ISSN 2398-2977      

Reproduction: intracytoplasmic sperm injection

pequis

Synonym(s): ICSI


Introduction

  • Intracytoplasmic sperm injection (ICSI) is the in vitro injection of a sperm cell (spermatozoa) into the cytoplasm of a mature oocyte using a micromanipulator microscope.
  • ICSI differs from both gamete intrafallopian transfer (GIFT) Reproduction: gamete intrafallopian transfer and oocyte transfer (OT) Reproduction: oocyte transfer in that fertilization occurs outside of the female body, in a laboratory.
  • Sperm cells are sourced from fresh, chilled or frozen semen, or epididymal sperm cells collected after a stallion’s demise or castration.
  • Oocytes may be sourced from live mares Reproduction: oocyte transfer, or from deceased mares’ ovaries.
  • Oocytes can be recovered from live mares by a referring veterinarian, and shipped overnight to a laboratory for ICSI, without any decrease in oocyte or embryo viability.
  • Both germinal vesicle (GV) stage oocytes from immature follicles and mature metaphase II (MII) oocytes from pre-ovulatory follicles can be used with and without in vitro maturation (IVM) respectively.
  • ICSI in the horse was developed largely in reaction to the fact that conventional in vitro fertilization is very unsuccessful in the horse.
  • Typically, following ICSI, horse embryos are cultured in the laboratory for 7-10 days, and then those which have successfully cleaved and formed blastocysts, are then either transferred into the uterus of a synchronized recipient mare Embryo Transfer or cryopreserved for future use.
  • ICSI is a highly specialized technique which is unlikely to be performed outside of specialized Universities / referral institutions, due to the level of expertise and the equipment required. However, it is of use to practitioners to be familiar with the technique in order to be able to discuss it with their clients as a possible treatment in cases of severe stallion infertility, or of very limited sperm availability.

Uses

  • Because during ICSI fertilization takes place in vitro and the sperm cell is injected directly into the oocyte, ICSI provides a means of overcoming male fertility problems which otherwise render a stallion infertile, such as problems with sperm motility; sperm capacitation; the acrosome reaction; zona pellucida penetration and sperm-egg membrane fusion.
  • Furthermore, because only one sperm cell is need to achieve fertilization using ICSI, the technique is of use where available sperm numbers are very limited – for example if a stallion has died but some frozen sperm has been stored, or if using sperm retrieval from the epididymis of castrated or deceased horses, or if a stallion is unable to produce enough motile sperm for a standard insemination dose.
  • ICSI also overcomes certain mare infertility issues that prevent normal ovulation or oviductal transport and early embryonic maturation required for other ART procedures such as Embryo transfer. It does not however overcome mare infertility due to poor oocyte quality.

Advantages

  • Provides a method of achieving pregnancies in cases of male infertility relating to poor semen quality / limited sperm numbers and in certain mare infertility issues allowing preservation of valuable genetics which may otherwise be lost. 
  • This is useful since in other species in vitro fertilization is often used to overcome such cases of male subfertility, in horses in vitro fertilization is comparatively unsuccessful.
  • Oocytes and semen can be shipped to remote laboratories undertaking ICSI techniques, and then embryos can be transferred into a recipient Embryo transfer if normal blastocyst development results from ICSI and in vitro culture of embryos.

Disadvantages

  • Low success rates (blastocyst production following ICSI is typically <40%).

Requirements

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Procedure

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Aftercare

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Outcomes

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Further Reading

Publications

Refereed Papers

  • Recent references from PubMed and VetMedResource.
  • Hinrichs K (2018) Assisted reproductive techniques in mares. Reprod Dom Anim 53 (2), 4–13 PubMed.
  • Choi Y H, Roasa L M et al (2004) Blastocyst formation rates in vivo and in vitro of in vitro-matured equine oocytes fertilized by intracytoplasmic sperm injection. Biol Reprod 70 (5), 1231-1238 PubMed.
  • Choi Y H, Love C C et al (2002) Developmental competence in vivo and in vitro of in vitro-matured equine oocytes fertilized by intracytoplasmic sperm injection with fresh or frozen-thawed spermatozoa. Reproduction 123 (3), 455-465 PubMed.
  • Galli C, Crotti G et al (2002) Frozen-thawed embryos produced by Ovum Pick Up of immature oocytes and ICSI are capable to establish pregnancies in the horse. Theriogenology 58 (2-4), 705-708.
  • Cochran R, Meintjes M et al (2000) Production of live foals from sperm-injected oocytes harvested from pregnant mares. J Reprod Fertil Suppl 56, 503-512 PubMed.
  • McKinnon A O, Lacham-Kaplan O & Trounson A O (2000) Pregnancies produced from fertile and infertile stallions by intracytoplasmic sperm injection (ICSI) of single frozen-thawed spermatozoa into in-vivo matured oocytes. J Reprod Fertil Suppl 56, 513-517 PubMed.
  • Squires E L, Wilson J M et al (1996) A pregnancy after intracytoplasmic sperm injection into equine oocytes matured in vitro. Theriogenology 45, 306.

Other sources of information

  • Choi Y-H & Hinrichs K (2011) Intracytoplasmic Sperm Injection (ICSI). In: Equine Reproduction. Eds: McKinnon A O, Squires E L, Vaala W E & Varner D D. Blackwell Publishing Ltd, UK. pp 2948 – 2951
  • Hinrichs K (2010) Application of assisted reproductive technologies (ART) to clinical practice. In: Proc of the Annual Convention of the AAEP. pp 195-206.
  • McKinnon A O, Trounson A & Silber S J (2009) Intracytoplasmic Sperm Injection (ICSI). In: Proc of the 11th AAEP Annual Resort Symposium. pp 58-80.

Can’t find what you’re looking for?

We have an ever growing content library on Vetlexicon so if you ever find we haven't covered something that you need please fill in the form below and let us know!