DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Applicants’ amendments and arguments filed on June 22, 2026, have been received and entered. Claims 1, 2, 4, 13, 17 and 22 have been amended have been amended, while claims 3, 5-12, 14-16 and 18- 21 have been canceled. Claims 24-28 are newly added. In view of amendments to the base claim 1, the objection to claim is hereby withdrawn. Claims 1, 2, 4, 13, 17, 22-28 are pending in the instant application.
Election/Restrictions
Applicants’ election with traverse of claims 1-5 and 18 (group I) in the reply filed on November 9, 2025, was acknowledged. The traversal is on the ground(s) that shared feature that the infusion solution comprises 0.12-2 mM Mg2+ and 0.12-2 mM Ca2+ was inventive over the disclosure of prior art. This was not found persuasive because as stated in previous office action the invention of group I and II-VII lack unity of invention because even though the inventions of these groups require the technical feature of a chimeric embryo comprising aggregating a tetraploid embryo with embryonic stem cells to form a new reconstructed embryo or a chimeric embryo. This special technical feature does not contribute to prior art of record for the reasons discussed in the office action mailed on March 23, 2026. It was indicated that Applicant has amended the claims to incorporate the limitation of other non-elected independent claims, however, as stated in the previous office action these groups do not share the same or corresponding technical feature for the reasons discussed on page 4 of the restriction requirement mailed on September 11, 2025. Therefore, instant application was examined to the extent claims are drawn to the elected invention of a method for preparing a chimeric embryo or a nonhuman animal (group 1). As stated in previous office action, any claim drawn to method of preparing targeting vector, preparing cell line or preparing a nonhuman animal model using targeting vector and using primer would be withdrawn. A telephone call was made to applicant’s representative on two separate occasions on February 21, 2026, to clarify the election, however no response was returned. The requirement was deemed proper and is therefore made FINAL.
Priority
This application is a 371 of PCT/CN2020/101681 filed on 07/13/2020, which claims foreign priority from CN202010151592.2 filed on 03/16/2020 and CN202010375045.2 filed on 04/30/2020. Applicant’s submission of certified English translation copies of the priorities CN202010151592.2 and CN202010375045.2 is acknowledged.
Claims 1, 2, 4, 13, 17, 22-28 are under consideration.
Withdrawn-Claim Rejections - 35 USC § 112-scope of enablement
Claims 1-5, 7-8, 10, 12-13, 15-22 and 23 were rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, because the specification, because the specification fails to provide an enablement for the full scope of the claimed invention. In view of applicant’s amendments to the base claim limiting the scope to a mouse embryo or mouse, previous rejection of claims is hereby withdrawn. Applicants’ arguments with respect to the withdrawn rejections are thereby rendered moot.
Withdrawn-Claim Rejections - 35 USC § 101
Claims 5 and 16 were rejected under 35 U.S.C. 101 because the claimed invention is directed to a natural product without significantly more. Applicants’ cancellation of claims 5 and 16 renders their rejections moot.
Withdrawn-Claim Rejections - 35 USC § 112
Claims 2 and 4 were rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. In view of applicant’s amendments to claims 2 and 4, the previous rejection of claim is hereby withdrawn. Applicants’ arguments with respect to the withdrawn rejections are thereby rendered moot. Applicants’ cancellation of claim 7 renders their rejections moot.
Maintained & New-Claim Rejections - 35 USC § 112- necessitated by amendments
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 13, 22-27 and 28 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 13 is vague and indefinite to the extent it is unclear as to step of introducing a target human derived gene into the mouse ES cell occurs before step (iv) of claim 1 occurs after step (i), (ii) or (III). The claimed method steps relate to any of the preceding method step of (iv). Therefore, scope of method set forth in claim 13 could not be ascertained. Further, claim 13 recites the limitation "the mouse embryonic stem cells before step (iv)" in lines 2-3. There is insufficient antecedent basis for this limitation in the claim. Claims 22-27 are included in the rejection because claims 22-28 directly or indirectly depend on the rejected base claims. Appropriate correction is required.
Claim 22 is vague and indefinite to the extent claims recite step of introducing the targeting vector and a vector linked with an sgRNA into a mouse-derived embryonic stem cell. It is unclear as to how a mouse-derived embryonic stem cell set forth claim 22 relates to the mouse ES cells of claim 13. There is no nexus between introducing vector linked with an sgRNA into a mouse-derived embryonic stem cell and introducing a target human-derived gene into the mouse embryonic stem cell before step (iv) as set forth in claim 13. Is introducing the targeting vector and a sgRNA into a moue ES cell is same as the mouse ES cells before step (iv) of claim 13? Claims 23-27 and 28 are included in the rejection because they directly or indirectly depend on the rejected base claims 1, 13 or 22. Appropriate correction is required.
Withdrawn -Claim Rejections - 35 USC § 102
Claims 5 and 16 were rejected under 35 U.S.C. 102(a)(1) as being anticipated by Nagy et al (Proc. Natl. Acad. Sci, USA, 1993, 90, 8424-8428, IDS). Applicants’ cancellation of claims 5 and 16 renders their rejections moot.
Withdrawn-Claim Rejections - 35 USC § 103
Claims 1, 5, 15-17 and 18 were rejected under 35 U.S.C. 103 as being unpatentable over Ohta (US20090178150, dated 07/09/2009) and McLaughlin (Method of Enzymology, 1991, 55, vol 275, 919-930)/ Darbandi (Int J Reprod BioMed, 2017, Vol. 15. No. 10. 601-612) in view of Suo et al (Journal of Reproduction and Development, 2009, 55, No. 4, 383-385). Applicants’ cancellation of claims 3, 5, 15-16 and 18 renders their rejections moot. In view of applicants’ amendments to the claims introducing the limitation of 0.15-0.30 mM of Mg2+ and 0.15-0.30 mM of Ca2+, the previous rejection is rendered moot and hereby withdrawn. Applicants’ arguments with respect to the withdrawn rejections are thereby rendered moot. The claims are, however, subject to new rejections over the prior art of record.
New-Claim Rejections - 35 USC § 103- necessitated by amendments
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-2, 4 and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Ohta (US20090178150, dated 07/09/2009), McLaughlin (Method of Enzymology, 1991, 55, vol 275, 919-930), Suo et al (Journal of Reproduction and Development, 2009, 55, No. 4, 383-385) , Hackett (Nature Communications 2018, 1492, 1-13) as evidenced by Li et al (Cell, 2019, 179, 687-702, e1-e9).
Applicants’ cancellation of claims 3, 5, 15-16 and 18 renders their rejections moot.
With respect to claim 1, Ohta teaches a method of preparing a chimeric embryo, said method comprising:
obtaining an animal 2-cell embryo
placing a number of two-cell stage embryos that linearly-arranged and then both sides of the embryos are sandwiched with a parallel-double electrode in a medium for electrofusion to select and obtain tetraploid embryos
culturing the tetraploid embryo in culture for overnight (see para 24)
transferring the ES cells to the tetraploid embryos and cultured to produce chimeric embryos (see para. 27), wherein cells may be transferred as cell aggregation (see para. 44), wherein the ES cell and the animal is a mouse ES cells and mouse respectively to produce chimeric mouse embryo (See example 3-4).
Regarding claims 2, Ohta teaches implanting the chimeric embryos to a pseudo pregnant mouse to produce chimeric mouse (see claim 1 of ‘150, para. 35 example 3 and 4).
With respect to claim 17, it is noted that claim recites an intended use of mouse medical research. To the extent, the mouse disclosed in Ohta has same genotype it must necessarily be capable for the use model animals for pathological study and development of new therapy and research of new medicine (see para. 59). The cells derived from the ES mice produced by tetraploid embryo appear to be structurally and functionally similar to one claimed in the instant application. Ohta differs from claimed invention by not disclosing that the electrofusion solution comprises 0.15- 0.3 mM ofMg2+ and 0.15-0.3 mM ofCa2+. (limitation of claims 1 and 2).
However, before the effective filing date of instant application, McLaughlin teaches in order to create an ac field in aqueous solution, a nonelectrolyte is required as a salt to obtain a normal medium osmolarity. The most commonly used nonelectrolyte is mannitol. Small amounts of calcium and magnesium help in membrane healing. BSA acts as a lubricant to minimize adhesion of the embryos to the walls of the chamber and the pipette and to facilitate rotation of the embryos. The contents of the fusion medium are as follows: 0.3 M mannitol, 0. I mM MgSO4, 50uM CaC12, and 3% BSA (see page 926, last para.). The combination of reference differs from claimed invention by not disclosing electrofusion solution comprises 0.15- 0.3 mM ofMg2+ and 0.15-0.3 mM ofCa2+.
However, before the effective filing date of instant application, it was routine in prior art to equilibrate the fusion in solution at varying condition and voltage to get optimal electrofusion. Suo teaches identifying different concentration of Ca2+ ranging from 0.1mM to 1.4mM that included 0.2mM of Ca2+, 0.1mM of Mg2+ and 300mM of mannitol at varying electric field ranging from 0.6 to 1.4KV/cm to determine the optimal concentration of Ca2+ and electric field for the fusion solution (see page fig. 1, 2 and 3, page 384, col. 1, para. 1). The combination of references differs from claimed invention by not disclosing electrofusion solution containing comprises 0.15-3 mM ofMg2+.
However, before the effective filing date of instant application, Hackett teaches an electrofusion solution comprising 280mM mannitol and 0.15mM Mg2+ to produce tetraploid embryo (see page 9, col. 2, para. 3) that is then transferred into KSOM medium containing 0.20mM Mg2+ as evidenced from Li (see page e5, para. 1).
Therefore, it would have been prima facie obvious for a person of ordinary skill in the art to combine the teachings of prior art to modify the method of Ohta by optimizing the medium for electrofusion as suggested by McLaughlin to optimize the concentration of divalent as suggested in Suo in view of Hackett, to successfully produce tetraploid embryo, as instantly claimed, with a reasonable expectation of success, before the effective filing date of the instant invention. Said modification amounting to combining prior art elements according to known methods to yield predictable results. Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. It would have been customary for an artisan of ordinary skill to determine the optimal concentration of Mg2+, Ca2+ and electric field to achieve the desired results of obtaining tetraploid embryo. Thus, absent some demonstration of unexpected results from the claimed parameter, the optimization of concentration of Mg2+, Ca2+ and electric field would have been obvious before the effective time of filing of instant invention. "Where the general conditions of a claim are disclosed in prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). See MPEP 2144.05 One of ordinary skill in the art would be motivated to do so as use of small amounts of calcium and magnesium help in membrane healing of embryo during electrofusion, while BSA acts as a lubricant to minimize adhesion of the embryos to the walls of the chamber and the pipette that also facilitate rotation of the embryos (see McLaughlin).. Absent evidence of any unexpected superior result, one of skill in the art would have been expected to have a reasonable expectation of success in using the electrofusion solution for preparing tetraploid embryo because prior art successfully reputed optimizing the concentration of divalent ions ranging from 0.1mM to 1.4mM that included 0.2mM of Ca2+ and 015-0.2mM of Mg2+ as evident from the teaching of Suo, Hackett and Li for the fusion solution to prepare tetraploids embryo.. It should be noted that the KSR case forecloses the argument that a specific teaching, suggestion, or motivation is required to support a finding of obviousness See the recent Board decision Ex parte Smith, --USPQ2d--, slip op. at 20, (Bd. Pat. App. & Interf. June 25, 2007) (citing KSR, 82 USPQ2d at 1396) (available at http: www. uspto.gov/web/offices/dcom/bpai/prec/fd071925.pdf).
Response to arguments
To the extent that Applicants’ arguments are pertinent to the new rejections, they are addressed as follows:
Applicants disagree with the rejection arguing at 0.2 mM Mg2+ and 0.2 mM Ca²⁺, the fusion efficiency reached 100% (see paragraph [0273] of the specification). This is the specific dual-ion condition identified by Applicant, not a condition taught or suggested by the cited art. Applicants’ arguments have been fully considered but are not found persuasive.
In response to applicants’ argument of unexpected results, it should be noted that unexpected results have to be commensurate with the scope of the invention. "Whether the unexpected results are the result of unexpectedly improved results or a property not taught by the prior art, the "objective evidence of nonobviousness must be commensurate in scope with the claims which the evidence is offered to support." In other words, the showing of unexpected results must be reviewed to see if the results occur over the entire claimed range. In re Clemens, 622 F.2d 1029, 1036, 206 USPQ 289, 296 (CCPA 1980)." Example 10 (page 37 of the specification) discloses placing 2 cell embryos in electrofusion solution comprises 0.27M mannitol, 0.2mM Magnesium sulfate, 0.2mM calcium chloride, and 3 mg/ml of BSA that is subject to direct current at 60V for 50 microsecond to obtain tetraploid embryo (see page 39, para. 2). The results showed that the improved electrofusion solution enabled fusion efficiency to reach 100%. The claims are not so limited.
Conclusion
No claims allowed.
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Liu et al.,( Physiologia, vol. 71, no. 4, pp. 588-596, 18 June 2019) specifically teaches constructing an ACE2 knockout mouse model using CRISPR/Cas9 technology, and breeding, identifying and validating Ace2 knockout mice. By constructing vectors targeting knockout of Ace2 gene, microinjection of Cas9 mRNA and guide RNA (gRNA) into mouse zygotes in vitro, detection and identification of exon deletions from 3 to 18 of mouse Ace2 gene by PCR and TA clone sequencing, breeding of Ace2 knockout mice and verification of Ace2 mRNA and protein expression in the major organs of Ace2-/Y mice obtained using qRT-PCR and Western blot methods. The results showed successful construction of expressing gRNA vectors and in vitro transcription, successful direct injection of active gRNA and Cas9 mRNA into zygotes to obtain 6 positive F0 generation naïve mice, PCR and gene sequencing identified successful deletion of exons 3 to 18 of the mouse Ace2 gene; an F0 mouse was backcrossed to a wild type mouse to give 3 positive F1 mice, which were then crossed to a wild type mouse to
give an F2 generation in which an Ace2-/+ female heterozygote mouse was selected to be crossed to a wild type mouse to give an F3 generation Ace2-/Y male homozygote mouse.
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/ANOOP K SINGH/Primary Examiner, Art Unit 1632
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