Disclosed are a diacylglycerole acyltranferase, and a polynucleotide which codes for same. Provided are: a polynucleotide containing a base sequence represented by SEQ ID NO: 1 or 4; a polynucleotide which codes for a protein comprising an amino acid sequence represented by SEQ ID NO: 2; an expression vector and transformant containing said polynucleotide; a method for producing an aliphatic acid or a lipid using said transformant; and food containing the aliphatic acid or lipid which were produced by means of said method.