NCBI Rattus norvegicus Annotation Release 106

The RefSeq genome records for Rattus norvegicus were annotated by the NCBI Eukaryotic Genome Annotation Pipeline, an automated pipeline that annotates genes, transcripts and proteins on draft and finished genome assemblies. This report presents statistics on the annotation products, the input data used in the pipeline and intermediate alignment results.

The annotation products are available in the sequence databases and on the FTP site.

This report provides:

• Annotation Release information: The name of the release, important dates, the software version
• Assemblies: A brief description of the annotated assembly(ies)
• Gene and feature statistics: The counts and characteristics of the annotated features
• Alignment of the annotated proteins to a set of high-quality proteins: The number of annotated proteins with hits to a set of high-quality proteins
• Masking of genomic sequence: How much of the genome was masked
• Transcript and protein alignments: The number and type of evidence retrieved from public databases and used for gene prediction
• Similarity of alternate and reference assemblies: The similarity of the alternate assemblies to the reference
• Comparison of the current and previous annotations: What proportion of the genes changed in this annotation

For more information on the annotation process, please visit the NCBI Eukaryotic Genome Annotation Pipeline page.

Annotation Release information

This annotation should be referred to as NCBI Rattus norvegicus Annotation Release 106

Annotation release ID: 106
Date of Entrez queries for transcripts and proteins: Jul 7 2016
Date of submission of annotation to the public databases: Jul 27 2016
Software version: 7.1

Assemblies

The following assemblies were included in this annotation run:

Assembly name	Assembly accession	Submitter	Assembly date	Reference/Alternate	Assembly content
Rnor_6.0	GCF_000001895.5	Rat Genome Sequencing Consortium	07-01-2014	Reference	23 assembled chromosomes; unplaced scaffolds
Rn_Celera	GCF_000002265.2	Celera Genomics	12-06-2006	Alternate	21 assembled chromosomes; unplaced scaffolds

Gene and feature statistics

Counts and length of annotated features are provided below for each assembly.

Feature counts

Feature	Rnor_6.0	Rn_Celera
Genes and pseudogenes	39,430	36,625
protein-coding	23,347	21,823
non-coding	8,348	7,747
pseudogenes	7,735	7,055
genes with variants	13,116	4,174
mRNAs	56,098	28,000
fully-supported	54,958	27,224
with > 5% ab initio	488	299
partial	1,383	1,893
with filled gap(s)	110	71
known RefSeq (NM_)	17,538	17,336
model RefSeq (XM_)	38,560	10,664
Other RNAs	13,813	12,146
fully-supported	13,095	11,444
with > 5% ab initio	0	0
partial	2	14
with filled gap(s)	2	3
known RefSeq (NR_)	631	616
model RefSeq (XR_)	12,483	10,847
CDSs	56,580	28,378
fully-supported	54,958	27,224
with > 5% ab initio	589	358
partial	1,028	1,430
with major correction(s)	2,101	1,749
known RefSeq (NP_)	17,537	17,331
model RefSeq (XP_)	38,560	10,664

Detailed reports

Alignment of the annotated proteins to a set of high-quality proteins

The final set of annotated proteins was searched with BLASTP against the UniProtKB/Swiss-Prot curated proteins, using the annotated proteins as the query and the high-quality proteins as the target. Out of 22863 coding genes in the Rnor_6.0 primary assembly, 22142 genes had a protein with an alignment covering 50% or more of the query and 19510 had an alignment covering 95% or more of the query. Out of 21438 coding genes in the Rn_Celera assembly, 20762 genes had a protein with an alignment covering 50% or more of the query and 18422 had an alignment covering 95% or more of the query.

Definition of query and target coverage. The query coverage is the percentage of the annotated protein length that is included in the alignment. The target coverage is the percentage of the target length that is included in the alignment.

Below is a cumulative graph displaying the number of genes with alignments above a given query or target coverage threshold. For comparison, corresponding statistics for other organisms annotated by the NCBI eukaryotic annotation pipeline were added to the graph.

Query: annotated proteins
Target: UniProtKB/Swiss-Prot curated proteins

Masking of genomic sequence

Transcript and protein alignments are performed on the repeat-masked genome. Below are the percentages of genomic sequence masked by WindowMasker and RepeatMasker for each assembly. RepeatMasker results are only used for organisms for which a comprehensive repeat library is available.

For this annotation run, transcripts and proteins were aligned to the genome masked with WindowMasker only.

Assembly name	Assembly accession	% Masked with RepeatMasker	% Masked with WindowMasker
Rnor_6.0	GCF_000001895.5	41.98%	32.49%
Rn_Celera	GCF_000002265.2	41.52%	31.32%

Transcript and protein alignments

The annotation pipeline relies heavily on alignments of experimental evidence for gene prediction. Below are the sets of transcripts and proteins that were retrieved from Entrez, aligned to the genome by Splign or ProSplign and passed to Gnomon, NCBI's gene prediction software.

Depending on the other evidence available, long 454 reads (with average length above 250 nt) may be aligned as traditional evidence and reported in the Transcript alignments section or aligned with RNA-Seq reads and reported in the RNA-Seq alignments section.

Transcript alignments

RefSeq transcript alignment quality report

The known RefSeq transcripts (NM_ and NR_ accessions) are a set of hiqh-quality transcripts maintained by the RefSeq group at NCBI. Alignment statistics for this group of transcripts, such as percent and number of sequences not aligning at all, percent best alignments split between multiple scaffolds, and percent alignments not covering the full CDS are indicative of the genome quality and are provided below.

	Rnor_6.0 Primary Assembly	Rn_Celera Primary Assembly
Number of sequences retrieved from Entrez	18,365	18,365
Number (%) of sequences not aligning	38 (0.21%)	32 (0.17%)
Number (%) of sequences with multiple best alignments (split genes)	27 (0.15%)	102 (0.56%)
Number (%) of sequences with CDS coverage < 95%	414 (2.35%)	706 (4.05%)

RNA-Seq alignments

The following RNA-Seq reads from the Sequence Read Archive were also used for gene prediction:

  Hide alignments statistics, by sample (SAME, SAMN, SAMD, DRS)  Show alignments statistics, by run (ERR, SRR, DRR)

Protein alignments

Assembly-assembly alignments of alternate to reference assembly

When multiple assemblies of good quality are available for the organism, the annotation of all is done in coordination. The alternate assemblies are aligned to the reference assembly and the best reciprocal best hits are used to identify corresponding regions, that can then be annotated together.

Below are the percent coverage of one assembly by the other and the average percent identity of the alignments. The 'First pass' alignments are reciprocal best hits, while the 'Total' alignments also include 'Second pass' or non-reciprocal best alignments. For more information about the assembly-assembly alignment process, please visit the NCBI Genome Remapping Service page.

First Pass	Total
Rn_Celera (Alternate) Coverage: 95.12%	Rn_Celera (Alternate) Coverage: 95.44%
Rnor_6.0 (Reference) Coverage: 86.80%	Rnor_6.0 (Reference) Coverage: 90.81%
Percent Identity: 99.71%	Percent Identity: 99.66%

Comparison of the current and previous annotations

The annotation produced for this release (106) was compared to the annotation in the previous release (105) for each assembly annotated in both releases. Scores for current and previous gene and transcript features were calculated based on overlap in exon sequence and matches in exon boundaries. Pairs of current and previous features were categorized based on these scores, whether they are reciprocal best matches, and changes in attributes (gene biotype, completeness, etc.). If the assembly was updated between the two releases, alignments between the current and the previous assembly were used to match the current and previous gene and transcript features in mapped regions.

The table below summarizes the changes in the gene set for each assembly as a percent of the number of genes in the current annotation release, and provides links to the details of the comparison in tabular format and in a Genome Workbench project.

	Rnor_6.0 (Current) to Rnor_6.0 (Previous)	Rn_Celera (Current) to Rn_Celera (Previous)
Identical	32%	55%
Minor changes	41%	20%
Major changes	14%	11%
New	12%	12%
Deprecated	8%	7%
Other	1%	3%
Download the report	tabular, Genome Workbench	tabular, Genome Workbench

References

• RefSeq: Pruitt KD, Brown GR, Hiatt SM, Thibaud-Nissen F, Astashyn A, Ermolaeva O, Farrell CM, Hart J, Landrum MJ, McGarvey KM, Murphy MR, O'Leary NA, Pujar S, Rajput B, Rangwala SH, Riddick LD, Shkeda A, Sun H, Tamez P, Tully RE, Wallin C, Webb D, Weber J, Wu W, Dicuccio M, Kitts P, Maglott DR, Murphy TD, Ostell JM. Nucleic Acids Research 2014, 42(Database issue):D756-63
• RepeatMasker: Smit AFA, Hubley R, Green P. RepeatMasker Open-3.0. 1996–2004. http://www.repeatmasker.org
• WindowMasker: Morgulis A, Gertz EM, Schäffer AA, Agarwala R. Bioinformatics 2006, 2:134-41
• Splign: Kapustin Y, Souvorov A, Tatusova T, Lipman D. Biology Direct 2008, 3:20