Xiaobaitu Help: Company acquired, file i-485 EB based

My company was acquired. The company address is not changed, but as a subsidy of another company, my company will change name completely.

I will file my EB based I-485. My questions:
1) Is it required to explain that my company is acquired in the employment letter?
2) Is it required to explain that I am still and will do the same work as labor certificate says?
3) What else important message should be included in the employment verification letter
4) Does the acquistion require to file an amendment of I-140 with successor-in-interest before I can file I-485?

Thanks,
Audrey