Follistatin gene as a genetic marker for reproductive and performance traits in pigs

• US 20070186298A1
• Filed: 01/04/2006
• Published: 08/09/2007
• Est. Priority Date: 01/04/2006
• Status: Abandoned Application

• Current Assignee: Charlotte Blowe
• Original Assignee: Charlotte Blowe
• Inventors: Blowe, Charlotte
• Application Number:
  US11/324,526
• Publication Number:
  US 20070186298A1
• Time in Patent Office: Days
• US Class Current: 800/17
• CPC Class Codes: A01K 2227/108 Swine
• CPC Class Codes: C12Q 1/6876 Nucleic acid products used in the analysis of nucleic acids, e.g. primers or probes
• CPC Class Codes: C12Q 1/6883 for diseases caused by alterations of genetic material
• CPC Class Codes: C12Q 2600/124 Animal traits, i.e. production traits, including athletic performance or the like
• CPC Class Codes: C12Q 2600/156 Polymorphic or mutational markers

Abstract

Disclosed herein are genetic markers for overall pig reproductive traits, including litter size, number born alive, number weaned, weaning weight, and number of stillborns, and performance traits, including days to reach 250 lbs., average daily gain, and feed to gain conversion, methods for identifying such markers, and methods of screening pigs to determine those more or less likely to possess these favorable reproductive and performance traits and more or less likely to produce litters with offspring who also have that same genetic ability to have these desirable traits and preferably selecting those pigs for future breeding purposes. The markers are based upon the presence or absence of certain polymorphisms in the pig follistatin gene.

Claims

1. Genetic mutations within the porcine follistatin gene which have been found to be associated with overall reproductive performance and growth traits in pigs.

2. A method of screening pigs to determine those more likely to produce larger litters, possess other desirable reproductive traits and grow more efficiently and produce offspring also possessing those same abilities, which is comprised of:

obtaining a sample of genetic material from a pig and analyzing the genomic material obtained in (i) to determine which follistatin (FS) allele(s) is/are present in said sample.

3. A method as claimed in claim 2 wherein the determination of FS alleles in the analysis step encompasses determining the presence of at least one allele associated with at least one polymorphism in FS.

4. A method as claimed in claim 3 wherein the DNA markers are single nucleotide polymorphisms.

5. A method as claimed in claim 4 wherein the DNA marker is FS1 or FS2.

6. The method of claim 2 wherein said method of identifying the presence or absence of a polymorphism is selected from a group consisting of:

restriction fragment length polymorphism (RFLP) analysis, heteroduplex analysis, single strand conformational polymorphism (SSCP), denaturing gradient gel electrophoresis (DGGE), temperature gradient gel electrophoresis (TGGE), DNA sequencing or other similar technique that can be utilized to detect differences in sequence between DNA strands.

7. The preferred method of claim 2 wherein said step of assaying for the presence of said polymorphism comprises the steps of:

digesting said genetic material with a restriction enzyme that cleaves the pig follistatin gene in at least one place, separating the fragments obtained from said digestion, detecting a restriction pattern generated by said fragments, and comparing said pattern with a second restriction pattern for the pig follistatin gene obtained by using said restriction enzyme, wherein said second restriction pattern is associated with increased litter size, number born alive, number weaned, weaning weight, average daily gain, and feed to gain conversion as well as a decreased number of stillborns, and days to reach 250 lbs.

8. The method of claim 7 wherein said restriction enzyme is Mspl or other such restriction endonuclease that will differentially cut at FS1 polymorphism.

9. The method of claim 7 wherein said restriction enzyme is Fnu4Hl or other such restriction endonuclease that will differentially cut at FS2 polymorphism.

10. The method of claim 7 wherein said separation is by gel electrophoresis.

11. The method of claim 7 wherein said step of comparing said restriction patterns comprises identifying specific fragments by size and comparing the sizes of said fragments.

12. The method of claim 7 further comprising the step of amplifying the pig follistatin gene or a portion thereof which contains said polymorphism, prior to said digestion step.

13. The method of claim 7 wherein said polymorphism is a polymorphic Mspl restriction site if said amplification is of the region including exons 2 and 3 as well as the sequence between in the pig follistatin gene.

14. The method of claim 7 wherein said polymorphism is a polymorphic Fnu4Hl restriction site if said amplification is of the region including exons 3 and 4 as well as the sequence between in the pig follistatin gene.

15. The method of claim 12 wherein said pig follistatin gene is located on chromosome 16.

16. The method of claim 7 wherein said amplification is of the sequence spanning from exon 2 thru exon 3 or the sequence from exon 3 thru exon 4 includes selecting a forward and reverse sequence primer capable of amplifying a region pig follistatin gene which contains a polymorphic Mspl site or Fnu4Hl site.

17. The method of claim 16 wherein said forward and reverse primer sets amplify the region on chromosome 16 associated with the pig follistatin gene.

18. The method of claim 16 wherein said forward and reverse primers amplify a polymorphism found in the sequence of the follistatin gene, especially if that region covers the sequence from exon 2 thru exon 3 or exon 3 thru exon 4.

19. The method of claim 16 wherein said primers are SEQ ID NO:

1 and SEQ ID NO;

2 for FS1 marker and SEQ ID NO;

3 and SEQ ID NO;

4 for FS2 marker.

20. The method for identifying a polymorphism for pig reproductive and growth traits comprising the steps of:

determining the reproductive and growth traits of each animal, determining the polymorphism in the follistatin gene of each pig wherein the polymorphism is identifiable by amplification by a set of primers selected from the group consisting of the set of a forward primer SEQ ID NO;

1 and reverse primer SEQ ID NO;

2 or the set of a forward primer SEQ ID NO;

3 and reverse primer SEQ ID NO;

4, and associating the reproductive and performance traits of each pig with said polymorphism thereby identifying a polymorphism for pig reproductive and growth traits.

21. The method of claim 20 further comprising selecting pigs for breeding which are predicted to have favorable reproductive and growth traits by said marker.

22. The method of claim 20 wherein said analysis comprises digestion of PCR amplified DNA with the restriction enzyme Mspl if said amplification is of the region from exon 2 thru exon 3 or Fnu4Hl if said amplification is from exon 3 thru exon 4.

23. The method of claim 20 wherein said polymorphism associated with favorable reproductive and growth traits is amplified by use of forward and reverse primers comprising at least 4 consecutive bases in SEQ ID NOS:

1 and 2 or 3 and 4.

24. The method for determining the presence of a polymorphic site in the follistatin gene which is associated with favorable reproductive and growth traits in pigs comprising:

obtaining genetic samples from male and female pigs of the same breed, or breed cross, or derived from similar genetic lineages grown under normal conditions, determining reproductive traits of each pig from which a genetic sample was obtained, analyzing the genetic samples for polymorphisms in a gene associated with favorable reproductive and growth characteristics wherein the gene is the follistatin gene wherein the polymorphisms are identifiable by amplification by a set of primers selected from the group consisting of the set of a forward primer SEQ ID NO;

1 and reverse primer SEQ ID NO;

2 or the set of a forward primer SEQ ID NO;

3 and reverse primer SEQ ID NO;

4 or a comparable set of primers, performing an appropriate restriction digest or similar analysis to determine which FS alleles are present, and correlating the polymorphism(s) to reproductive and growth traits by comparing the presence of polymorphisms to each animals'"'"' records.