Identifier	Thesis 1881
Author	Thompson, David S.
Title	Refining the Location of the frizzy (fr) Mutation on Mus musculus Chromosome 7
Publisher	Central Connecticut State University
Date of Publication	2006
Resource Type	Master's Thesis
Abstract	The frizzy (fr) mutation in Mus musculus affects hair structure and formation. Early studies demonstrated that the gene responsible for frizzy assorts to mouse Chromosome 7 along with pink-eyed dilution (p), chinchilla (cch), and shaker-1 (sh-1). These last three phenotypic traits have been mapped with respect to modern molecular markers and assigned to known genes, but fr has not. Given that autosomal recessive genes affecting coat color and development frequently evince pleiotropic effects, it could be valuable to understand in detail what the molecular basis of the frizzy mutation is, what role(s) the wild type gene plays in normal mouse development, and how the frizzy mutation disrupts normal development. Prior to undertaking such an analysis, however, we need to identify the gene that harbors the fr defect. Recent complementation testing demonstrated both that fr is not allelic with fibroblast growth factor receptor 2 (Fgfr2 – a critical protein contributing to the formation of multiple tissue types), and that fr lies centromeric of Fgfr2. With Fgfr2 established as the telomeric flank for the fr region, and sh-1 the only known centromeric flank, we proposed to develop a fine-structure map of the interval between sh-1 and Fgfr2; hoping thus to isolate fr to an interval containing no more than about 20 genes. Using a backcross of standard inbred strains we generated a panel of 93 mice that segregated for frizzy. FS/EiJ (FS) provided the strain homozygous for fr. C57BL/6J (B6) provided the wild type strain. After extracting DNA from distal tail tips, we probed each sample for PCR scorable molecular markers to determine for each marker whether it traveled with or had recombined with fr. Using classical haplotype analysis we have identified progressively closer flanks for the interval containing fr. Our starting 32 megabase-pair (Mbp) interval contained over 530 genes. While we were not able to confine fr to a 20-gene interval, we have significantly reduced the search interval to the 6 Mbp between D7MIT41 on the centromeric flank and D7MIT165 on the telomeric flank. This interval, contains nearly 130 known genes; too large a number for candidate screening by tissue expression association and sequencing. To reach the goal of localizing fr to a region that includes only a small number of candidate genes, further mapping analysis is recommended. If more B6 vs. FS dimorphic markers can be found, the 93-member panel described here might be exploited to further restrict the critical interval, but the microsatellite markers currently available between D7MIT41 and D7MIT165 have not proven productive with respect to the amplimer products we resolved using 3.5% NuSieve agarose gels. Additional sequence-level B6 vs. FS dimorphisms in the D7MIT41 to D7MIT165 interval might be found either by repeating the current procedures using polyacrylamide gels to improve our ability to discern amplimer length differences less than 10 base pairs, or by seeking other types of markers. In either case, given the high gene density found in the critical region (on average we expect to find about 60 genes in a 6 Mbp interval), more recombinant mice will likely be needed to achieve the desired map resolution. To increase both the number of recombinants and the ease of discovering marker dimorphisms, it will probably be most productive to conduct a new backcross using FS and whichever standard strain (i.e., BALB, A/J, 129, or DBA/2) harbors the most sequence level differences compared to FS.
Subject	Mice -- Genetics
Department	Department of Biomolecular Sciences
Advisor	King, Thomas R.
Type	Text
Digital Format	application/pdf
Language	eng
OCLC number	713734335
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Refining the Location of the frizzy (fr) Mutation on Mus musculus Chromosome 7

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