By Donald Zuhn —

Last month, stART Licensing, Inc. announced that it had been granted U.S. Patent Nos. 7,304,204 and 7,307,198.  stART Licensing, Inc., an Austin, Texas-based joint venture between Geron Corp. and Exeter Life Sciences, Inc., manages and licenses a portfolio of patent rights related to animal reproductive technologies (including patents encompassing technology originally developed by the Roslin Institute for the cloning of Dolly the sheep (at right)).

The ‘204 and ‘198 patents, which are assigned to the Roslin Institute, relate to methods of cloning ungulate animals (hoofed mammals), fetuses, and embryos using differentiated cells.  The patents — the eighth and ninth U.S. patents to be awarded to the Roslin Institute — are part of a portfolio of patents and applications that the Roslin Institute has exclusively licensed to stART for non-human animal cloning applications.

According to stART’s statement, the Roslin Institute also expects to secure two additional patents from related U.S. Application Nos. 09/650,194 and 09/989,126, for which the U.S. Patent and Trademark Office recently issued notices of allowance.  stART noted that the allowance of the ‘194 and ‘126 applications was the result of successful interference proceedings between those applications and U.S. Patent Nos. 5,945,577 and 6,235,970, which are assigned to the University of Massachusetts and exclusively licensed to Advanced Cell Technology.  stART Chairman Jonathan Thatcher stated that "[t]he technology covered by the Roslin patents and patent applications has been widely adopted," and "has been used to clone a broad range of species including cattle, sheep, pigs, goats, horses, mice, rats, rabbits, cats and dogs."

The ‘204 and ‘198 patents issued from U.S. Application Nos. 09/989,125 and 09/989,128, respectively, both of which claim the benefit of U.S. Application Nos. 09/650,285 and 08/803,165 (the latter of which issued as U.S. Patent No. 6,252,133), International Application No. PCT/GB96/02098, and British application GB 9517779.6.  Representative independent claims 1 and 12 of the ‘204 patent recite:

1.  A method of cloning an ungulate by nuclear transfer comprising:
    (i) inserting a nucleus of an ungulate differentiated somatic cell, which has passed start in the mitotic cell cycle and is in the G1 phase of the cell cycle, into an unactivated, metaphase II-arrested, ungulate enucleated oocyte of the same species to reconstruct an embryo;
    (ii) maintaining the reconstructed embryo without activation for a sufficient time to allow the reconstructed embryo to become capable of developing to term;
    (iii) activating the resultant reconstructed embryo;
    (iv) culturing said activated, reconstructed embryo; and
    (v) transferring said cultured, reconstructed embryo to a host ungulate of the same species such that the reconstructed embryo develops to term.

12.  A method of cloning an ungulate fetus by nuclear transfer comprising:
    (i) inserting a nucleus of an ungulate differentiated somatic cell, which has passed start in the mitotic cell cycle and is in the G1 phase of the cell cycle, into an unactivated, metaphase II-arrested, ungulate enucleated oocyte of the same species to reconstruct an embryo;
    (ii) maintaining the reconstructed embryo without activation for a sufficient time to allow the reconstructed embryo to become capable of developing to term;
    (iii) activating the resultant reconstructed embryo;
    (iv) culturing said activated, reconstructed embryo; and
    (v) transferring said cultured, reconstructed embryo to a host ungulate of the same species such that the reconstructed embryo develops into a fetus.

Representative independent claims 1, 14, and 17 of the ‘198 patent recite:

1.  A method of cloning a pig, comprising:
    (i) inserting a nucleus of a differentiated pig cell, which is in the G1 phase of the cell cycle, into an unactivated, enucleated, metaphase II-arrested, pig oocyte, to reconstruct an embryo;
    (ii) maintaining the reconstructed embryo without activation for a sufficient time to allow the reconstructed embryo to become capable of developing to term;
    (iii) activating the resultant reconstructed embryo; and
    (iv) transferring said reconstructed embryo to a host pig such that the reconstructed embryo develops into a fetus,
    wherein the fetus is capable of developing to term.

14.  A method of cloning a pig, comprising:
    (i) inserting a nucleus of a cultured, differentiated pig embryonic disc cell, which is in the G1 phase of the cell cycle, into an unactivated, enucleated, metaphase II-arrested, pig oocyte, to reconstruct an embryo;
    (ii) maintaining the reconstructed embryo without activation for a sufficient time to allow the reconstructed embryo to become capable of developing to term;
    (iii) activating the resultant reconstructed embryo; and
(iv) transferring said reconstructed embryo to a host pig such that the reconstructed embryo develops into a fetus,
    wherein the fetus is capable of developing to term.

17.  A method of producing an ungulate embryo by nuclear transfer comprising:
    (i) transfer of a nucleus of an ungulate cell, which has passed start in the mitotic cell cycle and is in the G1 phase of the cell cycle, into an unactivated, enucleated, metaphase II-arrested ungulate oocyte of the same species;
    (ii) activation of the recipient oocyte containing the donor cell nucleus; and
    (iii) incubation of the activated oocyte to provide an embryo;
    wherein the donor cell nucleus is from an ungulate differentiated cell.