Leuticels, or luteal cells, are specialized cells found in the ovaries that arise from the transformation of follicular cells after ovulation. They play a crucial role in the reproductive cycle by producing hormones, particularly progesterone, which is essential for preparing the uterine lining for potential implantation of a fertilized egg. The presence of leuticels is vital for maintaining early pregnancy, as they help sustain the corpus luteum before it eventually degenerates if fertilization does not occur.