Several studies, which investigated environmental impacts on zebrafish sex ratio, found them either to result in limited change or show strong effects outside of the physiological range of the species. As we expected that a sex-determining chromosomal region would be present in 13 Temperature-dependent sex determination in fish revisited: Prevalence, a single sex ratio response pattern, and possible effects of climate change.
In order to search for sex-linked DNA markers in zebrafish, we used a total of FluoMEP primer combinations based on 29 common primers to screen pooled male and female zebrafish genomic DNA samples. Extensive genetic diversity and substructuring among zebrafish strains revealed through copy number variant analysis.
These data further strengthen the notion that zebrafish sex is not determined by a sex chromosomal pair.
Figure S2: Plots of the number of fish present in each population over time. Subsequent downregulation of the pathway through transgenic inhibition has resulted in a significant decrease of the proportion of males, providing functional proof for its importance in ovary formation [and possibly maintenance Sreenivasan and Jiang, personal communication ].
To verify that the decrease was due to selection pressure, we performed a control experiment with the D4F3 family by doing a mass cross for the F 2 generation without any selection Fig. This variation is then passed over to the next generation in the form of highly variable offspring sex ratios among different combinations of parental pairs.
However, no sex-linked DNA marker was found suggesting that there are no substantial differences between zebrafish male and female genomes. Enhancement and maintenance of sex-biased lines through multiple generations by full-sib selective breeding This experiment was carried out with the aim to determine if sex-biased ratios in lines can be maintained or increased by selecting for breeding pairs that produced brood with highly skewed sex ratios through several generations.
Nucleic Acids Res —