scholarly journals Sex Reversal and Performance in Fitness-Related Traits During Early Life in Agile Frogs

2021 ◽  
Vol 9 ◽  
Author(s):  
Veronika Bókony ◽  
Nikolett Ujhegyi ◽  
Zsanett Mikó ◽  
Réka Erös ◽  
Attila Hettyey ◽  
...  
Keyword(s):  
Early Life ◽  
Reproductive Organs ◽  
Sex Reversal ◽  
Chemical Pollution ◽  
Secondary Sexual Traits ◽  
Individual Fitness ◽  
Environmental Perturbations ◽  
Fitness Consequences ◽  
And Performance ◽  
Rana Dalmatina

Sex reversal is a mismatch between genetic sex (sex chromosomes) and phenotypic sex (reproductive organs and secondary sexual traits). It can be induced in various ectothermic vertebrates by environmental perturbations, such as extreme temperatures or chemical pollution, experienced during embryonic or larval development. Theoretical studies and recent empirical evidence suggest that sex reversal may be widespread in nature and may impact individual fitness and population dynamics. So far, however, little is known about the performance of sex-reversed individuals in fitness-related traits compared to conspecifics whose phenotypic sex is concordant with their genetic sex. Using a novel molecular marker set for diagnosing genetic sex in agile frogs (Rana dalmatina), we investigated fitness-related traits in larvae and juveniles that underwent spontaneous female-to-male sex reversal in the laboratory. We found only a few differences in early life growth, development, and larval behavior between sex-reversed and sex-concordant individuals, and altogether these differences did not clearly support either higher or lower fitness prospects for sex-reversed individuals. Putting these results together with earlier findings suggesting that sex reversal triggered by heat stress may be associated with low fitness in agile frogs, we propose the hypothesis that the fitness consequences of sex reversal may depend on its etiology.

scholarly journals Fitness consequences of environmental conditions at different life stages in a long-lived vertebrate

2014 ◽  
Vol 281 (1785) ◽  
pp. 20140276 ◽  
Author(s):  
Mathieu Douhard ◽  
Floriane Plard ◽  
Jean-Michel Gaillard ◽  
Gilles Capron ◽  
Daniel Delorme ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Early Life ◽  
Roe Deer ◽  
Developmental Trajectory ◽  
Evolutionary Medicine ◽  
Individual Fitness ◽  
Resource Limited ◽  
Fitness Consequences ◽  
Predictive Adaptive Response ◽  
Using Data

The predictive adaptive response (PAR) hypothesis proposes that animals adjust their physiology and developmental trajectory during early life in anticipation of their future environments. Accordingly, when environmental conditions in early life match environmental conditions during adulthood, individual fitness should be greater. Here, we test this hypothesis in a long-lived mammal, the roe deer, using data from two contrasting populations, intensively monitored for more than 35 years. In the highly productive site, the fitness of female roe deer increased with the quality of environment during adulthood and, contrary to predictions of PAR, individuals born in good conditions always outperformed those born under poor conditions. In the resource-limited site, the fitness of female roe deer born in poor years was better than those born in good conditions in poor years when the animals were adult, but not in good years. Although consistent with predictions of PAR, we showed that this pattern is likely to be a consequence of increased viability selection during the juvenile stage for animals born in poor years. While PARs are often advanced in evolutionary medicine, our findings suggest that detailed biological processes should be investigated before drawing conclusions about the existence of this phenomenon.

scholarly journals Sex reversal and ontogeny under climate change and chemical pollution: are there interactions between the effects of elevated temperature and a xenoestrogen on early development in agile frogs?

2020 ◽  
Author(s):  
Zsanett Mikó ◽  
Edina Nemesházi ◽  
Nikolett Ujhegyi ◽  
Viktória Verebélyi ◽  
János Ujszegi ◽  
...  
Keyword(s):  
Climate Change ◽  
High Temperature ◽  
Sex Determination ◽  
Body Mass ◽  
Endocrine Disrupting Chemicals ◽  
Sex Reversal ◽  
Chemical Pollution ◽  
Genetic Sexing ◽  
Simultaneous Exposure ◽  
Individual Fitness

Anthropogenic environmental change poses a special threat to species in which genetic sex determination can be overwritten by the thermal and chemical environment. Endocrine disrupting chemicals as well as extreme temperatures can induce sex reversal in such species, with wide-ranging consequences for fitness, demography, population viability and evolution. Despite accumulating evidence suggesting that chemical and thermal effects may interact in ecological contexts, little is known about their combined effects on sex reversal. Here we assessed the simultaneous effects of high temperature (masculinizing agent) and 17α-ethinylestradiol (EE2), a widespread xenoestrogen (feminizing agent), on sexual development and fitness-related traits in agile frogs (Rana dalmatina). We exposed tadpoles to a six-days heat wave (30°C) and/or an ecologically relevant concentration of EE2 (30 ng/L) in one of three consecutive larval periods, and diagnosed sex reversals two months after metamorphosis using species-specific markers for genetic sexing. We found that high temperature induced female-to-male sex reversal, decreased survival, delayed metamorphosis, decreased body mass at metamorphosis, and increased the proportion of animals that had no fat bodies, while EE2 had no effect on these traits. Simultaneous exposure to heat and EE2 had non-additive effects on juvenile body mass, which were dependent on treatment timing and further complicated by a negative effect of sex reversal on body mass. These results show that environmentally relevant exposure to EE2 does not diminish the masculinizing effects of high temperature. Instead, our findings on growth suggest that climate change and chemical pollution may have complex consequences for individual fitness and population persistence in species with environment-sensitive sex determination.

scholarly journals Chronic exposure to a glyphosate-based herbicide makes toad larvae more toxic

2017 ◽  
Vol 284 (1858) ◽  
pp. 20170493 ◽  
Author(s):  
Veronika Bókony ◽  
Zsanett Mikó ◽  
Ágnes M. Móricz ◽  
Dániel Krüzselyi ◽  
Attila Hettyey
Keyword(s):  
Larval Development ◽  
Pesticide Exposure ◽  
Sublethal Effects ◽  
Chemical Defence ◽  
Bufo Bufo ◽  
Chemical Pollution ◽  
Detectable Effect ◽  
Chemical Contaminants ◽  
Fitness Consequences ◽  
Outdoor Mesocosms

Chemical pollutants can exert various sublethal effects on wildlife, leading to complex fitness consequences. Many animals use defensive chemicals as protection from predators and diseases, yet the effects of chemical contaminants on this important fitness component are poorly known. Understanding such effects is especially relevant for amphibians, the globally most threatened group of vertebrates, because they are particularly vulnerable to chemical pollution. We conducted two experiments to investigate how exposure to glyphosate-based herbicides, the most widespread agrochemicals worldwide, affects the production of bufadienolides, the main compounds of chemical defence in common toads ( Bufo bufo ). In both experiments, herbicide exposure increased the amount of bufadienolides in toad tadpoles. In the laboratory, individuals exposed to 4 mg a.e./L glyphosate throughout their larval development had higher bufadienolide content at metamorphosis than non-exposed tadpoles, whereas exposure for 9 days to the same concentration or to 2 mg a.e./L throughout larval development or for 9 days had no detectable effect. In outdoor mesocosms, tadpoles from 16 populations exhibited elevated bufadienolide content after three-weeks exposure to both concentrations of the herbicide. These results show that pesticide exposure can have unexpected effects on non-target organisms, with potential consequences for the conservation management of toxin-producing species and their predators.

scholarly journals On the effects of castration and ovariotomy upon sheep

1912 ◽  
Vol 85 (576) ◽  
pp. 27-32 ◽  
Keyword(s):  
Old Age ◽  
Early Life ◽  
Complete Removal ◽  
Reproductive Organs ◽  
Fallow Deer ◽  
The Body ◽  
Male Characters ◽  
Game Birds ◽  
Male Plumage ◽  
The Face

It is well known that castration, when performed in early life and before sexual maturity has been reached, has a marked effect not only in inhibiting the development of the accessory male organs, but in changing the general conformation of the body. Thus in castrated guinea-pigs, oxen, and capons, as well as in eunuchs, the bones of the limbs tend to be abnormally long, this result depending upon an arrest in the ossification of epiphyses. The secondary male characters are also in many cases suppressed, so that there is an apparent approximation to the female type. Thus in red deer if the testes are removed in quite immature animals the antlers fail to make their appearance, and in fallow deer castration at birth limits the horn formation to the development of single dugs. Secondary sexual characters, however, are not always correlated with the presence of the essential reproductive organs, even in mammals. Thus the withers in the gelding resemble those of the horse rather than those of the mare, in which the witheres are lower. Moreover, in certain varieties of cattle in Italy, the horns in the ox, if castraction has been carried out young, are far longer than those of either the bull or the cow. Ovariotomy in the female is often said to lead to the assumption of male characters, but there is little experimental evidence that this is actually the case. In the human female complete removal of the ovaries, if carried out in early life, besides preventing the onset of puberty and the occurrence of menstruation, produces effects on the general form and appearance, individuals so operated upon being said, in some cases, to show resemblances to men. Abnormalities in the ovaries have been described as producing similar results. Thus, Rörig records three cases in which female deer possessed horns, and were shown on dissection to have had abnormal ovaries. Darwin states that female deer in old age have been known to acquire horns. It Wallace says that in old mares the neck tends to acquire an arch as in the stallion. The occasional growth of hair on the face in old women is a phenomenon of the same kind. Similar observations have been made upon birds, especially ducks, poultry, and game birds. Darwin mentions the case of a duck which, when 10 years old, acquired the plumage of the drake. Other cases are those of hens which in old age assumed secondary male characters and started to crow. Hunter mentions a hen pheasant which had male plumage associated with an abnormal ovary. Numerous other instances have been described, but it is not apparent that such an acquirement of male characters by female individuals is always correlated with an abnormality in the reproductive organs. According to Gurney the assumption of male plumage is generally associated with sterility in female gallinaceous birds, but not, as a rule, in female passerine birds. Thus Gurney describes a hen chaffinch with male plumage and a number of developing eggs.

Effects of handling dairy goat replacements in early life on behaviour when first entering the milking parlour

1996 ◽  
Vol 1996 ◽  
pp. 190-190
Author(s):  
K.M. Dedman ◽  
M.J. Bryant
Keyword(s):  
Early Life ◽  
Production Systems ◽  
Dairy Goat ◽  
And Performance

The handling of animals by their keepers, particularly in early life, has been shown to influence the subsequent behaviour and performance of various domestic farm species (Lyons, Price and Moberg, 1988; Hemsworth and Barnett, 1992). When production systems require animals to be handled frequently and in situations where their collaboration is essential, such as dairying, then the animals' placidity and tractability becomes essential. The aim of the experiment was to establish if handling goat kids for a few weeks after birth would influence behaviour when they were subsequently milked.

scholarly journals Early and adult social environments have independent effects on individual fitness in a social vertebrate

2015 ◽  
Vol 282 (1813) ◽  
pp. 20151167 ◽  
Author(s):  
Vérane Berger ◽  
Jean-François Lemaître ◽  
Dominique Allainé ◽  
Jean-Michel Gaillard ◽  
Aurélie Cohas
Keyword(s):  
Social Environment ◽  
Lifetime Reproductive Success ◽  
Social Environments ◽  
Long Term Effects ◽  
Delayed Effects ◽  
Individual Fitness ◽  
Fitness Consequences ◽  
Dominant Female ◽  
The Social ◽  
Independent Effects

Evidence that the social environment at critical stages of life-history shapes individual trajectories is accumulating. Previous studies have identified either current or delayed effects of social environments on fitness components, but no study has yet analysed fitness consequences of social environments at different life stages simultaneously. To fill the gap, we use an extensive dataset collected during a 24-year intensive monitoring of a population of Alpine marmots ( Marmota marmota ), a long-lived social rodent. We test whether the number of helpers in early life and over the dominance tenure length has an impact on litter size at weaning, juvenile survival, longevity and lifetime reproductive success (LRS) of dominant females. Dominant females, who were born into a group containing many helpers and experiencing a high number of accumulated helpers over dominance tenure length showed an increased LRS through an increased longevity. We provide evidence that in a wild vertebrate, both early and adult social environments influence individual fitness, acting additionally and independently. These findings demonstrate that helpers have both short- and long-term effects on dominant female Alpine marmots and that the social environment at the time of birth can play a key role in shaping individual fitness in social vertebrates.

Sign in / Sign up

Export Citation Format

Share Document