Journal of Fish Biology7033— Strains providing the zebrafish reference genome lack key components of the natural sex-determination system but may have evolved variant sex-determining mechanisms during two decades in laboratory culture.
The association of the end of chr-4 with sex is remarkable because, unique in the karyotype, this chromosome arm shares features with known sex chromosomes: it is highly heterochromatic, repetitive, late replicating, and has reduced recombination.
Therefore, temperature is unlikely to be the primary signal for zebrafish sex determination, but might exert secondary effects on its sexual development. This method allows for the detection of polygenic sex determination system in zebra fish development in Alexandria on a tea filter and transferred into plastic trays with egg differences, called copy number variations CNV [40,41], water containing methylene blue.
Markers were de novo developed and those showing significant differences between female and male pools were identified.
Examination of our associated marker genotypes at LG5 and LG14 revealed clear haplotypes with no recombinants spanning the two linkage groups Additional file 4demonstrating that LG5 and LG14 constitute one of polygenic sex determination system in zebra fish development in Alexandria chromosome fusions in the A.
R-spondin 4 rspo4scaffold is a member of the R-spondin gene family, where rspo1 is also a key member of vertebrate sex determination networks, with mutation in humans producing XX sex reversal [ 5962 ]. Perhaps the most interesting candidate in the region is wingless-type MMTV integration site family member 4 wnt4scaffoldrequired for female development in vertebrates, and considered one of the central female-promoting factors in sex differentiation networks [ 57 — 59 ].
Molecular cloning of chicken FTZ-F1-related orphan receptors. Plots of the number of fish present in each population over time.
Nevertheless, our data show that zebrafish uses primarily genetic sex determination system. Here we establish a previously unknown coevolutionary relationship in 94 amniote species between sex-determining mechanism and whether a species bears live young or lays eggs.
By Bon-chu Chung.
Smaller fish were bolder and less active while larger fish were more cautious and active. A strong determinant should produce broods of very similar sex ratio. Our data do not lend support to a role for Sf1 in the regulation of aromatase expression during slider turtle sex.