Kisspeptin signaling and its role in canine reproduction: a basic understanding

Abstract

There are several central and peripheral mechanisms that influence the GnRH secretion. For a long time it has been a mystery how these mechanisms influence the GnRH neurons. In recent years there have been exciting new discoveries in this field, especially with the discovery of kisspeptin and its receptor. Kisspeptin is a neuropeptide that seems to have an important role in the regulation of GnRH neurons in the hypothalamus in various mammalian species. It is, among other things, supposed to be involved in the onset of puberty and in the mediation of the positive feedback exhibited by estrogens on the GnRH neurons in females, which leads to the GnRH/LH surge.

Although a lot of research has already been done, to our best knowledge, kisspeptin and its receptor have not yet been researched in the dog. Because the kisspeptin signaling has been called a major gatekeeper of the gonadotropic axis, it would be interesting to discover its role in the canine reproduction. To lessen the amount of dogs that are yearly euthanized all over the world because of overpopulation, it is important to find a non-surgical method of contraception that prevents estrous cyclicity. The kisspeptin signaling pathway could be a suitable target for developing an effective, safe, long-term or permanent non-surgical contraceptive for the bitch.

The aims of the present study were to identify the canine KISS1 and KISS1R genes and to characterize the amino acid sequences of canine kisspeptin and the kisspeptin receptor. The identification and characterization were done in silico. The results show that the KiSS1 and the KiSS1R gene are present at the canine genome and a large homology is found between the canine peptides and the peptides found in other mammalian species. This gives a basis to believe that kisspeptin signaling is also important in GnRH secretion in the dog and that it may indeed be a suitable target for a non-surgical contraceptive.