Prior to DNA sequencing, enzymatic removal of primers and excess
dNTPs from PCR products was done by adding 3.2_L of 1 unit_L−1
shrimp alkaline phosphatase and 1.6_L of 10 units_L−1 exonuclease
(USB Corporation, Cleveland, OH, USA) to 8_L of PCR product
and incubating at 37 ◦C for 30 min followed by 80 ◦C for 15 min