Sex steroids levels in the plasma and testis during the reproductive cycle of lizard Podarcis s. sicula raf

Andò, Sebastiano; Ciarcia, Gaetano; Panno, Maria Luisa; Imbrogno, Enrica; Tarantino, Giovanni; Buffone, Mariano G.; Beraldi, Eliana; Angelini, F.; Botte, V.

doi:10.1016/0016-6480(92)90165-g

Cited by 52 publications

(34 citation statements)

References 21 publications

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“…This is in agreement with what has been documented previously in this species, with T levels peaking in the spring at the beginning of the activity period and breeding season [Eisen and DeNardo, 2000]. In another lizard species, P. s. sicula, a similar trend in seasonal T levels was seen, however, sampling increments were monthly rather than weekly [Ando et al, 1992] and levels peaked at approximately 200 ng/mL, much greater than the values reported in this study.…”

Section: Discussionsupporting

confidence: 93%

“…alligators [Alligator mississippiensis; Guillette et al, 1997;Bermudez et al, 2005], these studies have been conducted primarily in free-ranging animals. Studies on hormonal systems have been conducted on a few lizard species including male and female sex steroids in the lacertid lizard [Podarcis sicula ;Carnevali et al, 1991;Ando et al, 1992], the blue spiny lizard [Callard et al, 1972], and the mountain spiny lizard [Sceloporus jarrovi; Woodley and Moore, 1999]. Androgens were studied in the green anole [Anolis carolinesis; Wade, 1997] and the male eastern fence lizard [S. undulatus;McKinney and Marion, 1985].…”

Section: Introductionmentioning

confidence: 99%

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Reproductive and thyroid hormone profiles in captive Western fence lizards (Sceloporus occidentalis) after a period of brumation

2007

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Seasonal fluctuation in serum concentrations of sex steroid (testosterone [T] and 17beta-estradiol [E(2)]) and thyroid (triiodothyronine [T(3)] and thyroxine [T(4)]) hormones was determined in captive Western fence lizards (Sceloporus occidentalis). Samples were collected from male and female breeding pairs weekly for a 4-month period after their emergence from artificial brumation. Circulating levels of E(2) corresponded with the expected vitellogenic and ovulatory cycles in females, and surprisingly, E(2) in males followed a similar pattern, indicating a possible role in breeding behavior. Serum T was elevated in male lizards for the first 6 weeks after emergence from brumation, possibly related to an increase in the onset of active spermatogenesis. Thyroid hormones showed little cyclical activity throughout the breeding period, with the exception of small increases of T(3) at weeks 8 and 16, possibly implying an active role of this hormone with ovulation in females. Overall, these baseline hormone data are not only useful in developing this animal as a laboratory reptile model for assessment of endocrine-mediated toxicity, but also of value for understanding herpetological endocrinology and for application in the conservation of threatened species. Zoo Biol 27:36-48, 2008. (c) 2007 Wiley-Liss, Inc.

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Section: Discussionsupporting

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Reproductive and thyroid hormone profiles in captive Western fence lizards (Sceloporus occidentalis) after a period of brumation

2007

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“…DHEA is an androgen found in a variety of animals including mammals, birds, reptiles, and mollusks and is the most abundant circulating steroid in humans (Garstka et al 1991, Ando et al 1992, Croll & Wang 2007. While research on DHEA's role in human health and reproduction has increased dramatically over the past several years (Maninger et al 2009, Gleicher & Barad 2011, far less is known regarding its role in other vertebrates, especially wildlife models.…”

Section: Introductionmentioning

confidence: 99%

The reproductive hormone cycle of adult female American alligators from a barrier island population

Hamlin

Lowers²,

Kohno

et al. 2014

Reproduction

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Comparatively, little data are available detailing the geographic variation that exists in the reproductive endocrinology of adult alligators, especially those living in barrier islands. The Merritt Island National Wildlife Refuge (MI) is a unique barrier island environment and home to the Kennedy Space Center (FL, USA). Seasonal patterns of sex steroids were assessed in adult female American alligators from MI monthly from 2008 to 2009, with additional samples collected at more random intervals in 2006, 2007, and 2010. Plasma 17b-estradiol and vitellogenin concentrations peaked in April, coincident with courtship and mating, and showed patterns similar to those observed in adult female alligators in other regions. Plasma concentrations of progesterone, however, showed patterns distinctly different than those reported for alligator populations in other regions and remained relatively constant throughout the year. Plasma DHEA peaked in July around the time of oviposition, decreased in August, and then remained constant for the remaining months, except for a moderate increase in October. Circulating concentrations of DHEA have not been previously assessed in a female crocodilian, and plasma concentrations coincident with reproductive activity suggest a reproductive and/or behavioral role. Interestingly, plasma testosterone concentrations peaked in May of 2008, as has been shown in female alligator populations in other regions, but showed no peak in 2009, demonstrating dramatic variability from year to year. Surveys showed 2009 to be particularly depauperate of alligator nests in MI, and it is possible that testosterone could serve as a strong indicator of breeding success.

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“…The activity of Jun proteins in the testis of the lizard, Podarcis s. sicula, is associated with seasonal changes and correlates with steroidogenesis and spermatogenic activity (Andò et al 1992). This lizard presents an annual spermatogenic cycle with two periods of spermatogenic activity (spring and autumn); only during the spring does mating occur and there is complete development of secondary sexual characters.…”

Section: Discussionmentioning

confidence: 99%

“…It is relevant to note that steroid hormones regulate c-myc, c-Fos and c-Jun expression in reproductive tissue in rats (Schuchard et al 1993), birds (Subramaniam et al 1993), and sea stars (Marsh & Walker 1995). In this respect, it should be noted that in the plasma of P. s. sicula the peak of estradiol correlates well with the new annual spermatogenic wave (Andò et al 1992). However, the possibility does exist that in some months these proteins are not efficently translocated to the nucleus and are therefore present but not functional, or that these cells accumulate a stock of c-Jun proteins, without phosphorylation, which can be post-translationally activated upon mitogenic stimulation in order to play a role in cell division.…”

Section: Discussionmentioning

confidence: 99%

C-Jun phosphorylation (Ser-63) in the testis of the lizard, Podarcis s. sicula

Chieffi¹,

Picascia²,

Stanzione³

et al. 1999

Journal of Endocrinology

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Proto-oncogenes play an important role in the regulation of cellular growth and differentiation. C-Jun activity has been studied in the testis of a non mammalian vertebrate, the lizard Podarcis s. sicula, during two different periods: winter stasis and the breeding season. C-Jun protein was localized by immunocytochemistry in the cytoplasm of the spermatogonia (SPG) and stage I and II spermatocytes (SPC) during the winter stasis (from December until March), while the protein was present in the nuclei of the same cells during the active spermatogenic period (April/ May). The different localization of c-Jun has been confirmed by Western blot and immunoprecipitation analysis. In addition, when Jun is present in the nuclear compartment, it is phosphorylated on Ser-63 and is complexed with Fos protein.These data suggest that the nuclear localization of the Jun protein in the SPG and stage I and II SPC, with strong phosphorylation on Ser-63 during the breeding period, could be the signal of increasing transcriptional activity in the lizard testis.

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Sex steroids levels in the plasma and testis during the reproductive cycle of lizard Podarcis s. sicula raf

Cited by 52 publications

References 21 publications

Reproductive and thyroid hormone profiles in captive Western fence lizards (Sceloporus occidentalis) after a period of brumation

Reproductive and thyroid hormone profiles in captive Western fence lizards (Sceloporus occidentalis) after a period of brumation

The reproductive hormone cycle of adult female American alligators from a barrier island population

C-Jun phosphorylation (Ser-63) in the testis of the lizard, Podarcis s. sicula

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