The binary-BAC system for transformation of plants with high
molecular weight DNA was developed at the Plant Science Center,
I (CMH) joined the research group at the Plant Science Center
in March, 1992. The Plant Science Center was funded by a joint
USDA, NSF, DOE grant and was under the direction of Dr. Maureen
After about a year of work had been invested in the design
and construction of a binary-BAC vector, Dr. Steve Tanksley invited
me (CMH) to come to his lab group meetings and initiate a collaboration.
Steve Tanksley provided invaluable technical and scientific support,
and interacting with his research team at that time was as exciting
as it was productive.
Additional funding was obtained from the USDA Plant Genome
National Research Initiative, Plant Genome via the competitive
grant program. This funding was a three year “New Investigator
Award” ($255,000) to CMH. The USDA award made it possible
for me to hire Dr. Anne Frary and Yimin Xu who continued to work
on the project until I left Cornell in the spring of 1998.
To learn the “state of the art” of BAC library construction
I accepted an invitation to work with Dr. Hong-Bin Zhang in his
laboratory at Texas A&M. In addition to the USDA funding
and support from the Tanksley laboratory, funding for the construction
of two tomato genomic BIBAC libraries was provided by: Dr. Jonathan
Jones at the John Innes Institute, UK, Dr. Robert Fluhr at the
Weizmann Institute, Israel and Dr. Barbara Baker at UC Berkeley
BIBAC materials have been sent to hundreds of laboratories
and companies around the world. BIBAC materials “for research
purposes only” are currently available from the Plant Science
Center, Cornell University. BIBAC technology is available for
licensing from the Center for Technology Licencing at Cornell University (CTL). The Binary-BAC
vector is described in U.S. patents: The BIBAC vector Hamilton,
C. M. Binary BAC Vector. United States Patent No. 5,733,744.
Issued March 31, 1998. Cornell Research Foundation, Inc., Ithaca,
NY. And Binary BAC Vector Hamilton, C. M. United States Patent No. 5,977,439. Issued November 2, 1999. Cornell Research Foundation, Inc., Ithaca, NY.
USDA Final Report, due 23 Feb 1999:
National Research Initiative Competitive Grants Program
(NRICGP) Award: 9500764
“Evaluation and application of a new BAC library vector
designed for transfer of large DNA inserts to plants”
Plant Science Center
Ithaca, NY 14853-2703
The specific aims of this proposal were to 1) complete the
construction and test of a new vector suitable for transformation
of plant with high molecular weight 2) test the utility of this
vector for the construction of large insert genomic DNA libraries
3) establish the utility of this new vector by identifying a
gene of interest from a library constructed in this vector by
plant transformation and complementation of a phenotype.
A new binary-BAC (bacterial artificial chromosome) vector
was constructed. Evaluation of the new vector binary-BAC (BIBAC)
demonstrated that the BIBAC was be capable of transferring at
least 150 kb of DNA, intact, to the plant nuclear genome.
The vector was also designed to be suitable for the construction
of high molecular genomic DNA libraries so that additional subcloning
steps would not be needed. To demonstrate that the BIBAC vector
is suitable for constructing large insert genomic DNA libraries,
we set out to make high molecular DNA libraries for two different
tomato species, Lycopersicon esculentum, domesticated
tomato, and L. pennellii, a wild species of tomato. The
average insert sizes for these libraries were 125 and 90 kb respectively.
The final goal of the project, which was to demonstrate the
utility of the system by identification of a gene of interest
by using a BIBAC genomic library clone to complement a gene of
interest, has not yet been achieved. However, work is currently
underway in several laboratories that may serve to validate this
The advent of BIBAC technology has made it possible to consider
new approaches to long-standing problems in basic plant biology
and will facilitate the development of new elite varieties of
agronomic crops. BIBAC technology will accelerate the identification
of agriculturally important genes and make it possible to introduce
valuable traits into plants without dragging along deleterious
traits (a common problem for classical plant breeders). The ability
to introduce high molecular weight DNA, intact into plant chromosomes
will also make it possible to investigate long distance affects
on gene expression.
The BIBAC system for transfer of high molecular weight DNA
to plants would not have been successful without enhancing the
ability of Agrobacterium tumefaciens to effect DNA transfer
to the plant chromosomes. That is, this work included basic research
that has affected the plant transformation community. Several
groups have contacted have requested the virulence helper plasmids
that made BIBAC technology a success, not because they needed
BIBAC technology per se, but because they were interested
in improving the transformation efficiency for their plant system
of interest. In general this is a more common problem for agronomic
crops than for model system plants used for basic research.
The critical elements of this new technology, the bacterial
strains and plasmids, have been requested by hundred of laboratories,
academic and industrial, around the world. I have included the
list of “all recipients” of BIBAC materials as an indication
of the interest and potential impact of the development of this
In addition, various parties have expressed interest in licensing
BIBAC technology; these queries are directed to Cornell Research
Foundation. A US patent has been issued for the BIBAC vector
and foreign patents are pending. The Center for Advanced Technology/Biotechnology
at Cornell University supported the construction and maintains
a “BIBAC website” in support of BIBAC technology.
- “Big news for plant transformation”
R.W. Michelmore, Professor, Vegetable Crops
Nature Biotechnology 14:1653-1654, December 1996
- “Big news for plant transformation”
- Frary, A., and Hamilton, C.M. 1999. Evaluation of BIBAC technology for transformation of tomato plants with high molecular weight DNA. Manuscript in preparation.
- Hamilton, C. M., Frary, A., Xu, Y., Tanksley, S. D. and H. Zhang. 1999. Construction and characterization of BIBAC genomic DNA libraries of Lycopersicon esculentum andLycopersicon pennelli. The Plant Journal. 17: in press.
- Hamilton, C. M. Binary BAC Vector. United States Patent No. 5,733,744. Issued March 31, 1998. Cornell Research Foundation, Inc., Ithaca, NY.
- Hamilton, C. M. Binary BAC Vector. United States Patent No. 5,977,439. Issued November 2, 1999. Cornell Research Foundation, Inc., Ithaca, NY.
- Hamilton, C. M. 1998. BIBAC technology: progress and prospects. AgBiotech News and Information (CABI) 10: 23N-28N.
- Hamilton, C. M. 1997. A binary-BAC system for plant transformation with high-molecular-weight DNA. Gene 200: 107-116.
- Hamilton C. M., Frary, A. Lewis, C. and Tanksley, S. D. 1996. Stable transfer of intact high molecular weight DNA into plant chromosomes. Proc. Natl. Acad. Sci. USA 93: 9975-9979.
Contact at Cornell to obtain strains and plasmids:
Dr. Maureen Hanson
For scientific questions about the BIBAC vectors:
Carol M. Hamilton