The study looked at a gene called Kiss1 that makes the peptide kisspeptin in pig testes. It found that kisspeptin levels go up after puberty and that the protein is mainly in cells that make testosterone and developing sperm. The research shows kisspeptin helps start puberty and sperm production in boars, but it doesn’t give any tips you can use right now.

Kisspeptin, a neuropeptide encoded by the <i>Kiss1</i> gene, combines with its receptor Kiss1R to regulate the onset of puberty and male fertility by the hypothalamic-pituitary-gonadal axis. However, little is known regarding the expression signatures and molecular functions of <i>Kiss1</i> in the testis. H&amp;E staining revealed that well-arranged spermatogonia, spermatocytes, round and elongated spermatids, and spermatozoa, were observed in 4-, 6-, and 8-month-old testes compared to 1- and 3-month-old testes of Hezuo pigs; however, these were not observed in Landrance until 6 months. The diameter, perimeter, and cross-sectional area of seminiferous tubules and the perimeter and area of the tubular lumen increased gradually with age in both pigs. Still, Hezuo pigs grew faster than Landrance. The cloning results suggested that the Hezuo pigs' <i>Kiss1</i> CDS region is 417 bp in length, encodes 138 amino acids, and is highly conserved in the kisspeptin-10 region. qRT-PCR and Western blot indicated that the expression trends of <i>Kiss1</i> mRNA and protein were essentially identical, with higher expression levels at post-pubertal stages. Immunohistochemistry demonstrated that the Kiss1 protein was mainly located in Leydig cells and post-pubertal spermatogenic cells, ranging from round spermatids to spermatozoa. These studies suggest that Kiss1 is an essential regulator in the onset of puberty and spermatogenesis of boars.