What's in your next-generation sequence data? An exploration of unmapped DNA and RNA sequence reads from the bovine reference individual.

BackgroundNext-generation sequencing projects commonly commence by aligning reads to a reference genome assembly. While improvements in alignment algorithms and computational hardware have greatly enhanced the efficiency and accuracy of alignments, a significant percentage of reads often remain unmapped.ResultsWe generated de novo assemblies of unmapped reads from the DNA and RNA sequencing of the Bos taurus reference individual and identified the closest matching sequence to each contig by alignment to the NCBI non-redundant nucleotide database using BLAST. As expected, many of these contigs represent vertebrate sequence that is absent, incomplete, or misassembled in the UMD3.1 reference assembly. However, numerous additional contigs represent invertebrate species. Most prominent were several species of Spirurid nematodes and a blood-borne parasite, Babesia bigemina. These species are either not present in the US or are not known to infect taurine cattle and the reference animal appears to have been host to unsequenced sister species.ConclusionsWe demonstrate the importance of exploring unmapped reads to ascertain sequences that are either absent or misassembled in the reference assembly and for detecting sequences indicative of parasitic or commensal organisms

The Simmental Breed: Population Structure and Generation Interval Trends

Pedigree data from the American Simmental Association from 1986-2008 were used to analyze the pedigree structure and changes in generation intervals over time within the Simmental breed. The number of breeders that accounted for 10% of sires of sires (SS), sires of dams (SD), dams of sires (DS), and dams of dams (DD) were 3, 5, 5, and 16, respectively. States with the greatest influenceon the four pathways of selection (SS, SD, DS, and DD) included Montana, South Dakota, Kansas, and Texas. In general, generation intervals for the four pathways decreased by year of birth over the time span of the data analyzed, albeit numerically slight. Averagegeneration intervals for sires and dams also decreased by year of birth, while animals increased slightly

Efficacy of Newborn Bovine DNA Samples Taken Via Different Mediums in Assigning Paternity

DNA samples from 25 newborn calves taken via hair, ear notch, and nasal swabs were used to determine the efficacy of sampling method in assigning parentage. Nasal swab samples were collected at six time points from birth to 120 hours post-birth. Calf samples and all candidate sires were genotyped with a 99 SNP parentage panel. Nasal swab collection time did not result in significant differences in the ability to assign the correct sire, although differences were seen in apparent cleanliness of the sample. Clean nasal swab samples are comparable in efficacy to hair and ear notch samples in assigning parentage

What's in your next-generation sequence data? An exploration of unmapped DNA and RNA sequence reads from the bovine reference individual.

BackgroundNext-generation sequencing projects commonly commence by aligning reads to a reference genome assembly. While improvements in alignment algorithms and computational hardware have greatly enhanced the efficiency and accuracy of alignments, a significant percentage of reads often remain unmapped.ResultsWe generated de novo assemblies of unmapped reads from the DNA and RNA sequencing of the Bos taurus reference individual and identified the closest matching sequence to each contig by alignment to the NCBI non-redundant nucleotide database using BLAST. As expected, many of these contigs represent vertebrate sequence that is absent, incomplete, or misassembled in the UMD3.1 reference assembly. However, numerous additional contigs represent invertebrate species. Most prominent were several species of Spirurid nematodes and a blood-borne parasite, Babesia bigemina. These species are either not present in the US or are not known to infect taurine cattle and the reference animal appears to have been host to unsequenced sister species.ConclusionsWe demonstrate the importance of exploring unmapped reads to ascertain sequences that are either absent or misassembled in the reference assembly and for detecting sequences indicative of parasitic or commensal organisms

Exploring genetic variation and population structure in a threatened species, <i>Noturus placidus</i>, with whole-genome sequence data

AbstractThe Neosho madtom (Noturus placidusIctalurus punctatus)Danio reri

Identification of bovine CpG SNPs as potential targets for epigenetic regulation via DNA methylation.

Methylation patterns established and maintained at CpG sites may be altered by single nucleotide polymorphisms (SNPs) within these sites and may affect the regulation of nearby genes. Our aims were to: 1) identify and generate a database of SNPs potentially subject to epigenetic control by DNA methylation via their involvement in creating, removing or displacing CpG sites (meSNPs), and; 2) investigate the association of these meSNPs with CpG islands (CGIs), and with methylation profiles of DNA extracted from tissues from cattle with divergent feed efficiencies detected using MIRA-Seq. Using the variant annotation for 56,969,697 SNPs identified in Run5 of the 1000 Bull Genomes Project and the UMD3.1.1 bovine reference genome sequence assembly, we identified and classified 12,836,763 meSNPs according to the nature of variation created at CpGs. The majority of the meSNPs were located in intergenic regions (68%) or introns (26.3%). We found an enrichment (p<0.01) of meSNPs located in CGIs relative to the genome as a whole, and also in differentially methylated sequences in tissues from animals divergent for feed efficiency. Seven meSNPs, located in differentially methylated regions, were fixed for methylation site creating (MSC) or destroying (MSD) alleles in the differentially methylated genomic sequences of animals differing in feed efficiency. These meSNPs may be mechanistically responsible for creating or deleting methylation targets responsible for the differential expression of genes underlying differences in feed efficiency. Our methyl SNP database (dbmeSNP) is useful for identifying potentially functional "epigenetic polymorphisms" underlying variation in bovine phenotypes

Elucidating the genetic basis of an oligogenic birth defect using whole genome sequence data in a non-model organism, Bubalus bubalis

Recent strong selection for dairy traits in water buffalo has been associated with higher levels of inbreeding, leading to an increase in the prevalence of genetic diseases such as transverse hemimelia (TH), a congenital developmental abnormality characterized by absence of a variable distal portion of the hindlimbs. Limited genomic resources available for water buffalo required an original approach to identify genetic variants associated with the disease. The genomes of 4 bilateral and 7 unilateral affected cases and 14 controls were sequenced. A concordance analysis of SNPs and INDELs requiring homozygosity unique to all unilateral and bilateral cases revealed two genes, WNT7A and SMARCA4, known to play a role in embryonic hindlimb development. Additionally, SNP alleles in NOTCH1 and RARB were homozygous exclusively in the bilateral cases, suggesting an oligogenic mode of inheritance. Homozygosity mapping by whole genome de novo assembly also supported oligogenic inheritance; implicating 13 genes involved in hindlimb development in bilateral cases and 11 in unilateral cases. A genome-wide association study (GWAS) predicted additional modifier genes. Although our data show a complex inheritance of TH, we predict that homozygous variants in WNT7A and SMARCA4 are necessary for expression of TH and selection against these variants should eradicate TH

What’s in your next-generation sequence data? An exploration of unmapped DNA and RNA sequence reads from the bovine reference individual

BACKGROUND: Next-generation sequencing projects commonly commence by aligning reads to a reference genome assembly. While improvements in alignment algorithms and computational hardware have greatly enhanced the efficiency and accuracy of alignments, a significant percentage of reads often remain unmapped. RESULTS: We generated de novo assemblies of unmapped reads from the DNA and RNA sequencing of the Bos taurus reference individual and identified the closest matching sequence to each contig by alignment to the NCBI non-redundant nucleotide database using BLAST. As expected, many of these contigs represent vertebrate sequence that is absent, incomplete, or misassembled in the UMD3.1 reference assembly. However, numerous additional contigs represent invertebrate species. Most prominent were several species of Spirurid nematodes and a blood-borne parasite, Babesia bigemina. These species are either not present in the US or are not known to infect taurine cattle and the reference animal appears to have been host to unsequenced sister species. CONCLUSIONS: We demonstrate the importance of exploring unmapped reads to ascertain sequences that are either absent or misassembled in the reference assembly and for detecting sequences indicative of parasitic or commensal organisms. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12864-015-2313-7) contains supplementary material, which is available to authorized users