Luteal development, placentation, and plasma progesterone concentration in the viviparous lizard Sceloporus jarrovi

Guillette, Louis J.; Spielvogel, Sandra P.; Moore, Frank L.

doi:10.1016/0016-6480(81)90027-7

Cited by 70 publications

(47 citation statements)

References 21 publications

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“…However, the exact role of P, as well as interspecific variation in this role, is not well understood. The pregnancy maintenance properties of P in viviparous vertebrates include inhibition of follicular growth and oviductal contractility (Guillette et al, 1981) as well as maintenance of oviductal vascularity (Mead et al, 1981). Our results mimic those of a previous study (Bonnet et al, 2001) where P peaks early in gestation with a slow decline until parturition, suggesting that parturition may be stimulated by a drop in P levels.…”

Section: Discussionsupporting

confidence: 87%

Seasonal steroid hormone levels and their relation to reproduction in the Western Diamond-backed Rattlesnake, Crotalus atrox (Serpentes: Viperidae)

Taylor

DeNardo

Jennings

2004

General and Comparative Endocrinology

107

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We report seasonal variation in steroid hormone levels in blood samples from free ranging Western Diamond backed Rattle snakes (Crotalus atrox), and the relationship between these hormones and events in the reproductive cycle. At a field site in the Sonoran Desert of south central Arizona, we collected monthly blood samples over the course of two active seasons from 17 ra diotelemetered females, and over three active seasons from 103 randomly encountered males. We used radioimmunoassay to measure plasma levels of 17b estradiol, progesterone, corticosterone, and testosterone in samples from females, and corticosterone and testosterone in samples from males. Non reproductive females have consistently low levels of circulating 17b estradiol, pro gesterone, and testosterone throughout the year. In reproductive females, 17b estradiol levels increase dramatically and testosterone levels increase modestly during vitellogenesis in April and May, while progesterone levels increase dramatically at ovulation in June and then steadily decline until parturition in August. Corticosterone levels appear relatively constant in non reproductive females, whereas reproductive females show increased levels at the end of gestation. Plasma testosterone levels in males are low in early summer and are elevated during spring and late summer, corresponding to the two mating periods of C. atrox. Plasma cortico sterone levels in males did not vary seasonally and were not related to testosterone levels.

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Section: Discussionsupporting

confidence: 87%

Seasonal steroid hormone levels and their relation to reproduction in the Western Diamond-backed Rattlesnake, Crotalus atrox (Serpentes: Viperidae)

Taylor

DeNardo

Jennings

2004

General and Comparative Endocrinology

107

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“…These values are almost twice as great as those reported for the egg retaining species Sceloporus aeneus (Guillette & Jones, 1985). Fox (Weekes, 1935;Guillette et al, 1981;Guillette & Jones, 1985;Stewart, 1985). This thin membrane with little muscle or connective tissue allows an unobstructed view of most of the capillaries.…”

Section: Discussionmentioning

confidence: 65%

Changes in oviducal vascularity during the reproductive cycle of three oviparous lizards (Eumeces obsoletus, Sceloporus undulatus and Crotaphytus collaris)

Masson¹,

Guillette²

1987

Reproduction

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“…1A) and yolk-sac placentae ( Fig. 1C) with little morphological specialization (Weekes 1935, Bellairs et al 1955, Hoffman 1970, Yaron 1977, Guillette et al 1981, Stewart 1990. In contrast, viviparous skinks of the genera Niveoscincus, Pseudemoia, Chalcides, Eumecia, Mabuya, and Trachylepis exhibit complex chorioallantoic placentae and increasing reliance on placentotrophy (Weekes 1935, Blackburn et al 1984, Ghiara et al 1987, Blackburn 1992, Flemming & Branch 2001, Blackburn & Vitt 2002, Stewart & Thompson 2004, Adams et al 2005, Blackburn & Flemming 2012.…”

Section: R17mentioning

confidence: 98%

“…1A and B) and some form of yolk-sac placenta on the abembryonic pole ( Fig. 1C; Weekes 1935, Hoffman 1970, Guillette et al 1981, Blackburn 1992, Stewart 1992. Both placentae are formed via close appositions of uterine and embryonic tissues, and are defined as epitheliochorial in most viviparous reptiles (Blackburn & Vitt 2002, Adams et al 2005 because the embryonic tissues do not breach or invade uterine epithelia.…”

Section: Implantation and Placentationmentioning

confidence: 99%

The evolution of viviparity: molecular and genomic data from squamate reptiles advance understanding of live birth in amniotes

2014

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Squamate reptiles (lizards and snakes) are an ideal model system for testing hypotheses regarding the evolution of viviparity (live birth) in amniote vertebrates. Viviparity has evolved over 100 times in squamates, resulting in major changes in reproductive physiology. At a minimum, all viviparous squamates exhibit placentae formed by the appositions of maternal and embryonic tissues, which are homologous in origin with the tissues that form the placenta in therian mammals. These placentae facilitate adhesion of the conceptus to the uterus as well as exchange of oxygen, carbon dioxide, water, sodium, and calcium. However, most viviparous squamates continue to rely on yolk for nearly all of their organic nutrition. In contrast, some species, which rely on the placenta for at least a portion of organic nutrition, exhibit complex placental specializations associated with the transport of amino acids and fatty acids. Some viviparous squamates also exhibit reduced immunocompetence during pregnancy, which could be the result of immunosuppression to protect developing embryos. Recent molecular studies using both candidate-gene and next-generation sequencing approaches have suggested that at least some of the genes and gene families underlying these phenomena play similar roles in the uterus and placenta of viviparous mammals and squamates. Therefore, studies of the evolution of viviparity in squamates should inform hypotheses of the evolution of viviparity in all amniotes, including mammals.Reproduction (2014) 147 R15-R26

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Luteal development, placentation, and plasma progesterone concentration in the viviparous lizard Sceloporus jarrovi

Cited by 70 publications

References 21 publications

Seasonal steroid hormone levels and their relation to reproduction in the Western Diamond-backed Rattlesnake, Crotalus atrox (Serpentes: Viperidae)

Seasonal steroid hormone levels and their relation to reproduction in the Western Diamond-backed Rattlesnake, Crotalus atrox (Serpentes: Viperidae)

Changes in oviducal vascularity during the reproductive cycle of three oviparous lizards (Eumeces obsoletus, Sceloporus undulatus and Crotaphytus collaris)

The evolution of viviparity: molecular and genomic data from squamate reptiles advance understanding of live birth in amniotes

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