scholarly journals Epigenetics underpins phenotypic plasticity of protandrous sex change in fish

2021 ◽  
Author(s):  
Alyssa Budd ◽  
Julie Robins ◽  
Olivia Whybird ◽  
Dean Jerry
Keyword(s):  
Phenotypic Plasticity ◽  
Epigenetic Modification ◽  
Strong Association ◽  
Sex Change ◽  
Ecological Processes ◽  
Sea Temperature ◽  
Protandrous Hermaphrodite ◽  
Female Specific ◽  
Response To Environmental Change ◽  
Male To Female

Phenotypic plasticity is an important driver of species resilience. Often mediated by epigenetic changes, phenotypic plasticity enables individual genotypes to express variable phenotypes in response to environmental change. Barramundi (Lates calcarifer) is a protandrous (male-first) sequential hermaphrodite that exhibit plasticity in length-at-sex change between geographic regions. This plasticity is likely to be mediated by changes in DNA methylation (DNAm), a well-studied epigenetic modification. However, region-specific relationships between length, sex and DNAm in sequential hermaphrodites were previously unreported. To investigate these relationships, here we compare DNAm in four conserved vertebrate sex-determining genes in male and female barramundi of differing lengths from three regions of northern Australia. Despite a strong association between increasing length and male-to-female sex change, the data reveal that DNAm becomes more sex-specific (rather than more female-specific) with length. Significant differences in DNAm between males and females of similar lengths suggest that female-specific DNAm arises rapidly during sex change, rather than gradually with growth. The findings also reveal that region-specific differences in length-at-sex change are accompanied by differences in DNAm, and were concurrent with variability in remotely sensed sea temperature and salinity. Together, these findings provide the first in situ evidence for epigenetically and environmentally mediated sex change in a protandrous hermaphrodite, and offer significant insight into the molecular and ecological processes governing the marked and unique plasticity of sex in fish.

scholarly journals The earliest example of sexual dimorphism in bivalves—evidence from the astartid Nicaniella (Lower Jurassic, southern Germany)

2021 ◽  
pp. 1-10
Author(s):  
Baran Karapunar ◽  
Winfried Werner ◽  
Franz T. Fürsich ◽  
Alexander Nützel
Keyword(s):  
Principal Component Analysis ◽  
Life History ◽  
Shape Analysis ◽  
Principal Component ◽  
Sex Change ◽  
Lower Jurassic ◽  
Allocation Of Resources ◽  
Fourier Shape Analysis ◽  
Lower Height ◽  
Male To Female

Abstract Protandrous sex change (sex change from male to female) is one of the diverse sexual expressions exhibited by bivalves, but its expression in the shell is quite rare. Previous studies on living and fossil astartids suggest a relationship between protandrous sex change and the formation of crenulations on the ventral shell margin at later ontogenetic stages. Here we report the formation of such crenulations in the Early Jurassic astartid Nicaniella rakoveci (Kuhn, 1935) from the Amaltheenton Formation at Buttenheim, Franconia. This is the earliest known record of protandrous hermaphroditism in fossil bivalves, predating previous reports by at least 13 Myr. A principal component analysis of linear size measurements and Fourier shape analysis of the shell outlines revealed that the outline of Nicaniella rakoveci specimens varies from subquadrate to subcircular, but this variation is independent of the presence or absence of crenulations and therefore not associated with sex. Crenulated specimens exhibit a lower height/inflation ratio than non-crenulated ones, suggesting that the protandrous females have more inflated valves than the males. The formation of crenulations was probably related to allocation of resources for reproduction. The most likely function of the crenulations was to increase the internal shell volume in the female stage to accommodate more eggs rather than being an adaptation against predation as often assumed for other bivalves. The formation of crenulations is part of the protandrous life history and probably is controlled by a genetic mechanism that is also responsible for sex change.

Long-term follow-up of ?sex change? in 13 male-to-female transsexuals

1986 ◽  
Vol 15 (3) ◽  
pp. 187-210 ◽  
Author(s):  
Gunnar Lindemalm ◽  
Dag K�rlin ◽  
Nils Uddenberg
Keyword(s):  
Sex Change ◽  
Long Term Follow Up ◽  
Male To Female

Male-to-female sex change in widowed males of the protogynous damselfish Dascyllus aruanus

2015 ◽  
Vol 34 (1) ◽  
pp. 85-88 ◽  
Author(s):  
Tetsuo Kuwamura ◽  
Shohei Suzuki ◽  
Tatsuru Kadota
Keyword(s):  
Sex Change ◽  
Female Sex ◽  
Dascyllus Aruanus ◽  
Male To Female

Plant functional types: an alternative to taxonomic plant community description in biogeography?

2000 ◽  
Vol 24 (4) ◽  
pp. 515-542 ◽  
Author(s):  
Jennifer C. Duckworth ◽  
Martin Kent ◽  
Paul M. Ramsay
Keyword(s):  
Plant Community ◽  
Plant Functional Types ◽  
Prediction Of Response ◽  
Ecological Processes ◽  
Trade Off ◽  
Practical Applications ◽  
Functional Types ◽  
Complementary Approach ◽  
Traditional Taxonomy ◽  
Response To Environmental Change

This article critically reviews the concept of plant functional types as an alternative to the traditional taxonomic species-based approach to plant community description in biogeography and ecology. Originally formulated in the last century, there has been an acceleration in interest in the concept over the last decade. Plant functional types are nonphylogenetic groupings of species that show close similarities in their response to environmental and biotic controls. Functional classifications often cut across taxonomic classifications and may be more meaningful in terms of plant response, in addition to overcoming certain problems associated with the traditional taxonomic species-based approach. Plant functional types are derived from traits based on species morphology, physiology and/or life history, depending on the aims and scale of the research. Whilst some traits can be measured in the field, others require more detailed laboratory measurement and experimentation. A trade-off exists between the time and efficiency gained from using simple traits and those requiring more elaborate analysis, although certain ‘key traits’ may act as easily measured surrogates for others. Practical applications of plant functional types in biogeography and ecology are also reviewed. Plant functional types can aid in the understanding of ecological processes, such as the assembly and stability of communities and succession, and facilitate the detection and prediction of response to environmental change at a range of scales. Despite its potential, the plant functional type approach is probably best viewed as a complementary approach to description using traditional taxonomy.

Prevalence of Transsexualism Among New Zealand Passport Holders

2008 ◽  
Vol 42 (10) ◽  
pp. 887-889 ◽  
Author(s):  
Jaimie F. Veale
Keyword(s):  
New Zealand ◽  
Birth Certificate ◽  
Sex Change ◽  
Sex Reassignment Surgery ◽  
Sex Reassignment ◽  
Female Transsexualism ◽  
Male To Female

Objective: Most previous studies of the prevalence of transsexualism have used data from individuals seeking sex reassignment surgery. New Zealand is unique in that transsexual people can apply to have an ‘X’ for the sex on their passport if they have a name on their birth certificate that is congruent with the sex opposite to their birth assigned sex, and provide a statutory declaration stating they have lived as a member of that sex. Method: From information provided by the New Zealand Passports Office, it was ascertained that the prevalence of transsexualism among New Zealand passport holders was at least 1:6364. Results: The prevalence of male-to-female transsexualism was estimated at 1:3639, and the corresponding figure for female-to-male transsexualism was 1:22 714. Conclusions: These estimates were higher than most previous estimates of transsexualism prevalence. There was also a larger than expected ratio of male-to-female transsexual people to female-to-male transsexual people (6:1), which could in part be due to female-to-male transsexual people being relatively overrepresented among those transsexual people for whom we did not have data on the direction of sex change, or this may be indicative of the demography of transsexualism in Australasia.

scholarly journals DNA methylation site loss for plasticity-led novel trait genetic fixation

2020 ◽  
Author(s):  
Takafumi Katsumura ◽  
Suguru Sato ◽  
Kana Yamashita ◽  
Shoji Oda ◽  
Takashi Gakuhari ◽  
...  
Keyword(s):  
Gene Expression ◽  
Phenotypic Plasticity ◽  
Environmental Changes ◽  
Developmental Process ◽  
Epigenetic Modification ◽  
Nucleotide Substitutions ◽  
Cpg Sites ◽  
Standing Variation ◽  
Novel Traits ◽  
Gut Length

AbstractMany organisms exhibit phenotypic plasticity that changes their traits in response to their environment. Although whether or not this plasticity contributes to adaptive evolution is a fundamental question in evolutionary biology, various studies report that natural populations adapt to rapid environmental changes via plasticity, which leads to novel adaptive traits as “triggers.” Namely, phenotypic plasticity has considered allowing an accumulation of genetic mutations to fix the alternative phenotypes induced by nongenetic perturbations that include gene expression noise or epigenetic modification caused by environmental change. However, because the molecular mechanism of phenotypic plasticity is unknown, verification of the process from phenotypic plasticity to genetic fixation remains insufficient. Here we show that decrease in methylated CpG sites leads to loss of plasticity, which triggers genetic fixation of novel traits, in medaka fish (Oryzias latipes). We found that the gut length was correlated with the number of methylated CpG sites upstream of the Plxnb3 gene, which is involved in the developmental process of nerve axons. The medaka, in which the methylated DNA region is deleted by CRISPR/Cas9, showed a loss of plasticity in gut length and a lower survival rate caused by nonoptimal feeding environments. Moreover, standing variation in the promoter region of another gene, Ppp3r1, which is also related to nerve axon development, raised the gene expression and made a longer gut stably in wild medaka groups that lost the gut-length plasticity. Furthermore, our phylogenetic analysis revealed the timing of these evolutionary events, indicating that the loss of phenotypic plasticity by nucleotide substitutions initiates the process of genetic fixation of the novel trait. That is, while phenotypic plasticity plays a role as a buffer of evolution and contributes to environmental adaptation, as previously thought, our molecular data suggest that mutation on CpG site causing the loss of phenotypic plasticity, is the trigger for a generation of novel traits.

scholarly journals 17α-ethynylestradiol prevents the natural male-to-female sex change in gilthead seabream (Sparus aurata L.)

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
M. Pilar García Hernández ◽  
Isabel Cabas ◽  
M. Carmen Rodenas ◽  
Marta Arizcun ◽  
Elena Chaves-Pozo ◽  
...  
Keyword(s):  
Plasma Levels ◽  
Sparus Aurata ◽  
Recovery Period ◽  
Sex Change ◽  
Control Fish ◽  
Gilthead Seabream ◽  
Commercial Diet ◽  
The Third ◽  
Female Sex ◽  
Male To Female

AbstractExposure to 17α-ethynylestradiol (EE2, 5 μg/g food) impairs some reproductive events in the protandrous gilthead seabream and a short recovery period does not allow full recovery. In this study, spermiating seabream males in the second reproductive cycle (RC) were fed a diet containing 5 or 2.5 μg EE2/g food for 28 days and then a commercial diet without EE2 for the remaining RC. Individuals were sampled at the end of the EE2 treatment and then at the end of the RC and at the beginning of the third RC, 146 and 333 days after the cessation of treatment, respectively. Increased hepatic transcript levels of the gene coding for vitellogenin (vtg) and plasma levels of Vtg indicated both concentrations of EE2 caused endocrine disruption. Modifications in the histological organization of the testis, germ cell proliferation, plasma levels of the sex steroids and pituitary expression levels of the genes coding for the gonadotropin β-subunits, fshβ and lhβ were detected. The plasma levels of Vtg and most of the reproductive parameters were restored 146 days after treatments. However, although 50% of the control fish underwent sex reversal as expected at the third RC, male-to female sex change was prevented by both EE2 concentrations.

Pitfalls in the management of rectal cancer after male-to-female sex change procedure

2013 ◽  
Vol 15 (4) ◽  
pp. e199-e199
Author(s):  
T. G. Barnes ◽  
M. Christodoulidou ◽  
M. A. Lucky ◽  
G. Singh ◽  
D. Y. Artioukh
Keyword(s):  
Rectal Cancer ◽  
Sex Change ◽  
Female Sex ◽  
Male To Female

scholarly journals Faster juvenile growth promotes earlier sex change in a protandrous hermaphrodite (barramundi Lates calcarifer)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Brien H. Roberts ◽  
John R. Morrongiello ◽  
David L. Morgan ◽  
Alison J. King ◽  
Thor M. Saunders ◽  
...  
Keyword(s):  
Growth Rate ◽  
Life Histories ◽  
Sex Change ◽  
Maximum Size ◽  
Growth Potential ◽  
Lates Calcarifer ◽  
Individual Level ◽  
Trade Offs ◽  
Animal Populations ◽  
Protandrous Hermaphrodite

AbstractThe relationship between growth and sexual maturation is central to understanding the dynamics of animal populations which exhibit indeterminate growth. In sequential hermaphrodites, which undergo post-maturation sex change, the size and age at which sex change occurs directly affects reproductive output and hence population productivity. However, these traits are often labile, and may be strongly influenced by heterogenous growth and mortality rates. We analysed otolith microstructure of a protandrous (i.e., male-to-female) fish (barramundi Lates calcarifer) to examine growth in relation to individual variation in the timing of sex change. Growth trajectories of individuals with contrasting life histories were examined to elucidate the direction and extent to which growth rate influences the size and age individuals change sex. Then, the relationships between growth rate, maturation schedules and asymptotic maximum size were explored to identify potential trade-offs between age at female maturity and growth potential. Rapid growth was strongly associated with decreased age at sex change, but this was not accompanied by a decrease in size at sex change. Individuals that were caught as large females grew faster than those caught as males, suggesting that fast-growing individuals ultimately obtain higher fitness and therefore make a disproportionate contribution to population fecundity. These results indicate that individual-level variation in maturation schedules is not reflective of trade-offs between growth and reproduction. Rather, we suggest that conditions experienced during the juvenile phase are likely to be a key determinant of post-maturation fitness. These findings highlight the vulnerability of sex-changing species to future environmental change and harvest.

Sign in / Sign up

Export Citation Format

Share Document