SUPPLEMENT TO THE CURRENTLY EFFECTIVE PROSPECTUS:

                                -----------------

                                 CLASSES A AND C

                                  DWS GNMA Fund

Effective June 1, 2009, the following sections of the fund's prospectus are
replaced or modified as follows:

The Fee Table in the "How Much Investors Pay" section and the outline of
"Classes and Features" in the "Choosing a Share Class" section are changed to
reflect that the maximum sales charge (load) imposed on purchases of Class A
shares (as a % of offering price) is lowered to 2.75%.

The second footnote to the Fee Table in the "How Much Investors Pay" section is
replaced as follows:

(2)  The redemption of shares purchased at net asset value under the Large Order
     NAV Purchase Privilege (see "Choosing a Share Class -- Class A shares") may
     be subject to a contingent deferred sales charge of 0.50% if redeemed
     within 12 months of purchase.

The following replaces similar disclosure for Class A shares in the Expense
Example under "How Much Investors Pay" to reflect that the maximum sales charge
for Class A shares has been lowered:

--------------------------------------------------------------------------------
Example                   1 Year        3 Years        5 Years       10 Years
--------------------------------------------------------------------------------
Expenses, assuming you sold your shares at the end of each period and assuming
you kept your shares
--------------------------------------------------------------------------------
Class A shares              $355          $527           $712        $1,249
--------------------------------------------------------------------------------

The following replaces the sales charge table under "Choosing a Share Class --
Class A shares":

                          Front-end sales charge       Front-end sales charge
                            as a % of offering           as a % of your net
  Your investment              price(1),(2)                 investment(2)
--------------------------------------------------------------------------------
  Up to $100,000                 2.75%                        2.83%
--------------------------------------------------------------------------------
  $100,000 - $249,999            2.50                         2.56

--------------------------------------------------------------------------------
  $250,000 or more              see below                    see below

(1)  The offering price includes the sales charge.

(2)  Because of rounding in the calculation of the offering price, the actual
     front-end sales charge paid by an investor may be higher or lower than the
     percentages noted.

May 19, 2009                                              [DWS INVESTMENTS LOGO]
GNMA-3600                                                    Deutsche Bank Group


<PAGE>

The following replaces the Large Order NAV Purchase Privilege disclosure under
"Choosing a Share Class -- Class A shares":

If you're investing $250,000 or more, either as a lump sum or through one of the
sales charge reduction features described above, you may be eligible to buy
Class A shares without a sales charge ("Large Order NAV Purchase Privilege").
However, you may be charged a contingent deferred sales charge (CDSC) of 0.50%
on any shares you sell within 12 months of owning them. This CDSC is waived
under certain circumstances (see "Policies You Should Know About"). Your
financial advisor or Shareholder Services can answer your questions and help you
determine if you're eligible.

The following replaces similar disclosure under "Choosing a Share Class -- Class
C shares":

Orders to purchase Class C shares of $250,000 or more will be declined with the
exception of orders received from financial representatives acting for clients
whose shares are held in an omnibus account and certain employer-sponsored
employee benefit plans.

The following replaces similar disclosure for Class A shares in the
"Hypothetical Expense Summary" under the Appendix: DWS GNMA Fund -- Class A

         Maximum           Initial Hypothetical           Assumed Rate
      Sales Charge:             Investment:                of Return:
          2.75%                   $10,000                      5%
--------------------------------------------------------------------------------
                                                   Hypothetical
            Cumulative    Annual      Cumulative     Year-End
          Return Before    Fund      Return After  Balance After   Annual Fees
            Fees and      Expense      Fees and     Fees and           and
Year        Expenses       Ratios      Expenses     Expenses         Expenses
--------------------------------------------------------------------------------
   1         5.00%         0.81%        1.32%      $10,132.48      $  355.42
--------------------------------------------------------------------------------
   2        10.25%         0.81%        5.57%      $10,557.03      $   83.79
--------------------------------------------------------------------------------
   3        15.76%         0.81%        9.99%      $10,999.37      $   87.30
--------------------------------------------------------------------------------
   4        21.55%         0.81%       14.60%      $11,460.24      $   90.96
--------------------------------------------------------------------------------
   5        27.63%         0.81%       19.40%      $11,940.43      $   94.77
--------------------------------------------------------------------------------
   6        34.01%         0.81%       24.41%      $12,440.73      $   98.74
--------------------------------------------------------------------------------
   7        40.71%         0.81%       29.62%      $12,962.00      $  102.88
--------------------------------------------------------------------------------
   8        47.75%         0.81%       35.05%      $13,505.10      $  107.19
--------------------------------------------------------------------------------
   9        55.13%         0.81%       40.71%      $14,070.97      $  111.68
--------------------------------------------------------------------------------
  10        62.89%         0.81%       46.61%      $14,660.54      $  116.36
--------------------------------------------------------------------------------
Total                                                              $1,249.09


               Please Retain This Supplement for Future Reference.



May 19, 2009
GNMA-3600

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