orientation-specific directionality English orientation-specific orientation-specific directionality 5' arm 3' arm orientation-specific directionality orientation-specific English orientation-specific orientation-specific English orientation-specific English 3' arm 5' arm English directionality English 3' arm orientation-specific orientation-specific orientation-specific orientation-specific directionality 5' arm orientation-specific 3' arm directionality English orientation-specific directionality orientation-specific English 3' arm English directionality orientation-specific English English orientation-specific orientation-specific directionality orientation-specific orientation-specific orientation-specific 5′ ends 3' arm English directionality orientation-specific English orientation-specific directionality English 5' arm 3¡ä end and 5¡ä end orientation-specific orientation-specific 3' arm