SNP (Single Nucleotide Polymorphism) molecular marker for influencing chicken laying age in days by influencing PLCG2 gene expression and application of SNP molecular marker
By detecting the SNP polymorphism at position 15583049bp on chicken chromosome 11, a molecular marker-assisted selection method was constructed, which solved the problem of the difficulty in accurately controlling the age of chickens to start laying eggs in traditional breeding methods and achieved efficient breeding results.
Patent Information
- Application Number
- CN202511252631.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-03
- Publication Date
- 2025-10-28
AI Technical Summary
Existing technologies are insufficient to efficiently and accurately shorten the age of chickens to lay eggs in poultry breeding using traditional methods. They are also subject to interference from environmental factors and have limited genetic progress, failing to meet the needs of modern farming.
By detecting the SNP polymorphism at position 15583049bp on chicken chromosome 11, and using T/C polymorphism genotype detection, individuals with TT or CT genotypes were selected to start laying eggs earlier. A molecular marker-assisted selection method was constructed, and a kit was prepared for auxiliary breeding.
It enables accurate prediction of the age at which chickens begin laying eggs and molecular marker-assisted selection, improving breeding efficiency and production benefits.
Smart Images
Figure CN120843697A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the fields of molecular genetics and agricultural animal breeding, specifically to a molecular genetic marker that affects the age of chickens at the start of laying by influencing the expression of the PLCG2 gene and its application. Background Technology
[0002] With the continuous development of molecular breeding technology for livestock and poultry in my country, the poultry industry is playing an increasingly important role in ensuring the supply of high-quality animal protein and promoting rural economic growth. Age at first egg production, as an important economic trait for measuring the production performance of laying hens, is directly related to the length of the laying cycle, feed utilization efficiency, and overall economic benefits. Therefore, it has always been a core indicator of high concern in poultry genetic improvement. Especially in laying hen populations with short production cycles and stable market demand, shortening the age at first egg production not only helps to enter the high-production period earlier but also significantly increases egg production and breeding profits throughout the entire cycle. However, methods relying on traditional family selection and phenotypic selection are easily affected by environmental factors and have limited genetic progress, making it difficult to meet the demands of modern agriculture for precise and efficient breeding.
[0003] Among numerous candidate genes associated with reproductive traits, PLACG2 (phosphatidylinositol-specific phospholipase Cγ2), a key molecule in signal transduction pathways, has been shown to play a crucial role in regulating physiological processes such as ovarian development, follicle maturation, and hormone secretion. Recent studies have found that PLACG2 is specifically expressed in the poultry reproductive system and may regulate the time of egg onset by influencing follicle development rhythms. Its expression level is significantly correlated with the age at egg onset, suggesting that genetic variations in this gene may have a direct impact on poultry reproductive performance. Therefore, identifying key regulatory SNP sites around PLACG2 and assessing their effects on the age at egg onset is of significant application value for advancing molecular-assisted selection breeding in poultry. Summary of the Invention
[0004] The technical problem to be solved by this invention is to provide a SNP molecular marker that is significantly related to the age of chickens at the start of laying and its application in molecular marker-assisted breeding.
[0005] The technical solution of this invention is: the application of a substance for detecting SNP site polymorphism or genotype in assisted breeding of chickens with the age at first laying trait. The SNP site is located at position 15583049bp on chicken chromosome 11, with a reference genome version of GRCg7b. The bases at this position have T / C polymorphism. The substance is used to detect the genotype of the SNP site. Individuals with the genotype TT or CT at this position have an earlier age at first laying trait than individuals with the genotype CC.
[0006] The application of substances that detect SNP site polymorphism or genotype in the preparation of a chicken age-onset trait-assisted breeding kit, wherein the SNP site is located at position 15583049bp on chicken chromosome 11, with the reference genome version being GRCg7b. The bases at this position exhibit T / C polymorphism. Individuals with the genotype TT or CT at this position have an earlier age-onset trait than individuals with the CC genotype.
[0007] A method for molecular-assisted breeding of chickens with the age at first egg production trait involves detecting the genotype at the 15583049bp position on chromosome 11 of the chicken samples to be tested, with the reference genome version being GRCg7b. Individuals with the TT or CT genotype at this position exhibit the trait of earlier age at first egg production compared to individuals with the CC genotype.
[0008] Compared with the prior art, the present invention has the following beneficial effects:
[0009] This invention constructs a SNP molecular marker that is significantly correlated with the mRNA expression level of the PLCG2 gene, which can be used for predicting the age of chicken laying and for marker-assisted selection, providing a feasible and efficient technical approach for poultry breeding practices. Attached Figure Description
[0010] Figure 1 The PLCG2 eQTL was co-located with the GWAS of the age at which chickens begin laying.
[0011] Figure 2 Comparison of the age at labor for three genotypes at the SNP locus. Detailed Implementation
[0012] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods. Unless otherwise specified, the experimental materials used in the following embodiments were all purchased from commercial channels.
[0013] Example 1: Mining of SNP Molecular Markers
[0014] Low-depth whole-genome resequencing and age-onset phenotype collection were performed on a population of broiler laying hens (12,952 individuals). Combined with genome-wide association analysis (GWAS), a mutation signal significantly associated with age-onset was detected at Chr11:15583049 (reference genome version GRCg7b). The reference allele was T, and the mutant allele was C. The mutant allele frequency was 0.3947. The allele substitution effect of mutant allele C relative to the reference allele T was 0.6303 days (negative effect value indicates earlier onset of laying, positive effect value indicates delayed onset of laying). Figure 2 ).
[0015] Table 1. Basic information on genetic marker loci
[0016] mutation location Reference / Mutant Alleles Mutant gene frequency Mutation effect Chr11:15583049 T / C 0.3947 0.6303 days
[0017] Further eQTL analysis revealed that this SNP significantly affected the mRNA expression level of the PLACG2 gene: the C allele significantly upregulated PLACG2 expression. Colocalization analysis showed that this site was highly colocalized with the expression quantitative trait locus (eQTL) of the PLACG2 gene, with a posterior probability (PPH4) as high as 0.9922215, significantly higher than the threshold generally considered to be evidence of colocalization (typically 0.8). This indicates that this site likely affects the age at first laying in chickens by regulating the expression level of the PLACG2 gene.
[0018] Example 2: Detection of SNP molecular markers
[0019] Sample collection: Collect blood or other usable tissues from the sample chicken population, ensuring that the samples are uncontaminated, and label each sample with a number.
[0020] DNA extraction: Genomic DNA was extracted from the collected samples using commercial DNA extraction kits (such as Tiangen, QIAGEN, etc.) to ensure that the DNA quality met the requirements for PCR amplification.
[0021] Primer design: Design specific primers corresponding to the target SNP site. Online tools (such as Primer3, Primer-BLAST, etc.) are usually used to design primers to ensure that the primers can effectively amplify the target region.
[0022] PCR amplification: PCR amplification is performed using well-designed primers to ensure that the SNP sites of each sample are amplified under appropriate temperature and time conditions.
[0023] PCR product purification: After the PCR reaction is completed, primers, dNTPs and other impurities in the reaction system are removed using a DNA purification kit to obtain purified PCR products.
[0024] Genotyping: Using appropriate detection methods, such as restriction fragment length polymorphism (RFLP), high-resolution melting curve analysis (HRM), Sanger sequencing, etc., genotyping of PCR products is performed to determine the genotype of each sample at the target SNP locus.
[0025] Example 3: Application of SNP molecular markers
[0026] This molecular marker can be used in chicken breeding populations for assisted breeding to encourage hens to start laying eggs earlier and improve production efficiency.
[0027] (1) The genotype of the SNP locus in chicken samples was detected. Individuals with the genotype TT or TC at this location had an earlier age of laying than those with the CC genotype.
[0028] (2) The substance used to detect the genotype of this site can be prepared into a kit for use in the age-assisted selection of chickens at the start of laying.
Claims
1. Application of a substance for detecting SNP site polymorphism or genotype in assisted breeding of chickens with an early laying age trait. The SNP site is located at 15583049 bp on chicken chromosome 11, with a reference genome version of GRCg7b. The bases at this site exhibit T / C polymorphism. The substance is used to detect the genotype of the SNP site. Individuals with the genotype TT or CT at this site have an earlier laying age trait than individuals with the genotype CC.
2. Application of substances that detect SNP site polymorphism or genotype in the preparation of a chicken age-onset trait-assisted breeding kit. The SNP site is located at position 15583049bp on chicken chromosome 11, with the reference genome version being GRCg7b. The bases at this position exhibit T / C polymorphism. Individuals with the genotype TT or CT at this position have an earlier age-onset trait than individuals with the CC genotype.
3. A method for molecular-assisted breeding of chickens based on their age at first laying, characterized in that, The genotype at the 15583049bp position on chromosome 11 of the chicken samples to be tested was analyzed. The reference genome version was GRCg7b. Individuals with the TT or CT genotype at this position had an earlier age of onset of egg production than individuals with the CC genotype.