Immunolocalization of aromatase P450 in the epididymis of Podarcis sicula and Rattus rattus.

The goal of this study was to evaluate P450 aromatase localization in the epididymis of two different vertebrates: the lizard Podarcis sicula, a seasonal breeder, and Rattus rattus, a continuous breeder. P450 aromatase is a key enzyme involved in the local control of spermatogenesis and steroidogenesis and we proved for the first time that this enzyme is represented in the epididymis of both P. sicula and R.

Pituitary adenylate cyclase-activating peptide (PACAP) and its receptors in Mus musculus testis.

To enlighten the involvement of PACAP/receptors system in the control of mammal testis, we investigated the expression of PACAP and the localization of PACAP and its receptors PAC1, VPAC1, and VPAC2 in the testis of Mus musculus. By molecular and immunohistochemical investigations, we highlighted that PACAP and its receptors are widely represented in germ cells of Mus testis, particularly in spermatocytes I, spermatids, and spermatozoa, strongly suggesting their involvement in spermatogenesis process. Moreover, for the first time in the adult mouse testis we highlighted that PACAP is present within Leydig cells, as PACAP receptors, confirming its involvement in the control of steroidogenesis in mouse.

Seasonal expression and cellular distribution of star and steroidogenic enzymes in quail testis.

The quail Coturnix coturnix is a seasonal breeder with a physiological switch on/off of gonadic activity. Photoperiod and temperature are the major environmental factors regulating the spermatogenesis. To more thoroughly comprehend the steroidogenic pathways that govern the seasonal reproductive cycle, we have investigated the localization of StAR protein and steroidogenic enzymes (3β-HSD, 17β-HSD, P450 aromatase, and 5α-Red) as well as androgen and estrogen levels, in the testis of reproductive and nonreproductive quails.

The expression of estrogen receptors during the Mytilus galloprovincialis ovarian cycle.

The aim of this paper is to assess, by real-time polymerase chain reaction and in situ hybridization, the expression of estrogen receptors ER1 and ER2 during the ovarian cycle of Mytilus galloprovincialis. By considering four phases of the reproductive cycle, that is stasis and previtellogenic stage (Stage 0), early vitellogenesis (Stage I), vitellogenesis (Stage II), full-grown oocyte (Stage III), our investigation demonstrates that the two receptors are differently expressed during the phases investigated of the ovarian cycle: ER1 reaches the highest level at Stage III, whereas ER2 reaches the highest level at Stage II, with ER2 always present at higher levels than ER1. The stage-dependent receptor expression was recorded within oocytes, follicle cells, and adipogranular cells.