SNP (Single Nucleotide Polymorphism) molecular marker of gene PIP4P2 related to long-life character of dairy cow and application of SNP molecular marker

Abstract

The invention discloses an SNP (Single Nucleotide Polymorphism) molecular marker of a gene PIP4P2 related to the longevity character of a dairy cow and application of the SNP molecular marker. Whole genome re-sequencing is carried out on 670 dairy cows, five SNP loci related to the long life character of the dairy cows are found in 10000bp of upstream and downstream regulation regions and all exon regions of the PIP4P2 gene, and the dominant genotype of each SNP locus is found through correlation analysis. The SNP loci and dominant genotypes found in the invention have important significance for auxiliary identification and early screening of dairy cow groups with longevity characters, improvement of longevity of the dairy cow groups, improvement of lifetime benefits of the dairy cow groups and economic benefits of dairy cow breeding.

Description

Technical Field

[0001] This invention belongs to the field of biotechnology, specifically relating to genes related to longevity traits in dairy cows. PIP4P2 SNP molecular markers and their applications. Background Technology

[0002] Dairy farming is an important part of animal husbandry. With rising living standards, the demand for milk has increased significantly, driving the rapid development of the dairy farming industry. Longevity is a fundamental factor in the profitability of dairy production. Besides production traits, longevity has the greatest economic value and is one of the most important functional traits in dairy cattle breeding. Improving the longevity of dairy cows can extend their profitable period, resulting in higher profits; it can reduce the number of replacement heifers needed, lowering the cost of herd renewal; with a constant herd size, it allows for a higher proportion of active culling on farms, increasing selection intensity and accelerating genetic progress; longer-lived herds mean higher overall health, requiring less investment in veterinary drugs and veterinary care.

[0003] However, dairy cows have low heritability, and many factors influence their lifespan, making them difficult to raise. Longevity traits have been used as an important breeding indicator in many developed dairy countries, but they have not yet been incorporated into production performance indicators in my country. Currently, my country's dairy cattle industry is still in its early stages, characterized by "large quantity, low quality, high cost, and low yield." The average parity of dairy cows is less than 2.7, resulting in short productive lifespans, frequent culling, and difficulty in maintaining dairy production efficiency. Therefore, breeding long-lived dairy cows is urgently needed.

[0004] In China, longevity is primarily measured by productive lifespan, defined as the time span from first calving to culling. Its length directly impacts final milk production and is a key indicator for assessing the economic value of dairy cows. A longer productive lifespan means higher final milk production and better economic benefits. Many factors influence the longevity of dairy cows; all factors that affect culling will influence longevity. Due to the complexity of longevity-influencing factors, diverse trait definitions, unique data distribution, late trait expression, and low heritability, longevity is one of the most complex and difficult traits to breed in dairy cattle.

[0005] More and more breeding companies are now incorporating genomic information into longevity selection, further improving the accuracy and efficiency of dairy cattle breeding. Domestic and international researchers, through techniques such as genome-wide association studies (GWAS), have discovered genes associated with longevity in dairy cattle, such as MFGE8, SRC, DGAT1, CSN2, and CAST. By mining genetic markers related to longevity traits, useful information can be provided for genomic selection of this trait, thereby improving the longevity of cattle herds, increasing the lifetime profitability of dairy cows, and continuously enhancing the economic benefits of dairy farming.

[0006] PIP4P2 The PIP4P2 gene (ARS_UCD2.0) is located on chromosome 14 in a cow, and has a sequence of 7,1873 bp, and is composed of 7 exons and 6 introns. SUMMARY

[0007] The present application aims to provide a SNP molecular marker of a gene related to a long-life trait of a cow and application thereof. PIP4P2

[0008] To achieve the above-mentioned purpose, the present application first provides a new use of a substance for detecting polymorphism or genotype of at least one of the five SNP sites.

[0009] The present application provides application of the substance for detecting polymorphism or genotype of at least one of the five SNP sites in identifying or assisting in identifying a long-life trait of a cow or in preparing a product for identifying or assisting in identifying a long-life trait of a cow.

[0010] The present application also provides application of the substance for detecting polymorphism or genotype of at least one of the five SNP sites in screening or assisting in screening a long-life cow or in preparing a product for screening or assisting in screening a long-life cow.

[0011] The present application also provides application of the substance for detecting polymorphism or genotype of at least one of the five SNP sites in cow breeding or in preparing a product for cow breeding.

[0012] To achieve the above-mentioned purpose, the present application further provides a method for identifying or assisting in identifying a long-life trait of a cow.

[0013] The method for identifying or assisting in identifying a long-life trait of a cow provided by the present application is any one of the following X1)-X5): X1) comprising the following steps: detecting whether the genotype of SNP1 site of a test cow is GG, GA or AA, and judging the long-life trait of the test cow according to the genotype of the SNP1 site: the production life and group life of a cow with GG and GA genotypes are higher than that of a cow with AA genotype; the GG genotype is a homozygote with G at the SNP1 site, the GA genotype is a heterozygote with G and A at the SNP1 site, and the AA genotype is a homozygote with A at the SNP1 site.

[0014] ​X2) includes the following steps: detecting whether the genotype of the SNP2 locus of the tested dairy cow is CC, CA or AA, and determining the longevity trait of the tested dairy cow based on the genotype of the SNP2 locus: the productive lifespan and herd lifespan of dairy cows with CC and CA genotypes are higher than those of dairy cows with AA genotypes; the CC genotype is homozygous for all SNP2 loci being C, the CA genotype is heterozygous for SNP2 loci being C and A, and the AA genotype is homozygous for all SNP2 loci being A.

[0015] X3) includes the following steps: detecting whether the genotype of the SNP3 locus of the tested dairy cow is TT, CT, or CC, and determining the longevity trait of the tested dairy cow based on the genotype of the SNP3 locus: dairy cows with TT and CT genotypes have a higher productive lifespan and herd lifespan than dairy cows with CC genotypes; the TT genotype is homozygous for all SNP3 loci being T, the CT genotype is heterozygous for SNP3 loci being C and T, and the CC genotype is homozygous for all SNP3 loci being C.

[0016] X4) includes the following steps: detecting whether the genotype of the SNP4 locus of the tested dairy cow is TT, TG, or GG, and determining the longevity trait of the tested dairy cow based on the genotype of the SNP4 locus: dairy cows with TT and TG genotypes have a higher productive lifespan and herd lifespan than dairy cows with GG genotype; the TT genotype is homozygous for all SNP4 loci being G, the TG genotype is heterozygous for SNP4 loci being T and G, and the GG genotype is homozygous for all SNP4 loci being G.

[0017] X5) includes the following steps: detecting whether the genotype of the SNP5 locus of the tested dairy cow is CC, CA or AA, and determining the longevity trait of the tested dairy cow based on the genotype of the SNP5 locus: dairy cows with CC and CA genotypes have a longer productive lifespan and herd lifespan than dairy cows with AA genotypes; the CC genotype is homozygous for all SNP5 loci being C, the CA genotype is heterozygous for SNP5 loci being C and A, and the AA genotype is homozygous for all SNP5 loci being A.

[0018] The application of the above method in screening or assisting in the screening of long-lived dairy cows or in dairy cow breeding also falls within the scope of protection of this invention.

[0019] To achieve the above objectives, the present invention also provides a method for screening or assisting in the screening of long-lived dairy cows.

[0020] The method for screening or assisting in screening long-lived dairy cows provided by this invention is any one of the following Y1)-Y5): Y1) includes the step of selecting cows with the genotype GG or GA at the SNP1 locus; Y2) includes the step of selecting cows with the genotype CC or CA at the SNP2 locus; Y3) includes the step of selecting dairy cows with the genotype TT or CT at the SNP3 locus; Y4) includes the step of selecting cows with the genotype TT or TG at the SNP4 locus; Y5) includes the step of selecting dairy cows with the genotype CC or CA at the SNP5 locus.

[0021] To achieve the above objectives, the present invention also provides a method for breeding dairy cows.

[0022] The method for breeding dairy cows provided by the present invention includes the step of using long-lived dairy cows selected according to the above method as breeding material for breeding.

[0023] To achieve the above objectives, the present invention finally provides a product; the function of the product is any one of the following Z1)-Z3): Z1) Identification or auxiliary identification of longevity traits in dairy cows; Z2) Screening or assisted screening of long-lived dairy cows; Z3) Dairy cow breeding.

[0024] The product provided by this invention includes a substance for detecting polymorphism or genotype of at least one of five SNP loci.

[0025] The five SNP sites mentioned above are SNP1, SNP2, SNP3, SNP4, and SNP5.

[0026] The polymorphism of any of the SNP1 sites mentioned above is G or A, corresponding to the 204th nucleotide from the 5' end of SEQ ID No. 1 in the sequence listing.

[0027] The polymorphism of any of the SNP2 sites mentioned above is C or A, corresponding to nucleotide 4057 from the 5' end of SEQ ID No. 1 in the sequence listing.

[0028] The polymorphism of any of the SNP3 sites mentioned above is C or T, corresponding to the 9084th nucleotide from the 5' end of SEQ ID No. 1 in the sequence listing.

[0029] The polymorphism of any of the SNP4 sites mentioned above is T or G, corresponding to nucleotide 9341 from the 5' end of SEQ ID No. 1 in the sequence listing.

[0030] The polymorphism of any of the SNP5 sites mentioned above is C or A, corresponding to the 9515th nucleotide from the 5' end of SEQ ID No. 1 in the sequence listing.

[0031] The substance described above for detecting polymorphism or genotype of at least one of the five SNP sites includes a substance for detecting polymorphism or genotype of the SNP1 site and / or the SNP2 site and / or the SNP3 site and / or the SNP4 site and / or the SNP5 site.

[0032] Furthermore, the substance used to detect the polymorphisms or genotypes of the aforementioned SNP1 and / or SNP2 and / or SNP3 and / or SNP4 and / or SNP5 sites in the bovine genome can be reagents and / or instruments required to determine the polymorphisms or genotypes of the aforementioned SNP1 and / or SNP2 and / or SNP3 and / or SNP4 and / or SNP5 sites in the bovine genome using at least one of the following methods: DNA sequencing, restriction fragment length polymorphism, single-strand conformation polymorphism, denaturing high-performance liquid chromatography, and SNP arrays. The DNA sequencing includes Sanger sequencing, Roche 454 pyrosequencing, Illumina Solexa sequencing by synthesis, single-molecule fluorescence sequencing, and nanopore sequencing. The SNP chips include chips based on nucleic acid hybridization reactions, chips based on single-base extension reactions, chips based on allele-specific primer extension reactions, chips based on "one-step" reactions, chips based on primer ligation reactions, chips based on restriction endonuclease reactions, chips based on protein-DNA binding reactions, and chips based on fluorescent molecule-DNA binding reactions.

[0033] Furthermore, the DNA sequencing is whole-genome resequencing.

[0034] In some implementation schemes, whole-genome resequencing of genomic DNA from blood samples of individual dairy cows is performed by BGI Genomics Co., Ltd. After resequencing, the sequences are aligned to the bovine reference genome ARS_UCD2.0 to directly obtain the genotypes of the aforementioned SNP loci.

[0035] The products described above may be reagents, kits, or systems, and the systems may include combinations of reagents or kits, instruments, and analytical software.

[0036] The longevity trait described above includes productive lifespan and / or population lifespan.

[0037] The long-lived dairy cows mentioned above are dairy cows with high productive lifespan and / or high herd lifespan.

[0038] The productive lifespan mentioned above refers to the time between a cow's first calving and its departure from the herd.

[0039] The herd lifespan mentioned above refers to the time elapsed from birth to leaving the herd for a cow.

[0040] The indicators for dairy cow breeding mentioned above include longevity traits (such as productive lifespan or herd lifespan).

[0041] The purpose of any of the above-mentioned dairy cow breeding programs is to develop long-lived dairy cow breeds.

[0042] The dairy cows mentioned above can specifically be Chinese Holstein dairy cows (female cows).

[0043] This invention utilizes whole-genome resequencing of 670 dairy cows to achieve... PIP4P2 Five SNP loci associated with the longevity trait in dairy cows were identified within the 10,000 bp upstream and downstream regulatory regions and all exons. Association analysis revealed the dominant genotype for each SNP locus. The SNP loci and dominant genotypes discovered in this invention are of great significance for the auxiliary identification and early screening of dairy cow populations with longevity traits, improving the longevity of dairy cow populations, enhancing their lifetime benefits, and increasing the economic benefits of dairy farming. Detailed Implementation

[0044] The present invention will now be described in further detail with reference to specific embodiments. The given embodiments are merely illustrative of the invention and not intended to limit its scope. The embodiments provided below can serve as a guide for further improvements by those skilled in the art and do not constitute a limitation on the invention in any way.

[0045] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0046] The Chinese Holstein dairy cows (cows) in the following examples are from Hebei Shou Nong Livestock Development Co., Ltd.

[0047] In the following examples, productive lifespan refers to the time from a cow's first calving to its departure from the herd.

[0048] In the following examples, herd lifespan refers to the time elapsed from birth to leaving the herd for a cow.

[0049] In the following examples, the reasons for leaving the herd for Chinese Holstein dairy cows (cows) were all recorded as death or culling due to illness.

[0050] Example 1: Discovery and validation of SNP loci associated with longevity traits in dairy cows I. Relevant Basic Research The inventor's research group used the genotypes and longevity phenotypes of 1109 Chinese Holstein cattle as data, and through genome-wide association analysis, discovered... PIP4P2The gene is a key candidate gene for the longevity trait (productive lifespan ~ P<2.67E-10, population lifespan ~ P<4.90E-17).

[0051] II. Genotyping A total of 670 Holstein cows from Hebei Shou Nong Livestock Development Co., Ltd. were selected as the experimental population for gene polymorphism detection. Genomic DNA was extracted from blood samples of the 670 cows and whole-genome resequencing at a sequencing depth of 30× was performed by BGI Genomics Co., Ltd. to detect SNPs across the entire genome. The sequencing data were aligned to the bovine reference genome ARS_UCD2.0 to identify SNP loci. Extraction PIP4P2 The study included 71 SNPs, covering the 10,000 bp upstream and downstream regulatory regions of the gene and all exons. Table 1 shows the 71 SNPs and their related information.

[0052] Table 1 PIP4P2 71 SNPs discovered in genes

[0053] G.73363586G>A is designated as SNP1, g.73367439C>A as SNP2, g.73372466C>T as SNP3, g.73372723T>G as SNP4, and g.73372897C>A as SNP5. All five SNPs are located in... PIP4P2 In the flanking sequence 10,000 bp upstream of the gene.

[0054] The nucleotide at SNP1 is G or A, corresponding to position 204 of SEQ ID No. 1 in the sequence listing; the nucleotide at SNP2 is C or A, corresponding to position 4057 of SEQ ID No. 1 in the sequence listing; the nucleotide at SNP3 is C or T, corresponding to position 9084 of SEQ ID No. 1 in the sequence listing; the nucleotide at SNP4 is T or G, corresponding to position 9341 of SEQ ID No. 1 in the sequence listing; the nucleotide at SNP5 is C or A, corresponding to position 9515 of SEQ ID No. 1 in the sequence listing. SEQ ID No. 1 is... PIP4P2 10,000 bp upstream of the 5' end of the gene PIP4P2 The base sequence at the 5' end of the gene.

[0055] The allele frequencies and genotype frequencies of the above 5 SNP loci are shown in Table 2.

[0056] Table 2. Allele frequencies and genotype frequencies of the five SNP loci.

[0057] III. Correlation Analysis 1. Obtaining the test group The test population consisted of 670 Chinese Holstein cows.

[0058] 2. Obtaining longevity traits The longevity trait was calculated for each cow in the tested population. The longevity trait included two indicators: productive lifespan and herd lifespan. Productive lifespan (days) = date of separation from herd - date of first calving; herd lifespan (days) = date of separation from herd = date of birth. The longevity trait phenotypes are shown in Tables 3 and 4.

[0059] Each individual's record includes, in sequence, the cattle's individual number, father number, mother number, grandfather number, grandmother number, maternal grandfather number, maternal grandmother number, date of birth, date of first calving, date of separation from the herd, pasture, age at first calving, reproductive lifespan, and lifespan in the herd.

[0060] Table 3. Descriptive statistical results of phenotypic values ​​of two longevity traits in 670 Chinese Holstein dairy cows.

[0061] Table 4. Phenotypes of some longevity traits in 670 Chinese Holstein dairy cows

[0062] 3. Association analysis between SNP sites and traits Association analysis was performed on two indicators of longevity traits—productive lifespan, population lifespan, and genotype—using the MIXED procedure in SAS 9.4 software.

[0063] The association analysis used an animal model, and the specific model for the productive lifespan trait is as follows: Y = μ + h + b× M + G + a + e.

[0064] Where Y is the productive life phenotypic value; μ is the population mean; h is the field effect; M is the effect of age at first calving; b is the regression coefficient of age at first calving on the phenotypic value; G is the genotypic effect of the SNP locus; a is the individual random additive effect; and e is the random residual effect.

[0065] The specific model for population lifetime traits is as follows: Y = μ + h + G + a + e. Where Y is the population lifetime phenotypic value; μ is the population mean; h is the field effect; G is the genotypic effect of the SNP locus; a is the individual random additive effect; and e is the random residual effect.

[0066] PIP4P2 The association analysis results of the five SNP sites of the gene with the longevity trait are shown in Table 5.

[0067] Table 5 PIP4P2 Association analysis of five gene SNPs with longevity traits (least square mean ± standard error).

[0068]

[0069] Note: Different lowercase letters in the same column indicate significant differences (P<0.05), and different uppercase letters indicate extremely significant differences (P<0.01); * indicates a significant association (P<0.05), and ** indicates an extremely significant association (P<0.01).

[0070] Table 5 shows that SNP1 (g.73363586G>A) was significantly associated with productive lifespan and herd lifespan (P<0.0001), with G being the dominant allele. GG genotype dairy cows had higher productive and herd lifespans than GA genotype dairy cows, GA genotype dairy cows had higher productive and herd lifespans than AA genotype dairy cows, and there was no significant difference in productive and herd lifespans between GG and GA genotype dairy cows. SNP2 (g.73367439C) >A) The lifespan and herd lifespan were significantly associated with the traits of productive lifespan and herd lifespan (P=0.0427~0.0374), with the dominant allele being C. Cows with the CC genotype had longer productive and herd lifespans than those with the AA genotype, while cows with the CA genotype had longer productive and herd lifespans than those with the AA genotype. There was no significant difference in productive and herd lifespan between the CC and CA genotypes. The SNP3 locus (g.73372466C>T) was highly significant with both productive and herd lifespan traits. The association was significant (P < 0.0001). With the dominant allele being T, dairy cows with the TT genotype had longer productive and herd lifespans than those with the CC genotype, and dairy cows with the CT genotype had longer productive and herd lifespans than those with the CC genotype. At SNP4 (g.73372723T>G), the association with productive and herd lifespan traits was extremely significant (P < 0.0001). With the dominant allele being T, dairy cows with the TT genotype had longer productive and herd lifespans than those with the GG genotype. There were no significant differences in productive lifespan and herd lifespan between cows with the TG genotype and cows with the GG genotype. The SNP5 locus (g.73372897C>A) was highly significantly associated with productive lifespan and herd lifespan (P<0.0001), with the dominant allele being C. C cows with the CC genotype had higher productive lifespan and herd lifespan than cows with the AA genotype, and cows with the CA genotype had higher productive lifespan and herd lifespan than cows with the AA genotype.

[0071] IV. Analysis of Genetic Effects The significance of SNP additive effects, dominant effects, and substitution effects was tested using SAA 9.4 software.

[0072] The basic calculation formulas are as follows: a = (AA - BB) / 2, d = AB - (AA + BB) / 2, α = a + d (qp); a is the additive effect, d is the dominant effect, and α is the allele substitution effect; AA, AB, and BB are the least squares mean of the longevity trait of the corresponding genotypes; p is the frequency of allele A, and q is the frequency of allele B.

[0073] The results of tests for additive effects, dominant effects, and allele substitution effects are shown in Table 6.

[0074] Table 6 PIP4P2 Results of tests for additive, dominant, and substitution effects of alleles in 5 SNPs of the gene.

[0075] Note: * indicates a significant association (P<0.05), and ** indicates a highly significant association (P<0.01).

[0076] Table 6 shows that the SNP1 locus (g.73363586G>A) has a highly significant additive effect on productive lifespan and population lifespan; the SNP2 locus (g.73367439C>A) has a significant additive effect on both productive lifespan and population lifespan; the SNP3 locus (g.73372466C>T) has a highly significant additive effect on both productive lifespan and population lifespan; the SNP4 locus (g.73372723T>G) has a highly significant additive effect on both productive lifespan and population lifespan; and the SNP5 locus (g.73372897C>A) has a highly significant additive effect on both productive lifespan and population lifespan. The significant additive effects of these five SNP loci on productive lifespan and population lifespan indicate that the influence of these mutation sites on the aforementioned longevity traits is heritable.

[0077] The molecular markers disclosed in this invention can be used to assist in the identification of dairy cow populations with excellent longevity traits (productive lifespan and herd lifespan), and have the following advantages: simple, rapid, sensitive, reliable, stable and accurate results, suitable for the needs of large-scale laboratory testing.

[0078] The present invention has been described in detail above. For those skilled in the art, the invention can be practiced in a wide range of ways with equivalent parameters, concentrations, and conditions without departing from its spirit and scope, and without requiring unnecessary experiments. Although specific embodiments have been given, it should be understood that further modifications can be made to the invention. In summary, according to the principles of the invention, this application is intended to include any changes, uses, or improvements to the invention, including changes made using conventional techniques known in the art that depart from the scope disclosed herein. Some of the essential features can be applied within the scope of the following appended claims.

Claims

1. The application of substances that detect polymorphism or genotype of at least one of five SNP loci in the identification or auxiliary identification of longevity traits in dairy cows or in the preparation of products for the identification or auxiliary identification of longevity traits in dairy cows; wherein the five SNP loci are SNP1, SNP2, SNP3, SNP4 and SNP5. The polymorphism of the SNP1 site is G or A, corresponding to the 204th nucleotide from the 5' end of SEQ ID No. 1 in the sequence listing; The polymorphism of the SNP2 site is C or A, corresponding to nucleotide 4057 from the 5' end of SEQ ID No. 1 in the sequence listing; The polymorphism of the SNP3 site is C or T, corresponding to the 9084th nucleotide from the 5' end of SEQ ID No. 1 in the sequence listing; The polymorphism of the SNP4 site is T or G, corresponding to nucleotide 9341 from the 5' end of SEQ ID No. 1 in the sequence listing; The polymorphism of the SNP5 site is C or A, corresponding to the 9515th nucleotide from the 5' end of SEQ ID No. 1 in the sequence listing.

2. The application according to claim 1, characterized in that: The longevity trait includes productive lifespan and / or population lifespan.

3. The application of substances that detect polymorphisms or genotypes at at least one of the five SNP loci in screening or assisting in the screening of long-lived dairy cows or in the preparation of products that screen or assist in the screening of long-lived dairy cows; wherein the five SNP loci are SNP1, SNP2, SNP3, SNP4, and SNP5. The polymorphism of the SNP1 site is G or A, corresponding to the 204th nucleotide from the 5' end of SEQ ID No. 1 in the sequence listing; The polymorphism of the SNP2 site is C or A, corresponding to nucleotide 4057 from the 5' end of SEQ ID No. 1 in the sequence listing; The polymorphism of the SNP3 site is C or T, corresponding to the 9084th nucleotide from the 5' end of SEQ ID No. 1 in the sequence listing; The polymorphism of the SNP4 site is T or G, corresponding to nucleotide 9341 from the 5' end of SEQ ID No. 1 in the sequence listing; The polymorphism of the SNP5 site is C or A, corresponding to the 9515th nucleotide from the 5' end of SEQ ID No. 1 in the sequence listing.

4. The application of substances that detect polymorphisms or genotypes at at least one of the five SNP loci in dairy cattle breeding or the preparation of dairy cattle breeding products; wherein the five SNP loci are SNP1, SNP2, SNP3, SNP4, and SNP5. The polymorphism of the SNP1 site is G or A, corresponding to the 204th nucleotide from the 5' end of SEQ ID No. 1 in the sequence listing; The polymorphism of the SNP2 site is C or A, corresponding to nucleotide 4057 from the 5' end of SEQ ID No. 1 in the sequence listing; The polymorphism of the SNP3 site is C or T, corresponding to the 9084th nucleotide from the 5' end of SEQ ID No. 1 in the sequence listing; The polymorphism of the SNP4 site is T or G, corresponding to nucleotide 9341 from the 5' end of SEQ ID No. 1 in the sequence listing; The polymorphism of the SNP5 site is C or A, corresponding to the 9515th nucleotide from the 5' end of SEQ ID No. 1 in the sequence listing.

5. A method for identifying or assisting in the identification of longevity traits in dairy cows, comprising any one of the following X1)-X5): X1) includes the following steps: detecting whether the genotype of the SNP1 locus of the tested dairy cow is GG, GA or AA, and judging the longevity trait of the tested dairy cow based on the genotype of the SNP1 locus: the productive lifespan and herd lifespan of dairy cows with the GG and GA genotypes are higher than those of dairy cows with the AA genotype. X2) includes the following steps: detecting whether the genotype of the SNP2 locus of the tested dairy cow is CC, CA or AA, and judging the longevity trait of the tested dairy cow based on the genotype of the SNP2 locus: dairy cows with CC and CA genotypes have a higher productive lifespan and herd lifespan than dairy cows with AA genotypes. X3) includes the following steps: detecting whether the genotype of the SNP3 locus of the tested dairy cow is TT, CT or CC, and judging the longevity trait of the tested dairy cow based on the genotype of the SNP3 locus: dairy cows with TT and CT genotypes have a higher productive lifespan and herd lifespan than dairy cows with CC genotypes. X4) includes the following steps: detecting whether the genotype of the SNP4 locus of the tested dairy cow is TT, TG or GG, and judging the longevity trait of the tested dairy cow based on the genotype of the SNP4 locus: dairy cows with TT and TG genotypes have a higher productive lifespan and herd lifespan than dairy cows with GG genotype. X5) includes the following steps: detecting whether the genotype of the SNP5 locus of the tested dairy cow is CC, CA or AA, and judging the longevity trait of the tested dairy cow based on the genotype of the SNP5 locus: dairy cows with CC and CA genotypes have a higher productive lifespan and herd lifespan than dairy cows with AA genotypes.

6. The method according to claim 5, characterized in that: The longevity trait includes productive lifespan and / or population lifespan.

7. The application of the method of claim 5 or 6 in screening or assisting in the screening of long-lived dairy cows or in dairy cow breeding.

8. A method for screening or assisting in the screening of long-lived dairy cows, comprising any one of the following Y1)-Y5): Y1) includes the step of selecting cows with the genotype GG or GA at the SNP1 locus; Y2) includes the step of selecting cows with the genotype CC or CA at the SNP2 locus; Y3) includes the step of selecting dairy cows with the genotype TT or CT at the SNP3 locus; Y4) includes the step of selecting cows with the genotype TT or TG at the SNP4 locus; Y5) includes the step of selecting cows with the genotype CC or CA at the SNP5 locus; The polymorphism of the SNP1 site is G or A, corresponding to the 204th nucleotide from the 5' end of SEQ ID No. 1 in the sequence listing; The polymorphism of the SNP2 site is C or A, corresponding to nucleotide 4057 from the 5' end of SEQ ID No. 1 in the sequence listing; The polymorphism of the SNP3 site is C or T, corresponding to the 9084th nucleotide from the 5' end of SEQ ID No. 1 in the sequence listing; The polymorphism of the SNP4 site is T or G, corresponding to nucleotide 9341 from the 5' end of SEQ ID No. 1 in the sequence listing; The polymorphism of the SNP5 site is C or A, corresponding to the 9515th nucleotide from the 5' end of SEQ ID No. 1 in the sequence listing.

9. A method for breeding dairy cows, comprising the step of using long-lived dairy cows selected according to the method of claim 5 or 6 as breeding material for breeding.

10. A product comprising a substance for detecting polymorphism or genotype at at least one of five SNP loci; said product having the function of any one of the following Z1)-Z3): Z1) Identification or auxiliary identification of longevity traits in dairy cows; Z2) Screening or assisted screening of long-lived dairy cows; Z3) Dairy cow breeding; The five SNP loci are SNP1, SNP2, SNP3, SNP4, and SNP5. The polymorphism of the SNP1 site is G or A, corresponding to the 204th nucleotide from the 5' end of SEQ ID No. 1 in the sequence listing; The polymorphism of the SNP2 site is C or A, corresponding to nucleotide 4057 from the 5' end of SEQ ID No. 1 in the sequence listing; The polymorphism of the SNP3 site is C or T, corresponding to the 9084th nucleotide from the 5' end of SEQ ID No. 1 in the sequence listing; The polymorphism of the SNP4 site is T or G, corresponding to nucleotide 9341 from the 5' end of SEQ ID No. 1 in the sequence listing; The polymorphism of the SNP5 site is C or A, corresponding to the 9515th nucleotide from the 5' end of SEQ ID No. 1 in the sequence listing.

Images