Multicellular living organisms and unmodified parts thereof and – Method of introducing a polynucleotide molecule into or...
Reexamination Certificate
2001-02-20
2003-10-07
Bui, Phuong T. (Department: 1638)
Multicellular living organisms and unmodified parts thereof and
Method of introducing a polynucleotide molecule into or...
C536S023100, C536S024100, C536S024500, C435S320100, C435S419000, C435S069100, C435S091400, C800S295000
Reexamination Certificate
active
06630614
ABSTRACT:
TECHNICAL FIELD
The present invention relates generally to plant molecular biology. More specifically, it relates to nucleic acids and methods for modulating their expression in plants.
BACKGROUND OF THE INVENTION
In the fission yeast
Schizosaccharomyces pombe,
the Rad21 gene is involved in the repair of double-stranded breaks in DNA and is essential for mitotic growth (Birkenbihl, R P and Subramani, S,
Nucleic Acid Res.
20: 6605-6611, 1992; Birkenbihl, R P and Subramani, S,
J. Biol. Chem.
270: 7703-7711, 1995). The Rad21 gene encodes a protein of 628 amino acids. A single base substitution of this gene, resulting in a mutation of isoleucine to threonine at amino acid residue 67, completely abolishes the double strand break repair activity. The Rad21 protein has been shown to be a nuclear, cell cycle-regulated phosphoprotein. Expression of both mRNA and the protein are maximal at the G1-S transition. (Birkenbihl, R P and Subramani, S J.,
Biol. Chem.
270: 7703-7711, 1995). Orthologues of the
S. pombe
Rad21 gene have been identified in human, mouse,
C. elegans,
and budding yeast (McKay M J et al.,
Genomics
36: 305-315, 1996; Heo S J et al.,
Mol. Gen. Genet.
257: 149-156, 1998).
Very recently, two groups have independently reported the presence of Rad21-like genes, SYN1 and DIF1, in
Arabidopsis thaliana
(Bai X et al.,
Plant Cell
11: 417-430, 1999; Bhatt A M et al.,
Plant J.
19: 463-472, 1999). Taken together, all of these studies indicate that these Rad21 orthologues make up a large gene family collectively identified as the Rad21/REC8/Cohesin gene family. These studies have also shown the requirement of these Rad21 orthologues of higher eukaryotes in meiosis and chromosomal segregation in addition to their role in recombination and DNA repair.
The regulation of meiotic recombination by the modulation of Rad21, as well as the regulation of DNA double-strand-break repair, can provide improved and expanded methods of producing agriculturally important crop species such as maize. The present invention provides for these and other advantages.
SUMMARY OF THE INVENTION
Generally, it is the object of the present invention to provide nucleic acids and proteins relating to Rad21. It is an object of the present invention to provide transgenic plants comprising the nucleic acids of the present invention, and methods for modulating, in a transgenic plant, the expression of the nucleic acids of the present invention. It is further an object of the present invention to provide methods to modulate repair activity, meiotic recombination, transformation efficiency, and provide a male sterile phenotype or seedless fruits.
The present invention teaches a full-length cDNA for a maize orthologue of the Rad21/REC8/cohesin family. The modulation of Rad21 provides for the modulation of meiotic recombination and DNA double-strand break repair activity. For example, during back-crossing for the production of inbred and hybrid crops, an overexpression of Rad21 may enhance chromosomal segregation allowing rapid exchange of genetic information. On the other hand, a controlled reduction in the levels of maize Rad21 in meiotic tissues such as anthers or ovules may interfere with chromosomal segregation and meiotic double strand break repair/recombination leading to a male sterile phenotype or seedless fruits.
Therefore, in one aspect the present invention relates to an isolated nucleic acid comprising a member selected from the group consisting of (a) a polynucleotide having a specified sequence identity to a polynucleotide encoding a polypeptide of the present invention; (b) a polynucleotide which is complementary to the polynucleotide of (a); and, (c) a polynucleotide comprising a specified number of contiguous nucleotides from a polynucleotide of (a) or (b). The isolated nucleic acid can be DNA.
In other aspects the present invention relates to: 1) recombinant expression cassettes, comprising a nucleic acid of the present invention operably linked to a promoter, 2) a host cell into which has been introduced the recombinant expression cassette, and 3) a transgenic plant comprising the recombinant expression cassette. The host cell and plant are optionally a maize cell or maize plant, respectively.
Definitions
Units, prefixes, and symbols may be denoted in their SI accepted form. Unless otherwise indicated, nucleic acids are written left to right in 5′ to 3′ orientation; amino acid sequences are written left to right in amino to carboxy orientation, respectively. Numeric ranges recited within the specification are inclusive of the numbers defining the range and include each integer within the defined range. Amino acids may be referred to herein by either their commonly known three letter symbols or by the one-letter symbols recommended by the IUPAC-IUB Biochemical Nomenclature Commission. Nucleotides, likewise, may be referred to by their commonly accepted single-letter codes. Unless otherwise provided for, software, electrical, and electronics terms as used herein are as defined in The New IEEE Standard Dictionary of Electrical and Electronics Terms (5
th
edition, 1993). The terms defined below are more fully defined by reference to the specification as a whole.
By “amplified” is meant the construction of multiple copies of a nucleic acid sequence or multiple copies complementary to the nucleic acid sequence using at least one of the nucleic acid sequences as a template. Amplification systems include the polymerase chain reaction (PCR) system, ligase chain reaction (LCR) system, nucleic acid sequence based amplification (NASBA, Cangene, Mississauga, Ontario), Q-Beta Replicase systems, transcription-based amplification system (TAS), and strand displacement amplification (SDA). See, e.g.,
Diagnostic Molecular Microbiology: Principles and Applications,
D. H. Persing et al, Ed., American Society for Microbiology, Washington, D.C. (1993). The product of amplification is termed an amplicon.
As used herein, “antisense orientation” includes reference to a duplex polynucleotide sequence that is operably linked to a promoter in an orientation where the antisense strand is transcribed. The antisense strand is sufficiently complementary to an endogenous transcription product such that translation of the endogenous transcription product is often inhibited.
By “encoding” or “encoded”, with respect to a specified nucleic acid, is meant comprising the information for translation into the specified protein. A nucleic acid encoding a protein may comprise non-translated sequences (e.g., introns) within translated regions of the nucleic acid, or may lack such intervening non-translated sequences (e.g., as in cDNA). The information by which a protein is encoded is specified by the use of codons. Typically, the amino acid sequence is encoded by the nucleic acid using the “universal” genetic code. However, variants of the universal code, such as are present in some plant, animal, and fungal mitochondria, the bacterium
Mycoplasma capricolum,
or the ciliate Macronucleus, may be used when the nucleic acid is expressed therein.
When the nucleic acid is prepared or altered synthetically, advantage can be taken of known codon preferences of the intended host where the nucleic acid is to be expressed. For example, although nucleic acid sequences of the present invention may be expressed in both monocotyledonous and dicotyledonous plant species, sequences can be modified to account for the specific codon preferences and GC content preferences of monocotyledons or dicotyledons as these preferences have been shown to differ (Murray et al.
Nucl. Acids Res.
17: 477-498 (1989)). Thus, the maize preferred codon for a particular amino acid may be derived from known gene sequences from maize. Maize codon usage for 28 genes from maize plants is listed in Table 4 of Murray et al., supra.
As used herein “full-length sequence” in reference to a specified polynucleotide or its encoded protein means having the entire amino acid sequence of, a native (non-synthetic), endogenous, biologically active form of the s
Bui Phuong T.
Helmer Georgia
Pioneer Hi-Bred International , Inc.
Pioneer Hi-Bred International Inc.
LandOfFree
Rad21 orthologue and uses thereof does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Rad21 orthologue and uses thereof, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rad21 orthologue and uses thereof will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3175510