An exotic species is a species that is not native to its current habitat and is known as invasive if it negatively impacts this habitat. There have been a variety of attempts to eradicate invasive species in different areas, but they have not been particularly successful. In an effort to find a better method for eradicating invasive fish species, Gutierrez and Teem proposed a method involving s...

Although the effects of POPs on the health of free ranging loggerhead sea turtles (Caretta caretta) has been well investigated (Keller et al. 2004; Keller et al. 2006a; Keller et al. 2006b), there was only one previous study on the toxicological effects of POPs on sea turtle embryonic development (Podreka et al. 1998). However, there are a number of studies on freshwater turtles that have inves...

The primary testis-determining function is exerted by a gene in the sex-determining region of the human Y chromosome. This gene is termed the sex-determining factor or TDF. A zinc finger gene, ZFY, residing in this region has been cloned and characterized. It is a candidate for TDF. A challenge to future molecular research is to clarify the function of a zinc finger gene on the X chromosome, ZF...

The terms pseudo-hermaphroditism and hermaphroditism have been used in different senses by various authors and for this reason they were discarded by Wilkins (1950). He describes as 'intersexes' (hermaphrodites) those cases in which the sexual dimorphism is not due to a demonstrable endocrine abnormality, and as cases of 'sex reversal' those in which there is an endocrine abnormality. Hormonal ...

Evolutionary transitions between sex-determining mechanisms (SDMs) are an enigma. Among vertebrates, individual sex (male or female) is primarily determined by either genes (genotypic sex determination, GSD) or embryonic incubation temperature (temperature-dependent sex determination, TSD), and these mechanisms have undergone repeated evolutionary transitions. Despite this evolutionary lability...

Environmental sex determination (ESD) occurs in divergent, phylogenetically unrelated taxa, and in some species, co-occurs with genetic sex determination (GSD) mechanisms. Although epigenetic regulation in response to environmental effects has long been proposed to be associated with ESD, a systemic analysis on epigenetic regulation of ESD is still lacking. Using half-smooth tongue sole (Cynogl...

BACKGROUND 46,XY sex reversal is a rare disorder and familial cases are even more rare. The purpose of the present study was to determine the molecular basis for a family with three affected siblings who had 46,XY sex reversal. METHODS DNA was extracted from three females with 46,XY sex reversal, two normal sisters, and both unaffected parents. All protein coding exons of the SRY and NR5A1 ge...

It has previously been shown that, in the heterozygous state, mutations in the SOX9 gene cause campomelic dysplasia (CD) and the often associated autosomal XY sex reversal. In 12 CD patients, 10 novel mutations and one recurrent mutation were characterized in one SOX9 allele each, and in one case, no mutation was found. Four missense mutations are all located within the high mobility group (HMG...

The sexual differentiation of gonads has been shown to be temperature-sensitive in many species of amphibians and reptiles. In two close species of salamanders, Pleurodeles poireti and P. waltl, both displaying a ZZ/ZW mechanism of genotypic sex determination (GSD), the rearing of larvae at high temperatures (30 degrees-32 degrees C) produces opposite effects: ZZ genotypic males of Pleurodeles ...

We simulated a meta-population with random dispersal among demes but local mating within demes to investigate conditions under which a dominant female-determining gene W, with no individual selection advantage, can invade and become fixed in females, changing the population from male to female heterogamety. Starting with one mutant W in a single deme, the interaction of sex ratio selection and ...