Molecular marker related to early-stage weight traits of Sansui ducks and breeding method

Abstract

The invention provides a molecular marker related to early-stage body weight traits of Sansui ducks and a breeding method, and belongs to the field of breeding direction. Whole genome deep sequencing is carried out on a Sansui duck group, comparison with the whole genome sequence of Beijing ducks in a gene bank finds that a 17bp insertion mutation exists at the 3'end of the ALMS1 gene and a 51bp deletion mutation exists in the 7th intron region of the PBX1 gene, and a character correlation analysis result shows that the mutation significantly influences the early weight of the Sansui ducks.

Description

Technical Field

[0001] The invention relates to the technical field of livestock and poultry breeding, and in particular to a molecular marker related to the early body weight trait of Sansui ducks and a breeding method. Background Art

[0002] Sansui duck is an important local duck genetic resource in Guizhou Province. It belongs to a small egg-laying duck breed. It has the characteristics of early maturity, high egg production, strong vitality, tender meat, unique flavor, etc., but also has disadvantages such as slow growth. Low-fat local duck breeds such as Sansui duck. The rapid growth period is in the first 9-12 weeks, while the rapid growth period of meat duck breeds such as Beijing duck and Cherry Valley duck is in the first 5 weeks. Early growth performance has a great influence on duck market weight, daily weight gain, feed utilization rate and meat performance, and is an important economic trait in Sansui duck breeding. In order to carry out breeding to improve the early growth performance of Sansui duck, explore the genetic mechanism of early weight traits of Sansui duck, dig out the main effect genes or genetic markers affecting this trait, and construct genetic marker-assisted breeding technology, which is of great significance to improving the early growth performance and weight traits of Sansui duck, and ultimately improving its market weight and slaughter meat performance and reducing costs and increasing efficiency. The present invention is based on this to carry out related research. Summary of the invention

[0003] The present invention carried out whole-genome deep sequencing on the Sansui duck population and compared it with the whole-genome sequence of Beijing duck in the gene bank. It was found that there was a 17bp insertion mutation at the 3' end of the ALMS1 gene and a 51bp deletion mutation in the 7th intron region of the PBX1 gene. The results of trait association analysis showed that the above mutations significantly affected the early body weight of Sansui duck.

[0004] ALMS1 (centrosome and basal body associated protein) is a protein present in the cytoplasm, cytoskeleton, microtubule organization, cell centrosome and cilia base. Studies have shown that it is widely distributed and ubiquitous. Some studies have shown that it is related to energy metabolism and homeostasis, cell differentiation and cell cycle control, but its function is not yet fully understood. ALMS1 gene mutations can lead to a variety of symptoms in humans and mice, such as appetite disorders, type 2 diabetes, cardiomyopathy, renal damage, male infertility, adolescent growth retardation and short stature.

[0005] PBX1 (PBX homeobox 1, pre-B cell leukemia homeobox 1) is a three amino acid loop extension (TALE) transcription factor, whose target genes include multiple ubiquitous developmental genes such as PAX1 / PAX9, WNT9B / WNT3, PITX3, etc., and is therefore an important developmental regulator that drives cell proliferation, pluripotency and differentiation, and regulates axial limb development, organogenesis and hematopoiesis during the embryonic period. Mutations in the PBX1 gene are associated with a variety of congenital diseases, such as congenital kidney and urinary tract anomalies, skeletal malformations, congenital heart disease, embryonic insufficiency of spleen, and gender differentiation disorders. After birth, PBX1 plays an important role in maintaining self-renewal and pluripotency.

[0006] The present invention utilizes the insertion and deletion mutations of ALMS1 and PBX1 genes found in the Sansui duck population to carry out molecular marker-assisted breeding, which can select and breed the early weight traits of Sansui ducks, eliminate inferior individuals, reduce costs and increase efficiency, aggregate superior genotypes from a genetic perspective, improve breeding efficiency, and ultimately improve the early growth performance or weight traits of the Sansui duck population, and indirectly improve adult weight and slaughter traits. Therefore, a molecular marker related to the early weight traits of Sansui ducks and a breeding method are provided.

[0007] The specific technical scheme of the present invention is:

[0008] In the first aspect, the present invention provides an application of a molecular marker related to the early weight trait of Sansui duck in the breeding of the early weight trait of Sansui duck, wherein the molecular marker is site A and / or site B, wherein site A is located at position 3426 of the 3' end of the ALMS1 gene, and corresponds to position 348 of the nucleotide sequence shown in SEQ ID NO.1; site B is located at position 68799 of the 7th intron region of the PBX1 gene, and corresponds to position 344 of the nucleotide sequence shown in SEQ ID NO.2.

[0009] Preferably, there is an insertion-deletion mutation at the 348 position, and the insertion-deletion mutation includes three alleles A1, I1 and D1, wherein A1 corresponds to base A, I1 corresponds to base A and the sequence shown in SEQ ID NO.3, and D1 corresponds to the deletion of base A and the sequence shown in SEQ ID NO.3;

[0010] There is an insertion-deletion mutation at the 344 position, and the insertion-deletion mutation includes three alleles A2, I2 and D2, wherein A2 corresponds to base A, I2 corresponds to base A and the sequence shown in SEQ ID NO.4, and D2 corresponds to the missing base A and the sequence shown in SEQ ID NO.4.

[0011] In a second aspect, the present invention provides a method for breeding early body weight traits of Sansui ducks, comprising:

[0012] Step 1, extract the genomic DNA of Sansui duck to be tested,

[0013] Step 2, using a primer pair and the genomic DNA of the Sansui duck to be tested as a template, PCR amplification and sequencing of the molecular markers described in the first aspect;

[0014] Step 3, determining the genotype of the molecular marker based on the sequencing results;

[0015] Step 4: Select and cultivate individuals based on the genotype results.

[0016] Preferably, the sequences of the primer pairs for detecting the A site are shown in SEQ ID NO:5 and SEQ ID NO:6; the sequences of the primer pairs for detecting the B site are shown in SEQ ID NO:7 and SEQ ID NO:8.

[0017] Preferably, in step 3, the genotype of molecular marker site A is A1A1, I1I1, I1A1 and D1D1, and the genotype of molecular marker site B is I2I2, I2A2 and D2D2.

[0018] Further preferably, in the molecular marker site A, the PCR product of the A1A1 genotype includes sites 130 to 489 of the sequence shown in SEQ ID NO.1, corresponding to sites 74459660 to 74460019 on the duck chromosome 4 sequence in the GenBank database, and sites 3208 to 3567 at the 3' end of the ALMS1 gene;

[0019] The PCR product of the I1I1 genotype is inserted into the sequence shown in SEQ ID NO.3 relative to the A1A1 genotype;

[0020] The PCR product sequences of the I1A1 genotype contained two sequences at the same time, one identical to the A1A1 genotype and the other identical to the I1I1 genotype;

[0021] The PCR product of the D1D1 genotype lacks base A at position 348 of the SEQ ID NO.1 sequence, position 74459877 on the duck chromosome 4 sequence in the GenBank database, and position 3426 at the 3' end of the ALMS1 gene relative to the A1A1 genotype;

[0022] In the molecular marker site B, the PCR product of the I2I2 genotype includes sites 180 to 540 of the sequence shown in SEQ ID NO.2, corresponding to sites 10269420 to 10269780 on the duck chromosome 8 sequence in the GenBank database, and sites 68635 to 68995 of the PBX1 gene;

[0023] The PCR product of the I2A2 genotype contains two sequences at the same time: one sequence is relative to the I2I2 genotype, lacking the sequence shown in SEQ ID NO.4; and the other sequence is the same as the I2I2 genotype;

[0024] Compared with the I2I2 genotype, the PCR product of the D2D2 genotype lacks the sequence shown in SEQ ID NO.4, and lacks base A at position 344 of the corresponding SEQ ID NO.2 sequence, position 10269583 on the duck chromosome 1 sequence in the GenBank database, and position 68798 of the PBX1 gene.

[0025] Preferably, in step 5, the individual selection criteria are: for site A, select A1A1 genotype individuals and eliminate individuals of other genotypes; for site B, select I2I2 genotype individuals and eliminate individuals of other genotypes.

[0026] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0027] The present invention studies the molecular marker A located at the 3426 position of the 3' end of the ALMS1 gene and corresponding to the 348 position of the nucleotide sequence shown in SEQ ID NO.1, and the molecular marker B located at the 68799 position of the 7th intron region of the PBX1 gene and corresponding to the 344 position of the nucleotide sequence shown in SEQID NO.2, and finds that the above two markers have insertion / deletion mutations. Through the detection and genotyping of the above two sites, a breeding method for the early weight traits of Sansui ducks is further developed. The method is not affected by age, gender, etc., and DNA can be extracted at any stage of breeding to carry out detection and breeding, improve the weight traits of the offspring of the Sansui duck group, and has important economic value and practical significance. At the same time, the method is not affected by the feeding environment and feed nutrition, can improve the weight traits from the genetic nature, aggregate the dominant genotype, and can quickly improve the breeding progress. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0029] Figure 1It shows the information of primer sequences, insertion mutations, deletion sequences, etc. in SEQ ID NO.1 and SEQ ID NO.2 of the present invention, wherein Figure A corresponds to SEQ ID NO.1 and Figure B corresponds to SEQ ID NO.2.

[0030] Figure 2 Box plot for performance comparison of different genotypes of ALMS1 molecular marker A.

[0031] Figure 3 Box plot comparing the performance of different genotypes of PBX1 molecular marker B.

[0032] Figures 2-3 In the figure, the horizontal axis represents the genotypes of ALMS1 and PBX1, and the vertical axis represents the body weight trait at 42 days of age. DETAILED DESCRIPTION

[0033] In the description of the present invention, it should be noted that, if the specific conditions are not specified in the examples, the experiments were carried out according to conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used, if the manufacturer is not specified, are all conventional products that can be purchased commercially.

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not 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.

[0035] Example 1

[0036] This example provides the discovery process of the Sansui duck ALMS1 gene and PBX1 gene molecular markers, which are as follows:

[0037] 1. Test materials

[0038] The experiment used 665 Sansui ducks (483 female ducks and 172 male ducks) from the breeding duck farm of Sansui County Qianlishan Food Technology Co., Ltd. Male and female ducks were mixed and raised under the same batch hatching, same feeding conditions and environment.

[0039] 2. Molecular marker detection

[0040] When the ducks were raised to 160 days of age, 1.5 mL of blood was collected from the wing vein, anticoagulated with EDTA, and 10× deep whole-genome resequencing was performed by Beijing Compson Agricultural Technology Co., Ltd.

[0041] After deep sequencing and comparative analysis of the database genome, it was found that a 17bp insertion mutation was found at position 3426 of the 3' end of the Sansui duck ALMS1 (centrosomeand basal body associated protein) gene relative to the Beijing duck genome (https: / / www.ncbi.nlm.nih.gov / datasets / genome / GCA_015476345.1 / ). This position also corresponds to position 348 of the nucleotide sequence shown in SEQ ID NO.1. The detection found that the site includes three alleles A1, I1 and D1, among which A1 corresponds to base A, I1 corresponds to base A and the 17bp insertion sequence shown in SEQ ID NO.3, and D1 corresponds to the missing base A and the 17bp sequence shown in SEQ ID NO.3 (tccaaacagctccaccg).

[0042] At the same time, it was found that compared with the Beijing duck genome, Sansui duck had a 51bp deletion mutation at position 68799 in the 7th intron region of the PBX1 (PBX homeobox 1, pre-B cell leukemia homeobox 1) gene. This position also corresponds to position 344 of the nucleotide sequence shown in SEQID NO.2. The detection found that the site includes three alleles A2, I2 and D2, among which A2 corresponds to base A, I2 corresponds to base A and the 51bp deletion sequence shown in SEQ ID NO.4, and D2 corresponds to the deletion of base A and the 51bp deletion sequence shown in SEQID NO.4 (gcacggcagc agccaggtta tttttaagcc agtgttttta cacctaccca t).

[0043] Example 2

[0044] This example provides a method for detecting ALMS1 and PBX1 molecular markers and trait association analysis, as follows:

[0045] 1. Test materials

[0046] The experiment used 65 Sansui ducks from the breeding duck farm of Sansui County Qianlishan Food Technology Co., Ltd. Male and female ducks were mixed and raised under the same batch hatching, same feeding conditions and environment.

[0047] 2. ALMS1 gene molecular marker detection

[0048] Blood was collected from the wing vein at around 50 days of age, and blood DNA was extracted using the TIANamp Blood DNA Kit. Primers were designed using the GenBank database online tool and the primer sequences were synthesized (commissioned by a biochemical technology company).

[0049] The PCR amplification primer sequence information is as follows:

[0050] Upstream primer F: 5'-TCAGGCATCTCTGGCATGTG-3'; (as shown in SEQ ID NO.5)

[0051] Downstream primer R: 5'-CAGGTGCTGAAAGGCAACAC-3'; (as shown in SEQ ID NO.6).

[0052] PCR reaction system: 1 μL DNA template, 1 μL upstream and downstream primers, 10 μL 2×Taq PCR MasterMix reagent, add ddH2O to 20 μL. PCR amplification reaction procedure: ① Pre-denaturation. 95℃5min, ② Amplification reaction. 95℃ denaturation for 30s, 60℃ annealing for 30s, 72℃ extension for 30s, 35 cycles; finally 72℃ extension for 5min. PCR products were entrusted to Nosai Genomics Research Center Co., Ltd. for sequencing.

[0053] After sequencing, the sequences were aligned and genotyped using DNAMAN software. The alignment results of each genotype sequence are as follows:

[0054] (1) The nucleotide sequence of the PCR amplification product of the A1A1 genotype is shown in SEQ ID NO.1, including the 130-489 region, corresponding to the 74459660 to 74460019 sites on the duck chromosome 4 sequence in the GenBank database, and the 3' end 3208 to 3567 sites of the ALMS1 gene. The primer sequence, insertion mutation, deletion sequence and other information in SEQ ID NO.1 are shown in Figure 1 shown.

[0055] (2) The PCR product of the I1I1 genotype is 377 bp in length. Compared with the A1A1 genotype, the 17 bp sequence shown in SEQ ID NO.3 is inserted at position 348 shown in SEQ ID NO.1.

[0056] (3) There are two lengths of PCR products for the I1A1 genotype: one is 360 bp in length, with the same sequence as the A1A1 genotype, and the other is 377 bp in length, with the same sequence as the I1I1 genotype.

[0057] (4) The PCR product of the D1D1 genotype was 359 bp in length. Compared with the A1A1 genotype, there was a deletion of base A at position 348 of SEQ ID NO.1, position 74459877 of duck chromosome 4 in the GenBank database, and position 3426 at the 3' end of the ALMS1 gene.

[0058] The genotyping results of ALMS1 molecular marker detection are shown in Table 1. Among the 65 Sansui duck samples, 48 ​​individuals with A1A1 genotype, 3 individuals with I1I1 genotype, 12 individuals with I1A1 genotype, and 2 individuals with D1D1 genotype were finally detected.

[0059] 3. PBX1 gene molecular marker detection

[0060] Blood was collected from the wing vein at around 50 days of age, and blood DNA was extracted using the TIANamp Blood DNA Kit. Primers were designed using the GenBank database online tool and the primer sequences were synthesized (commissioned by a biochemical technology company).

[0061] The PCR amplification primer sequence information is as follows:

[0062] Upstream primer F: 5'-GCCCCAAAACGGCATCTTTT-3'; (as shown in SEQ ID NO.7)

[0063] Downstream primer R: 5'-TCTGTTTAAGCCGCTCCCTG-3'; (as shown in SEQ ID NO. 8).

[0064] PCR reaction system: 1 μL DNA template, 1 μL upstream and downstream primers, 10 μL 2×Taq PCR MasterMix reagent, add ddH2O to 20 μL. PCR amplification reaction procedure: ① Pre-denaturation. 95℃5min, ② Amplification reaction. 95℃ denaturation for 30s, 60℃ annealing for 30s, 72℃ extension for 30s, 35 cycles; finally 72℃ extension for 5min. PCR products were entrusted to Nosai Genomics Research Center Co., Ltd. for sequencing.

[0065] After sequencing, the sequences were aligned and genotyped using DNAMAN software. The alignment results of each genotype sequence are as follows:

[0066] (1) The nucleotide sequence of the PCR amplification product of the I2I2 genotype is shown in SEQ ID NO.2, which is 361 bp in total and includes sites 180 to 540 of the sequence shown in SEQ ID NO.2, corresponding to sites 10269420 to 10269780 on the duck chromosome 8 sequence in the GenBank database and sites 68635 to 68995 of the PBX1 gene; the primer sequences, insertion mutations, deletion sequences, etc. in SEQ ID NO.2 are shown in Figure 1 shown.

[0067] (2) There are two lengths of PCR products for the I2A2 genotype: one is 310 bp, which lacks the 345-395 position shown in SEQ ID NO.2, i.e., the 51 bp sequence shown in SEQ ID NO.4, compared with the I2I2 genotype; the other is 361 bp, with the same sequence as the I2I2 genotype;

[0068] (3) The PCR product of the D2D2 genotype was 309 bp in length. Compared with the I2I2 genotype, it lacked the sequence shown in SEQ ID NO.2, as well as base A at position 344 of the corresponding SEQ ID NO.2 sequence, position 10269583 on the duck chromosome 1 sequence in the GenBank database, and position 68798 of the PBX1 gene.

[0069] (4) The genotyping results of PBX1 gene molecular marker detection are shown in Table 1. As shown in Table 1, 52 individuals with I2I2 genotype, 3 individuals with D2D2 genotype, and 10 individuals with I2A2 genotype were detected in 65 Sansui duck samples.

[0070] 4. Growth data determination

[0071] The birth weight was measured, and then the body weight of Sansui ducks was measured every 2 weeks. The body weight at 42 days of age (D42) was used as an early body weight trait indicator for association analysis. The data results of body weight at 42 days of age (D42) are shown in Table 1.

[0072] Table 1 Molecular marker genotyping and 42-day body weight (D42, unit g) data of each sample

[0073]

[0074]

[0075] In this embodiment, the weight at 42 days of age (D42) is used as an early body weight trait for only an example. The weight below 70 days of age can be used as an early body weight trait, preferably at 40-50 days of age.

[0076] 5. Association analysis between molecular marker genotype and D42 trait

[0077] SPSS 22.0 software was used to draw box plots of different genotypes of ALMS1, see attached Figure 2 .from Figure 2 It can be seen that among the four genotypes, the body weight at 42 days of age (D42) of individuals with the ALMS1 gene molecular marker A1A1 was significantly better than that of individuals with other genotypes.

[0078] SPSS22.0 software was used to draw box plots of different genotypes of PBX1, see attached Figure 3 .from Figure 3It can be seen that among the three genotypes, the body weight at 42 days of age (D42) of individuals with the PBX1 gene molecular marker I2I2 was significantly better than that of individuals with other genotypes.

[0079] The results of multiple comparisons and significance tests of various traits of different genotypes are shown in Table 2. The letters above the mean values ​​in the table indicate significant test results, different lowercase letters indicate significant differences (P<0.05), different uppercase letters indicate extremely significant differences (P<0.01), and the same letters or no mark indicate insignificant differences.

[0080] As shown in Table 2, the D42 trait of the ALMS1 gene A1A1 genotype is significantly higher than that of individuals with other genotypes. There is a significant difference in the D42 trait between I1A1 and I1I1, while there is no significant difference in the D42 trait between individuals with the D1D1 genotype and those with the I1A1 and I1I1 genotypes.

[0081] From Table 2, we can see that the D42 trait of the PBX gene I2I2 genotype is significantly higher than that of individuals with other genotypes, and there is no significant difference in the D42 trait between I2A2 and D2D2 individuals.

[0082] Table 2 Comparison results of D42 traits of each genotype

[0083]

[0084] Example 3

[0085] This example uses ALMS1 and PBX1 molecular markers for breeding of D42 traits, as follows:

[0086] 1. Test materials and growth data determination:

[0087] The sources of the test materials are the same as those in Example 2. The results of the D42 trait and molecular marker genotype detection of 65 samples are shown in Table 1.

[0088] 2. Individual selection and elimination

[0089] Individuals are selected and eliminated based on the genotype of the loci. Individuals with the A1A1 genotype at the A locus and the I2I2 genotype at the B locus are selected, and individuals with other genotypes are eliminated.

[0090] Among the 65 Sansui duck samples, there were 48 individuals with the A1A1 genotype at the ALMS1 gene molecular marker A site, but two individuals (A066 and S3944) had the D2D2 genotype at the PBX1 gene molecular marker B site, and four individuals (A090, S3910, S3958 and S9567) had the I2A2 genotype at the PBX1 gene molecular marker B site. Therefore, 42 individuals were finally retained and 23 individuals were eliminated.

[0091] 3. Evaluation of the selection and retention effect

[0092] In order to evaluate the breeding effect of this method, the ducks were not actually eliminated, but were raised under the same feeding and management conditions until they were released, and the daily average weight was calculated, and the growth and meat traits were measured at slaughter. The measured indicators included daily average weight, live weight before slaughter, carcass weight, half-eviscerated weight, full-eviscerated weight, breast muscle weight, and leg muscle weight. The indicator measurement was carried out in accordance with the "Terminology and Measurement Statistical Methods of Poultry Production Performance: Agricultural Industry Standard of the People's Republic of China NY / T823-2004".

[0093] The performance of the selected individuals and the eliminated individuals was compared. The data of each index are expressed as mean ± standard deviation. The shoulder letters above the mean value in the table indicate significant test results. Different lowercase letters indicate significant differences (P<0.05), different uppercase letters indicate extremely significant differences (P<0.01), and the same letters or no mark indicate insignificant differences. The comparison results are shown in Table 3.

[0094] Table 3 Comparison of traits of each population Unit: g

[0095] D42 Daily average weight gain Pre-slaughter weight Carcass weight all 808.15±123.23 3.22±0.97 1285.25±169.01 1182.52±161.09 Select <![CDATA[868.82±79.95 A ]]> 3.12±1.07 <![CDATA[1330.48±167.20 A ]]> <![CDATA[1221.88±158.52 A ]]> disuse <![CDATA[697.38±111.42 B ]]> 3.41±0.76 <![CDATA[1202.66±141.28 B ]]> <![CDATA[1110.66±142.51 B ]]> Half eviscerated weight Full eviscerated weight Chest muscle weight Leg muscle weight all 1070.98±151.06 792.61±100.45 125.62±22.71 121.21±19.96 Select <![CDATA[1108.61±150.68 A ]]> <![CDATA[813.37±105.48 a ]]> 129.31±23.87 <![CDATA[125.61±21.29 a ]]> disuse <![CDATA[1002.25±128.17 B ]]> <![CDATA[754.69±79.36 b ]]> 118.86±19.09 <![CDATA[113.16±14.48 b ]]>

[0096] As shown in Table 3, the early body weight (D42) of the selected group was significantly higher than that of the eliminated group. After market release (160 days of age), the live weight, carcass weight, and half-eviscerated weight of the selected group were significantly higher than those of the eliminated group. The eviscerated weight and leg muscle weight of the selected group were significantly higher than those of the eliminated group. There was no significant difference between the daily average weight gain and breast muscle weight.

[0097] In summary, the present invention found that the insertion and deletion mutations in the 3' end of the ALMS1 gene and the 7th intron region of the PBX1 gene were significantly associated with the early growth traits (weight at 42 days of age) of Sansui ducks through whole genome deep sequencing and association analysis with traits. The present invention constructs a molecular marker-assisted breeding method based on ALMS1 and PBX1 genes to improve the early growth traits of Sansui ducks, and provides a new breeding technology for the breeding of Sansui duck meat products. Since early growth traits can affect the final meat traits, the application of this method indirectly improves the adult weight and slaughter traits of Sansui ducks, which is of great economic value and scientific significance for accelerating the genetic improvement of Sansui ducks, tapping their meat performance potential, and cultivating new strains of low-fat and high-quality local meat ducks, and improving the germplasm resources of local ducks and reducing costs and increasing efficiency.

[0098] Although the embodiments of the present invention have been shown and described, it is understood that a person of ordinary skill in the art may make various changes, modifications, substitutions and variations to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the attached claims and their equivalents. The above-described embodiments only express several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that a person of ordinary skill in the art may make several variations and improvements without departing from the concept of the present invention, and these all belong to the scope of protection of the present invention. Therefore, the scope of protection of the patent of the present invention shall be based on the attached claims.

Claims

1. Application of a molecular marker related to the early body weight trait of Sansui duck in the breeding of the early body weight trait of Sansui duck, characterized in that: The molecular marker is site A and / or site B, wherein site A is located at position 3426 of the 3' end of the ALMS1 gene and corresponds to position 348 of the nucleotide sequence shown in SEQ ID NO.1; site B is located at position 68799 of the 7th intron region of the PBX1 gene and corresponds to position 344 of the nucleotide sequence shown in SEQ ID NO.

2.

2. The use according to claim 1, characterized in that: There is an insertion-deletion mutation at position 348, and the insertion-deletion mutation includes three alleles A1, I1 and D1, wherein A1 corresponds to base A, I1 corresponds to base A and the sequence shown in SEQ ID NO.3, and D1 corresponds to the deletion of base A and the sequence shown in SEQ ID NO.3; There is an insertion-deletion mutation at the 344 position, and the insertion-deletion mutation includes three alleles A2, I2 and D2, wherein A2 corresponds to base A, I2 corresponds to base A and the sequence shown in SEQ ID NO.4, and D2 corresponds to the missing base A and the sequence shown in SEQ ID NO.

4.

3. A method for breeding Sansui ducks for early body weight traits, characterized in that: include: Step 1, extract the genomic DNA of Sansui duck to be tested, Step 2, using a primer pair and the genomic DNA of the Sansui duck to be tested as a template, PCR amplifying and sequencing the molecular marker described in claim 1 or 2; Step 3, determining the genotype of the molecular marker based on the sequencing results; Step 4: Select and cultivate individuals based on the genotype results.

4. The breeding method according to claim 3, characterized in that: The sequences of the primer pairs for detecting the A site are shown in SEQ ID NO:5 and SEQ ID NO:6; the sequences of the primer pairs for detecting the B site are shown in SEQ ID NO:7 and SEQ ID NO:

8.

5. The breeding method according to claim 3, characterized in that: In step 3, the genotypes of molecular marker site A are A1A1, I1I1, I1A1 and D1D1, and the genotypes of molecular marker site B are I2I2, I2A2 and D2D2.

6. The breeding method according to claim 4 or 5, characterized in that: In the molecular marker site A, the PCR product of the A1A1 genotype includes sites 130 to 489 of the sequence shown in SEQ ID NO.1, corresponding to sites 74459660 to 74460019 on the duck chromosome 4 sequence in the GenBank database, and sites 3208 to 3567 at the 3' end of the ALMS1 gene; the PCR product of the I1I1 genotype is inserted into the sequence shown in SEQ ID NO.3 relative to the A1A1 genotype; The PCR product sequences of the I1A1 genotype contained two sequences at the same time, one identical to the A1A1 genotype and the other identical to the I1I1 genotype; The PCR product of the D1D1 genotype lacks base A at position 348 of the SEQ ID NO.1 sequence, position 74459877 on the duck chromosome 4 sequence in the GenBank database, and position 3426 at the 3' end of the ALMS1 gene relative to the A1A1 genotype; In the molecular marker site B, the PCR product of the I2I2 genotype includes sites 180 to 540 of the sequence shown in SEQ ID NO.2, corresponding to sites 10269420 to 10269780 on the duck chromosome 8 sequence in the GenBank database, and sites 68635 to 68995 of the PBX1 gene; The PCR product of the I2A2 genotype contains two sequences at the same time: one sequence is relative to the I2I2 genotype, lacking the sequence shown in SEQ ID NO.4; and one sequence is the same as the I2I2 genotype; Compared with the I2I2 genotype, the PCR product of the D2D2 genotype lacks the sequence shown in SEQ ID NO.4, and lacks base A at position 344 of the corresponding SEQ ID NO.2 sequence, position 10269583 on the duck chromosome 1 sequence in the GenBank database, and position 68798 of the PBX1 gene.

7. The breeding method according to any one of claims 3 to 6, characterized in that: In step 5, the individual selection criteria are: for site A, individuals with A1A1 genotype are selected and individuals with other genotypes are eliminated; for site B, individuals with I2I2 genotype are selected and individuals with other genotypes are eliminated.

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