In two families, we managed to generate an all-male offspring in the F3 generation Fig. Each array contained thousand probes 55—70mers with median spacing of about 10 kb. Spiers, H. Physiol Rev 1— Molecular Reproduction and Development81—
Male-biased offspring. Despite some larval lethality, the average percentage of dead fish in each density group from experiment 2 did not differ significantly indicating that larval death did not contribute to the observed higher percentage of males in the high density group Table S1 and Fig.
B chromosomes have a functional effect on female sex determination in Lake Victoria cichlid fishes. Here we identify two loci impacting sex determination in the riverine haplochromine A. Totowa, NJ: Humana Press;
Repeated colonization and hybridization in Lake Malawi cichlids. Mutations of CYP17A1 in humans produce low androgen levels and ambiguous or female external genitalia in XY individuals [ 47 ]. It was found that under hypoxic conditions there was a reduction of estrogen synthesis leading to an increase of androgen to estrogen ratio which favors male development .
We infer that this paternal haplotype is tightly linked to a dominant Y male sex determination allele. Ospina-Alvarez N, Piferrer F. Female development in mammals is regulated by Wnt-4 signalling. These breeding data also indicate that zebrafish sex determination is unlikely to be based primarily on sex chromosomes.
Genomic analyses of sex chromosome evolution.
This cannot account for the wide-ranging sex ratios among families; hence we reckon that zebrafish does not use a primary environmental sex determination system. Mol Psychiatry ; 18 : — A germ-line-selective advantage rather than an increased mutation rate can explain some unexpectedly common human disease mutations.