Said additional constant region segment comprises a switch region and human constant region coding segment, wherein {HEAD ~ the constant region coding segment} is operably linked to {TAIL ~ a switch region} that it is not normally associated with, i.e., a non cognate switch region 
is operably linked to
Said additional constant region segment comprises a switch region and human constant region coding segment , wherein { HEAD ~ the constant region coding segment } is operably linked to { TAIL ~ a switch region } that it is not normally associated with , i.e. , a non cognate switch region
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH