Dietary L-carnitine affects the expression of genes involved in apoptosis and fatty acid metabolism in rooster testes.

Thirty-six 12-week-old breeder roosters (Ross 308) were randomly allocated into three groups to receive L-carnitine (LC): LC-0, LC-250 or LC-500 mg/kg of diet to evaluate the effects of dietary LC on the expression of apoptotic-related genes and desaturases and elongase mRNA transcript levels, in the cockerel testicles. Alteration of Bak (Bcl2 antagonist/killer), Bcl2, Cas3, Cas8, Cas9, Elovl2, Elovl4, Elovl5, Fads1, Fads2 and Scd expression at 24 and 34 weeks of age was compared by real-time quantitative PCR. The expression of Bcl2 and Elovl5 was significantly up-regulated (p < .05), while Cas8 expression (p < .05) and Bak/Bcl2 ratio were reduced (p < .02) in the cockerel testicles at 24 weeks of age. Although Bak mRNA abundance decreased by dietary LC, Bak/Bcl2 ratio was not affected by the treatments at 34 weeks of age. The expression of Cas3 was down-regulated, while Fads2 was up-regulated in the cockerel testicles by dietary LC at 34 weeks of age (p < .05). The results demonstrate the beneficial effects of LC supplementation in suppression of the Bak/Bcl2 ratio by altering Bak and Bcl2 mRNA abundance and, ultimately, prevention of apoptosis. Furthermore, LC increased the expression of Elovl5 and Fads2 genes which are involved in the metabolism of long chain fatty acids.