INIBIOMA   20415
INSTITUTO DE INVESTIGACIONES EN BIODIVERSIDAD Y MEDIOAMBIENTE
Unidad Ejecutora - UE
artículos
Título:
How males synchronize their reproductive cycles with females to cope with seasonal climate: An endocrinal and ultrastructural study of Phymaturus zapalensis lizards (Liolaemidae)
Autor/es:
BORETTO JM; GA JAHN; MW FORNÉS; VE CUSSAC; NR IBARGÜENGOYTÍA
Revista:
HERPETOLOGICAL JOURNAL
Editorial:
BRITISH HERPETOL SOC
Referencias:
Año: 2012 vol. 22 p. 33 - 42
ISSN:
0268-0130
Resumen:
Phymaturus zapalensis inhabits harsh thermal environments in the steppe of Patagonia, Argentina, characterized by climate
conditions that impose constraints on reproduction, providing an appealing model to study the role of steroid hormones in
the regulation of seasonal reproductive events. Males of P. zapalensis exhibited a postnuptial spermatogenic cycle with
spermiation in mid-spring in synchrony with female ovulation time when mating occurs, followed by testicular recrudescence,
but do not show sperm reservoir during hibernation period in winter. Females of P. zapalensis can reproduce annually
or biennially. Here, we studied the steroidogenic functions of testicular compartments of P. zapalensis by analysing serum
testosterone and ultrastructure related to steroidogenic activity in Sertoli and Leydig cells, as a possible mechanism for the
synchronization of male and female reproductive cycles. The testosterone cycle resembles the gonadal cycle in P. zapalensis
previously described by morphology and histology of testes. Testosterone concentration is highest in mid-spring and lowest
in early summer, with an initial recovery at the beginning of a new spermatogenic cycle in late summer and early autumn.
Ultrastructural morphological features indicative of steroidogenic activity in Leydig and Sertoli cells were observed during
the spermatogenic cycle. Evidence of temporal asynchrony in steroidogenic activity between compartments were found in
males captured in summer and autumn, while synchronous activity was found during mating in spring. Temporal separation
of steroidogenic activity serves to synchronize male and female cycles in P. zapalensis and assures the adjustment of
reproductive activity to physiological and environmental constraints.