NCBI Drosophila simulans Annotation Release 103

The RefSeq genome records for Drosophila simulans 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
• BUSCO results: Annotation completeness assessed with BUSCO
• 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 Drosophila simulans Annotation Release 103

Annotation release ID: 103
Date of Entrez queries for transcripts and proteins: Oct 28 2021
Date of submission of annotation to the public databases: Nov 3 2021
Software version: 9.0

Assemblies

The following assemblies were included in this annotation run:

Assembly name	Assembly accession	Submitter	Assembly date	Reference/Alternate	Assembly content
Prin_Dsim_3.1	GCF_016746395.2	Princeton University	10-05-2021	Reference	6 assembled chromosomes; unplaced scaffolds

Gene and feature statistics

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

Feature counts

Feature	Prin_Dsim_3.1
Genes and pseudogenes	15,845
protein-coding	14,256
non-coding	1,432
Transcribed pseudogenes	3
Non-transcribed pseudogenes	154
genes with variants	4,441
Immunoglobulin/T-cell receptor gene segments	0
other	0
mRNAs	26,225
fully-supported	25,925
with > 5% ab initio	162
partial	31
with filled gap(s)	0
known RefSeq (NM_)	0
model RefSeq (XM_)	26,225
non-coding RNAs	2,562
fully-supported	1,914
with > 5% ab initio	0
partial	0
with filled gap(s)	0
known RefSeq (NR_)	0
model RefSeq (XR_)	2,273
pseudo transcripts	3
fully-supported	3
with > 5% ab initio	0
partial	0
with filled gap(s)	0
known RefSeq (NR_)	0
model RefSeq (XR_)	3
CDSs	26,225
fully-supported	25,925
with > 5% ab initio	174
partial	31
with major correction(s)	147
known RefSeq (NP_)	0
model RefSeq (XP_)	26,225

Detailed reports

The counts below do not include pseudogenes.

BUSCO analysis of gene annotation

BUSCO v4.1.4 (Simão et al 2015, PMID: 26059717) was run in "protein" mode on the annotated gene set picking one longest protein per gene, and run using the diptera_odb10 lineage dataset. Results are reported for the gene set from the primary assembly unit, and presented in BUSCO notation (C:complete [S:single-copy, D:duplicated], F:fragmented, M:missing, n:number of genes used).

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

The final set of annotated proteins was searched with BLASTP against the Drosophila melanogaster known RefSeq proteins, using the annotated proteins as the query and the high-quality proteins as the target. Out of 14256 coding genes, 13914 genes had a protein with an alignment covering 50% or more of the query and 13068 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: Drosophila melanogaster known RefSeq 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 (if calculated), for each assembly. RepeatMasker results are only calculated for organisms with complete Dfam HMM model collections.

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

Assembly name	Assembly accession	% Masked with RepeatMasker	% Masked with WindowMasker
Prin_Dsim_3.1	GCF_016746395.2		22.68%

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, minimap2, or ProSplign and passed to Gnomon, NCBI's gene prediction software.

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
Prin_Dsim_3.1 (Current) Coverage: 99.55%	Prin_Dsim_3.1 (Current) Coverage: 99.55%
Prin_Dsim_3.0 (Previous) Coverage: 99.54%	Prin_Dsim_3.0 (Previous) Coverage: 99.54%
Percent Identity: 99.99%	Percent Identity: 99.99%

Comparison of the current and previous annotations

The annotation produced for this release (103) was compared to the annotation in the previous release (102) 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.

	Prin_Dsim_3.1 (Current) to Prin_Dsim_3.0 (Previous)
Identical	14%
Minor changes	80%
Major changes	3%
New	3%
Deprecated	2%
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
• Minimap2: Li H. Bioinformatics 2018 Sep 15;34(18):3094-3100