depends on your lender and financing criteria. you should talk to your loan officer to find out your options.
is this a loan or a gift? this is a critical distinction, a loan requires some repayment, so in the lenders eyes you've taken on a new debt that will need to be calculated into your debt to income ratio. a gift is something else, lenders have rules about gift documentation.
let your 'gifter' know ahead of time that the lender is going to want to see their bank statements to source the funds. a lot of people are surprised by this requirement and feel that it's intrusive - keep in mind you are asking a bank to loan you a LOT of money, they need to assess the risk and knowing the source of funds is not only important to them, but they are required to ask a for a lot of paperwork because of federal and state banking regulations.