Using BioMart to Export Data from Ensembl
Exercise 1 — Finding Genes by Protein Domain
Download the sequences of all mouse proteins with Signalp cleavage sites located on chromosome 9.
Exercise 2 – Export homologues
Export the human orthologues of these Ciona savignyi Ensembl genes:
Exercise 3 – Convert IDs
BioMart is a very handy tool when you want to convert IDs from different databases. Below is a list of 29 IDs of human proteins from the NCBI RefSeq database:
(a) Generate a list that shows to which Ensembl Gene IDs and to which HGNC symbols these RefSeq protein IDs correspond. Do these 29 proteins correspond to 29 genes?
NP_001218, NP_203125, NP_203124, NP_203126, NP_001007233, NP_150636, NP_150635, NP_001214, NP_150637, NP_150634, NP_150649, NP_001216, NP_116787, NP_001217, NP_127463, NP_001220, NP_004338, NP_004337, NP_116786, NP_036246, NP_116756, NP_116759, NP_001221, NP_203519, NP_001073594, NP_001219, NP_001073593, NP_203520, NP_203522
Exercise 4 – Export structural variants
You can use BioMart to query variants, not just genes. (Make sure you use the right Datasets.)
(a) Export the study accession, source name, chromosome, sequence region start and end (in bp) of human structural variations (SV) on chromosome 1, starting at 130,408 and ending at 210,597.
(b) In a new BioMart query, find the alleles, phenotype descriptions, and associated genes for the human SNPs rs566014072 and rs754099015. Can you view this same information in the Ensembl browser?
Exercise 5 – Find genes associated with array probes
Forrest et al. performed a microarray analysis of peripheral blood mononuclear cell gene expression in benzene-exposed workers (Environ Health Perspect. 2005 June; 113(6): 801–807). The microarray used was the human Affymetrix U133A/B (also called U133 plus 2) GeneChip. The top 25 up-regulated probe-sets are below.
(a) Retrieve for the genes corresponding to these probe-sets the Ensembl Gene and Transcript IDs as well as their HGNC symbols and descriptions.
(b) In order to analyse these genes for possible promoter/enhancer elements, retrieve the 2000 bp upstream of the transcripts of these genes.
(c) In order to be able to study these human genes in mouse, identify their mouse orthologues. Also retrieve the genomic coordinates of these orthologues
207630_s_at, 221840_at, 219228_at, 204924_at, 227613_at, 223454_at, 228962_at, 214696_at, 210732_s_at, 212370_at, 225390_s_at, 227645_at, 226652_at, 221641_s_at, 202055_at, 226743_at, 228393_s_at, 225120_at, 218515_at, 202224_at, 200614_at, 212014_x_at, 223461_at, 209835_x_at, 213315_x_at