passages.id: split_6_test_1719_passage
passages.type: progene_text
passages.text: The genome is 7564 nt in size , excluding the 3' - terminal poly(A) tail , is characterized by an extremely high cytosine content ( ca. 50 % ) , and contains four putative open reading frames and untranslated regions of 291 and 35 nt at the 5 ' and 3' ends , respectively .