Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: June 1, 1996
Publication Date: N/A
We have constructed relatively high resolution microsatellite (ms) linkage maps of the cattle (>1200 ms), sheep (>500 ms) and swine (>1000 ms) genomes by integrating all published markers for each species across USDA-MARC reference families. The cattle and sheep genetic maps have been integrated into a comparative (bovid) linkage map by typing bovine ms across a single, ,large sheep map reference population. Marker order and interval are remarkably similar suggesting there is limited rearrangement of loci within syntenic groups between these species. A significant number of ms have been linked within known regions of conserved synteny in cattle, sheep and swine identified by chromosomal paints and gene assignment. In cattle, BTA is covered by ~15 ms. Approximately 14 ms cover BTA. In swine ~11 ms are tight linked to 2 ms within SSC and 12 anchored by RYR1(CRC) and GPI within SSC. However, chromosomal paints do not always provide well defined margins of synteny (e.g., immunoglobulin alpha (IGA) at HSA 19q3.2 to SSC 7q2.6). Therefore, we are currently using a directed (linkage) mapping strategy to integrate the genetic and physical maps of each species by assigning polymorphic markers to regions of conserved synteny through a process of iterative PCR-screening of YAC libraries. In brief, YACs are PCR-amplified through a series of pools with primer pairs from previously linked markers or developed from gene sequences selected from HGB and the clone assigned. Microsatellites are developed from the same (YAC)clone if the primary marke used to isolate the clone is not informative. This approach allows us to determine the centromeric and telomeric limits of linkage groups and begin to define syntenic boundaries and gene order.