Mapping of sox2 and sox14 in tilapia (Oreochromis spp.).

Sox genes encode transcription factors that are involved in a variety of embryonic developmental pathways. Sox2 and Sox14 are located on the same chromosomal arm in several mammalian and bird species and on the basis of comparative maps were suggested as candidate genes for the major sex-determining locus on tilapia LG3. We have sequenced the sox2 and sox14 genes in four tilapia species and mapped them to different chromosomes, LG17 and LG23 respectively. Although excluded as being one of the major sex-determining genes so far mapped in tilapia, sox14 did fall within a QTL region for growth, stress response, embryonic mortality and a minor effect on sex determination.