Abstract: This invention relates to a gene associated with male fertility, labeled Ms41-A, and a recessive mutant form thereof, labelled ms41-A, which confers male sterility. The Ms41-A gene is isolated from Arabidopsis, while the related gene Zm41-A is isolated from maize. Male-sterile plants are useful for the production of hybrid plants by sexual hybridization.

Abstract: Compounds having highly specific endoribonuclease activity are described. The compounds of this invention, also known as ribozymes, comprise ribonucleotides having two hybridizing regions with predetermined sequences capable of hybridizing with a plant, animal or viral target RNA, a region of defined sequence and a base paired stem region.

Abstract: A cell comprising a synthetic non-naturally occurring oligonucleotide compound comprises nucleotides whose sequence defines a conserved catalytic region and nucleotides whose sequence hybridizes with a predetermined target sequence within a MoMLV Psi packaging sequence on the HIV tat sequence. The catalytic region may be derived from a hammerhead ribozyme, a hairpin ribozyme a hepatitis delta ribozyme, an PNAase P ribozyme, a group I intron or a group II intron.

Abstract: This invention provides catalytic molecules capable of cleaving target nucleotide sequences. More specifically, the invention provides an endonuclease having nucleotide sequences which are of sufficient length to allow hybridisation to a target nucleotide sequence desired to be cleaved. The endonuclease contains a catalytic region comprising ribonucleotides and/or deoxyribonucleotides, or derivatives thereof which act to cleave a phosphodiester bond of the substrate nucleotide sequence. The catalytic region comprises nucleotides or derivatives thereof which are linked by linking groups which may comprise ribonucleotides, deoxyribonucleotides or combinations thereof.The endonucleases of the invention are useful in the cleavage of target RNAs associated with disease in humans and animals and in the inactivation of RNA transcripts in eukaryotic and prokaryotic cells, as well as the cleavage of RNA transcripts in-vitro.

Abstract: This invention is directed to improved catalytic compounds, hammerhead ribozymes, capable of hybridizing with a target RNA to be cleaved. These improved compounds have optimized stems (X)m * (X)m', loops (X)b and hybridizing arms. The invention is also directed to compositions for enhanced RNA cleavage which comprise a first synthetic non-naturally occurring oligonucleotide compound which comprises nucleotides whose sequence defines a conserved catalytic region and nucleotides whose sequence is capable of hybridizing with a predetermined target sequence and a second synthetic non-naturally occurring oligonucleotide which does not contain the predetermined target sequence and is complementary to at least a portion of the first oligonucleotide compound. The invention is also directed to synthetic non-naturally occurring oligonucleotide compounds embedded in a tRNA. The ribozymes and compositions of the present invention may be used in vitro or in vivo. They may be used as diagnostic or therapeutic agents.

Abstract: The present invention relates generally to an in vivo system for gene expression and, more particularly, to the use of the system to screen for molecules which are capable of inhibiting, reducing, altering or otherwise modulating expression of a target nucleotide sequence or the activity of a gene product. The in vivo system of the present invention is particularly but not exclusively useful for screening for antisense, sense or ribozyme constructs or transdominant polypeptides, small peptides or other chemical compounds that are capable of inhibiting, reducing, altering or otherwise modulating expression of target genes or target genetic sequences or the activity of target gene products of commercial importance such as in medical, agricultural and industrial fields.

Abstract: This invention is directed to a synthetic non-naturally occurring oligonucleotide compound which comprises nucleotides whose sequence defines a conserved catalytic region and nucleotides whose sequence is capable of hybridizing with a predetermined target sequence within a packaging sequence of an RNA virus. Preferably, the viral packaging sequence is a retrovirus packaging sequence or the HIV-1 Psi packaging sequence. The RNA virus may be HIV-1, Feline Leukemia Virus, Feline Immunodeficiency Virus or one of the viruses listed in Table I. The conserved catalytic region may be derived from a hammerhead ribozyme, a hairpin ribozyme, a hepatitis delta ribozyme, an RNAase P ribozyme, a group I intron, a group II intron.

Abstract: Compounds having highly specific endoribonuclease activity are described. The compounds of this invention, also known as ribozymes, comprise ribonucleotides having two hybridizing regions with predetermined sequences capable of hybridizing with a target RNA, a region of defined sequence and a base paired stem region.