Transgenic non-human animals expressing a truncated activin type II receptor

Abstract

The present invention provides a substantially purified growth differentiation factor (GDF) receptor, including a GDF-8 (myostatin) receptor, as well as functional peptide portions thereof. In addition, the invention provides a virtual representation of a GDF receptor or a functional peptide portion thereof. The present invention also provides a method of modulating an effect of myostatin on a cell by contacting the cell with an agent that affects myostatin signal transduction in the cell. In addition, the invention provides a method of ameliorating the severity of a pathologic condition, which is characterized, at least in part, by an abnormal amount, development or metabolic activity of muscle or adipose tissue in a subject, by modulating myostatin signal transduction in a muscle cell or an adipose tissue cell in the subject. The invention also provides a method of modulating the growth of muscle tissue or adipose tissue in a eukaryotic organism by administering an agent that affects myostatin signal transduction to the organism.

1 - 5 . (canceled)  
     
     
         6 . A non-human transgenic animal whose genome contains a nucleic acid sequence comprising a myostatin prodomain and a muscle-specific promoter operably linked and integrated into the genome of the animal, wherein the nucleic acid sequence is expressed so as to result in elevated levels of myostatin prodomain and increased muscle mass in the animal as compared to a corresponding corresponding nontransgenic animal.  
     
     
         7 . The transgenic animal of  claim 6 , wherein the myostatin prodomain comprises about amino acid residues 1 to 262 of a promyostatin polypeptide selected from the group consisting of SEQ ID NOS: 2, 4, 6, 8, 10, 12, 14, 16, 18 and 20, or a functional peptide portion of said myostatin prodomain.  
     
     
         8 . The transgenic animal of  claim 6 , wherein the myostatin prodomain comprises an amino acid sequence selected from the group consisting of: 
 amino acid residues about 20 to 263 as set forth in SEQ ID NO: 4;    amino acid residues about 20 to 262 as set forth in SEQ ID NO: 2;    amino acid residues about 20 to 262 as set forth in SEQ ID NO: 10;    amino acid residues about 20 to 262 as set forth in SEQ ID NO: 12;    amino acid residues about 20 to 262 as set forth in SEQ ID NO: 8;    amino acid residues about 20 to 263 as set forth in SEQ ID NO: 6;    amino acid residues about 20 to 262 as set forth in SEQ ID NO: 18;    amino acid residues about 20 to 262 as set forth in SEQ ID NO: 14;    amino acid residues about 20 to 262 as set forth in SEQ ID NO: 16;    amino acid residues about 20 to 262 as set forth in SEQ ID NO: 20; and    a functional peptide portion thereof.    
     
     
         9 . The transgenic animal of  claim 6 , wherein the myostatin prodomain further comprises a myostatin signal peptide.  
     
     
         10 . The transgenic animal of  claim 6 , wherein the muscle-specific promoter is a myosin light chain promoter/enhancer.  
     
     
         11 . A non-human transgenic animal whose genome contains a nucleic acid sequence comprising a follistatin gene and a muscle-specific promoter operably linked and integrated into the genome of the animal, wherein the nucleic acid sequence is expressed so as to result in elevated levels of follistatin and increased muscle mass in the animal as compared to a corresponding corresponding nontransgenic animal.  
     
     
         12 - 14 . (canceled)  
     
     
         15 . An expression cassette comprising a DNA segment encoding a myostatin prodomain gene operably linked to a muscle-specific control sequence.  
     
     
         16 . The expression cassette of  claim 15  wherein the muscle-specific promoter is a myosin light chain promoter/enhancer.  
     
     
         17 - 19 . (canceled)  
     
     
         20 . A cell or cell line isolated from the animal of claim  1 , wherein said cell expresses truncated Activin Type II receptor, myostatin prodomain, or follistatin, respectively.  
     
     
         21 - 39 . (canceled)  
     
     
         40 . A method of producing a chimeric non-human animal, the method comprising: 
 obtaining an ovum from animal ovaries;    maturing the ovum in vitro;    fertilizing the mature ovum in vitro to form a zygote;    introducing into the zygote in vitro a nucleic acid construct comprising in operable association a DNA sequence encoding a truncated Activin Type II receptor, a myostatin propeptide, or follistatin, and a regulatory sequence that promotes expression of the DNA sequence encoding the polypeptide;    maturing the zygote to a preimplantation stage embryo in vitro; and    transplanting the embryo into a recipient female animal, wherein the female animal gestates the embryo to produce a chimeric animal.    
     
     
         41 - 42 . (canceled)  
     
     
         43 . A cell or cell line isolated from the animal of  claim 6 , wherein said cell expresses truncated Activin Type II receptor, myostatin prodomain, or follistatin, respectively.  
     
     
         44 . A cell or cell line isolated from the animal of  claim 11 , wherein said cell expresses truncated Activin Type II receptor, myostatin prodomain, or follistatin, respectively.