Step #1
Paste the sequence into nucleotide blast and select the mouse database. The BLAST results returns the gene Pax6.
Step #2
Click the accession link to the Pax6 gene from your BLAST results.
On the accession page, scroll down to find the entire Pax6 protein sequence. This is listed under "CDS" or CoDing Sequence.
Highlight and copy just the amino acid sequence (the part after /translation=).
Go back to the NCBI BLAST page and start a new search. Use protein blast on the amino acid sequence, and set the database as shown above.
When the search finishes, you find the human Pax6 homolog accession number is NP_001595.
Note that there are dozens of matches. The first one is the most correct answer, with 99% identity to the mouse. If you read through the other matches,
they are similar to predicted (but not confirmed) proteins or other proteins in the Pax family.
Step #3
Go back to your protein blast search. This time remove homo sapiens from the organism (leave it blank). Repeat the search. Now you can find homologs
of Pax6 in many organisms. Some example are rat (Rattus), chicken (Gallus), and frog (Xenopus).
Alternatively, step #3 can be combined into step #2 by just searching all species in step #2. Notice that homo sapiens is still visible in the results
from step #3.
Step #4
There are several ways to perform this step. Here are two examples:
Option #1: Go to the mouse genome browser and type "Pax6". Get the mRNA sequence and nucleotide blast it against the human database.
Option #2: Read through the NP_001595 accession page. Follow the reference links to get the mRNA transcript for the gene. Nucleotide blast
this transcript against the mouse genome.
The approximate identity between the mouse and human genomic sequence of the genes (excluding introns) is approximately 98%.