the uniformity of chromosome behaviour in all plants and animals with its implications for evolution. His major conclusions relate to the origin of chiasmata and the properties of sex chromosomes and were based on light microscopy before the era of molecular cytogenetics in the 1970s. Since his day the field has been transformed by electron microscopy, FISH, immunofluorescence of chromosomal proteins, meiotic mutants in yeast and mice and by DNA mapping and sequencing. Progress in understanding chromosome structure and synapsis in meiotic and somatic cells since Darlington will be briefly summarised with emphasis on the unknown. Genome conservation and the nature of non-coding DNA at synapsis sites, and the threedimensional structure of chromosomal proteins (eg, those of axial filaments), should be among the topics for discussion at this and future Chromosome Conferences. 20th International Chromosome Conference (ICCXX) 35120th International Chromosome Conference (ICCXX). 50th Anniversary, University of Kent, Canterbury, 1st–4th September 2014.Dinosaurs hold a unique place both in the history of the earth and the imagination of many. They dominated the terrestrial environment for around 170 million years during which time they diversified into at least 1000 different species. Reptilia, within which they are placed is one of the most remarkable vertebrate groups, consisting of two structurally and physiologically distinct lineages – the birds and the non-avian reptiles, of which there are 10,000 and 7,500 extant species respectively. The dinosaurs are without doubt the most successful group of vertebrate to have existed. They survived several mass extinction events before finally non-avian dinosaurs were defeated 66 million years ago in the Cretaceous-Paleogene extinction event, leaving the neornithes (modern birds) as their living descendants. Aside from the huge phenotypic diversity seen in this group, the birds and non-avian reptiles interestingly display similar karyotypic patterns (with the exception of crocodilians); with the characteristic pattern of macro and micro chromosomes, small genome size and few repetitive elements, suggesting that these were features exhibited in their common ancestor. In this study, the availability of multiple reptile genome sequences (including birds) on an interactive browser (Evolution Highway) allowed us to identify multi species homologous synteny blocks (msHSBs) between the putative avian ancestor (derived from six species of extant birds), the Lizard (Anolis carolensis) and the Snake (Boa constrictor). From these msHSBs we were able to produce a series of contiguous ancestral regions (CARs) representing the most likely ancestral karyotype of the Saurian (ancestor of archosaurs and lepidosaurs) that diverged from the mammalian lineage 280 mya. From this we have hypothesised the series of inter and intra-chromosomal rearrangements that have occurred along the dinosaur (archosaur) lineage to the ancestor of modern birds (100 mya) and along the lepidosaur lineage to the modern snake and lizard using the model of maximum parsimony. Our study shows that relatively few chromosomal rearrangements took place over this period with an average of one inter or intra-chromosomal (translocations and inversions respectively) rearrangement occurring approximately every 2 million years. The majority of these rearrangements appear to be intra-chromosomal suggesting an overall karyotypic stability, which is consistent with that of that of modern birds. Our results support the hypothesis that the characteristically avian genome was present in the saurian ancestor and that it has remained remarkably stable in the 280 million years since. It is credible therefore to suggest that this ‘avian-style’ genome may be one of the key factors in the success of this extraordinarily diverse animal group.