Apex domains cannot have CNAME records.
Question and response
Question
dig IGAMMA.RU. NS
Answer
IGAMMA.RU. 4 NS dns1.yandex.net.
IGAMMA.RU. 4 NS dns2.yandex.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0