SNP (Single Nucleotide Polymorphism) molecular marker related to healthy piglet number character of pig and application of SNP molecular marker

Abstract

The invention provides an SNP (Single Nucleotide Polymorphism) molecular marker related to the character of the number of healthy piglets of a pig and application, and relates to the technical field of biology. According to the application, a substance for detecting the SNP sites is applied to preparation of a product for predicting the character of the number of healthy piglets born by pigs, and the SNP sites comprise one or more of the SNP site rs318687930 and the SNP site rs329759452. The SNP sites are related to the character of healthy litter size of the pigs, and can be used for predicting the character of healthy litter size of the pigs and screening and breeding sows with the character of high healthy litter size and low abnormal litter size.

Description

Technical Field

[0001] The present invention relates to the field of biotechnology, and in particular to a SNP molecular marker associated with the trait of healthy piglet number and an application thereof. Background Art

[0002] The following statements merely provide background information related to the present disclosure and do not necessarily constitute prior art.

[0003] Pig fertility traits are important indicators for measuring the reproductive capacity of sows, including litter size, piglet birth weight, number of teats, lactation capacity (21-day-old litter weight) and number of finished piglets at weaning, etc. These traits are extremely important for the pig farming industry. Good fertility performance of sows means that each sow can produce more healthy piglets within a certain period of time, which can reduce breeding costs and improve production efficiency.

[0004] The trait of healthy piglets born is of great significance for the evaluation of sow reproductive efficiency and pig breeding. By studying the trait of healthy piglets born, we can screen out breeding pigs with high potential for healthy piglets, accelerate the transmission and fixation of excellent genes, improve the reproductive capacity of the pig herd, and provide a scientific basis for breeding and genetic improvement of breeding pigs.

[0005] Therefore, the identification of genes related to pig litter size can provide important clues for explaining the genetic mechanisms of fetal growth and development in pigs and other mammals, and provide a theoretical basis for the genetic improvement of pig reproductive traits.

[0006] In view of this, the present invention is proposed. Summary of the invention

[0007] The purpose of the present invention is to overcome the defects of the prior art and provide a SNP molecular marker related to the pig litter size trait and its application.

[0008] In order to solve the above technical problems, the present invention particularly adopts the following technical solutions:

[0009] In a first aspect, a method for preparing a product for predicting pig litter size is provided, wherein the SNP site comprises one or more of SNP site rs318687930 and SNP site rs329759452.

[0010] In a second aspect, a kit for predicting piglet size is provided, the kit comprising at least one of the following primer pairs:

[0011] The primer pair used to amplify the SNP site rs318687930 has nucleotide sequences shown in SEQ ID NOs. 1 and 2, respectively; and, the primer pair used to amplify the SNP site rs329759452 has nucleotide sequences shown in SEQ ID NOs. 3 and 4, respectively.

[0012] In a third aspect, a method for predicting the trait of healthy piglet number in pigs is provided, the method comprising predicting a sow that meets at least one of (i) and / or (ii) as a sow with a high trait of healthy piglet number:

[0013] (i) The genotype of SNP site rs318687930 is GA;

[0014] (ii) The genotype of SNP site rs329759452 is AA.

[0015] In a fourth aspect, a method for screening sows with high productivity and healthy piglet number traits is provided, the screening method comprising screening sows with high productivity and healthy piglet number traits predicted by the method described in the third aspect.

[0016] In a fifth aspect, a method for breeding sows with high-yield and healthy piglet number traits is provided, the breeding method comprising enabling the sow to obtain at least one of the following genotypes:

[0017] (i) The genotype of SNP site rs318687930 is GA;

[0018] (ii) The genotype of SNP site rs329759452 is AA.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention uses low-depth resequencing and whole-genome association analysis methods to find SNP molecular markers related to pig litter size traits, and finds that two SNP sites rs318687930 and SNP site rs329759452 are related. Sows with specific genotypes at the above two sites have higher healthy piglets. This SNP molecular marker related to pig litter size traits can be used to predict pig litter size traits and screen sows with high litter size traits, as well as a breeding method for obtaining sows with high litter size traits. The use of this SNP site helps to improve the reproductive performance of sows and bring higher economic benefits to the pig farming industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 This is a genotype detection peak diagram obtained by capillary electrophoresis detection of SNP site rs318687930 in an embodiment of the present invention;

[0023] Figure 2 This is a genotype detection peak diagram obtained by capillary electrophoresis detection of SNP site rs329759452 in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] cAMP response element binding protein 3 (CREB3 regulatory factor, CREBRF), also known as Luman / CREB3 recruiting factor (Luman recruiting factor, LRF), is a regulatory factor of Luman / CREB3 protein (cyclic adenosinemonophosphate response element binding protein 3, Luman / CREB3). Studies have shown that the prolactin level of CREBRF knockout mice is significantly lower than that of normal mice, glucocorticoid signaling is affected, maternal behavior is severely defective, and the instinct to care for pups is lacking. The CREBRF gene is expressed at a high level in the ovaries and uterus during estrus and metestrus, suggesting that CREBRF may be involved in cell differentiation, embryonic development and implantation. Another study showed that CREBRF can participate in regulating the apoptosis of GCs by mediating the ERS pathway and plays a key role in mouse follicle selection. The expression of CREBRF can be inhibited by E2, but can be induced by P4, and CREBRF can regulate decidualization during pregnancy by regulating the proliferation of mouse uterine stromal cells. Therefore, the CREBRF gene plays an important regulatory role in animal growth, development and reproduction, especially in follicle growth and development, cell differentiation, embryonic development and implantation. Moreover, the polymorphism of the CREBRF gene SNP site is related to the estrogen level, and then the hormone level is used to regulate the reproductive efficiency of sows. The number of healthy piglets is an important indicator for measuring the reproductive traits of sows, so the present invention explores the correlation between the single nucleotide polymorphism site of the CREBRF gene and the number of healthy piglets.

[0026] The present invention uses low-depth resequencing and whole-genome association analysis methods to conduct association analysis on the polymorphism of the CREBRF gene and important reproductive traits, and finds SNP molecular markers significantly associated with the pig litter size trait in the pig genome. The present invention found that two SNP sites, rs318687930 and rs329759452, are associated with the pig litter size trait.

[0027] The SNP site rs318687930 of the porcine CREBRF gene is the nucleotide at position 51174074 on chromosome 16 of the pig (the reference genome is Sscrofa11.1). When the genotype of this SNP site is GA, that is, the nucleotide at position 51174074 on chromosome 16 of the pig is a heterozygous of G and A, the sow has the trait of high number of healthy piglets per litter.

[0028] The SNP site rs329759452 of the porcine CREBRF gene is the nucleotide at position 51221411 on chromosome 16 of the pig (the reference genome is Sscrofa11.1). When the genotype of this SNP site is AA, the sow has the trait of low number of primiparous deformities.

[0029] In this article, "healthy piglets" refers to the number of piglets born by a mother animal after giving birth that are not only alive but also healthy and have no obvious physical defects or diseases. This indicator is an important parameter for measuring the reproductive quality of mother animals and the survival ability of offspring, especially in livestock farming to evaluate reproductive efficiency and the initial health status of young animals. "High healthy piglets" refers to the number of healthy piglets born that is higher than the average number of healthy piglets born for the breed.

[0030] In this article, "birth deformity" refers to the number of piglets born during the birthing process of the mother animal with obvious morphological or structural abnormalities. These deformities can affect any part of the piglet's body, including but not limited to the head, limbs, internal organs, etc., and usually result in the piglets being unable to survive or develop normally. "Low birth deformity" means the birth deformity is lower than the average birth deformity for the breed.

[0031] Unlike the number of piglets born alive, the number of healthy piglets born focuses more on the quality of piglets rather than just the number. Healthy piglets have better survival ability and growth potential, which means higher breeding success rate and economic benefits for farmers. Therefore, improving the number of healthy piglets born is not only a matter of increasing the number of piglets, but more importantly, it is to ensure that these piglets can grow healthily, thus providing a high-quality population foundation for subsequent fattening or reproduction.

[0032] Based on the above findings, in a first aspect, a method is provided for using a substance for detecting SNP sites in preparing a product for predicting piglet size, wherein the SNP sites include one or more of SNP sites rs318687930 and SNP sites rs329759452.

[0033] In an optional embodiment, the trait of healthy piglets born by pigs includes at least one of the following: the number of healthy piglets born in the first parity, the number of healthy piglets born in multiple parities, and the number of deformed piglets.

[0034] In an optional embodiment, the product includes a substance for detecting the SNP site rs318687930, and the trait of healthy piglet number includes the number of healthy piglets born at first birth.

[0035] In an optional embodiment, the product includes a substance for detecting the SNP site rs329759452, and the trait of healthy piglet birth includes the number of deformities.

[0036] In an optional embodiment, the product includes substances for detecting: SNP site rs318687930 and SNP site rs329759452.

[0037] In an optional embodiment, the substance for detecting SNP sites includes, but is not limited to, one or more of reagents for nucleic acid amplification, reagents for detecting nucleic acid amplification products, reagents for constructing sequencing libraries, and reagents for sequencing. More specifically, the substance for detecting SNP sites includes, but is not limited to, primers, probes, enzymes for nucleic acid amplification reactions, fluorescent markers, buffer reagents, dNTPs, salts, etc. Depending on the specific detection means, those skilled in the art can select the above-mentioned reagents for nucleic acid amplification, reagents for detecting nucleic acid amplification products, reagents for constructing sequencing libraries, and reagents for sequencing according to general and more specific teaching materials, references, process manuals, product descriptions, and standard documents, etc., and the present invention does not limit this.

[0038] In an optional embodiment, the material for detecting SNP sites includes at least one of the following primer pairs: a primer pair for amplifying SNP site rs318687930, whose nucleotide sequences are shown in SEQ ID NOs. 1 and 2, respectively; and a primer pair for amplifying SNP site rs329759452, whose nucleotide sequences are shown in SEQ ID NOs. 3 and 4, respectively.

[0039] In the second aspect, a kit for predicting the piglet size trait is provided, which comprises at least one of the following primer pairs: a primer pair for amplifying the SNP site rs318687930, the nucleotide sequences of which are shown in SEQ ID NOs. 1 and 2, respectively; and a primer pair for amplifying the SNP site rs329759452, the nucleotide sequences of which are shown in SEQ ID NOs. 3 and 4, respectively.

[0040] In a third aspect, a method for predicting the trait of healthy piglet number in pigs is provided, the method comprising predicting a sow that meets (i) and / or (ii) as a sow with a high trait of healthy piglet number:

[0041] (i) The genotype of SNP site rs318687930 is GA;

[0042] (ii) The genotype of SNP site rs329759452 is AA.

[0043] In an optional embodiment, the method comprises predicting the sows meeting the above (i) and (ii) as sows having the trait of high productivity and healthy piglet number.

[0044] In an optional embodiment, the method for predicting the trait of healthy piglet number in pigs comprises predicting a sow whose genotype at SNP site rs318687930 is GA as a sow having a trait of high healthy piglet number in primiparity.

[0045] In an optional embodiment, the method for predicting the trait of healthy piglet number predicts sows with a genotype of AA at the SNP site rs329759452 as sows with a low number of deformities.

[0046] The method for predicting the pig litter size trait provided in the third aspect includes using one or more of the SNP site rs318687930 and the SNP site rs329759452 as the only identification target; it can also be combined with other targets, such as other polymorphic molecular markers (such as SSR molecular markers, STR molecular markers or InDel molecular markers), or other screening methods known in the art to assist in the prediction of the pig litter size trait.

[0047] In a fourth aspect, a method for screening sows with high productivity and healthy piglet number traits is provided, comprising screening sows with high productivity and healthy piglet number traits predicted by the method described in the third aspect.

[0048] In a fifth aspect, a method for breeding sows with high-yield and healthy litter size traits is provided, the breeding method comprising enabling the sow to obtain at least one of the following genotypes:

[0049] (i) The genotype of SNP site rs318687930 is GA;

[0050] (ii) The genotype of SNP site rs329759452 is AA.

[0051] The specific means for obtaining a specific genotype in a sow can be achieved by a person skilled in the art using conventional methods known in the art, and the present invention is not limited thereto. In an optional embodiment, an offspring with a target genotype is obtained by obtaining a parent with a known genotype. In an optional embodiment, an offspring with a target genotype is obtained by a gene editing method.

[0052] In an optional embodiment, the pig in any of the above embodiments is a Large White pig.

[0053] The present invention is further described below by means of specific examples. However, it should be understood that these examples are only used for more detailed description and should not be construed as limiting the present invention in any form.

[0054] Example 1

[0055] 1. Experimental sample collection

[0056] The experimental population of this embodiment is 226 British Large White pigs from Shandong Rizhao Breeding Farm, 165 Canadian Large White pigs from Xinjiang Tiankang Jiamei Breeding Branch, and 199 Danish Large White pigs from the great-grandparent breeding farm of Xinjiang Tiankang Animal Husbandry Technology Co., Ltd. A total of 590 Large White pigs were used for CREBRF gene SNP typing. Ear tissue samples were collected one by one, placed in 75% alcohol and stored at -20°C for DNA extraction.

[0057] 2. Extraction and library construction of porcine genomic DNA

[0058] (1) Take an appropriate amount of pig ear tissue, chop it into small pieces and place it into a 1.5 mL Axgen tube.

[0059] (2) Take a 50 mL BD centrifuge tube, mix proteinase K with a final concentration of 0.4 mg / mL and lysis buffer, and add 0.5 mL of lysis buffer to the 1.5 mL centrifuge tube containing pig ear tissue for lysis.

[0060] (3) Place the centrifuge tubes evenly and in parallel on the rocking plate of the constant temperature hybridization oven (close the tube lid tightly to prevent liquid leakage). Place at 55°C for more than 6 hours (it is very important to fully mix the samples during the digestion process. The basis for judgment is that there is no obvious pig ear tissue visible to the naked eye and the mixed solution after digestion is milky).

[0061] (4) After the samples are fully lysed, remove the centrifuge tubes and add 0.3 mL of saturated sodium chloride solution to each tube. Invert and mix thoroughly 6-8 times, then place on ice and place in an ice bath for 15 minutes.

[0062] (5) After the ice bath, centrifuge at 12,000 rpm for 15 minutes at room temperature. Carefully and slowly transfer the supernatant to a new 1.5 mL Axgen centrifuge tube (be careful to avoid pouring out the precipitate with the supernatant. Keep the pouring technique consistent and keep the amount of supernatant in each tube the same).

[0063] (6) Add 0.7 mL of isopropanol (the amount of isopropanol added varies with the amount of supernatant poured out, and the two are equal in volume) to each tube and invert until flocculent precipitation appears in the solution (if no flocculent precipitation occurs, the solution can be placed in a -20°C refrigerator for 2 hours or in a 4°C refrigerator overnight).

[0064] (7) Centrifuge at 12000 rpm for 15 minutes at room temperature and remove the supernatant.

[0065] (8) Add 0.5 mL of 70% ethanol to each centrifuge tube and gently invert to fully rinse the precipitated DNA.

[0066] (9) Centrifuge at 10,000 rpm for 30 seconds. Use a 200 μL micropipette to remove the ethanol in the centrifuge tube, leaving the precipitated DNA in the tube.

[0067] (10) Air-dry the DNA for 10 minutes.

[0068] (11) Use a pipette to add 0.1 mL of TE buffer to each tube, redissolve the DNA precipitate, and place it at 55°C for 2 hours, shaking it several times periodically to fully dissolve the DNA.

[0069] (12) After the DNA is fully dissolved, the concentration is measured by UV spectrophotometer, and the quality is tested by agarose gel electrophoresis. The quality of the DNA is further tested using Qbuit, and qualified samples are tested for library construction.

[0070] (13) Library construction: The sequencing library was prepared using the BGI library construction kit.

[0071] (14) On-line sequencing: After library preparation is completed and quality is tested, DNBSEQ-T7 is used for PE150 sequencing.

[0072] 3. SNP chip genotype determination and genotype data quality control

[0073] 590 DNA samples of Large White pigs were sent to Beijing Gezhi Boya Biotechnology Co., Ltd. for 20× deep sequencing and low-depth resequencing.

[0074] The default parameters of fastp v0.23.2 were used to remove low-quality sequencing data and obtain clean reads. The default parameters of bwa-mem v0.7.17 were used to align clean reads to the reference genome, and then the alignment results were converted into bam files and sorted using Samtools software. Picard MarkDuplicates was used to remove duplicate reads from the sorted bam files. GATK-HaplotypeCaller software was used to detect genomic variations and generate gvcf files for single samples. GATK CombineGVCFs and GenotypeGVCFs were then used to merge gvcf and perform genotyping. The filtering parameters for SNPs and Indels are shown in Table 1.

[0075] Table 1 Filtration parameters

[0076] Filter parameters SNP Indel QD <2.0 <2.0 QUAL <30.0 <30.0 MQ <40.0 <40.0 SOR >3.0 FS >60.0 >200.0 MQRankSum <-12.5 ReadPosRankSum <-8.0 <-20.0

[0077] 4. Data collation and analysis

[0078] (1) Phenotypic data analysis: The collected phenotypic data of healthy piglets born from 590 Large White pigs were sorted in Excel. Descriptive statistics were performed on the phenotypic data of healthy piglets born, and the sample size, mean, standard deviation, standard error, maximum value, minimum value and quartile of each variable were calculated.

[0079] (2) Statistical analysis: Excel 2021 was used to calculate various polymorphism indicators. The relevant polymorphism indicator calculation formula is as follows:

[0080] (2.1) Gene frequency (AF)

[0081]

[0082] (2.2) Genotype frequency (GF)

[0083]

[0084]

[0085] (2.3) Genetic heterozygosity (He)

[0086]

[0087] (2.4) Effective number of alleles (Ne)

[0088]

[0089] (2.5) Polymorphic Information Content (PIC)

[0090]

[0091] (2.6) Correlation analysis

[0092] The LSD method was used for "Anova" analysis, and the reproductive phenotypes of different genotypes were expressed as mean ± standard deviation. The linear model of plink software was used for association analysis between genotype and reproductive phenotype, and the field effect was used as a covariate correction. P ≤ 0.05 was considered a significant difference, and P ≤ 0.01 was considered an extremely significant difference.

[0093] 5. Capillary electrophoresis detection of SNP

[0094] (1) Determine the number of reactions N. During the test, a no-template control (nuclease-free pure water) should be tested simultaneously: N = number of samples to be tested (n) + no-template control (1) + 1.

[0095] (2) Place the enzyme mixture on ice and thaw the remaining components at room temperature until they are completely melted. Mix using a vortex oscillator for 10 seconds and centrifuge using a microcentrifuge for 10 seconds to concentrate the liquid at the bottom of the tube.

[0096] (3) Prepare the reaction system except the template according to Table 2. Take a centrifuge tube, add each component, mix using a vortex oscillator for 10 seconds, centrifuge using a microcentrifuge for 10 seconds, and take 9 μL and dispense it into a PCR reaction tube. The primer sequences are shown in Table 3.

[0097] Table 2 Reaction system configuration

[0098] Serial number Component name Standard system addition amount (μL) Reaction number N Addition volume (μL) 1 2.5×PCR reaction solution 4 4N 2 Primer mix 1 1N 3 Nuclease-free water 4 4N total 9 9N

[0099] Note: PCR products should be stored at 2-8℃ and tested within 24h, or stored at -20℃±5℃ and tested within 7 days. The number of freeze-thaw cycles should not exceed 3 times.

[0100] Table 3 Primer sequences

[0101]

[0102] (4) Add 1 μL of the sample to be tested to each tube of the aliquoted reaction system. Record the number sequence, mix using a vortex oscillator for 10 seconds, and centrifuge using a microcentrifuge for 10 seconds.

[0103] (5) Place each reaction tube in the reaction tank of a PCR instrument and run the PCR program. The PCR amplification program is shown in Table 4.

[0104] Table 4 PCR program

[0105]

[0106] (6) PCR product electrophoresis detection: Take an appropriate amount of PCR product and load it on a 2% to 3% agarose gel for electrophoresis to detect whether the amplification is successful.

[0107] Capillary electrophoresis detection:

[0108] (1) The PCR amplification product was centrifuged at 3500 rpm for 2 min in a benchtop or plate centrifuge;

[0109] (2) Prepare a mixture of HiDi and Liz500, mix the mixture using a vortex oscillator for 10 seconds, centrifuge it using a microcentrifuge for 10 seconds, and dispense 9 μL into a 96-well plate. Add 1 μL of PCR product supernatant (stock solution or dilution) to each well;

[0110] (3) Cover with a rubber pad and centrifuge briefly using a benchtop or plate centrifuge;

[0111] (4) 95°C, denature for 5 min, then immediately place on ice for 3 min;

[0112] (5) Perform capillary electrophoresis using a gene analyzer. Select the "Fragment" electrophoresis method. Data analysis was performed using ELISA software (Applied Biosystems).

[0113] 6. Results Analysis

[0114] Table 5

[0115]

[0116] Table 6(1)

[0117]

[0118] Table 6(2)

[0119]

[0120] The genotype test results showed that:

[0121] For the SNP (rs318687930) site, the genotype of 246 pigs was GG genotype, and the genotype of 186 pigs was GA genotype; for the SNP (rs329759452) site, the genotype of 246 pigs was AA genotype, and the genotype of 162 pigs was AT genotype.

[0122] The allele frequency and gene frequency results of the porcine CREBRF gene in the detected pig population are shown in Table 5:

[0123] For the SNP (rs318687930) site, the GG genotype frequency was 0.4331, the GA genotype frequency was 0.3275, the GG genotype frequency was higher than that of GA, and the GG allele was the dominant gene; for the SNP (rs329759452) site, the AA genotype frequency was 0.4648, the AT genotype frequency was 0.2852, the AA genotype frequency was higher than that of AT, and the AA allele was the dominant gene.

[0124] As can be seen from Table 6: Among 590 large white pigs, there are 246 GG genotypes and 186 GA genotypes at the SNP (rs318687930) site. There is a very significant difference between CREBRF and the number of healthy piglets born at the first litter, with the GA type being greater than the GG type. Among 590 large white pigs, there are 264 AA genotypes and 162 AT genotypes at the SNP (rs329759452) site. There is a very significant difference between CREBRF and the number of deformities born at the first litter, with the AT type being greater than the AA type.

[0125] The linear model of plink software was used to conduct association analysis between genotype and healthy litter size phenotype, and the field effect was used as a covariate correction. The results are shown in Table 6:

[0126] The SNP (rs318687930) locus has a significant effect on the number of healthy piglets born at birth. The number of healthy piglets born at birth with the GA genotype is significantly higher than that with the GG genotype. Therefore, in actual pig breeding, the GA genotype pigs have more healthy piglets born at birth. Capillary electrophoresis was performed to verify the genotype of the SNP locus. The test results are shown in Figure 1 .

[0127] The SNP (rs329759452) locus has a significant effect on the number of first-birth malformations. The first-birth malformations of the AA genotype are significantly lower than those of the AT genotype. Therefore, in actual pig breeding, the AA genotype pigs have fewer first-birth malformations. The test results are shown in Figure 2 .

[0128] In summary, the nucleotides at the SNP (rs318687930) site of the pig CREBRF gene can be used to determine whether the pig individual is GA genotype or GG genotype, thereby assisting in identifying the number of healthy piglets: the number of healthy piglets born with the GA genotype is significantly higher than that with the GG genotype. The GA genotype is a heterozygous G and A nucleotide at position 51174074 on chromosome 16 of the pig; the GG genotype is a homozygous G nucleotide at position 51174074 on chromosome 16 of the pig.

[0129] The nucleotides at the SNP (rs329759452) site of the pig CREBRF gene can be used to determine whether the pig individual is of the AT genotype or the AA genotype, thereby assisting in identifying the number of deformities: the number of first-birth deformities of the AA genotype is significantly lower than that of the AT genotype. The AA genotype is a homozygous A at the 51221411th nucleotide on the pig chromosome 16; the AT genotype is a heterozygous A and T at the 51221411th nucleotide on the pig chromosome 16.

[0130] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. Use of a substance for detecting SNP sites in the preparation of a product for predicting piglet size, wherein the SNP sites include: One or more of SNP site rs318687930 and SNP site rs329759452.

2. The use according to claim 1, characterized in that: The trait of healthy piglets born includes at least one of the number of healthy piglets born in the first parity, the number of healthy piglets born in the second parity and the number of deformed piglets.

3. The use according to claim 2, characterized in that: The product includes a substance for detecting the SNP site rs318687930, and the pig litter size trait includes the first litter size; and / or, The product includes a substance for detecting the SNP site rs329759452, and the pig litter size trait includes the number of deformed piglets.

4. The use according to any one of claims 1 to 3, characterized in that: The substance for detecting SNP sites includes one or more of a reagent for nucleic acid amplification, a reagent for detecting nucleic acid amplification products, a reagent for constructing a sequencing library, and a reagent for sequencing.

5. The use according to claim 4, characterized in that: The substance for detecting the SNP site includes at least one of the following primer pairs: The primer pair used to amplify the SNP site rs318687930 has nucleotide sequences shown in SEQ ID NOs. 1 and 2, respectively; and, the primer pair used to amplify the SNP site rs329759452 has nucleotide sequences shown in SEQ ID NOs. 3 and 4, respectively.

6. A kit for predicting piglet size, characterized in that: Includes at least one of the following primer pairs: The primer pair used to amplify the SNP site rs318687930 has nucleotide sequences shown in SEQ ID NOs. 1 and 2, respectively; and, the primer pair used to amplify the SNP site rs329759452 has nucleotide sequences shown in SEQ ID NOs. 3 and 4, respectively.

7. A method for predicting the number of healthy piglets born, characterized in that: Including predicting sows meeting (i) and / or (ii) as sows with high litter size traits: (i) The genotype of SNP site rs318687930 is GA; (ii) The genotype of SNP site rs329759452 is AA.

8. The method for predicting the number of healthy piglets born according to claim 7, characterized in that: This includes predicting sows with a genotype of GA at the SNP site rs318687930 as sows with a high number of healthy piglets at first birth; And / or, comprising predicting sows with genotype AA corresponding to SNP site rs329759452 as sows with a low number of birth defects.

9. A method for screening sows with high-yield and healthy piglet number traits, characterized in that: The method comprises screening sows having the trait of high production and healthy piglet number predicted by the method described in claim 7 or 8.

10. A method for breeding sows with high-yield and healthy piglet number traits, characterized in that: The method comprises providing the sow with at least one of the following genotypes: (i) The genotype of SNP site rs318687930 is GA; (ii) The genotype of SNP site rs329759452 is AA.

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