Gonadal Sex Differentiation in Frogs: How Testes Become Shorter than Ovaries

Haczkiewicz, Katarzyna; Ogielska, Maria

doi:10.2108/zsj.30.125

Cited by 42 publications

(59 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During testis development the distal part gradually became reduced and disappeared. The final testis developed from 2-4 anterior gonomeres (Haczkiewicz and Ogielska 2013). The authors concluded that the testes shorten during development.…”

Section: Discussionmentioning

confidence: 97%

Evolutionary trend for metamery reduction and gonad shortening in Anurans revealed by comparison of gonad development

Piprek¹,

Pecio²,

Kloc³

et al. 2014

Int. J. Dev. Biol.

View full text Add to dashboard Cite

The gonads develop as the metameric mesodermal structures at the ventral surface of the mesonephroi. To study the evolutionary trends for anuran gonads, we performed comparative analysis of three species from the basal paraphyletic group -Archaeobatrachia (Bombina bombina, Xenopus laevis, Pelobates fuscus) and five species from more derived monophyletic Neobatrachia group (Hyla arborea, Bufotes viridis, Rana dalmatina, Rana arvalis, Rana temporaria). Light and scanning electron microscopy analysis showed that in Archaeobtrachia the undifferentiated gonads and ovaries, but not the testes, have pronounced external metamery. In contrast, Neobatrachia lacked external gonadal metamery and the internal metamery was well pronounced in the ovaries, but only rudimentary in the testes. There was also a difference in the site of genital ridge formation between these two groups. In Archaeobatrachia, the genital ridges developed along almost the entire length of mesonephroi, while in Neobatrachia they were limited to the anterior parts of the mesonephroi. A transient form was observed in P. fuscus, where the gonads formed along the anterior half of the mesonephroi. There was also an evolutionary trend for gradual postero-anterior shortening of the gonadal anlagen. In summary, our study indicates that among anurans there is an evolutionary trend for the gradual loss of metamery and shortening of the gonad.

show abstract

Section: Discussionmentioning

confidence: 97%

Evolutionary trend for metamery reduction and gonad shortening in Anurans revealed by comparison of gonad development

Piprek¹,

Pecio²,

Kloc³

et al. 2014

Int. J. Dev. Biol.

View full text Add to dashboard Cite

show abstract

“…Ovaries in common frogs develop from the whole gonadal primordia into a large whitish/yellowish structure with distinct lobes, and a characteristic granular aspect conferred by the many oocytes embedded in the cortex [31]. By contrast, testes develop from the anterior part of the gonadal primordia only (the posterior part degenerates) into a small oblong structure, with a smooth cortex covered with melanic spots [32]. In case of doubt, gonads were considered as undifferentiated and sex was not assigned (NA).…”

Section: Materials and Methods (A) Field Sampling And Husbandrymentioning

confidence: 99%

Sex-chromosome differentiation and ‘sex races’ in the common frog ( Rana temporaria )

et al. 2015

View full text Add to dashboard Cite

Sex-chromosome differentiation was recently shown to vary among common frog populations in Fennoscandia, suggesting a trend of increased differentiation with latitude. By rearing families from two contrasted populations (respectively, from northern and southern Sweden), we show this disparity to stem from differences in sex-determination mechanisms rather than in XY-recombination patterns. Offspring from the northern population display equal sex ratios at metamorphosis, with phenotypic sexes that correlate strongly with paternal LG 2 haplotypes (the sex chromosome); accordingly, Y haplotypes are markedly differentiated, with male-specific alleles and depressed diversity testifying to their smaller effective population size. In the southern population, by contrast, a majority of juveniles present ovaries at metamorphosis; only later in development do sex ratios return to equilibrium. Even at these later stages, phenotypic sexes correlate only mildly with paternal LG 2 haplotypes; accordingly, there are no recognizable Y haplotypes. These distinct patterns of gonadal development fit the concept of 'sex races' proposed in the 1930s, with our two populations assigned to the 'differentiated' and 'semi-differentiated' races, respectively. Our results support the suggestion that 'sex races' differ in the genetic versus epigenetic components of sex determination. Analysing populations from the 'undifferentiated race' with high-density genetic maps should help to further test this hypothesis.

show abstract

“…Ovaries in common frogs develop from the whole gonadal primordia into a large whitish/yellowish structure with distinct lobes, and a characteristic granular aspect conferred by the many oocytes embedded in the cortex (Ogielska and Kotusz, 2004). In contrast, testes develop from the anterior part of the gonadal primordia only (the posterior part degenerates) into a small oblong structure, with a smooth cortex covered by melanic spots (Haczkiewicz and Ogielska, 2013). In case of doubt, gonads were considered as undifferentiated and sex was not assigned.…”

Section: Frog Sampling and Pedigree Buildingmentioning

confidence: 99%

The genetic contribution to sex determination and number of sex chromosomes vary among populations of common frogs (Rana temporaria)

et al. 2016

View full text Add to dashboard Cite

The patterns of sex determination and sex differentiation have been shown to differ among geographic populations of common frogs. Notably, the association between phenotypic sex and linkage group 2 (LG 2 ) has been found to be perfect in a northern Swedish population, but weak and variable among families in a southern one. By analyzing these populations with markers from other linkage groups, we bring two new insights: (1) the variance in phenotypic sex not accounted for by LG 2 in the southern population could not be assigned to genetic factors on other linkage groups, suggesting an epigenetic component to sex determination; (2) a second linkage group (LG 7 ) was found to co-segregate with sex and LG 2 in the northern population. Given the very short timeframe since post-glacial colonization (in the order of 1000 generations) and its seemingly localized distribution, this neo-sex chromosome system might be the youngest one described so far. It does not result from a fusion, but more likely from a reciprocal translocation between the original Y chromosome (LG 2 ) and an autosome (LG 7 ), causing their cosegregation during male meiosis. By generating a strict linkage between several important genes from the sex-determination cascade (Dmrt1, Amh and Amhr2), this neo-sex chromosome possibly contributes to the 'differentiated sex race' syndrome (strictly genetic sex determination and early gonadal development) that characterizes this northern population.

show abstract

Gonadal Sex Differentiation in Frogs: How Testes Become Shorter than Ovaries

Cited by 42 publications

References 26 publications

Evolutionary trend for metamery reduction and gonad shortening in Anurans revealed by comparison of gonad development

Evolutionary trend for metamery reduction and gonad shortening in Anurans revealed by comparison of gonad development

Sex-chromosome differentiation and ‘sex races’ in the common frog ( Rana temporaria )

The genetic contribution to sex determination and number of sex chromosomes vary among populations of common frogs (Rana temporaria)

Contact Info

Product

Resources

About