Comparative Gene Mapping: A Fine-Scale Survey of Chromosome Rearrangements between Ruminants and Humans

Abstract

A total of 202 genes were cytogenetically mapped to goat chromosomes, multiplying by five the total number of regional gene localizations in domestic ruminants (255). This map encompasses 249 and 173 common anchor loci regularly spaced along human and murine chromosomes, respectively, which makes it possible to perform a genome-wide comparison between three mammalian orders. Twice as many rearrangements as revealed by ZOO-FISH were observed. The average size of conserved fragments could be estimated at 27 and 8 cm with humans and mice, respectively. The position of evolutionary breakpoints often correspond with human chromosome sites known to be vulnerable to rearrangement in neoplasia. Furthermore, 75 microsatellite markers, 30 of which were isolated from gene-containing bacterial artificial chromosomes (BACs), were added to the previous goat genetic map, achieving 88% genome coverage. Finally, 124 microsatellites were cytogenetically mapped, which made it possible to physically anchor and orient all the linkage groups. We believe that this comprehensive map will speed up positional cloning projects in domestic ruminants and clarify some aspects of mammalian chromosomal evolution.[The sequence data described in this paper have been submitted to the GenBank data library under accession nos. G40978–G41020,AF083170–AF083184, AF088286, AF08287, AF083401–AF083406, AF082884, and AF082885.]

Multiple genomic signatures of selection in goats and sheep indigenous to a hot arid environment

“…These efforts culminated in the first draft of the ovine reference genome (Archibald et al, 2010), which has been improved further and the current released reference assembly, Oar v3.1, has a contig N50 length of~40 Kb and a total assembled length of 2.61 Gb, with~99% anchored onto the 26 autosomes and the X chromosome (Jiang et al, 2014). In contrast, similar efforts at developing and refining the goat genome have lagged behind, but recent years have witnessed a slow increase in gene mapping data since the first genetic and cytogenetic maps were produced (Vaiman et al, 1996;Schibler et al, 1998) and 550 loci have been mapped to the goat genome using linkage maps of low resolution (Schibler et al, 2009). The initial release of the goat genome sequence (Dong et al, 2013) was based entirely on short-read de novo sequencing that yielded an~2.66 Gb assembly with a contig N50 length of 3.06 Mb.…”

A presentation of the differences between the sheep and goat genetic maps

“…There has been a relatively greater effort in the goat to cytogenetically map loci [23], with almost 500 loci mapped cytogenetically [13]. This contrasts with the sheep where only about 350 loci have been cytogenetically mapped [2].…”

“…The current version (4.2) best positions sheep genetic map [3] was aligned with the most recent goat linkage map [23]. …”

Could Tissue-Specific Genes be Silenced in Cattle Carrying the Rob(1;29) Robertsonian Translocation?

“…Schibler et al, (1998) presented a high resolution integrated bovine comparative map where the analysis of break point regions revealed specific repeated density patterns, suggesting that transposons (TEs) may have played a significant role in chromosome evolution and genome plasticity. However, bovines have a morphologically simple karyotype, corresponding to 2n=60, XX; XY.…”