A SNP molecular module related to eggshell weight and its application

Abstract

The present invention relates to the technical field of laying hen breeding, and in particular to a SNP molecular module related to egg shell weight and its application. The SNP molecular module provided by the present invention avoids the problem that breeding with a single molecular marker cannot fully realize its production potential, can more accurately select laying hens with higher egg shell weight, and has a significant effect on regulating the egg shell weight of laying hens throughout the entire breeding cycle; it can help save production costs and accelerate genetic progress, has great economic application value and scientific research value, and is an optimization and upgrade of molecular marker technology.

Description

Technical Field

[0001] The invention relates to the technical field of laying hen breeding, and in particular to a SNP molecular module related to egg shell weight and an application thereof. Background Art

[0002] Poultry eggshells are formed by the mineralization and deposition of inorganic ions and organic proteins in the uterus. Their interaction determines the structure and weight of the eggshell. Having a heavier eggshell can improve the eggshell strength, reduce the egg breakage rate, and also reduce the possibility of microbial contamination. As the laying hen ages, the eggshell weight continues to decrease, resulting in a weakening of the eggshell strength and an increase in the breakage rate. Therefore, breeding hens with high eggshell weight has great economic application value.

[0003] With the development of high-throughput genotyping platforms, eggshell weight can be genetically improved through molecular markers. Genetic variation associated with eggshell weight can be linked to genetic markers, thereby improving eggshell weight through selection of markers.

[0004] However, current molecular marker methods are not widely applicable and their breeding accuracy is poor. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a SNP molecular module related to eggshell weight and its application. The SNP molecular module provided by the present invention can give full play to the role of molecular markers, and has the advantages of high accuracy and wide practicality compared with single-point molecular markers. It can be applied to the early selection of eggshell weight and assist in chicken breeding, which can help save production costs and accelerate genetic progress, and has great economic application value and scientific research value.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a SNP molecular module related to eggshell weight of eggs, wherein the SNP molecular module comprises a first SNP molecular marker and a second SNP molecular marker;

[0008] The first SNP molecular marker is: the nucleotide at the site with rs number rs316666018 is T or G;

[0009] The second SNP molecular marker is: the nucleotide at the position with rs number rs734208310 is T or C.

[0010] The present invention also provides the application of the SNP molecular module described in the above technical solution in laying hen genetic breeding.

[0011] Preferably, the eggshell weight of hens with rs316666018 and rs734208310 genotypes is higher than that of hens with other genotypes.

[0012] The present invention also provides a method for breeding hens with relatively highest eggshell weight, comprising the following steps:

[0013] Determine the genotype of the hen to be bred; the genotype is the genotype of the SNP molecular module described in the above technical solution;

[0014] The hens with TT genotype at both rs316666018 and rs734208310 were selected as the hens with the highest eggshell weight.

[0015] Preferably, the method for determining the genotype comprises determining the genotype using a gene analysis chip.

[0016] Preferably, the gene analysis chip comprises 600K Affymetrix Axiom Chicken Genotyping Array.

[0017] Beneficial effects:

[0018] The present invention provides a SNP molecular module related to eggshell weight, the SNP molecular module includes a first SNP molecular marker and a second SNP molecular marker; the first SNP molecular marker is: the nucleotide at the rs316666018 position is T or G; the second SNP molecular marker is: the nucleotide at the rs734208310 position is T or C. The SNP molecular module provided by the present invention avoids the problem that breeding with a single molecular marker cannot fully realize its production potential, can more accurately select laying hens with higher eggshell weight, and has a significant effect on regulating the eggshell weight of laying hens throughout the entire breeding cycle; it can help save production costs and accelerate genetic progress, has great economic application value and scientific research value, and is an optimization and upgrade of molecular marker technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the embodiments are briefly introduced below.

[0020] Figure 1 This is the eggshell weight curve of different genotype combinations of eggshell weight SNP molecular markers in laying hens of different ages. DETAILED DESCRIPTION

[0021] The present invention provides a SNP molecular module related to eggshell weight of eggs, wherein the SNP molecular module comprises a first SNP molecular marker and a second SNP molecular marker;

[0022] The first SNP molecular marker is: the nucleotide at the site with rs number rs316666018 is T or G;

[0023] The second SNP molecular marker is: the nucleotide at the position with rs number rs734208310 is T or C.

[0024] The rs316666018 site of the present invention is the corresponding rs number on the NCBI website, and the corresponding position is the 78073944th position of the positive strand of chromosome 1 in the sequence information of the chicken reference genome Gallus_gallus-6.0 version; the rs734208310 site is the corresponding rs number on the NCBI website, and the corresponding position is the 851625th position of the positive strand of chromosome 28 in the sequence information of the chicken reference genome Gallus_gallus-6.0 version.

[0025] The SNP molecular module provided by the present invention modularly combines two dominant sites on the whole genome (i.e., screening laying hens with relatively the heaviest eggshells based on the genotypes of the two SNP sites), avoiding the problem that breeding with a single molecular marker cannot fully tap its production potential, and can more accurately select the eggshell weight of eggs.

[0026] The present invention also provides the application of the SNP molecular module described in the above technical solution in laying hen genetic breeding. In the present invention, the application preferably includes: the eggshell weight of hens with rs316666018 and rs734208310 loci both being TT genotypes is higher than that of hens with other genotypes.

[0027] The genotype of the rs316666018 site of the present invention is a genotype composed of bases at the rs316666018 site and its corresponding allele site; the genotype of the rs734208310 site is a genotype composed of bases at the rs734208310 site and its corresponding allele site.

[0028] The SNP molecular module provided by the present invention can be applied to the early selection of eggshell weight and assist in chicken breeding, which can help save production costs and accelerate genetic progress, and has great economic application value and scientific research value.

[0029] The present invention also provides a method for breeding hens with relatively highest eggshell weight, comprising the following steps:

[0030] Determine the genotype of the hen to be bred; the genotype is the genotype of the SNP molecular module described in the above technical solution;

[0031] The hens with TT genotype at both rs316666018 and rs734208310 were selected as the hens with the highest eggshell weight.

[0032] In the present invention, the method for determining the genotype preferably includes determining using a gene analysis chip. The present invention has no special requirements for the source of the gene analysis chip, and commercially available products known to those skilled in the art can be used. The gene analysis chip in the embodiment of the present invention preferably uses 600K Affymetrix Axiom Chicken Genotyping Array from Affymetrix, USA, catalog number: 902148.

[0033] The present invention discovers a new molecular marker that is significantly correlated with eggshell weight, and fully considers the interaction between the two molecular markers. When the rs316666018 locus is the TT genotype and the rs734208310 locus is the TT genotype, laying hens have a higher eggshell weight, which is 0.18 grams higher than the mean (the mean of all genotype combinations); if only one of the molecular markers is selected for breeding (rs316666018 locus is the TT genotype or the rs734208310 locus is the TT genotype), the eggshell weight under this molecular module cannot be achieved.

[0034] To further illustrate the present invention, a SNP molecular module related to eggshell weight and its application provided by the present invention are described in detail below in conjunction with the accompanying drawings and examples, but they should not be construed as limiting the scope of protection of the present invention.

[0035] Example 1

[0036] Confirmation of the correlation between rs316666018 SNP and rs734208310 SNP and eggshell weight 1. Eggshell weight determination

[0037] The eggshell weight of 1393 F2 generation laying hens of Bailaihang and Dongxiang green-shell laying hens at 44 weeks of age was measured. The measurement method is as follows: break the eggs to be tested, remove the egg white and yolk, wipe the remaining egg white with a paper towel, weigh with an electronic balance (accuracy of 0.1g) and record the data.

[0038] 2. SNP Detection

[0039] 1. Genomic DNA Extraction

[0040] Blood was collected from the wing vein of the chicken to be tested, and the blood was anticoagulated with ACD anticoagulant, then lysed and digested with protease (purchased from Sangon Biotech (Shanghai) Co., Ltd., item number B600169-0002), DNA was extracted using the phenol imitation method, and dissolved in sterile double distilled water; the ACD anticoagulant consisted of the following components in the following concentrations: 13.2 g / L sodium citrate, 4.8 g / L citric acid, and 14.7 g / L glucose.

[0041] 2. Genotyping

[0042] The genomic DNA of each chicken to be tested was obtained, and the 600K Affymetrix Axiom Chicken Genotyping Array (product catalog number: 902148) of Affymetrix, USA was used to detect the genotype of each individual.

[0043] 3. Genome-wide association analysis of egg-laying traits in hens

[0044] Statistical analysis was performed using the mixed linear model of the genome-wide efficient mixed-model association (GEMMA) statistical analysis software. For details, please refer to: [Xiang Z, Stephens M. Genome-wide Efficient Mixed Model Analysis for Association Studies [J]. Nature Genetics, 2012, 44 (7): 821-824.] and [Zhou X, Stephens M. Efficient multivariate linear mixed model algorithms for genome-wide association studies.].

[0045] The statistical analysis model is:

[0046] y=Wa+xβ+μ+ε;

[0047] y represents individual phenotypic values;

[0048] W represents covariate;

[0049] a represents the corresponding coefficient;

[0050] x represents the SNP genotype;

[0051] β represents the corresponding SNP effect;

[0052] μ represents the residual polygenic effect;

[0053] ε represents the remaining residual effect.

[0054] Data analysis was performed using GeneTitan (Affymetrix, Inc., USA) gene chip automatic processing system, and the data analysis software was Affymetrix PowerTools.

[0055] The results showed that in the sequence information of the chicken reference genome Gallus_gallus-6.0 version, the SNP site at position 78073944 on chromosome 1 (i.e., site rs316666018) and the SNP site at position 851625 on chromosome 28 (i.e., site rs734208310) were both significantly correlated with eggshell weight at 44 weeks.

[0056] Example 2

[0057] Association analysis between rs316666018T / G genotype and rs734208310T / C genotype and eggshell weight in F2 generation

[0058] 1. Experimental materials: 1393 F2 individuals of white Leghorn laying hens and Dongxiang green-shell laying hens. The F2 individuals were obtained as follows:

[0059] WL / DBS group: 6 white Leghorn laying hens (WL) (♂) × 133 Dongxiang green-shell laying hens (DBS) (♀) were randomly mated to produce the F1 generation;

[0060] DBS / WL group: 6 Dongxiang green-shell laying hens (♂) × 80 white Leghorn laying hens (♀) were randomly mated to produce the F1 generation;

[0061] In the two F1 groups, 25 males and 406 females from the WL / DBS group and 24 males and 233 females from the DBS / WL group were randomly selected, and the female and male chickens selected from the two F1 groups were housed together and randomly mated to produce the F2 generation.

[0062] The eggshell weight of each individual of the F2 generation was measured at the beginning of laying (denoted as AFE) and at 32, 36, 40, 44, 48, 52, 56, 60, 66, and 72 weeks of age.

[0063] 2. The SNP detection method is the same as step 2 in Example 1. The genotype step results are shown in Tables 1 and 2.

[0064] Table 1 Distribution of rs316666018T / G genotype in the F2 population.

[0065]

[0066] From the results in Table 1, it can be seen that the TG genotype is the dominant genotype in the experimental population.

[0067] Table 2 Distribution of rs734208310T / C genotype in the F2 population.

[0068]

[0069] From the results in Table 2, it can be seen that the TT genotype is the dominant genotype in the experimental population.

[0070] 3. Analysis of association between genotype combination and eggshell weight at 44 weeks

[0071] The genotypes of the two molecular markers rs316666018 and rs734208310 were combined, and the 44-week eggshell weights under different combinations were counted.

[0072] The results are shown in Table 3.

[0073] Table 3 Eggshell weight of individuals with different genotype combinations at 44 weeks

[0074]

[0075] Note: The calculation method of the average eggshell weight of individuals with different genotype combinations in Table 3 (i.e. 4.63 corresponding to All) is: add the average value corresponding to each genotype combination × the corresponding number of individuals, and then divide by the total number of individuals.

[0076] As can be seen from Table 3, laying hens with both chromosome 1 rs316666018 (TT) and chromosome 5 rs734208310 (TT) genotypes had higher eggshell weight, which was 0.18 g higher than the average eggshell weight of all genotypes.

[0077] The average eggshell weight of individuals with different genotype combinations in the F2 generation from the beginning of laying to 72 weeks was measured. The results are as follows Figure 1 As shown in Table 4, Figure 1 and AFE in Table 4 represent the age at calving.

[0078] Table 4 Eggshell weight of eggshell heavy molecular module combination in laying hens of different ages (g)

[0079]

[0080]

[0081] Depend on Figure 1 As shown in Table 4, the egg weight molecular module combination TT+TT has higher eggshell weight than other genotypes from the beginning of laying to 72 weeks of age, and can be used to breed laying hens with relatively higher eggshell weight.

[0082] In summary, the present invention avoids the drawbacks of breeding with a single molecular marker to the greatest extent. Breeding according to the molecular modules provided in this patent can give full play to the role of molecular markers and accurately increase the eggshell weight of eggs. It has great economic application value and scientific research value, and is an optimization and upgrade of molecular marker technology.

[0083] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. Application of a SNP molecular module in laying hen eggshell weight genetic breeding, wherein the SNP molecular module comprises a first SNP molecular marker and a second SNP molecular marker; The first SNP molecular marker is: the nucleotide at the site with rs number rs316666018 is T or G; The second SNP molecular marker is: the nucleotide at the position of rs734208310 is T or C; The eggshell weight of hens with TT genotype at both rs316666018 and rs734208310 loci is higher than that of hens with other genotypes; the hens are F2 generation individuals of the hybrid of White Leghorn laying hens and Dongxiang Green Shell laying hens.

2. A method for breeding hens with the highest eggshell weight, characterized in that: The following steps are involved: Determining the genotype of the hens to be bred; the hens to be bred are F2 generation individuals hybridized between white Leghorn laying hens and Dongxiang green shell laying hens; The genotype is a genotype of a SNP molecular module; the SNP molecular module includes a first SNP molecular marker and a second SNP molecular marker; The first SNP molecular marker is: the nucleotide at the site with rs number rs316666018 is T or G; The second SNP molecular marker is: the nucleotide at the position of rs734208310 is T or C; The hens with TT genotype at both rs316666018 and rs734208310 were selected as the hens with the highest eggshell weight.

3. The method according to claim 2, characterized in that The method for determining the genotype includes determining the genotype using a gene analysis chip.

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