Every so often present review of genetic material before writing article at the start of November (3,3,4)
I believe the answer is:
now and then
'every so often' is the definition.
(thesaurus)
'present review of genetic material before writing article at the start of november' is the wordplay.
'present' becomes 'now' (both can mean the current period).
'review of genetic material' becomes 'and' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'before writing' says to put letters next to each other.
'article' becomes 'the' (the definite article in English).
'at the start of' says to take the initial letters (I've seen 'at the start' mean this).
The initial letter of 'november' is 'n'.
'now'+'and'+'the'+'n'='NOW AND THEN'
Can you help me to learn more?
(Other definitions for now and then that I've seen before include "Sometimes" , "At times" , "Occasionally" , "making a historical contrast" .)