Environmental sex determination of green sea turtles affected by climate change

AccessScience ◽  
2018 ◽  
Keyword(s):  
Climate Change ◽  
Sex Determination ◽  
Sea Turtles ◽  
Environmental Sex Determination ◽  
Green Sea Turtles

scholarly journals Climate change and green sea turtle sex ratio – Preventing possible extinction

2020 ◽  
Author(s):  
Jana Blechschmidt ◽  
Meike J. Wittmann ◽  
Chantal Blüml
Keyword(s):  
Climate Change ◽  
Sex Ratio ◽  
Nest Site ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Change Scenario ◽  
Green Sea Turtles ◽  
The Face ◽  
Nest Depth

AbstractClimate change poses a threat to species with temperature-dependent sex determination. A recent study on green sea turtles (Chelonia mydas) at the northern Great Barrier Reef (GBR) showed a highly female-skewed sex ratio with almost all juvenile turtles being female. This shortage of males might eventually cause population extinction, unless rapid evolutionary rescue, migration or conservation efforts ensure a sufficient number of males. We built a stochastic individual-based model inspired by C. mydas, but potentially transferrable to other species with TSD. Nest depth, level of shade, and pivotal temperature were evolvable traits. Additionally, we considered the effect of crossbreeding between the northern and southern GBR, nest-site philopatry, and conservation efforts. Among the evolvable traits, nest depth was the most likely to rescue the population in the face of climate change, but even here the more extreme climate-change scenario led to extinction. Surprisingly, nest-site philopatry elevated extinction rates. Conservation efforts to artificially increase nest depth promoted population survival and did not preclude trait evolution. Although extra information is needed to make reliable predictions for the fate of green sea turtles, our results illustrate how evolution can shape the fate of long lived, vulnerable species in the face of climate change.Graphical Abstract

scholarly journals Co-option of the bZIP transcription factor Vrille as the activator of Doublesex1 in environmental sex determination of the crustacean Daphnia magna

PLoS Genetics ◽  
2017 ◽  
Vol 13 (11) ◽  
pp. e1006953 ◽  
Author(s):  
Nur Syafiqah Mohamad Ishak ◽  
Quang Dang Nong ◽  
Tomoaki Matsuura ◽  
Yasuhiko Kato ◽  
Hajime Watanabe
Keyword(s):  
Transcription Factor ◽  
Sex Determination ◽  
Daphnia Magna ◽  
Bzip Transcription Factor ◽  
Environmental Sex Determination

scholarly journals Genetic contribution to sex determination in turtles with environmental sex determination

1994 ◽  
Vol 63 (2) ◽  
pp. 117-127 ◽  
Author(s):  
Marc Girondot ◽  
Patrick Zaborski ◽  
Jean Servan ◽  
Claude Pieau
Keyword(s):  
Sex Determination ◽  
Incubation Temperature ◽  
Natural Populations ◽  
Low Frequency ◽  
Theoretical Models ◽  
Temperature Sensitive ◽  
Environmental Sex Determination ◽  
Sexual Phenotype ◽  
Second Category

SummaryIn many reptiles, sex determination is temperature-sensitive. This phenomenon has been shown to take place in the laboratory as well as in nature, but its effect on natural populations remains questionable. In the turtle Emys orbicularis, the effects of temperature override a weak mechanism of genetic sex determination which is revealed in incubation at pivotal temperature. At this temperature, the sexual phenotype is concordant with the expression of the serologically defined H-Y antigen (H-Ys) in non-gonadal tissues; males are H-Ys negative (H-Y−) whereas females are H-Ys positive (H-Y+). To estimate the importance of sexual inversion (sexual phenotype and H-Ys expression discordant) in populations of Brenne (France), the frequencies of male and female sexual phenotypes among H-Ys phenotypes were determined. The frequencies of sex reversed individuals are low, only 6 % of phenotypic females being H-Y− and 11 % of phenotypic males being H-Y+. According to these data, two theoretical models have been constructed to estimate the contribution to sex determination of individuals in relation to their genotype. The first model excludes any influence of incubation temperature and sexual phenotype on the fitness of individuals. The second one considers that these parameters influence fitness because this model has been previously shown to favour environmental sex determination. In both models, it appears that sex determination can be viewed as genotypic and monogenic with some individuals sexually inverted by theaction of temperature. One category of homozygous animals differentiates mainly into one sex, and the heterozygous animals differentiate mainly into the other sex. The second category of homozygotes has a low frequency in the populations and can differentiate as male or female without high constraint. Then it is estimated that in Brenne approximately 83% of the eggs are incubated in conditions allowing the genetic component to influence sex determination.

Climate change overruns resilience conferred by temperature-dependent sex determination in sea turtles and threatens their survival

2015 ◽  
Vol 21 (8) ◽  
pp. 2980-2988 ◽  
Author(s):  
Pilar Santidrián Tomillo ◽  
Meritxell Genovart ◽  
Frank V. Paladino ◽  
James R. Spotila ◽  
Daniel Oro
Keyword(s):  
Climate Change ◽  
Sex Determination ◽  
Sea Turtles ◽  
Temperature Dependent

scholarly journals Climate change and pollution speed declines in zebrafish populations

2015 ◽  
Vol 112 (11) ◽  
pp. E1237-E1246 ◽  
Author(s):  
A. Ross Brown ◽  
Stewart F. Owen ◽  
James Peters ◽  
Yong Zhang ◽  
Marta Soffker ◽  
...  
Keyword(s):  
Climate Change ◽  
Sex Determination ◽  
Water Temperature ◽  
Endocrine Disrupting Chemicals ◽  
Population Viability Analysis ◽  
Population Viability ◽  
Interactive Effects ◽  
Environmental Sex Determination ◽  
Estrogen Synthesis ◽  
Inbred Populations

Endocrine disrupting chemicals (EDCs) are potent environmental contaminants, and their effects on wildlife populations could be exacerbated by climate change, especially in species with environmental sex determination. Endangered species may be particularly at risk because inbreeding depression and stochastic fluctuations in male and female numbers are often observed in the small populations that typify these taxa. Here, we assessed the interactive effects of water temperature and EDC exposure on sexual development and population viability of inbred and outbred zebrafish (Danio rerio). Water temperatures adopted were 28 °C (current ambient mean spawning temperature) and 33 °C (projected for the year 2100). The EDC selected was clotrimazole (at 2 μg/L and 10 μg/L), a widely used antifungal chemical that inhibits a key steroidogenic enzyme [cytochrome P450(CYP19) aromatase] required for estrogen synthesis in vertebrates. Elevated water temperature and clotrimazole exposure independently induced male-skewed sex ratios, and the effects of clotrimazole were greater at the higher temperature. Male sex ratio skews also occurred for the lower clotrimazole exposure concentration at the higher water temperature in inbred fish but not in outbred fish. Population viability analysis showed that population growth rates declined sharply in response to male skews and declines for inbred populations occurred at lower male skews than for outbred populations. These results indicate that elevated temperature associated with climate change can amplify the effects of EDCs and these effects are likely to be most acute in small, inbred populations exhibiting environmental sex determination and/or differentiation.

scholarly journals Climate Change and Green Sea Turtle Sex Ratio—Preventing Possible Extinction

Genes ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 588 ◽  
Author(s):  
Jana Blechschmidt ◽  
Meike J. Wittmann ◽  
Chantal Blüml
Keyword(s):  
Climate Change ◽  
Sex Ratio ◽  
Nest Site ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Climate Change Scenarios ◽  
Population Extinction ◽  
Green Sea Turtles ◽  
Nest Depth

Climate change poses a threat to species with temperature-dependent sex determination (TSD). A recent study on green sea turtles (Chelonia mydas) at the northern Great Barrier Reef (GBR) showed a highly female-skewed sex ratio with almost all juvenile turtles being female. This shortage of males might eventually cause population extinction, unless rapid evolutionary rescue, migration, range shifts, or conservation efforts ensure a sufficient number of males. We built a stochastic individual-based model inspired by C. mydas but potentially transferrable to other species with TSD. Pivotal temperature, nest depth, and shading were evolvable traits. Additionally, we considered the effect of crossbreeding between northern and southern GBR, nest site philopatry, and conservation efforts. Among the evolvable traits, nest depth was the most likely to rescue the population, but even here the warmer climate change scenarios led to extinction. We expected turtles to choose colder beaches under rising temperatures, but surprisingly, nest site philopatry did not improve persistence. Conservation efforts promoted population survival and did not preclude trait evolution. Although extra information is needed to make reliable predictions for the fate of green sea turtles, our results illustrate how evolution can shape the fate of long lived, vulnerable species in the face of climate change.

SEX DETERMINATION OF FETUS PRENATAL FROM MATERNAL PLASMA BY USING DUPLEX PCR TECHNIQUE IN GOAT

2014 ◽  
Vol 13 (1) ◽  
pp. 50-59
Author(s):  
A NisreenYasirJasim ◽  
Tahir A. Fahid ◽  
Talib Ahmed Jaayid
Keyword(s):  
Sex Determination ◽  
Maternal Plasma ◽  
Duplex Pcr
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