SNP (Single Nucleotide Polymorphism) molecular marker related to sheep meat quality traits, primer group, kit and application

Abstract

The invention belongs to the field of biotechnology and livestock breeding, and relates to an SNP (Single Nucleotide Polymorphism) molecular marker related to sheep meat quality traits, a primer group, a kit and application. The nucleotide sequence of the SNP molecular marker is as shown in SEQ ID NO.4, and Ggt exists at the 46th bp position of the sequence as shown in SEQ ID NO.4; a is a mutation site. By rapidly and accurately detecting the SNP marker related to the meat quality traits of the'Auodurou Lake 'sheep genetic resource population, the'Auodurou Lake' sheep variety dominant genetic resource population can be rapidly established, so that the marker-assisted selection breeding process of the sheep meat quality traits is accelerated.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of biotechnology and livestock breeding, and relates to a SNP molecular marker related to sheep meat quality traits, a primer set, a kit and application. BACKGROUND

[0002] Animal breeding techniques mainly include conventional breeding techniques based on phenotypes and phenotype values, and molecular breeding techniques based on DNA polymorphism. As an important part of the molecular breeding technique system, marker-assisted selection (MAS) breeding technique is a trait selection based on molecular markers significantly related to genetic traits. By analyzing the genetic composition of individuals at the DNA level, the genotype is directly selected to improve the directionality of breeding objectives, and the superiority is achieved in early selection, non-destructive trait evaluation and selection, and improvement of backcross breeding efficiency. Finding important functional genes, screening genetic variation sites of genes, and analyzing the correlation between genetic variation sites of genes and traits are the premise and key of the application of marker-assisted selection technology.

[0003] Single nucleotide polymorphism (SNP) refers to DNA sequence polymorphism caused by single nucleotide variation at the genome level. By analyzing the individual genome using SNP, the individual phenotype difference can be better explained, which has important significance in animal molecular breeding. SNPs are distributed throughout the genome, most of which are located in known gene regions, and some are located in key regions that determine gene function, such as promoter regions and exon regions. It can play a regulatory function at the transcription and post-transcriptional levels through various ways, which suggests that the SNP on the above may play an important role through regulating gene expression and other ways.

[0004] Common SNP detection methods include sequencing, enzyme digestion, gene chip, SNPshot, KASP (Kompetitive Allele Specific polymerase chain reaction, competitive allele-specific PCR) method, etc. However, sequencing, enzyme digestion, gene chip, SNPshot and other methods have the problems of low positive rate, high equipment requirement, high cost, etc. KASP has the following advantages: (1) excellent accuracy and detection effect, accuracy > 99.8%; (2) super flexibility, supporting low, medium and high throughput detection and individual repetition; (3) low cost, no need for expensive labeled probes, and lower DNA sample amount. KASP has gradually become one of the main SNP detection methods at present, and plays an important role in SNP typing research.

[0005] Early selection of meat quality traits of sheep has been one of the problems in the breeding industry, and the improvement of meat quality traits of sheep is the key to the development of related industries and the acquisition of economic benefits. In order to solve this problem, it is necessary to screen and detect molecular markers closely related to the meat quality traits of sheep at the DNA level. At present, there is no report on the SNP markers related to the meat quality traits of sheep derived from CCBL1 genes or genes. CCBL1 The application provides a SNP molecular marker detection reagent for identifying meat quality traits of sheep or sheep assisted breeding. SUMMARY

[0006] The application provides a SNP molecular marker detection reagent for identifying meat quality traits of sheep or sheep assisted breeding.

[0007] The application solves the technical problems by adopting the following technical solutions: In a first aspect, the application provides a SNP molecular marker detection reagent for identifying meat quality traits of sheep or sheep assisted breeding, wherein the nucleotide sequence of the SNP molecular marker is shown in SEQ ID NO. 4, and the sequence shown in SEQ ID NO. 4 has a G>A mutation site at the 46th bp.

[0008] As a preferred embodiment of the application, the meat quality traits are one or more of backfat thickness (mm), eye muscle height (mm), and eye muscle area (cm 2 ).

[0009] As a preferred embodiment of the application, the meat quality traits of individuals with the GG genotype are better than those of individuals with the GA genotype.

[0010] In a second aspect, the application provides a primer set for amplifying the SNP molecular marker, which comprises KASP primers consisting of an upstream typing primer FAM, an upstream typing primer VIC, and a downstream primer R: The upstream typing primer FAM is: 5'-GAAGGTGACCAAGTTCATGCTATGCCTGACTTGCCCGGAGCGGCAG-3'; The upstream typing primer VIC is: 5'-GAAGGTCGGAGTCAACGGATTATGCCTGACTTGCCCGGAGCGGCAA-3'; The downstream primer R is: 5'-CCTTATTCTTGATCATCCACTTGACGAAG-3'.

[0011] In a third aspect, the present application provides a kit comprising the primer set.

[0012] In a fourth aspect, the present application provides a detection reagent comprising the primer set.

[0013] In a fifth aspect, the present application provides a use of the primer set, the kit or the detection reagent in identifying meat quality traits of sheep.

[0014] In a sixth aspect, the present application provides a use of the primer set, the kit or the detection reagent in assisted breeding of sheep.

[0015] In a seventh aspect, the present application provides a method for identifying meat quality traits of sheep, comprising the following steps: extracting whole genome DNA of the sheep to be tested; amplifying a gene fragment containing the mutation site using the primer set as a template of the whole genome DNA; CCBL1 identifying the genotype of the mutation site based on the analysis results of the fluorescence type and intensity of the amplification product, and judging the meat quality traits of the sheep according to the genotype.

[0016] As a preferred embodiment of the present application, the meat quality traits of the individual with the mutation site of GG are better than those of the individual with the mutation site of GA, and the meat quality traits are backfat thickness, eye muscle height or eye muscle area.

[0017] As a preferred embodiment of the present application, the amplification reaction procedure is as follows: pre-denaturation at 95 ℃ for 10 min; denaturation at 95 ℃ for 15 s, annealing at 61 ℃ for 60 s, for a total of 9 cycles, and the annealing temperature is reduced by 0.6 ℃ after each cycle; denaturation at 95 ℃ for 15 s, annealing at 55 ℃ for 60 s, for a total of 31 cycles.

[0018] As a preferred embodiment of the present application, each 10 μL reaction system is composed of the following components: FLu-Arms 2×PCR Mix 5 μL, 25 ng of the genome DNA of the sample to be tested, 0.5 μL of 50 μM primer mixture; the rest is supplemented with ddH2O; the molar ratio of the upstream typing primer FAM, the upstream typing primer VIC and the downstream primer R is 1-2:1-2:3-6.

[0019] As a preferred embodiment of the present application, the fluorescence type and intensity are analyzed after the amplification reaction procedure is completed by using a qPCR instrument.

[0020] As a preferred embodiment of the present application, the identification of the genotype specifically comprises the following steps: according to the intensity of different types of fluorescence matched with the linker sequence carried by the KASP primer (specifically two upstream typing primers), the genotype of the mutation site is identified. CCBL1 ​The GG and GA genotypes of the single nucleotide polymorphism site are typed.

[0021] As a preferred embodiment of the present application, the sheep is the Australian White Sheep three-way cross offspring, that is, the "Aodu Lake" genetic resource population.

[0022] The beneficial effects of the present application are embodied in: According to the results of the association analysis of the sheep CCBL1 single nucleotide polymorphism site (chr3: 7459873) and the "Aodu Lake" sheep genetic resource population meat quality traits, it is found for the first time that different genotypes of the site are significantly related to sheep meat quality traits, and there is a molecular marker for early selection of improving sheep meat quality traits, the meat quality traits are backfat thickness, eye muscle height or eye muscle area, and the individuals with genotype GG are obviously superior to the individuals with genotype GA in these meat quality traits. The amplification primer designed and the detection method established can be used to accurately establish a sheep population with excellent meat quality, thereby accelerating the marker-assisted selection breeding process of sheep meat quality traits.

[0023] The KASP method can accurately genotype and identify the sheep CCBL1 single nucleotide polymorphism site (chr3: 7459873), which has the advantages of simplicity, rapidness and low cost. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The figure is the KASP detection result of the sheep CCBL1 SNP site (chr3: g. 7459873), wherein Allele2 / Allele2 represents the GG genotype, and Allele1 / Allele2 represents the GA genotype.

[0025] Figure 2 The figure is the amplification product sequencing diagram of the sheep CCBL1 SNP site (chr3: g. 7459873); wherein: the upper sequencing peak diagram represents the genotype GA, and the lower sequencing peak diagram represents the genotype GG, and the boxed base position is the SNP site. DETAILED DESCRIPTION

[0026] The present application will be further described in detail below in combination with the drawings and examples, which are an explanation of the present application, but not a limitation of the protection scope of the present application.

[0027] The "Aodu Lake" sheep breed involved in the present application is recorded in "Shi Hui-bin, Wang Yuqin, Wu Zibo, et al. Growth and development performance and blood physiological and biochemical index determination of Aodu Lake crossbred sheep [J]. Animal Husbandry and Veterinary Medicine, 2019, 51 (4): 1-6." (I) Identification of sheep CCBL1 SNP and analysis of single nucleotide genetic variation A CCBL1 single nucleotide variation site was found by Sanger sequencing using the Australian White Sheep three-way cross offspring "Aodu Lake" sheep genetic resource population pool sample, which is a G>A variation site located at chr3: g. 7459873, and the reference genome is derived from the UCSC database Sheep Nov. 2015 (Oar_v4 / oviAri4), CCBL1 The gene (also known as KYAT1 The gene belongs to chromosome 3, chr3:7450768~7460701, and the mutation position is CHR3:7459873, located at the 9106bp position of the gene. CCBL1

[0028] (2) Detection of CCBL1 single nucleotide polymorphism markers related to sheep meat quality traits The KASP method was used to detect the "Aodu Lake" sheep genetic resource population CCBL1 Single nucleotide polymorphism site (chr3:g. 7459873), and the association analysis of different genotypes and sheep meat quality related traits was carried out to determine that the single nucleotide polymorphism site can be used as a candidate molecular marker for auxiliary selection in sheep meat quality related traits molecular breeding. The specific description is as follows.

[0029] 1. Experimental reagents and reagents 1.1, biochemical reagents and biological reagents ① Taq DNA polymerase (purchased from Fermantas, MBI company); ② Proteinase K (purchased from Huawme Biological Engineering Company); ③ Marker I (purchased from Tian Gen Biochemical Technology (Beijing) Co., Ltd.).

[0030] 1.2, general reagents General reagents were purchased from Huawme Biological Engineering Company, which were imported and packaged products: citric acid, sodium citrate, glucose, Tris, EDTA, NaCl, NaOH, KCl, Na2HPO4, KH2PO4, Tris saturated phenol, chloroform, isoamyl alcohol, anhydrous ethanol, sodium acetate, sodium dodecyl sulfate (SDS), ethidium bromide (EB), bromophenol blue, dimethylbenzene cyanine FF, acetic acid, sucrose, boric acid, agarose, etc.

[0031] 1.3, solution and buffer All solutions and buffers were prepared with deionized ultrapure water. The high-pressure sterilization condition was 15 bf / in (1.034x10 5 Pa), 25 min. The preparation method was referred to Sambrook et al. "Molecular Cloning Experiment Guide".

[0032] 1) The solution used for extracting blood sample DNA​ ① PBS buffer: weigh NaCl (8 g), KCl (0.2 g), Na2HPO4 (1.44 g), KH2PO4 (0.24 g), and add ultrapure water to make up to 1000 mL. Adjust pH to 7.4, and autoclave.

[0033] ② DNA extraction solution (500 mL): 10 mmol / L Tris (pH 8.0) / MW121.14 0.6057 g, 0.1 mol / L TDA / MW372.24 18.612 g, and 0.5% SDS / MW288.38 2.5 g, and make up to 500 mL. Adjust pH to 8.0, and autoclave.

[0034] ③ Common solution for genomic DNA extraction 2) Solutions for agarose gel electrophoresis analysis ① 0.5x TBE buffer: take 10x TBE 50 mL, and make up to 1000 mL.

[0035] ② Loading buffer: 0.25% bromophenol blue and 0.25% dimethylbenzene cyanine FF, solvent is 40.0% (w / v) sucrose aqueous solution.

[0036] 2. Design KASP primers for CCBL1 SNP site Search for sheep CCBL1 gene sequences on UCSC, and use Primer 6.0 to design PCR primer pairs that can amplify the SNP site (chr3: g. 7459873) upstream of the start codon of CCBL1. The specific primer sequences are as follows: Upstream typing primer FAM: 5'- GAAGGTGACCAAGTTCATGCTATGCCTGACTTGCCCGGAGCGGCAG-3', SEQ ID NO. 1; Upstream typing primer VIC: 5'- GAAGGTCGGAGTCAACGGATTATGCCTGACTTGCCCGGAGCGGCAA-3', SEQ ID NO. 2; Downstream primer R: 5'- CCTTATTCTTGATCATCCACTTGACGAAG-3', SEQ ID NO. 3.

[0037] 3. Obtain sheep blood sample DNA and meat quality trait phenotype values 3.1. Meat quality trait data and blood sample collection The animals used in the test are the Australian White Sheep three-way cross offspring genetic resource population (Australian White Sheep and Duopo Sheep and Lake Sheep cross population - "Aodu Lake" population). 320 blood samples were collected from the Australian White Sheep three-way cross - "Aodu Lake" population, and the samples were collected from July 2024 to August 2024 (sampling site: Inner Mongolia Hulunbuir Australian White Sheep Pasture Co., Ltd. in Inner Mongolia Autonomous Region), and the morphological phenotype of the samples was determined by a unified standard, including backfat thickness (mm), eye muscle height (mm), eye muscle area (cm 2 );Using a disposable vacuum blood collection tube containing EDTA-2K anticoagulant, the sheep jugular vein blood was collected. After collection, mix immediately and store in a -4℃ refrigerator for temporary storage, and after the sample is returned to the laboratory, store it in a -20℃ refrigerator for standby.

[0038] 3.2, Extraction of genomic DNA from blood samples 1) Thaw the frozen blood samples in a room temperature water bath environment.

[0039] 2) Transfer the thawed blood sample to a 2mL sterile centrifuge tube.

[0040] 3) Centrifuge at 12000rpm for 10min at 4℃.

[0041] 4) Remove the supernatant, retain the precipitate, add 1.5mL PBS buffer, vortex to suspend the precipitate, and gently shake on ice for 15min.

[0042] 5) Centrifuge at 12000rpm for 10min at 4℃.

[0043] 6) Repeat steps 4 and 5 once.

[0044] 7) Crush the precipitate into a flocculent state.

[0045] 8) Add DNA extraction solution 500μL, protease K 8μL to the centrifuge tube.

[0046] 9) Incubate in a 65℃ water bath for about 16h until the cell precipitate is completely digested and the solution is clear.

[0047] 10) Add 1mL Tris-saturated phenol, gently shake on ice for 20min.

[0048] 11) Centrifuge at 12000rpm for 10min at 4℃.

[0049] 12) Transfer the upper aqueous phase to another 2.0mL centrifuge tube using a pipette.

[0050] 13) Add 0.5mL saturated phenol and 0.5mL chloroform, gently shake on ice for 20min.

[0051] 14) 12000 rpm centrifugation for 10 min at 4°C.

[0052] 15) The upper aqueous phase was transferred to another 2.0 mL centrifuge tube using a pipette.

[0053] 16) 1 mL chloroform was added, and it was gently shaken on ice for 20 min.

[0054] 17) 12000 rpm centrifugation for 10 min at 4°C.

[0055] 18) The upper aqueous phase was transferred to another 1.5 mL centrifuge tube using a pipette.

[0056] 19) 1 mL pre-cooled (-20°C) anhydrous ethanol was added, and it was gently shaken several times until the DNA precipitated, and it was placed at -20°C for 3 min.

[0057] 20) 12000 rpm centrifugation for 10 min at 4°C. The ethanol was removed.

[0058] 21) 1 mL 70% ethanol was added, and it was gently shaken on ice for 10 min.

[0059] 22) 12000 rpm centrifugation for 10 min at 4°C. The ethanol was removed, and the rinsing was repeated once.

[0060] 23) It was inverted at room temperature for 30 min, and it was placed in a 60°C oven for 30 s.

[0061] 24) 50 μL ultrapure water was added, and it was stored at 4°C until the DNA was completely dissolved, and it was detected.

[0062] 3.3, Spectrophotometric detection of DNA The OD values of the DNA sample at 260 nm and 280 nm were determined by ultraviolet spectrophotometry. The ratio of OD 260 / OD 280 was calculated. If the ratio of OD 260 / OD 280 was less than 1.6, it indicated that the DNA sample contained a lot of protein or phenol, and it should be purified; if the ratio was greater than 1.8, it should be considered to remove RNA purification.

[0063] DNA concentration (ng / μL) = 50 × OD 260 value × dilution factor After the DNA detection was qualified, a certain amount of DNA solution was taken out, diluted to 50 ng / μL template DNA, and stored at -20°C. The rest was stored at -80°C.

[0064] 4, Detection of SNP sites by KASP method 4.1, KASP reaction system First, add 10 μL of paraffin oil to each 96-well plate, and then add the KASP reaction system (10 μL): 5 μL of FLu-Arms 2×PCR Mix; 25 ng of genomic DNA (template DNA) of the sample to be tested; 0.5 μL of 50 μM primer mixture (upstream typing primer FAM: upstream typing primer VIC: downstream primer R molar ratio = 1:1:3); the rest is made up with ddH2O.

[0065] 4.2 KASP reaction procedure The reaction procedure is: (1) Pre-denaturation: denaturation at 95°C for 10 min; (2) Touchdown PCR: denaturation at 95°C for 15 s, annealing at 61-55°C for 60 s (-0.6°C / cycle), for a total of 9 cycles; (3) Amplification: denaturation at 95°C for 15 s, annealing at 55°C for 60 s, for a total of 31 cycles; (4) Reading: 30°C for 25 seconds (read), 1 cycle.

[0066] 5. Identification of the “Aodu Lake” sheep genetic resource population CCBL1 KASP typing of genetic variation sites KASP typing was performed based on the intensity of different types of fluorescence. In the KASP typing results, the GG and GA genotypes of the sheep CCBL1 chr3:NC_000009:g7459873 mutation site were clearly divided into two clusters, with Allele2 / Allele2 representing the GG genotype and Allele1 / Allele2 representing the GA genotype.

[0067] 6. "Aodu Lake" sheep genetic resource population CCBL1 Frequency statistical analysis of genetic variation sites Genotype frequency refers to the ratio of the number of individuals with a certain genotype of a trait to the total number of individuals in a population: Where, P YY Indicates the YY genotype frequency at a certain site; N YY represents the number of individuals with YY genotype in the population; N is the total number of the test population.

[0068] The formula for calculating allele frequency is: Where, P Y represents the frequency of allele Y, N YY represents the number of individuals with YY genotype in the population, N YaiThe number of individuals with Yai genotype in the population (ai = a1, a2,..., an), a1~an are n different complex alleles of allele Y.

[0069] The gene frequency of the chr3: NC_000009:g7459873 variation site in the "Aodu Lake" sheep genetic resource population is shown in Table 2.

[0070] Table 2. CCBL1 genetic variation site gene frequency distribution of "Aodu Lake" sheep genetic resource population As can be seen from Table 2, the frequencies of GG and GA genotypes in the "Aodu Lake" sheep genetic resource population are 0.919 and 0.081, respectively, and the frequency of AA genotype is 0. According to Hardy-Weinberg disequilibrium analysis, the chr3: g. 7459873 G>A variation site is in Hardy-Weinberg equilibrium state in the "Aodu Lake" sheep genetic resource population (P>0.05), which is a SNP site. P >0.05), which is a SNP site.

[0071] The nucleotide sequence of the SNP molecular marker containing the variation site is: GAAGGTGACCAAGTTCATGCTATGCCTGACTTGCCCGGAGCGGCAS, SEQ ID NO. 4, wherein S is base G or A.

[0072] 7. Association analysis of CCBL1 SNP site variation gene effect of "Aodu Lake" sheep genetic resource population Genotype data: GG and GA genotypes of chr3: g. 7459873 G>A variation site.

[0073] Meat quality trait data: backfat thickness, eye muscle height and eye muscle area of sheep measured.

[0074] Association analysis model: SPSS (25.0) software was used to analyze the correlation between SNP site and meat quality traits. First, descriptive statistical analysis of the obtained data was performed to determine whether there were outliers. Then, according to the characteristics of the data, t analysis was used to analyze the effect of genotype. In the process of data processing, considering the effect of individuals, the interaction between genes and the effect of genotypes, a fixed model was used for correlation analysis. In addition, according to the actual conditions, the complete model: Y ijlm = μ+S i +HYS j +G l +e ijlm ; wherein, Y ijlm : individual phenotype record; μ: overall mean; S i: year effect; HYS j : mean of sheep population; G l : fixed effect of genotype; e ijlm : random error. The analysis results are shown in Table 3.

[0075] Table 3. Correlation analysis of SNP site (chr3: NC_000009:g7459873) and meat quality traits of "Aodu Lake" sheep genetic resource population Note: the means with the same letter on the shoulder are not significantly different among different genotypes, the means with letters a and b on the shoulder are significantly different, and the means with letters a and c on the shoulder are extremely significantly different.

[0076] As can be seen from Table 3, the SNP site (chr3: g. 7459873) can significantly affect the meat quality traits of "Aodu Lake" sheep genetic resource population CCBL1 The different genotypes of SNP (chr3: g. 7459873) have a significant effect on backfat thickness and eye muscle height (P<0.05), and an extremely significant effect on eye muscle area (P<0.01), and the individuals with genotype GG are obviously superior to the individuals with genotype GA in these meat quality traits, with a statistical difference. Therefore, the GG genotype of CCBL1 SNP (chr3: g. 7459873) site can be used as a candidate SNP marker for improving the meat quality traits of sheep. P <0.05), and an extremely significant effect on eye muscle area (P<0.01), and the individuals with genotype GG are obviously superior to the individuals with genotype GA in these meat quality traits, with a statistical difference. Therefore, the GG genotype of CCBL1 SNP (chr3: g. 7459873) site can be used as a candidate SNP marker for improving the meat quality traits of sheep. P

[0077] In summary, the present application finds that the sheep CCBL1 SNP can significantly affect the meat quality traits of "Aodu Lake" sheep genetic resource population, and as a molecular marker for early selection of improving the meat quality traits of "Aodu Lake" sheep genetic resource population, it can be used for quickly establishing the superior genetic resource population of "Aodu Lake" sheep genetic resource population, thereby accelerating the molecular breeding process of "Aodu Lake" sheep genetic resource population, and being beneficial to improving the meat production performance of sheep and enhancing the related industrial benefits.​

Claims

1. A detection reagent for SNP molecular markers for use in identifying sheep meat quality traits or sheep assisted breeding, characterized in that: The nucleotide sequence of the SNP molecular marker is shown in SEQ ID NO.4, and the 46th bp of the sequence shown in SEQ ID NO.4 has a G>A mutation site.

2. The use according to claim 1, characterized in that The meat quality traits are one or more of backfat thickness, eye loin height, and eye loin area.

3. The use according to claim 2, characterized in that The meat quality traits of individuals with the GG genotype at the mutation site are better than those of individuals with the GA genotype.

4. A primer set for amplifying the SNP molecular marker according to claim 1, characterized in that: The primer set includes a KASP primer consisting of an upstream typing primer FAM, an upstream typing primer VIC and a downstream primer R: Upstream typing primer FAM: 5'-GAAGGTGACCAAGTTCATGCTATGCCTGACTTGCCCGGAGCGGCAG-3'; Upstream typing primer VIC: 5'-GAAGGTCGGAGTCAACGGATTATGCCTGACTTGCCCGGAGCGGCAA-3'; Downstream primer R: 5'-CCTTATTCTTGATCATCCACTTGACGAAG-3'.

5. A kit comprising the primer set according to claim 4. A detection reagent comprising the primer set according to claim 4 .

7. Use of the primer set according to claim 4, the kit according to claim 5, or the detection reagent according to claim 6 in identifying sheep meat quality traits or sheep assisted breeding, characterized in that: The meat quality traits are one or more of backfat thickness, eye loin height, and eye loin area.

8. A method for identifying sheep meat quality traits, characterized in that: The following steps are involved: Extract the whole genome DNA of the sheep to be tested; Using the whole genome DNA as a template, the primer set according to claim 4 is used to amplify the region containing the mutation site. CCBL1 gene fragments; The genotype of the mutation site is identified based on the analysis results of the fluorescence type and intensity of the amplified product, and the meat quality traits of the sheep are judged according to the genotype; the meat quality traits of individuals with the GG mutation site are better than those of GA-type individuals, and the meat quality traits are backfat thickness, eye muscle height or eye muscle area.

9. The method for identifying sheep meat quality traits according to claim 8, characterized in that: The amplification reaction program was as follows: pre-denaturation at 95°C for 10 min; denaturation at 95°C for 15 s, annealing at 61-55°C for 60 s, for a total of 9 cycles, with the annealing temperature decreasing by 0.6°C after each cycle; denaturation at 95°C for 15 s, annealing at 55°C for 60 s, for a total of 31 cycles.

10. The method for identifying sheep meat quality traits according to claim 8, characterized in that: Each 10 μL reaction system consists of the following components: 5 μL of FLu-Arms 2×PCR Mix, 25 ng of genomic DNA of the sample to be tested, and 0.5 μL of 50 μM primer mixture; the remainder is made up with ddH2O; the molar ratio of upstream typing primer FAM, upstream typing primer VIC, and downstream primer R is 1~2:1~2:3~6.

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