Artificial insemination: new hormone substitutes

Scientists in the Joint Research Unit for Reproductive and Behavioural Physiology (PRC) have identified antibodies which will constitute innovative tools in support of artificial insemination.

Insémination artificielle des chèvres. Extraction d'une paillette de sperme congelé en azote liquide. © LIMOUZIN Claude
Updated on 09/18/2017
Published on 07/05/2012

Artificial insemination is widely employed at present to manage dairy herds, and to a lesser extent in suckler herds.  In small ruminants, and particularly goats and sheep, reproduction is highly seasonal, which means that milk production fluctuates throughout the year.  In order to achieve out-of-season breeding and year-long milk production, livestock farmers use a serum hormone called eCG (equine Chorionic Gonadotropin) to synchronise ovulation.  But markedly immunogenic, this glycoprotein triggers a defence action by the organism – the synthesis of antibodies – in females treated with this hormone in preparation for artificial insemination.  This leads to a major reduction in insemination success rates.

Unusual observations due to molecules with an unexpected mode of action….

However, although the success rates of artificial insemination in the goat oscillate around 65% under normal conditions, 100% success rates have been observed in goats secreting anti-eCG antibodies.  The research team was able to isolate anti-eCG antibodies with astonishing properties in goats that were hyper-receptive to hormone stimulation.
Under normal conditions, the binding of eCG hormone to its receptor (the FSH receptor) causes the formation of an eCG/FSHR complex that will activate the cell and trigger the hormone synthesis necessary to reactive the menstrual cycle.  This activation passes via two signal transduction pathways, the "G-protein-dependent" and "β-arrestin" pathways, which through a cascade of biochemical reactions, both trigger the production of ovarian hormones.
When these isolated anti-eCG antibodies were present, the researchers saw that the antibody/hormone complex retained an ability to bind to the eCG receptor, and that depending on the complexed antibody, this binding only stimulated one of the two signalling pathways, or both at the same time.  This signal modulation exerted a stimulating effect on ovulation, and in the goats under study enabled an improvement in their insemination success rates.

… for an innovative application!

These antibodies, which did not present with any harmful side effects during supplementary studies, represent a practical alternative to the hormone treatments used in the context of artificial insemination.
These patented compounds are now the subject of an exclusive licensing agreement between INRA and the start-up enterprise ReproPharm (see the article on Marie-Christine Maurel, an exceptional research engineer and the creator of ReproPharm).  This company is now working on developing a treatment protocol based on these antibodies that will be as efficient as standard hormone therapy and should be available in a few years' time.

Contact(s)
Scientific contact(s):

  • Florian Guillou (+33(0)6 31 47 40 72) Unité Mixte de Recherche Physiologie de la Reproduction et du Comportement
  • Eric Reiter (+33(0)2 47 42 77 83) Unité Mixte de Recherche Physiologie de la Reproduction et du Comportement
Contact(s) partner(s):
Marie-Christine Maurel - REPROPHARM (+33 (0) 2 47 42 79 57)