EX-99.23(g)(21)

                                  AMENDMENT TO
                              AMENDED AND RESTATED
                             MUTUAL FUND CUSTODY AND
                               SERVICES AGREEMENT


         This Amendment dated the 6th day of February, 2008, to the Amended and
Restated Mutual Fund Custody and Service Agreement effective as of May 1, 2001
(the "Agreement") by and between JNL Series Trust and JNL Investors Series Trust
(each individually the "Trust") and Mellon Trust of New England, N.A. (formerly
Boston Safe Deposit and Trust Company) (the "Custodian").

         WHEREAS, the Trust and the Custodian have entered into the Agreement;

         WHEREAS, in order to reflect a change in Officers to add Danielle A.
Hernandez as Anti-Money Laundering Officer for JNL Investors Series Trust.

         NOW, THEREFORE, the parties hereto agree to amend the Agreement as
follows:

1.       To delete Appendix B of the Agreement and substitute it with Appendix B
         attached hereto.

3.       Except as specifically amended hereby, the Agreement shall remain in
         full force and effect in accordance with its terms.

4.       The Trust and the Custodian hereby each represent and warrant to the
         other that it has full authority to enter into this Amendment upon the
         terms and conditions hereof and that the individual executing this
         Amendment on its behalf has the requisite authority to bind the Trust
         or Custodian to this Amendment.

         IN WITNESS WHEREOF, the parties hereto have executed this Amendment as
of the date set forth above.


JNL SERIES TRUST                              MELLON TRUST OF NEW ENGLAND, N.A.
JNL INVESTORS SERIES TRUST

By:      /s/ Mark D. Nerud                    By:     /s/ Candice Walker
Name:    Mark D. Nerud                        Name:   Candice Walker
Title:   President                            Title:  Vice President

                                   APPENDIX B
                                 TRUST OFFICERS


     I,  Susan S.  Rhee,  the  Secretary  of the JNL  Series  Trust  and the JNL
Investors  Series  Trust,  a  business  trust  organized  under  the laws of the
Commonwealth  of  Massachusetts  (each  individually,  the  "Trust"),  do hereby
certify that:

     The following  individuals serve in the following  positions with the Trust
and each individual has been duly elected or appointed to each such position and
qualified therefore in conformity with the Trust's governing  instrument and the
specimen signatures set forth opposite their respective names are their true and
correct signatures:



                         
NAME                                POSITION                             SIGNATURE


Mark D. Nerud                       President, and                       /s/ Mark D. Nerud
                                    and Chief Executive Officer

Daniel W. Koors                     Vice President, Treasurer,           /s Daniel W. Koors
                                    and Chief Financial Officer

Michael Piszczek                    Vice President                       /s/ Michael Piszczek

William V. Simon                    Vice President, and                  /s/ William V. Simon
                                    and Assistant Treasurer

Susan S. Rhee                       Vice President, Secretary            /s/ Susan S. Rhee
                                    and Counsel

Kelly L. Crosser                    Assistant Secretary                  /s/ Kelly L. Crosser

Steven J. Fredricks                 Chief Compliance Officer             /s/ Steven J. Fredricks

Danielle A. Hernandez               Anti-Money Laundering Officer        /s/ Danielle A. Hernandez
                                    (JNL INVESTORS SERIES TRUST ONLY)

                                                                         JNL SERIES TRUST
                                                                         JNL INVESTORS SERIES TRUST

                                                                          By:    /s/ Susan S. Rhee
                                                                          Name:  Susan S. Rhee, Secretary
                                                                          Dated:  February 6, 2008