Tgct2^129S1/SvImJ
QTL Variant Detail

Summary

• QTL variant: Tgct2^129S1/SvImJ
• Name: testicular germ cell tumor 2; 129S1/SvImJ
• MGI ID: MGI:3054754
• QTL: Tgct2 Location: Chr19:3328551-20539663 bp Genetic Position: Chr19, Syntenic

Variant origin

• Strain of Specimen: 129S1/SvImJ

Variant description

• Allele Type: QTL

Notes

Mapping and Phenotype information for this QTL, its variants and associated markers

J:81573

A locus influencing susceptibility to testicular germ cell tumors, Tgct1, mapped to mouse Chromosome 19 in a cross between 129S1/SvImJ and MOLF/Ei. The 129.MOLF-Chr19 consomic line carries a MOLF/Ei-derived chromosome 19 on a 129S1/SvImJ genetic background and exhibits a 70%-82% incidence of testicular germ cell tumors (of which 55% are bilateral). The background strain 129S1/SvImJ exhibits a 5% incidence of testicular germ cell tumors. Several chromosome 19 single and double subcongenic strains were created to further dissect this locus.

Analysis of 10 single congenic strains and 3 double congenic strains delineated the Tgct1 locus into 5 separate regions. Region I (Tgct1) is a 12 cM interval between the centromere (0 cM) and D19Mit28 (12 cM). Region II (Tgct2) is a 13.1 cM interval between D19Mit32 (4.5 cM) and D19Mit60 (15 cM). Region III (Tgct3) is an 8.7 cM interval between D19Mit111 (15 cM) and D19Mit46 (24 cM). Region IV (Tgct4) is a 4.3 cM interval between D19Mit132 (21.9 cM), D19Mit133 (24 cM), andD19Mit5 (34 cM). Region V (Tgct5) is a 30.8 cM interval between D19Mit19 (26 cM) and the telomere. Several epistatic and additive genes are believed to exist in these 5 regions. The combined effect of these 5 regions results in a tumor frequency of about68%. The tumor frequency of the 129.MOLF-Chr19 congenic is roughly 71%.

Tgct4 shows evidence of epistatic interactions with Tgct1, Tgct2, and Tgct3. Tgct4 does not increase susceptibility to testicular germ cell tumors by itself unless combined with Tgct1, Tgct2, or Tgct3.

The Tcgt5 locus contributes to 11.5% of the testicular germ cell tumor frequency. The remaining loci are estimated to contribute 25-30% of the tumor frequency. Tcgt5 is believed to have an additive effect.

It was also noted that the 129.MOLF-Chr19 consomic displays a decreased incidence (5%) of testicular abnormalities compared to parental strain 129S1/SvImJ (15% frequency). This trait has an association with the centromeric part of chromosome 19 in the region of Tgct1.

References

• Original: J:81573 Youngren KK, et al., Testicular cancer susceptibility in the 129.MOLF-Chr19 mouse strain: additive effects, gene interactions and epigenetic modifications. Hum Mol Genet. 2003 Feb 15;12(4):389-98
• All: 1 reference(s)