NCBI Oreochromis niloticus Annotation Release 104

The RefSeq genome records for Oreochromis niloticus 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 current and previous assembly: The similarity of the current and previous assembly
• 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 Oreochromis niloticus Annotation Release 104

Annotation release ID: 104
Date of Entrez queries for transcripts and proteins: Jul 20 2018
Date of submission of annotation to the public databases: Jul 26 2018
Software version: 8.1

Assemblies

The following assemblies were included in this annotation run:

Assembly name	Assembly accession	Submitter	Assembly date	Reference/Alternate	Assembly content
O_niloticus_UMD_NMBU	GCF_001858045.2	University of Maryland	06-29-2018	Reference	23 assembled chromosomes; unplaced scaffolds

Gene and feature statistics

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

Feature counts

Feature	O_niloticus_UMD_NMBU
Genes and pseudogenes	42,622
protein-coding	29,550
non-coding	12,030
transcribed pseudogenes	4
non-transcribed pseudogenes	685
genes with variants	14,756
immunoglobulin/T-cell receptor gene segments	353
other	0
mRNAs	61,666
fully-supported	59,685
with > 5% ab initio	931
partial	398
with filled gap(s)	77
known RefSeq (NM_)	183
model RefSeq (XM_)	61,483
non-coding RNAs	17,707
fully-supported	14,403
with > 5% ab initio	0
partial	9
with filled gap(s)	2
known RefSeq (NR_)	0
model RefSeq (XR_)	15,713
pseudo transcripts	5
fully-supported	4
with > 5% ab initio	0
partial	0
with filled gap(s)	0
known RefSeq (NR_)	0
model RefSeq (XR_)	5
CDSs	62,032
fully-supported	59,685
with > 5% ab initio	1,070
partial	403
with major correction(s)	765
known RefSeq (NP_)	183
model RefSeq (XP_)	61,496

Detailed reports

The counts below do not include pseudogenes.

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 29537 coding genes, 25215 genes had a protein with an alignment covering 50% or more of the query and 10948 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
O_niloticus_UMD_NMBU	GCF_001858045.2	5.40%	30.48%

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

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 current to previous assembly

When the assembly changes between two rounds of annotation, genes in the current and the previous annotation are mapped to each other using the genomic alignments of the current assembly to the previous assembly so that gene identifiers can be preserved. The success of the remapping depends largely on how well the two assembly versions align to each other.

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
O_niloticus_UMD_NMBU (Current) Coverage: 99.99%	O_niloticus_UMD_NMBU (Current) Coverage: 99.99%
MKQE01 (Previous) Coverage: 99.58%	MKQE01 (Previous) Coverage: 99.58%
Percent Identity: 100.00%	Percent Identity: 100.00%

Comparison of the current and previous annotations

The annotation produced for this release (104) was compared to the annotation in the previous release (103) 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.

	O_niloticus_UMD_NMBU (Current) to ASM185804v2 (Previous)
Identical	9%
Minor changes	66%
Major changes	9%
New	16%
Deprecated	6%
Other	<1%
Download the report	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