Centromere-linked microsatellite markers for linkage groups 3, 4, 6, 7, 13, and 20 of zebrafish (Danio rerio)

A large number of interesting mutations affecting development and organogen esis have been identified through genetic screens in zebrafish. Mapping of these mutations to a chromosomal region can be rapidly accomplished using h alf-tetrad analysis. However, knowledge of centromere-linked markers on eve ry chromosome is essential to this mapping method. Centromeres on all 25 li nkage groups have been mapped on the RAPD zebrafish genetic map. However, s pecies specificity and the lack of codominance make RAPD markers less pract ical for mapping than microsatellite-based markers. On the microsatellite-b ased genetic map, centromere-linked markers have been identified for 19 lin kage groups. No direct evidence has been published linking microsatellite m arkers to the centromeres of linkage groups 3, 4, 6, 7, 13, and 20. Therefo re, we compared the microsatellite-based genetic map with the RAPD map to i dentify markers most likely linked to the centromeres of these 6 linkage gr oups. These candidate markers were tested for potential centromere linkage using four panels of half-tetrad embryos derived by early-pressure treatmen t of eggs from four different female zebrafish. We have identified microsat ellite markers for linkage groups 3, 4, 6, 7, 13, and 20 to within 1.7 dill of their centromeres, These markers will greatly facilitate the rapid mapp ing of mutations in zebrafish by half-tetrad analysis. (C) 2000 Academic Pr ess.