Sex is determined by multiple factors derived from somatic and germ cells in vertebrates. We have identified
- Award ID(s):
- 1928770
- PAR ID:
- 10308516
- Date Published:
- Journal Name:
- Frontiers in Endocrinology
- Volume:
- 11
- ISSN:
- 1664-2392
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Schartl, Manfred (Ed.)more » « less
amhy ,dmrt1 ,gsdf as male andfoxl2 ,foxl3 ,cyp19a1a as female sex determination pathway genes in Nile tilapia. However, the relationship among these genes is largely unclear. Here, we found that the gonads ofdmrt1 ;cyp19a1a double mutants developed as ovaries or underdeveloped testes with no germ cells irrespective of their genetic sex. In addition, the gonads ofdmrt1 ;cyp19a1a ;cyp19a1b triple mutants still developed as ovaries. The gonads offoxl3 ;cyp19a1a double mutants developed as testes, while the gonads ofdmrt1 ;cyp19a1a ;foxl3 triple mutants eventually developed as ovaries. In contrast, the gonads ofamhy ;cyp19a1a ,gsdf ;cyp19a1a ,amhy ;foxl2 ,gsdf ;foxl2 double andamhy ;cyp19a1a ;cyp19a1b ,gsdf ;cyp19a1a ;cyp19a1b triple mutants developed as testes with spermatogenesis via up-regulation ofdmrt1 in both somatic and germ cells. The gonads ofamhy ;foxl3 andgsdf ;foxl3 double mutants developed as ovaries but with germ cells in spermatogenesis due to up-regulation ofdmrt1 . Taking the respective ovary and underdeveloped testis ofdmrt1 ;foxl3 anddmrt1 ;foxl2 double mutants reported previously into consideration, we demonstrated that oncedmrt1 mutated, the gonad could not be rescued to functional testis by mutating any female pathway gene. The sex reversal caused by mutation of male pathway genes other thandmrt1 , including its upstreamamhy and downstreamgsdf , could be rescued by mutating female pathway gene. Overall, our data suggested thatdmrt1 is the only male pathway gene tested indispensable for sex determination and functional testis development in tilapia. -
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Abstract The evolutionary direction of gonochorism and hermaphroditism is an intriguing mystery to be solved. The special transient hermaphroditic stage makes the little yellow croaker (
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Tworzydlo, W and (Ed.)Sex determination and sexual development are highly diverse and controlled by mechanisms that are extremely labile. While dioecy (separate male and female functions) is the norm for most animals, hermaphroditism (both male and female functions within a single body) is phylogenetically widespread. Much of our current understanding of sexual development comes from a small number of model systems, limiting our ability to make broader conclusions about the evolution of sexual diversity. We present the calyptraeid gastropods as a model for the study of the evolution of sex determination in a sequentially hermaphroditic system. Calyptraeid gastropods, a group of sedentary, filter-feeding marine snails, are sequential hermaphrodites that change sex from male to female during their life span (protandry). This transition includes resorption of the penis and the elaboration of female genitalia, in addition to shifting from production of spermatocytes to oocytes. This transition is typically under environmental control and frequently mediated by social interactions. Males in contact with females delay sex change to transition at larger sizes, while isolated males transition more rapidly and at smaller sizes. This phenomenon has been known for over a century; however, the mechanisms that control the switch from male to female are poorly understood. We review here our current understanding of sexual development and sex determination in the calyptraeid gastropods and other molluscs, highlighting our current understanding of factors implicated in the timing of sex change and the potential mechanisms. We also consider the embryonic origins and earliest expression of the germ line and the effects of environmental contaminants on sexual development.more » « less
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ABSTRACT Although physiological responses to the thermal environment are most frequently investigated using constant temperatures, the incorporation of thermal variability can allow for a more accurate prediction of how thermally sensitive species respond to a rapidly changing climate. In species with temperature-dependent sex determination (TSD), developmental responses to incubation temperature are mediated by several genes involved in gonadal differentiation. Kdm6b and Dmrt1 respond to cool incubation temperatures and are associated with testis development, while FoxL2 and Cyp19A1 respond to warm incubation temperatures and are associated with ovary development. Using fluctuating incubation temperatures, we designed two studies, one investigating how conflicting thermal cues affect the timing of commitment to gonadal development, and another investigating the rapid molecular responses to conflicting thermal cues in the red-eared slider turtle (Trachemys scripta). Using gene expression as a proxy of timing of commitment to gonadal fate, results from the first study show that exposure to high amounts of conflicting thermal cues during development delays commitment to gonadal fate. Results from the second study show that Kdm6b splice variants exhibit differential responses to early heat wave exposure, but rapidly (within 2 days) recover to pre-exposure levels after the heat wave. Despite changes in the expression of Kdm6b splice variants, there was no effect on Dmrt1 expression. Collectively, these findings demonstrate how short exposures to heat early in development can change how embryos respond to heat later in development.
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.3389/fendo.2020.542942
