A SNP molecular marker associated with pigs reaching 115 kg body weight at age and its application

Abstract

The present invention discloses a molecular marker associated with the age at which pigs reach 115 kg of weight. The molecular marker is a G>A mutation located at the 160284793 bp site of chromosome 1 of the international porcine genome Sscrofa11.1 version or a G>A mutation represented by M at the 131st site as shown in SEQ ID NO: 1. The molecular marker is significantly associated with the age at which pigs reach 115 kg of weight. By using the molecular marker, an efficient and accurate molecular marker-assisted breeding technology can be established, which can be applied to genetic improvement of reducing the age at which breeding pigs reach 115 kg of weight, thereby increasing the growth rate of the pig population, improving the economic profit of the enterprise, and increasing core competitiveness. By optimizing the dominant allele of the SNP molecular marker, the dominant allele frequency can be increased from generation to generation, the age at which core group breeding pigs reach 115 kg of weight can be reduced, and the improvement progress of breeding pig-related growth traits can be accelerated, thereby effectively improving the economic benefits of breeding pigs.

Description

Technical Field

[0001] The present invention relates to the field of animal genetic breeding, and in particular to a SNP molecular marker associated with the age at which pigs reach 115 kg in weight and an application thereof. Background Art

[0002] The age at which pigs reach 115 kg (approximately 115 kg) is directly related to their growth performance. Slower growth rates mean they reach 115 kg (approximately 115 kg) at an older age, increasing feeding costs and reducing the economic benefits of the pig farm. Therefore, studying the age at which pigs reach 115 kg (approximately 115 kg) has important breeding research and practical implications.

[0003] Compared to traditional breeding methods based on phenotypic selection, genome-wide association studies (GWAS) using molecular markers are more efficient, rapid, and cost-effective. GWAS uses single-nucleotide polypeptide sites across the entire pig genome and genome-wide association analysis to identify genetic variation markers associated with pigs reaching 115 kg body weight per day. Ultimately, the discovered molecular markers are used in marker-assisted selection and genomic selection techniques to increase pig growth rates and enhance genetic progress in improving pig growth traits. Summary of the Invention

[0004] The purpose of the present invention is to provide a SNP molecular marker related to the age at which pigs reach 115 kg body weight and its application, so as to solve the above problems.

[0005] According to the first aspect of the present invention, a SNP molecular marker related to the age at which pigs reach a weight of 115 kg is provided. The SNP molecular marker is located at the G>A base mutation at the 160284793bp site of chromosome 1 of the international porcine genome Sscrofa11.1 version. The molecular marker is significantly correlated with the age at which pigs reach a weight of 115 kg. By using the molecular marker, an efficient and accurate molecular marker-assisted breeding technology can be established, which can be applied to the genetic improvement of reducing the age at which breeding pigs reach a weight of 115 kg, thereby improving the growth performance of the pig population, increasing the economic profit of the enterprise, and increasing core competitiveness. By optimizing the dominant allele of the SNP molecular marker, the frequency of the dominant allele can be increased from generation to generation, reducing the age at which the core group breeding pigs reach a weight of 115 kg, accelerating the improvement progress of the relevant growth traits of breeding pigs, and effectively improving the economic benefits of breeding pigs.

[0006] In certain embodiments, the upstream and downstream gene sequences of the SNP molecular marker are shown in SEQ ID NO: 1, and the SNP molecular marker is located at the G>A base mutation represented by M at the 131st position shown in SEQ ID NO: 1.

[0007] According to the second aspect of the present invention, there is provided a method for using a SNP molecular marker in breeding pig breeds with a weight of as low as 115 kg per day. The molecular marker is a G>A mutation located at the 160284793bp site of chromosome 1 of the international porcine genome Sscrofa11.1 version, or a G>A mutation represented by M located at the 131st site as shown in SEQ ID NO: 1. By screening the genotypes of reserve breeding pigs and selecting breeding pig individuals with GG or AG for expansion, the frequency of the allele G in the offspring pig population is increased generation by generation, thereby breeding pig breeds with a weight of as low as 115 kg per day. In this way, the age at which breeding pigs reach a weight of 115 kg can be reduced, thereby improving the growth performance of the offspring pig population, increasing the economic profits of the enterprise, and increasing its core competitiveness.

[0008] In some embodiments, the application comprises the following steps:

[0009] 1) Detecting a G>A mutation at position 160284793 bp on chromosome 1 or a G>A mutation represented by M at position 131 as shown in SEQ ID NO: 1 in a replacement breeding pig;

[0010] 2) retaining the breeding pig individuals with the molecular marker genotype of GG or AG in step 1), and eliminating the individuals with the AA genotype;

[0011] 3) The individuals selected in step 2) are used as sows for breeding, and the sows with the molecular marker genotype of GG or AG in step 1) are further selected from the offspring, while the individuals with the AA genotype are eliminated; thereby gradually increasing the frequency of the allele G in the offspring pig population, thereby breeding a pig breed with a body weight of as low as 115 kg per day.

[0012] According to a third aspect of the present invention, a SNP molecular marker is provided for use in screening piglets for a genetic trait of a weight-at-age of less than 115 kg. The SNP molecular marker is a T>C mutation located at the 160284793bp site on chromosome 1 of the international porcine genome Sscrofa11.1. By screening the genotype of the molecular marker in the piglets to be tested, piglets with a genetic trait of a weight-at-age of less than 115 kg can be selected for breeding at the piglet stage. This allows the pig herd to be sorted at the piglet stage, and individual piglets with GG or AG genes to be raised as replacement pigs, effectively reducing the number of piglets in the reserve pig group that reach a weight of 115 kg, thereby achieving better economic value.

[0013] In some embodiments, the application comprises the following steps:

[0014] 1) Detecting a G>A mutation at position 160284793 bp of chromosome 1 or a G>A mutation represented by M at position 131 as shown in SEQ ID NO: 1 in the piglets to be screened;

[0015] 2) When the genotype of the molecular marker detected in step 1) is GG or AG, the piglets to be screened have a genetic trait of weight-per-day as low as 115 kg and are retained; when the genotype is AA, the piglets to be screened have a genetic trait of weight-per-day as high as 115 kg and are eliminated.

[0016] According to a fourth aspect of the present invention, there is provided a method for genetic improvement of pigs for reducing the age at which they reach 115 kg body weight, wherein the method comprises the following steps:

[0017] 1) Detecting a G>A mutation at position 160284793 bp on chromosome 1 or a G>A mutation represented by M at position 131 as shown in SEQ ID NO: 1 in a replacement breeding pig;

[0018] 2) retaining the breeding pig individuals with the molecular marker genotype of GG or AG in step 1), and eliminating the individuals with the AA genotype;

[0019] 3) The individuals selected in step 2) are used as sows for breeding, and the sows with the molecular marker genotype of GG or AG in step 1) are continuously selected from the offspring, while the individuals with the AA genotype are eliminated; thereby gradually increasing the frequency of the allele G in the offspring pig population, thereby reducing the age at which the offspring pigs reach a weight of 115 kg.

[0020] This method can effectively reduce the pig's weight-at-age trait of 115 kg, increase the pig's growth rate, and improve the market competitiveness and market economic value of the pig breed.

[0021] According to a fifth aspect of the present invention, a primer pair is provided for detecting a G>A mutation located at position 160284793 bp on chromosome 1 or a G>A mutation represented by M at position 131 as shown in SEQ ID NO: 1 in pigs, wherein the nucleotide sequence of the primer pair is as follows:

[0022] P001-F: 5'-GAGAGAGCACAGTAGATGGTGTCAG-3',

[0023] P002-R: 5'-GCTTCTTCCTGAGTTCCAGGTCAC-3'.

[0024] This primer pair can be used to efficiently detect SNP molecular markers associated with pigs reaching a weight of 115 kg. This can establish efficient and accurate molecular marker-assisted breeding technology, quickly and accurately improve the sexual selection of breeding pigs as low as 115 kg in weight, and accelerate breeding progress.

[0025] According to a sixth aspect of the present invention, a kit is provided for detecting a G>A mutation located at position 160284793 bp on chromosome 1 or a G>A mutation represented by M at position 131 as shown in SEQ ID NO: 1 in pigs, wherein the kit comprises the following primer pairs:

[0026] P001-F: 5'-GAGAGAGCACAGTAGATGGTGTCAG-3',

[0027] P002-R: 5'-GCTTCTTCCTGAGTTCCAGGTCAC-3'.

[0028] This kit can be used to efficiently detect SNP molecular markers associated with pigs reaching a weight of 115 kg. It can also establish efficient and accurate molecular marker-assisted breeding technology, quickly and accurately improve the sexual selection of breeding pigs as low as 115 kg in weight, and accelerate breeding progress.

[0029] According to a seventh aspect of the present invention, there is provided a primer pair for use in identifying the trait of pigs reaching 115 kg body weight at day of age, wherein the use comprises the following steps:

[0030] 1) PCR was performed on the pigs to be tested using a primer pair, and then genotyping was performed on the PCR products. The primer pair was:

[0031] P001-F: 5'-GAGAGAGCACAGTAGATGGTGTCAG-3',

[0032] P002-R: 5'-GCTTCTTCCTGAGTTCCAGGTCAC-3';

[0033] 2) When the genotype detected in step 1) is GG or AG genotype, the pig to be tested has a genetic trait of a weight-per-day age as low as 115 kg; when the genotype detected is AA genotype, the pig to be tested has a genetic trait of a weight-per-day age as high as 115 kg.

[0034] This primer pair can be used to efficiently detect SNP molecular markers related to pigs reaching 115 kg body weight. It can also be used to establish efficient and accurate molecular marker-assisted breeding technology, quickly and accurately improve the sexual selection of breeding pigs as low as 115 kg body weight, and accelerate breeding progress.

[0035] According to an eighth aspect of the present invention, there is provided a SNP molecular marker, a primer pair for detecting the molecular marker, or a kit containing the primer pair for use in screening pigs for the 115 kg weight-at-age trait, identifying the 115 kg weight-at-age trait in pigs, breeding pigs with the 115 kg weight-at-age trait, reducing the 115 kg weight-at-age trait in pigs, and genetically improving pig growth traits. Thus, using the SNP molecular marker, the primer pair for detecting the molecular marker, or the kit containing the primer pair, efficient and accurate molecular marker-assisted breeding technology can be established, allowing for rapid and accurate selection and improvement of breeding pigs with the 115 kg weight-at-age trait, thereby accelerating breeding progress.

[0036] Beneficial effects of the present invention:

[0037] 1. A new molecular marker associated with the age at which pigs reach 115 kg in weight is disclosed. The molecular marker is a G>A mutation located at the 160284793bp site of chromosome 1 of the international porcine genome Sscrofa11.1 version, or a G>A mutation represented by M at the 131st site as shown in SEQ ID NO: 1. The molecular marker is significantly associated with the age at which pigs reach 115 kg in weight. By using the molecular marker, an efficient and accurate molecular marker-assisted breeding technology can be established, which can be applied to genetic improvement to reduce the age at which sows reach 115 kg in weight, thereby improving the growth performance of the pig population, increasing the economic profits of the enterprise, and increasing core competitiveness. By optimizing the dominant allele of the SNP molecular marker, the dominant allele frequency can be increased from generation to generation, reducing the age at which core group sows reach 115 kg in weight, accelerating the improvement of sow-related growth traits, and effectively improving the economic benefits of sow breeding.

[0038] 2. Disclosed is the application of this molecular marker in breeding pig breeds with weights as low as 115 kg per day. By screening the genotypes of reserve breeding pigs and selecting GG or AG individuals for multiplication, the frequency of the G allele in the subsequent pig population is gradually increased, thereby breeding pig breeds with weights as low as 115 kg per day. This can reduce the age at which breeding pigs reach 115 kg, thereby improving the growth performance of subsequent pig populations, increasing the company's economic profits, and enhancing its core competitiveness.

[0039] 3. Disclosed is the application of this molecular marker in screening piglets for the genetic trait of weighing as little as 115 kg at day-of-age. By screening the genotype of the molecular marker in the piglets to be tested, piglets with the genetic trait of weighing as little as 115 kg at day-of-age can be selected for breeding at the piglet stage. This allows for sorting the pig herd at the piglet stage, and individual piglets with GG or AG genes are raised as replacement pigs, effectively reducing the number of piglets in the reserve pig population that reach 115 kg at day-of-age, thereby achieving better economic value.

[0040] 4. A genetic improvement method for reducing the age at which pigs reach 115 kg in weight is disclosed. This method can effectively reduce the age at which pigs reach 115 kg in weight, increase the growth rate of pigs, and improve the market competitiveness and market economic value of pig breeds.

[0041] 5. Disclosed is a primer pair for detecting SNP molecular markers associated with the age at which pigs reach a weight of 115 kg. This primer pair can be used to efficiently detect SNP molecular markers associated with the age at which pigs reach a weight of 115 kg, establish an efficient and accurate molecular marker-assisted breeding technology, and quickly and accurately perform sexual selection and improvement on breeding pigs as low as 115 kg in weight, thereby accelerating breeding progress.

[0042] 6. Disclosed are a SNP molecular marker and a kit for detecting SNPs associated with the age at which pigs reach a weight of 115 kg. The kit can be used to efficiently detect SNP molecular markers associated with the age at which pigs reach a weight of 115 kg, establish an efficient and accurate molecular marker-assisted breeding technology, and quickly and accurately perform sexual selection and improvement on breeding pigs as low as 115 kg in weight, thereby accelerating breeding progress.

[0043] 7. Disclosed is the application of a primer pair for detecting SNP molecular markers associated with the age at which pigs reach a weight of 115 kg in identifying the trait of the age at which pigs reach a weight of 115 kg. This primer pair can efficiently detect SNP molecular markers associated with the age at which pigs reach a weight of 115 kg, establish an efficient and accurate molecular marker-assisted breeding technology, quickly and accurately carry out sexual selection and improvement of breeding pigs as low as 115 kg in weight, and accelerate breeding progress.

[0044] 8. Disclosed are the uses of a SNP molecular marker associated with the age at which pigs reach 115 kg, a primer pair for detecting the molecular marker, or a kit containing the primer pair for screening pigs for the 115 kg age trait, identifying pigs for the 115 kg age trait, breeding pigs for the 115 kg age trait, reducing the 115 kg age trait in pigs, and genetically improving pig growth traits. Using the SNP molecular marker, the primer pair for detecting the molecular marker, or the kit containing the primer pair, efficient and accurate molecular marker-assisted breeding technology can be established, allowing for rapid and accurate selection and improvement of breeding pigs for the 115 kg age trait, accelerating breeding progress. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 Manhattan plot of genome-wide association analysis of Large White, Landrace and Duroc pigs on chromosome 1 for the trait of age at reaching 115 kg body weight; the horizontal axis represents the chromosomal position of the pig; the vertical axis represents the -logP value. DETAILED DESCRIPTION

[0046] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0047] Example 1

[0048] (1) Experimental animals

[0049] The experimental pig herd used in the present invention is a total of 2,990 purebred Large White pigs, Landrace pigs and Duroc pigs of Guangdong Guangken Animal Husbandry Group Co., Ltd., which is the core herd of the company.

[0050] In this experiment, Large White pigs, Landrace pigs and Duroc pigs were selected from this resource group. The pigs were allowed to eat and drink freely, and the entire feeding method and breeding conditions were always kept consistent, which was a conventional method.

[0051] (2) Sample collection

[0052] The tail or ear tissues of the above piglets were collected and immersed in a 75% ethanol solution, and stored in a -20°C refrigerator for later use.

[0053] (3) Pig whole genome 50k SNP chip typing

[0054] Ear tissue or tail tissue was collected from each of the 2,990 Large White, Landrace, and Duroc pigs in the above-mentioned resource population. Whole-genome DNA was extracted using the standard phenol-chloroform method. The DNA concentration and OD ratio (OD260 / 280, OD260 / 230) of each sample were accurately measured using a Nanodrop2000 / 2000C nucleic acid protein detector. DNA samples that passed the NanoDrop2000 / 2000C nucleic acid protein detector were diluted to approximately 50 ng / μL according to the test concentration. Six μL of the extracted DNA sample to be tested was then mixed with 2 μL of Loading Buffer and loaded onto a 1% mass-to-volume agarose gel. Electrophoresis was performed at 150 V for 25 minutes. The DNA integrity was observed and photographed using a UV spectrophotometer and gel imaging equipment.

[0055] DNA samples were sent to Beijing Compson Biotechnology Co., Ltd. for genotyping using a porcine whole genome 50k SNP chip (SMIC No. 1 breeding chip, Beijing Compson Biotechnology Co., Ltd.). According to strict quality control standards, individuals with a detection rate below 90%, a family Mendelian error rate above 0.1, a minimum allele frequency below 0.05, and a Hardy-Weinberg equilibrium significance level above 10 were eliminated. -6 Finally, valid genotype data of 27,843 SNPs were obtained.

[0056] (4) Genome-wide association (GWAS) analysis

[0057] In order to eliminate the population stratification effect, the present invention uses gcta software to calculate the principal component characteristic quantities of all individuals based on the whole genome sequence information, and uses the first three principal components and sex as covariates to correct the impact of potential population stratification on the results. The present invention uses the linear mixed model in GEMMA software to perform GWAS analysis of the age-to-weight trait of reaching 115 kg. The Bonferrini method is used to determine the significance threshold of the degree of association between SNP and the age-to-weight trait of reaching 115 kg. The genome-level significance threshold is 0.05 divided by the number of effective SNP sites, that is, the genome-level significance threshold is 1.80E-06, that is, 0.05 / 27843 (effective SNP number); the chromosome-level significance threshold is 1 divided by the number of effective SNP sites, that is, the chromosome-level significance threshold is 3.59E-05, that is, 1 / 27843 (effective SNP number).

[0058] GWAS analysis results are as follows Figure 1 As shown. Figure 1 It can be seen that there is a site on chromosome 1 in the Large White, Landrace and Duroc pig populations that significantly affects the age of pigs reaching 115 kg body weight (the site is located at the 160284793bp T>C mutation on chromosome 1 of the international porcine genome Sscrofa11.1 version). The upstream and downstream gene sequences of the significantly associated SNP site are shown in SEQ ID No: 1, wherein the SNP site is located at the 131st site of the sequence shown in SEQ ID No: 1, which is a T>C mutation represented by M. The molecular marker can be abbreviated as g.131G>A mutation (P value is 3.08e-07) in the text. The upstream and downstream gene sequences of the SNP are shown in SEQ ID No: 1:

[0059]

[0060] Note: The M marked in the sequence table is the mutation site. The M site is a G>A mutation, which is displayed in bold font (the mutated base in brackets, i.e., allele mutation). The underline + italic font at the beginning and end of the sequence indicates the position of the designed primer sequence.

[0061] (5) Correlation analysis between different genotypes and phenotypes at age of 115 kg

[0062] Table 1 shows that the molecular marker g.131G>A is highly significantly correlated with the age at 115 kg (P<0.001) in pigs, indicating that this molecular marker significantly affects the age at 115 kg (P<0.001). Selecting for this SNP in pigs could reduce the age at 115 kg (P<0.01), thereby accelerating breeding efforts. Furthermore, Table 1 shows that individuals with the GG genotype reach 115 kg at a lower age than those with the AG and AA genotypes, and that the two traits vary synergistically. The mean phenotypic values ​​for GG individuals are 2.57 and 5.68 lower than those for AG and AA, respectively. Furthermore, the results of an analysis of variance (ANOVA) based on the two phenotypes indicate that the distribution of the age at 115 kg (P<0.01) phenotypes among the three genotypes is highly significantly different (P<0.01). Therefore, gradually retaining the TT genotype of breeding pigs in order to increase the frequency of allele G at this site from generation to generation can significantly reduce the age at which breeding pigs reach 115 kg in weight, thus bringing more economic benefits to breeding companies.

[0063] Table 1 Statistical analysis of the molecular marker mutation site 160284793 on chromosome 1 and the age at which the weight reaches 115 kg

[0064]

[0065] Note: *** indicates extremely significant difference

[0066] Example 2 Target DNA sequence amplification and sequencing

[0067] (1) Primer design

[0068] The DNA sequence of SEQ ID NO: 1 on porcine chromosome 1 was downloaded from the Ensembl website (http: / / asia.ensembl.org / index.html), and primers were designed using the primer design software Oligo 7. The DNA sequences of the designed primers are shown below:

[0069] P001-F: 5'-GAGAGAGCACAGTAGATGGTGTCAG-3' (SEQ ID NO: 2),

[0070] P002-R: 5'-GCTTCTTCCTGAGTTCCAGGTCAC-3' (SEQ ID NO: 3);

[0071] (2) PCR amplification

[0072] To a 10 μL reaction system, add 1 μL of DNA template, 3.4 μL of double-distilled water, 5 μL of 2× Tag PCR StanMix with Loading Dye, and 0.3 μL each of primers P001-F and P002-R. PCR reaction conditions were: 94°C denaturation for 5 minutes, followed by 35 cycles of denaturation at 94°C for 30 seconds, annealing at 57.6°C for 30 seconds, and extension at 72°C for 45 seconds, with a final extension at 72°C for 5 minutes.

[0073] (3) DNA sequence determination

[0074] DNA sequencing was performed at Shenzhen BGI Genomics Co., Ltd., using both forward and reverse reactions. The resulting sequence was compared with the NCBI genome sequence to identify mutations at the corresponding SNP sites. Sequencing results were consistent with SEQ ID NO: 1.

[0075] Example 3 Analysis of the molecular marker g.131G>A effect

[0076] As shown in Table 1, the dominant allele type GG of the molecular marker g.131G>A can reduce the age of reaching 115 kg by 5.68 days compared with the inferior allele type AA. Therefore, through molecular marker-assisted selection or genomic selection, gradually selecting and retaining pigs with the GG type within the population can significantly increase the frequency of the dominant allele G, thereby facilitating the reduction of the age of reaching 115 kg in breeding pigs, accelerating the breeding and improvement process of pigs, and ultimately effectively improving the economic benefits of breeding pigs.

[0077] Example 4 Application of molecular marker g.131G>A in breeding pig breeds with a body weight as low as 115 kg

[0078] 1) Detection of molecular marker g.131G>A genotype in reserve breeding pigs;

[0079] 2) retaining the breeding pig individuals with the molecular marker genotype of GG or AG in step 1), and eliminating the individuals with the AA genotype;

[0080] 3) The individuals selected in step 2) are used as sows for breeding, and the sows with the molecular marker genotype of GG or AG in step 1) are further selected from the offspring, while the individuals with the AA genotype are eliminated; thereby gradually increasing the frequency of the allele G in the offspring pig population, thereby breeding a pig breed with a body weight of as low as 115 kg per day.

[0081] Example 5 Application of molecular marker g.131G>A in screening piglets with genetic traits as low as 115 kg body weight at day age

[0082] 1) Detection of molecular marker g.131G>A in the pigs to be screened;

[0083] 2) When the genotype of the molecular marker detected in step 1) is GG or AG, the pig to be screened has a genetic trait of weight-per-day age as low as 115 kg and is retained; when the genotype is AA, the pig to be screened has a genetic trait of weight-per-day age as high as 115 kg and is eliminated.

[0084] Example 6 A genetic improvement method for reducing the age of pigs reaching 115 kg body weight

[0085] 1) Detection of molecular marker g.131G>A in reserve breeding pigs;

[0086] 2) retaining the breeding pig individuals with the molecular marker genotype of GG or AG in step 1), and eliminating the individuals with the AA genotype;

[0087] 3) The individuals selected in step 2) are used as sows for breeding, and the sows with the molecular marker genotype of GG or AG in step 1) are continuously selected from the offspring, while the individuals with the AA genotype are eliminated; thereby gradually increasing the frequency of the allele G in the offspring pig population, thereby reducing the age at which the offspring pigs reach a weight of 115 kg.

[0088] Example 7 Application of the Primer Pair Detecting Molecular Marker g.131G>A in Identifying Pigs Reaching 115 kg Weight at Days of Age

[0089] 1) performing PCR on the pig to be tested using the primer pair of SEQ ID NO: 2 / SEQ ID NO: 3, and then performing genotyping detection on the PCR product;

[0090] 2) When the genotype detected in step 1) is GG or AG genotype, the pig to be tested has a genetic trait of a weight-per-day age as low as 115 kg; when the genotype detected is AA genotype, the pig to be tested has a genetic trait of a weight-per-day age as high as 115 kg.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. Application of SNP molecular markers in breeding pig breeds with a body weight of 115 kg at a young age, including: The upstream and downstream gene sequences of the SNP molecular marker are shown in SEQ ID NO: 1, and the SNP molecular marker is located at the 131st site shown in SEQ ID NO: 1, where the base mutation G>A is represented by M. The application comprises the following steps: 1) Detection of SNP molecular markers in replacement breeding pigs; 2) Select the breeding pigs with molecular marker genotypes of GG or AG in step 1) and eliminate the individuals with AA genotype; 3) The individuals selected in step 2) are used as breeding pigs for breeding, and the breeding pigs with the molecular marker genotype of GG or AG in step 1) are continued to be selected from the offspring, and the individuals with the AA genotype are eliminated; so as to increase the frequency of the allele G in the offspring pig population generation by generation, thereby breeding a pig breed with a body weight of 115 kg at a young age.

2. Application of SNP molecular markers in screening piglets with low-grade traits up to 115 kg body weight per day, including: The upstream and downstream gene sequences of the SNP molecular marker are shown in SEQ ID NO: 1, and the SNP molecular marker is located at the 131st site shown in SEQ ID NO: 1, where the base mutation G>A is represented by M. The application comprises the following steps: 1) Detecting the SNP molecular markers in the piglets to be screened; 2) When the genotype of the molecular marker detected in step 1) is GG or AG, the piglet to be screened has a low genetic trait of reaching a weight of 115 kg per day and is retained; when the genotype is AA, the piglet to be screened has a high genetic trait of reaching a weight of 115 kg per day and is eliminated.

3. Use of a primer pair for detecting SNP molecular markers or a kit containing the primer pair in screening or identifying pigs with a body weight of 115 kg at day age, wherein: The upstream and downstream gene sequences of the SNP molecular marker are shown in SEQ ID NO: 1, and the SNP molecular marker is located at the 131st site shown in SEQ ID NO: 1, where the base mutation G>A is represented by M.

4. The use according to claim 3, wherein The nucleotide sequences of the primers are as follows: P001-F: 5'-GAGAGAGCACAGTAGATGGTGTCAG-3', P002-R: 5'-GCTTCTTCCTGAGTTCCAGGTCAC-3'.

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