CN113061661A - Application of MiR-125a-5p in early development of embryo - Google Patents

Abstract

The invention discloses an application of evaluating the early development potential of embryos and improving the early development capability of old embryos. The invention screens out microRNA (microRNA) miR-125a-5p which is highly expressed in the sperms of the elderly males and plays a key role in the development of the elderly embryos by a microRNA high-throughput sequencing and bioinformatics method, and experiments prove that the miR-125a-5p is obviously highly expressed in the sperms of the elderly mice; by microinjecting the miR-125a-5p simulator in the prokaryotic embryo formed by a young mouse, the blastocyst formation rate is obviously reduced, and the embryo is blocked at the morula/blastocyst stage; the miR-125a-5p inhibitor is injected in a prokaryotic embryo formed by an old mouse by a microinjection method, and the miR-125a-5p inhibitor can be observed to effectively improve the blastocyst formation rate of the old embryo. The invention can be used as a new target for detecting the embryonic development potential of mice and improving the embryonic development of old mice, and provides a new method for improving the embryo quality.

Description

Application of MiR-125a-5p in early development of embryo

Technical Field

The invention belongs to the technical field of biomedicine, and particularly relates to application of miR-125a-5p in detection of early development potential of an embryo and application of an miR-125a-5p inhibitor in preparation of a product for improving early development of the embryo.

Background

With the dramatic increase of the working pressure of modern society, the aging of population, the progress of assisted reproductive technology and the release of comprehensive two-fetus policy, more and more couples postpone the birth until the later age stage, and the understanding of the influence of age factors on the fertility becomes more and more important. The negative effects of maternal age on egg quality, embryonic development potential are well known, but little is known about the effect of paternal age on fertility.

The results of a number of epidemiological studies have shown that the decline in semen quality associated with male age includes: sperm concentration, sperm forward motility percentage, teratospermia rate, sperm DNA Fragmentation Index (DFI), and the like. Studies have found that DFI and Oxidative Stress Adducts (OSA) increase with age, while an increase in sperm DFI is often associated with poor embryonic development and poor pregnancy outcome. Numerous studies have demonstrated that paternal age is a risk factor for spontaneous abortion and may lead to adverse reproductive fates such as schizophrenia, autism and several X-linked recessive and autosomal dominant genetic diseases. Therefore, the research on the influence of the factors of the advanced age of the male on the germ cells, the embryonic development and the like has certain practical significance.

MicroRNAs (miRNAs) are small RNAs that play an important role in post-transcriptional regulation of gene expression in various tissues, while miRNAs in sperm may be a typical epigenetic regulation agent and may be involved in regulation of sperm function and early embryonic development. Some recent studies, microinjecting mirnas into Prokaryotic (PN) stage embryos, provide direct evidence that changes in miRNA abundance during early embryonic development may affect the progression of embryonic development and may even induce progeny phenotype.

High-throughput sequencing is carried out on the aged/young sperms, ova and embryos to discover a large number of miRNAs with differential expression, wherein miR-125a-5p is up-regulated in the aged sperms and embryos and has no obvious difference in the expression in the aged ova; and miR-125a-5p has high human and mouse conservation and is related to the aging process. The literature reports that miR-125a-5p is increased in senescent thymus and is involved in age-related thymus degeneration by targeting FoxN 1; miR-125a-5p and many miRNAs are associated with heart aging and exhibit synergistic effects. Moreover, miR-125a-5p is up-regulated in senescent endothelial cells and can damage endothelial cell angiogenesis by targeting RTEF-1. Meanwhile, miR-125a-5p is elevated in the hyperlipidemia-hyperglycemia state, is associated with oxidative low density lipoprotein (oxLDL) -induced vascular endothelial cell necrosis, and leads to mitochondrial dysfunction and ROS elevation by targeting TET 2. In the reproductive system, miR-125a-5p also plays an important role, miR-125a-5p in preeclamptic placental tissues is increased, and miR-125a-5p mimics can reduce the migration, proliferation and angiogenesis capacity of HTR8/SVneo cells and induce more cells blocked in the S phase. Researches also find that the miR-125 family is an important regulatory factor for expression and maintenance of maternal effect genes in the early embryonic development process, and the expression of the maternal effect genes can be influenced by microinjection of miR-125 family members.

Although the research shows that miR-125a-5p plays a role in biological processes such as aging, mitochondrial function, maternal gene expression and maintenance, no document reports the role of miR-125a-5p highly expressed in aged sperms in early embryonic development. In the patent, the miR-125a-5p is found to be obviously highly expressed in the sperms of the aged mice; by microinjecting the miR-125a-5p simulator in the prokaryotic embryo formed by a young mouse, the blastocyst formation rate is obviously reduced, and the embryo is blocked at the morula/blastocyst stage; the miR-125a-5p inhibitor is injected in a prokaryotic embryo formed by an old mouse by a microinjection method, and the miR-125a-5p inhibitor can be observed to effectively improve the blastocyst formation rate of the old embryo. The invention can be used as a new method for detecting the development potential of the embryo of the mouse and improving the development of the embryo of the aged mouse, and provides a new target point and thought for improving the quality of the embryo.

Disclosure of Invention

The purpose of the invention is as follows:

provides the application of miR-125a-5p in early embryonic development. The method comprises the following steps: evaluating the development potential of the miR-125a-5 p-elevated embryo to provide a product for preparing and detecting the early development potential of the embryo by using a possible target; evaluating the restoration efficiency of the embryo development of the aged embryo after miR-125a-5p inhibitor injection to provide a possible method for improving the early development of the aged embryo.

The invention provides an application of the following substances in early development of embryo:

application of MiR-125a-5p in preparation of products for detecting early development potential of embryos.

Application of the MiR-125a-5p inhibitor in preparing products for improving early development of advanced embryos.

Including but not limited to, measuring miR-125a-5p content in sperm or embryo to assess embryonic development potential, or as a basis for cleavage stage transfer or blastocyst transfer

Including but not limited to altering miR-125a-5p content in sperm or embryos using miR-125a-5p inhibitors to improve embryonic early development potential.

The technical scheme is as follows:

the nucleotide sequence of the miR-125a-5p stimulant is sequence 1 in a sequence table, the effective dosage of the miR-125a-5p stimulant is 100nM 2.5pL, and the miR-125a-5p stimulant can be injected into a mouse embryo through microinjection to improve the expression level of miR-125a-5 p.

The miR-125a-5p inhibitor is miR-125a-5p inhibitor, and the nucleotide sequence is sequence 2 in the sequence table. The effective dosage of the miR-125a-5p inhibitor is 2mM x 2.5pL, and the miR-125a-5p inhibitor can be injected into mouse embryos by microinjection to reduce the expression level of miR-125a-5 p.

The embryo development potential detection stage is the potential of fertilized eggs developing into blastula;

the early embryo development is from the onset of zygote development to blastocyst formation.

The embryo is a mouse embryo; the aged embryo is formed by an aged male mouse (>12 months old) and a young female mouse (6-8 weeks old); the young embryo is formed by young male mice (6-8 weeks old) and young female mice (6-8 weeks old).

Experiments prove that the blastocyst formation rate of embryos obtained by the combination of old male mice and young female mice is remarkably reduced, the expression level of miR-125a-5p in the embryos is remarkably increased through detection, the blastocyst formation rate is also remarkably reduced through the microinjection of a miR-125a-5p simulator in the embryos obtained by the combination of the young male mice and the young female mice, and the blastocyst formation rate is remarkably increased after the microinjection of a miR-125a-5p inhibitor in the embryos obtained by the combination of the old male mice and the young female mice. The above results suggest: the miR-125a-5p can be used for preparing products for detecting the early development potential of embryos; the miR-125a-5p inhibitor can be used for preparing products for improving the early development of the advanced embryos. The invention provides a new idea for detecting the early development potential of the embryo and improving the early development of the embryo. The advantages of the invention are novel.

Drawings

The following drawings are included to illustrate specific embodiments of the invention and are not intended to limit the scope of the invention as defined by the claims.

FIG. 1 shows the high throughput sequencing results of miR-125 family in aged/young sperm (Sp), ovum (Oo), and embryo (Em).

FIG. 2 shows the results of the conservation of miR-125a-5p between different species;

FIG. 3 shows the expression levels of miR-125a-5p in advanced (Aging), Young (Young) sperm;

FIG. 4 shows DNA damage in older, young sperm;

FIG. 5 is a schematic diagram of the present invention for obtaining young and old zygotes;

FIG. 6 shows early development of young, advanced-age embryos;

FIG. 7 shows the percentage of each phase of young, old embryos;

FIG. 8 shows the expression levels of miR-125a-5p in older (Aging), Young (Young) embryos;

FIG. 9 shows the percentage of early embryos at each stage after injection of young embryos with control, miR-125a-5p or miR-125a-5p/miR-574 mixture;

FIG. 10 shows the expression levels of miR-125a-5p in young embryos after injection of a control, miR-125a-5p or miR-125a-5p/miR-574 mixture into blastocyst embryos;

FIG. 11 shows early development of young, old and miR-125a-5p inhibitor-injected old embryos;

FIG. 12 shows the percentage of each stage of young, old and miR-125a-5p inhibitor injected old embryos.

Detailed Description

The present invention is further illustrated by the following examples, which are intended to be purely exemplary and are not intended to limit the scope of the invention, as modifications and alterations to the methods, procedures or conditions of the invention may be made without departing from the spirit and nature of the invention.

The selected mice are ICR mice, and the miR-NC and miR-125a-5p mimics/inhibitor are purchased from Ruibo biology, Inc. of Guangzhou.

Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art; the reagents used in the examples are commercially available.

Example 1: expression level of miR-125a-5p in sperms of young and old mice

Based on the high-throughput sequencing results of early-aged/young sperms (Sp), ova (Oo) and embryos (Em), the miR-125a-5p is found to be highly expressed in the old sperms and embryos (figure 1) and shows high human-mouse homology (figure 2), and the expression level of the miR-125a-5p in the young and old mouse sperms is further detected.

Cervical dislocation of 1.16-8 weeks old C57 male mice and more than 18 months old C57 male mice is killed, 75% alcohol is sprayed on the abdomen of the male mice, the lower abdomen of the male mice is dissected, epididymis tails are taken out and soaked in HTF, the male mice are gently scratched under a body type microscope by using a 1mL syringe, milky sperm groups slowly swim out, and sperms are collected.

1.2 the sperm were washed twice with physiological saline, 1000g, 5 min. A part of sperms are taken to extract sperm RNA by a conventional Trizol method, reverse transcription is carried out by miR-125a-5p and U6 specific reverse transcription primers (purchased from Ruibo biology Co., Ltd.), and subsequent real-time quantitative detection is carried out. And taking another part of the sperms to detect the DNA damage condition of the sperms by a sperm chromatin diffusion method (SCD method).

1.3SCD method for detecting sperm DNA damage condition sperm DNA fragment detection kit of Boruide Biotechnology Limited is adopted.

1.3.1 incubate the fusible gel tube at 80 ℃ for 20 minutes, after it has completely melted, place the fusible gel tube at 37 ℃ until ready for use (the fusible gel tube needs to equilibrate at least 5 minutes to allow it to move from 80 ℃ to 37 ℃).

1.3.2 the sperm concentration is 5-10 x 10⁶Adding 60 mul/mL of a sample to be detected into a fused fusible gel tube (keeping constant temperature at 37 ℃), fully and uniformly mixing, and incubating at 37 ℃ for later use;

1.3.3 placing the coated glass slide in a refrigerator at 2-8 ℃ for precooling for 5min, taking out, and quickly adding 30 mu L of sperm suspension into the coated area of the glass slide;

1.3.4 cover the cover glass quickly (without applying pressure to the cover glass), avoid generating bubbles as much as possible, place in a refrigerator at 2-8 deg.C for 5min,

allowing it to solidify;

1.3.5 remove the slide from the refrigerator, carefully remove the cover slip covering it; immediately vertically immersing the glass slide into a reaction tank containing the reaction liquid A, and accurately reacting for 7min at 20-28 ℃;

1.3.6 taking out the slide glass, and sucking away the liquid remaining on the back surface and side edge of the slide glass (not contacting the specimen region) with filter paper; vertically immersing the glass slide into a reaction tank containing the reaction liquid B, and accurately reacting for 25min at 20-28 ℃;

1.3.7 washing in pure water for 2min, 70%, 90% and 100% ethanol for several times respectively, and naturally drying the glass slide in the air;

1.3.8 each glass slide is covered with 15-20 drops of Ruhrstan's dye, 30-40 drops of Ruhrstan's buffer solution are slowly added at a moment, the mixed dye is lightly blown by an ear washing ball (without destroying the dye to form surface tension), the mixture is placed at room temperature for 15min, and then the slide is lightly washed by running water; after natural air drying, 500 sperm cells were counted and observed under a microscope. A larger halo indicates better sperm quality.

As a result, miR-125a-5p is obviously highly expressed in the sperms of the aged mice (figure 3), and the DNA damage of the sperms of the aged mice is obviously increased (figure 4).

Example 2: early embryonic development and miR-125a-5p expression of aged mice

2.1 Experimental animals: the ICR female mice of 6-8 weeks old, the ICR male mice of 6-8 weeks old and the ICR male mice of 13 months old are all clean grade, and the mating and fertilized egg obtaining strategies are shown in figure 5. Fewer fertilized eggs are produced due to the mating of the old male mouse and the old female mouse; therefore, a fertilized egg produced by the mating of an old male mouse and a Young female mouse is defined as an old embryo (Aging Group), and a fertilized egg produced by the mating of a Young male mouse and a Young female mouse is defined as a Young embryo (Young Group)

2.2 reagent and consumable preparation:

2.2.1 preparation of PMSG and HCG

Diluting PMSG and HCG powder with physiological saline at a concentration of 50IU/mL, mixing well, filtering with 0.22mm filter according to a dose of 1 mL/branch, and subpackaging with 1.5mL sterile EP tube, storing at-20 deg.C, and protecting HCG from light.

2.2.2 Hyaluronidase concentrated stock solution

The hyaluronidase powder was diluted to 20mg/mL with M2 medium, mixed well, filtered through a 0.22mm filter, and dispensed into 0.5mL sterile PCR tubes at 200 mL/tube, and stored at-20 ℃.

2.2.3 egg removal needle preparation

Holding two ends of a glass capillary horizontally, placing the central part of the glass capillary in an alcohol lamp flame for heating, when the glass tube is burnt red by flame and becomes soft, holding the glass tube horizontally and slightly away from the flame, holding two ends of the glass capillary with two hands, stretching the glass capillary horizontally and reversely, cutting the central part of the glass capillary with a grinding wheel, instantaneously burning the broken end on the flame to smooth the broken end, and storing for later use after the inspection under a stereomicroscope is correct.

2.3 obtaining fertilized eggs of mice:

2.3.1 Induction of hyper ovulation and mating in mice

Injecting PMSG into the abdominal cavity of a female mouse, wherein the dosage is 8 IU/mouse; 46-48h later, the injection dose of HCG is 8 IU/mouse; after HCG injection, female mice and male mice are mated in the same cage according to the proportion of 1:1 (the grouping: young group: 8-week-old female mice x 8-week-old male mice; old group: 8-week-old female mice x 13-month-old male mice, next morning 8:00, vaginal embolus of the female mice are checked, the female mice with vaginal embolus are considered as mating success, the female mice are selected, and fertilized eggs are collected 18h after HCG injection.

2.3.2 Collection of mouse fertilized eggs

Diluting hyaluronidase to 1mg/mL, preheating a prepared M2 culture medium at 37 ℃ for 30 minutes in advance, killing female mice successfully mated by cervical dislocation, dissecting abdominal cavities, separating two lateral oviducts of the mice, placing the mice in a preheated M2 culture medium, tearing the ampulla of the oviduct under the observation of a stereoscopic microscope, allowing conglobate fertilized eggs wrapped by granular cells to flow out, digesting and removing cumulus granular cells wrapped at the periphery of an embryo by using hyaluronidase, transferring the fertilized eggs without the granular cells into a fresh M2 culture medium drop by using an egg transferring needle, washing the residual hyaluronidase, and removing the residual hyaluronidase; finally, the fertilized eggs are transferred into the prepared KSOM culture medium liquid drops and are placed in 5 percent CO₂37 ℃ incubator.

2.3.4 in vitro culture of mouse fertilized eggs

1) Preparation of KSOM culture microdroplets

Preparing culture microdroplets at night on the day of HCG injection;

secondly, distributing the KSOM culture medium at the bottom of a 35mm plate in a volume of 30 mu L/drop;

dripping tissue culture oil into the plate along the side wall, wherein the dripping dosage is proper for completely covering the surface of the liquid drop, the exposure time of the liquid drop in the air is reduced as much as possible, and the serial number of each liquid drop is marked at the bottom of the plate;

fourthly, placing the prepared culture microdroplets in 5 percent CO₂At 37 ℃ overnight, temperature and gas equilibration were carried out.

2) Fertilized egg in vitro culture and observation

The collected fertilized eggs are grouped and transferred into culture microdroplets prepared in advance the evening before for culture. Transferring 20-30 embryos into each microdroplet, and placing in 5% CO₂In the 37 ℃ incubator, theAnd (4) keeping the line temperature and the gas balance, marking each dish, and observing and photographing at regular time.

2.4 micro-RNA extraction

Each group of embryos cultured in vitro (morula and blastocyst) was transferred to an RNase-free microcentrifuge tube using a mouth pipette under a stereomicroscope. Use of

The RNA Isolation Kit extracts RNA of a micro-sample, and comprises the following specific steps:

2.4.1 adding 50 μ L lysis buffer into the microcentrifuge tube with collected embryo, and placing in 42 deg.C water bath for 30 min;

2.4.2 assembling a purification column, adding 250 mu L of conditioning buffer, standing at room temperature for 5 minutes, centrifuging at 16000g for 1 minute, and treating the purification column;

2.4.3 adding 50 μ L70% ethanol into the lysate treated in step 1, reversing the mixture up and down, mixing the mixture, transferring the suspension into a treated purification column, centrifuging the suspension for 2 minutes at 100g, and centrifuging the suspension for 30 seconds at 16000 g;

2.4.4 Add 100. mu.L wash buffer 1(W1) to the column and centrifuge at 8000g for 1 min;

2.4.5 adding 100 μ L wash buffer 2(W2), centrifuging at 8000g for 1 min, adding 100 μ L W2, 16000g for 2min, and then 16000g for 1 min;

2.4.6 transfer the column into a new 0.5mL RNase-free microcentrifuge tube, cover the 1.5mL EP tube, add 11. mu.L RNase-free water, stand at room temperature for 2 minutes, centrifuge at 1000g for 1 minute, centrifuge at 16000g for 1 minute, collect RNA for the next step. Reverse transcription and quantification of miR-125a-5p are referred to in example 1.

As a result, the blastula formation rate of the aged embryos is obviously reduced compared with that of the young embryos (figure 6 and figure 7), and the expression level of miR-125a-5p in the aged embryos is obviously increased (figure 8), which indicates that miR-125a-5p highly expressed in the aged sperms possibly plays a certain role in early embryo development.

Example 3: embryonic early development condition and miR-125a-5p expression condition after micro-injection of miR-125a-5p on young mouse fertilized eggs

3.1 experimental animal experiment, preparation of reagent consumables, acquisition of mouse fertilized eggs, embryo in-vitro culture, extraction of micro RNA, reverse transcription of miRNA and real-time fluorescent quantitative PCR refer to example 1 and example 2.

3.2 cytoplasmic microinjection and in vitro culture of fertilized eggs of young mice

3.2.1 grouping: a young group is injected with miR-NC in a micro-injection mode; ② young group + micro-injection of miR-125a-5p mimics; ③ young group and micro-injection of miR-125a-5p/miR-574 mimics; (based on our earlier researches, miR-574 also expresses in the aged sperm highly and affects the mitochondrial function, so that the group III is increased)

3.2.2 preparing miR-NC mimics, miR-125a-5p mimics and miR-125a-5p/miR-574mimics for injection (according to the instruction, 125 mul of RNase-free injection buffer solution is added into 0.5OD according to the instruction, concentrated storage with the concentration of 20 mul is prepared, then 2 mul of the concentrated storage with the concentration of 20 mul is diluted into microinjection solution with the concentration of 100nM, the microinjection solution is subpackaged into PCR tubes without RNase by 10 mul/tube, the PCR tubes are wrapped by tinfoil paper, and the microinjection solution is preserved at minus 80 ℃ for standby use in a dark place).

3.2.3 cytoplasmic microinjection of mouse fertilized eggs

Firstly, a clean 35mm dish is taken, M2 culture medium preheated at 37 ℃ is longitudinally dripped, tissue culture oil is covered on the dish, and the dish is placed on a constant temperature table at 37 ℃ on a micromanipulator.

And mounting an ovum holding needle and debugging the position.

And thirdly, sucking 3 mu L of microinjection reagent by using a micro sample loading capillary needle, adding an injection needle, avoiding the generation of bubbles as much as possible, if bubbles which are visible to naked eyes are generated, vertically holding the needle, flicking the tail end of the injection needle to discharge the bubbles, then installing the injection needle on a microinjection operation instrument, and pressing a Clean key to ensure that the injection needle is smooth.

And fourthly, transferring about 30 mouse fertilized eggs into an injection dish, and carrying out microinjection in batches. Under the high-power visual field of the injection system, fertilized eggs which discharge second polar bodies, have female pronuclei and male pronuclei and have good shapes and good refractivity are selected for microinjection.

Fifthly, after injection is finished, the embryo damaged by injection is removed; selecting embryos which are successfully injected and have complete morphology for further in vitro culture and observation; a timer is used for counting down in the operation process, so that the time for exposing the embryo outside the incubator is not more than 15min in the operation process.

3.2.4 in vitro culture of Pre-implantation embryos in mice

Microinjected embryos were grouped and transferred to culture microdroplets prepared in advance the evening before for culture. Transferring 20-30 embryos into each microdrop, placing the microdroplets in a 37 ℃ incubator with 5% CO2, balancing temperature and gas, marking each dish, and observing and photographing at regular time.

The results show that the blastocyst formation rate of the young mouse fertilized eggs is obviously reduced after miR-125a-5p is injected, and the blastocyst formation rate of the young mouse fertilized eggs is further reduced after miR-125a-5p/miR-574 mixture is injected (figure 9); and miR-125a-5p is obviously highly expressed in the embryo injected with miR-125a-5p, miR-125a-5p/miR-574 mixture (FIG. 10). Suggesting that miR-125a-5p can influence the early development of embryos, and the higher the expression of miR-125a-5p is, the lower the embryo blastocyst formation rate is.

Example 4: research on effect of miR-125a-5p inhibitor on improving early-stage development of advanced embryos

4.1 Experimental procedures for experimental animals, preparation of reagent consumables, obtaining of mouse fertilized eggs, microinjection and in vitro culture of embryos refer to examples 2 and 3.

Cytoplasmic microinjection and in vitro culture of fertilized eggs of 4.2 age-old mice

4.2.1 grouping: firstly, a young group; the second is the high age group; and thirdly, the aged group is injected with miR-125a-5p inhibitor in a micro-injection mode.

4.2.2 preparing miR-NC inhibitor and miR-125a-5p inhibitor for injection (according to the instruction, 125 mul of RNase-free injection buffer solution is added into every 0.5OD, the concentration is 20 mul of concentrated stock is prepared, then 2 mul of 20 mul of concentrated stock is diluted into 2 mul of microinjection solution, 10 mul/tube is respectively packed into a PCR tube without RNase, the PCR tube is wrapped by tinfoil, and the microinjection solution is preserved at minus 80 ℃ in the dark place for standby).

4.2.3 the remaining steps are as described in example 3.

The result shows that the blastocyst formation rate of fertilized eggs of the aged mice is obviously reduced; after injecting miR-125a-5p inhibitor into fertilized eggs of the old mice, the morula and blastocyst formation rate of the fertilized eggs is obviously improved (figure 11 and figure 12). The miR-125a-5p inhibitor can be used for improving the early development effect of the old embryos.

SEQUENCE LISTING

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Application of <120> MiR-125a-5p in early development of embryo

<130> XSQ-PAN-20210322-CZ

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<170> PatentIn version 3.5

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Claims (17)

1. Application of MiR-125a-5p in preparation of products for detecting early development potential of embryos.
2. Application of the MiR-125a-5p inhibitor in preparing products for improving early development of advanced embryos.
3. 3. Use according to claim 1, characterized in that: including but not limited to, measuring miR-125a-5p content in sperm or embryos to assess embryo development potential, or as a basis for cleavage stage transfer or blastocyst transfer.
4. 4. Use according to claim 2, characterized in that: including but not limited to altering miR-125a-5p content in sperm or embryos using miR-125a-5p inhibitors to improve embryonic early development potential.
5. 5. Use according to claim 1, characterized in that: the nucleotide sequence of the miR-125a-5p is shown as a sequence 1.
6. 6. Use according to claim 2, characterized in that: the nucleotide sequence of the miR-125a-5p inhibitor is shown in a sequence 2.
7. 7. Use according to claim 5, characterized in that: the miR-125a-5p is modified by 2-OMe.
8. 8. Use according to claim 6, characterized in that: the miR-125a-5p inhibitor is modified by 2-OMe.
9. 9. Use according to claim 5, characterized in that: the effective dosage of the miR-125a-5p stimulant is 100nM 2.5pL, and the miR-125a-5p stimulant can be injected into embryos by microinjection to increase the expression level of miR-125a-5 p.
10. 10. Use according to claim 6, characterized in that: the effective dosage of the miR-125a-5p inhibitor is 2 muM 2.5pL, and the miR-125a-5p inhibitor can be injected into embryos by microinjection to reduce the expression level of miR-125a-5 p.
11. 11. Use according to claim 1 or 5 or 7, characterized in that:

    the embryo early development potential detection stage is the potential of fertilized eggs to develop into blastula.
12. 12. Use according to claim 2 or 6 or 8, characterized in that:

    the early embryo development is from the onset of zygote development to blastocyst formation.
13. 13. Use according to any one of claims 1 to 10, characterized in that:

    the embryo is a mouse embryo.
14. 14. A miR-125a-5p mimetic agent for assessing early development of an embryo, said mimetic agent comprising the nucleotide sequence of any one of claims 5 or 7.
15. 15. An inhibitor of miR-125a-5p for improving early development of an embryo, wherein the inhibitor comprises the nucleotide sequence of any one of claims 6 or 8.
16. 16. Use according to claim 1, characterized in that: the product is a detection kit.
17. 17. Use according to claim 2, characterized in that: the product is a medicine.

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