Multi-Platform Next-Generation Sequencing of the Domestic Turkey (Meleagris gallopavo): Genome Assembly and Analysis

Turkey genome authors 

Abstract

A synergistic combination of two next-generation sequencing platforms with a detailed comparative BAC physical contig map provided a cost-effective assembly of the genome sequence of the domestic turkey (Meleagris gallopavo). Heterozygosity of the sequenced source genome allowed discovery of more than 600,000 high quality single nucleotide variants. Despite this heterozygosity, the current genome assembly (~1.1 Gb) includes 917 Mb of sequence assigned to specific turkey chromosomes. Annotation identified nearly 16,000 genes, with 15,093 recognized as protein coding and 611 as non-coding RNA genes. Comparative analysis of the turkey, chicken, and zebra finch genomes, and comparing avian to mammalian species, supports the characteristic stability of avian genomes and identifies genes unique to the avian lineage. Clear differences are seen in number and variety of genes of the avian immune system where expansions and novel genes are less frequent than examples of gene loss. The turkey genome sequence provides resources to further understand the evolution of vertebrate genomes and genetic variation underlying economically important quantitative traits in poultry. This integrated approach may be a model for providing both gene and chromosome level assemblies of other species with agricultural, ecological, and evolutionary interest.

Author Summary

In contrast to the compact sequence of viruses and bacteria, determining the complete genome sequence of complex vertebrate genomes can be a daunting task. With the advent of “next-generation” sequencing platforms, it is now possible to rapidly sequence and assemble a vertebrate genome, especially for species for which genomic resources—genetic maps and markers—are currently available. We used a combination of two next-generation sequencing platforms, Roche 454 and Illumina GAII, and unique assembly tools to sequence the genome of the agriculturally important turkey, Meleagris gallopavo. Our draft assembly comprises approximately 1.1 gigabases of which 917 megabytes are assigned to specific chromosomes. Comparisons of the turkey genome sequence with those of the chicken, Gallus gallus, and the zebra finch, Taeniopygia guttata, provide insights into the evolution of the avian lineage. This genome sequence will facilitate discovery of agriculturally important genetic variants.

Citation: Dalloul RA, Long JA, Zimin AV, Aslam L, Beal K, et al. (2010) Multi-Platform Next-Generation Sequencing of the Domestic Turkey (Meleagris gallopavo): Genome Assembly and Analysis. PLoS Biol 8(9): e1000475. doi:10.1371/journal.pbio.1000475

Academic Editor: Richard J. Roberts, New England Biolabs, United States of America

 

Received: December 21, 2009; Accepted: July 27, 2010; Published: September 7, 2010

This is an open-access article distributed under the terms of the Creative Commons Public Domain declaration which stipulates that, once placed in the public domain, this work may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose.

Funding: Funding for sequencing was supported by Roche Applied Science, the University of Minnesota (College of Veterinary Medicine, and College of Food, Agricultural & Natural Resource Sciences), the Utah State University (Center for Integrated Biosystems), the Virginia Bioinformatics Institute Core Lab Facility, Virginia Tech University (College of Agriculture & Life Sciences, Virginia Bioinformatics Institute, Fralin Biotechnology Center, Office of Vice President for Research), the Intramural Research Programs of the USDA Agricultural Research Service and the NIH National Institute on Aging, and Multi-State Research Support Program (USDA-NIFA-NRSP8). Funding for assembly, annotation and genomic analyses was provided by The Center for Genomics regulation and the European Community (Barcelona, Spain), “Landesstipendium Sachsen”, the Free State of Saxony under the auspices of the “Landesexzellenzinitiative LIFE” (Germany), the NIH National Human Genome Research Institute (#R01-HG002945), the NIH National Library of Medicine (#R01-LM006845), the National Science Foundation (#DMS0616585), The Quantomics Project from 7th Framework Programe of the European Union, the Spanish Ministry of Science, The Wellcome Trust, the USDA National Institute of Food and Agriculture Animal Genome Program (#'s 2005-35205-15451; 2007-0212704; 2007-35205-17880; 2008-04049; 2008-35205-18720; 2009-35205-05302; 2010-65205-20412) and Ministry of Science & Technology (Korea Science & Engineering Foundation) of Korea (R01-2007-000-20456-0). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.

Abbreviations: BAC, bacterial artificial chromosome; BES, BAC end sequence; CNV, copy number variation; ESTs, expressed sequence tags; FISH, fluorescence in situ hybridization; GO, gene ontology; LINE, long interspersed nuclear element; MHC, major histocompatibility complex; miRNA, micro-RNA; ncRNA, non-coding RNA; NGS, next-generation sequencing; RPG, rate pattern group; SINE, short interspersed nuclear element; snoRNA, small nucleolar RNA; SNP, single nucleotide polymorphism; SNV, single nucleotide variant (SNP/indel); TE, transposable element; TLR, Toll-like receptor; WGS, whole genome shotgun

* E-mail: reedx054@umn.edu