Genetic and physical mapping of the POLL locus to bovine chromosome 1 in a Bos indicus x Bos taurus cross /
Identification of genes influencing economically important traits in cattle has become an important goal in recent years. As such, one important, simple Mendelian trait is the horned/polled condition. A single major gene, POLL, is responsible for the development of horns in cattle. It has two all...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1998.
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| Summary: | Identification of genes influencing economically important traits in cattle has become an important goal in recent years. As such, one important, simple Mendelian trait is the horned/polled condition. A single major gene, POLL, is responsible for the development of horns in cattle. It has two alleles, P and p, where PP produces a polled animal, Pp produces animals that are either polled or have small horns, and pp individuals are horned. The positional comparative candidate cloning method was chosen as the best method to identify the POLL gene. Comparative mapping allows the utilization of the vast amount of human and mouse data, even though neither species has the horned/polled condition. As a first step for this approach, genetic and physical fine maps were constructed around POLL from the gene SOD1 to the microsatellite marker AGLA17, a distance of 3.8 cM or 5.7 Mb, using published and newly developed markers in a reciprocal backcross and F₂ Angus x Brahman beef cattle population. A BAC clone containing AGLA17 was partially sequenced and found to contain the gene SL5CA, which allowed both ends of the map to be anchored to the human radiation hybrid map of chromosome 21. Thirteen microsatellite markers and six SSCP markers were developed for genes or ESTs in the region and scored in 701 individuals in the mapping population. The region containing POLL was reduced to 1.6 cM and about 800 Kb. The corresponding region in humans has been completely sequenced, but only three genes exist, RACK17, IFNAR2, and CRBF4, none of which are likely candidates for POLL. Due to this problem, a bovine BAC contig was constructed in the critical region. The process of obtaining the sequence of these BAC clones is under way as a means to identify new genes in the interval by comparison to the human sequence and to evaluate them as candidates for POLL. |
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| Item Description: | Vita. "Major subject: Genetics". |
| Physical Description: | ix, 52 leaves : illustrations ; 28 cm. Issued also on microfiche from Lange Micrographics. |
| Bibliography: | Includes bibliographical references (leaves 42-47). |