Summary

人类囊胚活检和细胞化

Published: July 26, 2019
doi:

Summary

需要进行胚泡活检和保并口授,以便有效地进行植入前基因检测。一种方法,导致在授精后的第5-7天连续打开区域细胞和检索7-8个营养细胞,限制了所需的操作次数和胚胎在次优环境条件下的暴露。

Abstract

在IVF周期内进行胚泡活检,通过植入前基因测试获得可靠的基因诊断。然后,理想的工作流程需要一个安全有效的牙化协议,由于诊断技术的周转时间,并在下面的自然周期中在生理子宫内膜上移植选定的胚胎。活检方法包括连续打开区域细胞和检索5-10个营养细胞(理想情况下为7-8)限制所需的操作数量和胚胎在次优环境条件下的暴露。经过适当的训练后,该技术在不同的操作者之间可重复活检的时间(±8分钟,根据每盘的胚胎数量进行活检3-22分钟),获得结论性诊断(+97.5%)和玻璃化加热的花体胚泡转移后活产率(>40%)。活检、硝化和变暖后的存活率高达99.8%。气候变暖后1.5小时的再膨胀率高达97%,主要取决于活检和抗化(理想情况下为±30分钟)、胚泡形态质量和活检日之间的时间。一般来说,最好对坍塌的胚泡进行压化;因此,在非PGT周期中,可以进行激光辅助人工收缩,以诱导胚胎在冷冻保存前崩溃。最有希望的未来观点是,在胚泡培养后对IVF培养基进行非侵入性分析,作为胚胎DNA的假定来源。然而,这种潜在的前卫仍在调查之中,还需要定义和验证一个可靠的协议。

Introduction

现代人类胚胎学的主要目标是使每个刺激周期的活产数量最大化,并降低成本、时间和实现怀孕的努力。为了实现这一目标,应采用经验证的胚胎选择方法,在IVF周期中获得的一组胚胎中确定具有生殖能力的胚胎。根据最新证据,胚泡培养1结合全面的染色体检测和玻璃化加热的幼倍体胚胎移植(ET)是提高IVF效率的最有效框架2。显然,非倍体试验需要胚胎标本,目前主要代表从营养素(TE)中检索到的细胞,即囊胚中给予妊娠期间胚胎附件(例如胎盘)来源的部分.除了核类型分析,还可以从TE活检中评估单个基因突变,作为称为植入前基因测试的临床策略的一部分(PGT;-A用于非倍体,-SR用于结构染色体重组,-M用于单源性疾病)。其他卵母细胞/胚胎活检方法在过去几十年中已被进行解剖和临床采用,即极性身体活检和卵波粒活检。然而,现在减少了它们的使用,因为它们的程序性缺陷(例如,更高的工作量和生殖影响的风险)和诊断限制(例如单细胞分析问题)隐含地阻碍了成本、风险和好处(有关审查,请参阅3)。

在本文中,对TE活检的主要方案之一以及随后所需的保质化、加热和转移程序进行了详尽描述。此处概述的工作流非常适合繁忙的 PGT 单元。

如我们组4,5前面所述,该过程涉及完全扩张的胚泡的分子的连续打开和去除少数TE细胞(平均7-8)。与第3天激光辅助孵化为基础的胚泡活检方法6相比,这个程序可以简化IVF单元的日常时间表,其中必须及时执行诸如胚泡活检和葡萄光化等精细程序。一旦胚泡达到其完全膨胀,活检可以通过选择TE细胞进行去除,从而防止内细胞质量(ICM)的增生风险,否则会使手术具有挑战性。在文献中,也描述了胚泡活检的第三个方案,即一旦胚胎到达胚泡阶段,在手术5、7前几个小时进行激光辅助孵化。然而,这种方法更耗时,主要适合在经验有限的操作员手中实施TE活检的IVF单元,并且考虑到日工作量适中。

如果旨在进行IVF中的遗传分析,则细胞内体精子注射(ICSI)8应该是一种综合技术。同样,一个适当的培养系统,安全地将胚胎收获到胚泡阶段,对于实施TE活检策略也至关重要。足够数量的培养箱,以及使用低氧张力是这个目的的关键先决条件,不损害胚泡率9。同时,需要一个有效的冷冻保存程序来安全地管理PGT周期。在过去的十年中,牙化的实施提高了胚胎的存活率,甚至高达>99%10,11。这提供了足够的时间进行基因测试,并将胚胎移植推迟到下面的月经周期,在非刺激和可能更容易接受的子宫内膜12。

TE 活检和 Vitaita 化都是要求严格技能的任务,其有效性可能因经验不足的操作员而异。因此,在允许每个操作员临床执行这些程序之前,提倡一个特定的培训期;此外,应定期通过监测冷冻保存和活检程序的关键绩效指标(KPI)来评估操作人员技能的维持情况。每个IVF诊所应为此设置内部KPI,其中必须近似于国际财团公布的KPI和/或参考实验室公布的结果。

TE 活检、保质化加热和见证程序是我们部门验证的技术,这些技术已在之前三份出版物 11、13、14 中报告的所有操作员中标准化.

Protocol

这里描述的人类胚泡活检方案遵循了G.EN.E.R.A.人类研究伦理委员会的指导方针。 注:有关所需材料,请参阅材料表。所需材料包括实验室鞋类和服装、外科面罩、头发罩、手术手套、永久无毒标记物、钳子和消毒剂。使用手术服,一次性手术手套,面罩,头发盖是强制性的,以防止污染的风险。在开始任何程序之前,必须使用实验室消毒剂(例如 Oosafe)彻底清洁?…

Representative Results

图 6显示了活检程序的所有结果方案,可用于标准化协议并监控每个操作员的性能。主要程序结果是完成活检/活检的时间;主要技术结果是基因测试后产生的图的质量,可能导致结论性或无结论性诊断,后者要求对未诊断的胚泡进行重新活检;主要生物结果是变暖后的低温生存率和再膨胀率与退化率;最后,主要临床结果为玻璃化加热胚泡转移后的活产率。在…

Discussion

只有经验丰富的熟练胚胎学家谁完成了他们的训练期应进行TE活检和胚泡性牙菌。此外,需要证人监测程序,并保证在i期间有效追踪活检胚泡从活检盘(补充图1)到活检后盘的移动(补充图1)(补充图1)),然后到化板(补充图1),最后到硝化支持(补充图1);ii) 活检TE细胞从活检盘转移到PCR管(补充图1);iii) 诊断后的加热和转移步骤。有关所有见证步骤…

Offenlegungen

The authors have nothing to disclose.

Acknowledgements

AG 和 RM 收集了数据并起草了手稿。DC 分析数据,起草代表性结果,进行统计并修订稿件。FMU 和 LR 对结果和整个手稿进行了批判性讨论。

Materials

Equipment
Cold tube rack Biocision XTPCR96
Electronic pipette controller Fisher Scientific 710931
Flexipet adjustable handle set Cook G18674 Stripper holder
Gilson Pipetman Gilson 66003 p20
IVF Electronic Witness System CooperSurgical Fertility & Genomic Solutions RI Witness ART Management System
Inverted microscope Nikon Eclipse TE2000-U
Laminar Flow Hood IVF TECH Grade A air flow
Laser objective RI Saturn 5
Microinjectors Nikon Narishige NT-88-V3
Mini centrifuge for PCR tubes Eppendorf CSLQSPIN for 0.2ml PCR tubes
Stereomicroscope Leica Leica M80
Thermostat Panasonic MCO-5AC-PE
Tri-gas incubator Panasonic MCO-5M-PE 02/CO2
Consumables
Biopsy pipette RI 7-71-30FB35720 30µm ID, flat 35°C
Cryolock Cryolock CL-R-CT
CSCM complete Irvine Scientific 90165 IVF culture medium supplemented with HSA
Embryo Transfer Catheter Cook G17934
Flexipet pipette Cook G26712 140µm stripping pipette tip
Flexipet pipette Cook G46020 300µm stripping pipette tips
Holding pipette RI 7-71-IH35/20 30µm ID, flat 35°C
Human Serum Albumin Irvine Scientific 9988
IVF One well dish Falcon 353653
Mineral Oil for embryo culture Irvine Scientific 9305
Modified HTF Medium Irvine Scientific 90126 Hepes-Buffered medium
Nuclon Delta Surface Thermofisher scientific 176740 IVF dish 4-well plate with sliding lid
Primaria Cell culture dish Corning 353802 60x15mm
Reproplate Kitazato 83016
Serological pipette Falcon 357551 10ml
Sterile disposable Gilson tips Eppendorf 0030 075.021 200µl
Tubing Kit Provided by the genetic lab PCR tubes (0.2mL), loading solution, biopsy washing solution
Vitrification media Kitazato VT801 Equilibration and vitrification solutions
Warming media Kitazato VT802 Thawing and dilution solutions

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Maggiulli, R., Giancani, A., Cimadomo, D., Ubaldi, F. M., Rienzi, L. Human Blastocyst Biopsy and Vitrification. J. Vis. Exp. (149), e59625, doi:10.3791/59625 (2019).

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