Forms and Prevalence of Intersexuality and Effects of Environmental Contaminants on Sexuality in Cricket Frogs (Acris crepitans)

Reeder, A. L.; Foley, G. L.; Nichols, D. K.; Hansen, L. G.; Wikoff, B.; Faeh, S.; Eisold, J.; Wheeler, M. B.; Warner, R.; Murphy, J. E.; Beasley, V. R.

doi:10.2307/3434013

Cited by 33 publications

(41 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The majority of these were missing limbs or limb segments which could have resulted from either developmental malformations or traumatic amputations. A survey of Illinois cricket frogs in the early 1990s also identified only one skeletal malformation in 341 animals (Reeder et al, 1998). These studies suggest that, either A. crepitans is resistant to etiologic agents causing malformations among other anurans or that the causative factor(s) were not widely distributed during that time.…”

Section: Discussionmentioning

confidence: 96%

“…Despite the fact that malformations appear to occur at scales that would not contribute significantly to population declines (Carey, 2000) the increased malformation prevalence and declining populations are occurring in the same time frame, which may be more than coincidental. Many population reductions can be associated with habitat destruction, degradation, fragmentation, and contamination (Reeder et al, 1998;Beasley et al, 2002) but others appear to be occurring in areas less affected by human influences (Berger et al, 1998). Infectious diseases have been implicated as the proximate cause of declines or extinctions in some areas (for review, see Dazsak et al, 1999).…”

Section: Malformation and Declining Amphibian Populationsmentioning

confidence: 99%

See 1 more Smart Citation

Prevalence of Skeletal and Eye Malformations in Frogs From North-Central United States: Estimations Based on Collections From Randomly Selected Sites

Schoff

Johnson

Schotthoefer

et al. 2003

Journal of Wildlife Diseases

View full text Add to dashboard Cite

Skeletal malformation rates for several frog species were determined in a set of randomly selected wetlands in the north-central USA over three consecutive years. In 1998, 62 sites yielded 389 metamorphic frogs, nine (2.3%) of which had skeletal or eye malformations. A subset of the original sites was surveyed in the following 2 yr. In 1999, 1,085 metamorphic frogs were collected from 36 sites and 17 (1.6%) had skeletal or eye malformations, while in 2000, examination of 1,131 metamorphs yielded 16 (1.4%) with skeletal or eye malformations. Hindlimb malformations predominated in all three years, but other abnormalities, involving forelimb, eye, and pelvis were also found. Northern leopard frogs (Rana pipiens) constituted the majority of collected metamorphs as well as most of the malformed specimens. However, malformations were also noted in mink frogs (R. septentrionalis), wood frogs (R. sylvatica), and gray tree frogs (Hyla spp.). The malformed specimens were found in clustered sites in all three years but the cluster locations were not the same in any year. The malformation rates reported here are higher than the 0.3% rate determined for metamorphic frogs collected from similar sites in Minnesota in the 1960s, and thus, appear to represent an elevation of an earlier baseline malformation rate.

show abstract

Section: Discussionmentioning

confidence: 96%

Section: Malformation and Declining Amphibian Populationsmentioning

confidence: 99%

Prevalence of Skeletal and Eye Malformations in Frogs From North-Central United States: Estimations Based on Collections From Randomly Selected Sites

Schoff

Johnson

Schotthoefer

et al. 2003

Journal of Wildlife Diseases

View full text Add to dashboard Cite

show abstract

“…Already, it has been suggested that pesticides may play a role in amphibian declines (3,52,54,55). Also, Reeder et al (56) found that atrazine exposure may be associated with intersexual cricket frogs in the wild in the Illinois. Because the P value in the Reeder et al study was 0.07 and because no laboratory data were available, they concluded that ''[w]hether atrazine accounts for findings of intersexuality is less clear'' (ref.…”

Section: Discussionmentioning

confidence: 99%

Hermaphroditic, demasculinized frogs after exposure to the herbicide atrazine at low ecologically relevant doses

Hayes

Collins

Lee

et al. 2002

Proc. Natl. Acad. Sci. U.S.A.

1,002

656

View full text Add to dashboard Cite

Atrazine is the most commonly used herbicide in the U.S. and probably the world. It can be present at several parts per million in agricultural runoff and can reach 40 parts per billion (ppb) in precipitation. We examined the effects of atrazine on sexual development in African clawed frogs (Xenopus laevis). Larvae were exposed to atrazine (0.01-200 ppb) by immersion throughout larval development, and we examined gonadal histology and laryngeal size at metamorphosis. Atrazine (>0.1 ppb) induced hermaphroditism and demasculinized the larynges of exposed males (>1.0 ppb). In addition, we examined plasma testosterone levels in sexually mature males. Male X. laevis suffered a 10-fold decrease in testosterone levels when exposed to 25 ppb atrazine. We hypothesize that atrazine induces aromatase and promotes the conversion of testosterone to estrogen. This disruption in steroidogenesis likely explains the demasculinization of the male larynx and the production of hermaphrodites. The effective levels reported in the current study are realistic exposures that suggest that other amphibian species exposed to atrazine in the wild could be at risk of impaired sexual development. This widespread compound and other environmental endocrine disruptors may be a factor in global amphibian declines.

show abstract

“…Both forms can sometimes exist in a given population [58]. In addition, Witschi [59] observed that in controlled breeding, the parental type is transmitted.…”

Section: Hynobius Retardatus I [65]mentioning

confidence: 99%

Sex determination: the amphibian models

2004

View full text Add to dashboard Cite

-We review and discuss current knowledge about sex determination in amphibians. The astonishing wide variety of mechanisms of genotypic sex determination is presented and discussed in an evolutionary context. We recall the natural occurrence of transitory juvenile hermaphroditism in some species. Our present knowledge of the mechanisms of sex determination in amphibians is compared to that in mammals. The influence of epigenetic factors, and especially temperature is highlighted. In amphibians, the influence of temperature on sexual differentiation, that can prevail over genotypic sex determination, remains poorly considered in publications. We suggest that studies on genetic and epigenetic factors of gonadal sex differentiation in amphibians could provide substantial information on the evolutionary process of sex determination mechanisms in current living vertebrates.sex determination mechanisms / sexual differentiation / hermaphroditism / epigenetic factors

show abstract

Forms and Prevalence of Intersexuality and Effects of Environmental Contaminants on Sexuality in Cricket Frogs (Acris crepitans)

Cited by 33 publications

References 15 publications

Prevalence of Skeletal and Eye Malformations in Frogs From North-Central United States: Estimations Based on Collections From Randomly Selected Sites

Prevalence of Skeletal and Eye Malformations in Frogs From North-Central United States: Estimations Based on Collections From Randomly Selected Sites

Hermaphroditic, demasculinized frogs after exposure to the herbicide atrazine at low ecologically relevant doses

Sex determination: the amphibian models

Contact Info

Product

Resources

About