An integrative view to structure, function, ontogeny and phylogenetical significance of the male genital system in Pomacea canaliculata (Caenogastropoda, Ampullariidae).

GAMARRA-LUQUES C, WINIK BC, VEGA IA, ALBRECHT EA, CATALAN N & CASTRO-VAZQUEZ A.

BIOCELL

INCA

Lugar: MENDOZA; Año: 2006 vol. 30 p. 345 - 357

0327-9545

ABSTRACT: An integrated view to structure, function, ontogeny and phylogenetic significance of the male genital system is presented. Genital morphology within the Ampullariidae has evolved towards a greater complexity (reaching its maximum in the Neotropical genera Pomacea and Marisa) that includes the development of both a closed sperm channel ensuring internal fertilization, and a complex copulatory “apparatus” which is a derivative of the right mantle edge.  A single gonoduct is formed (as a merger of the primitive gonad, the left rudimentary kidney and the left ureter, from which the testis, vas deferens, seminal vesicle and prostate develop). Interestingly, xenobiotics inducing imposex do not affect gonoduct derivatives, but only the copulatory apparatus (a mantle edge derivative). The androtrophic control (i.e., the control of growth and development of the male genital system) seems exerted by both a neural input and a steroidal input (progesterone and androstenedione). The midgut gland appears as the main steroid producing organ, being the only one showing a high esterified to free cholesterol ratio. Blood-borne precursors should reach the copulatory apparatus to be converted there to the end products, where they should act paracrinally. Molecular evidence of the expression of progestin and androgen receptors has been found in both gonoduct and mantle edge derivatives.