Molecular analysis of the sex hormone-binding globulin gene in the rat hypodactylous mutation (Hd).
Sex hormone-binding globulin or ABP/SHBG is an extracellular androgen and oestrogen carrier. In the rat, ABP/SHBG is secreted by Sertoli cells of the testis and is thought to regulate androgen bioavailability in the male reproductive tract. During ontogenesis, ABP/SHBG is expressed in many mesoderm-derived tissues, including interdigital mesenchyme of the developing autopodium. Shbg is thus a candidate for Hd, comprising autopodium (hand and foot) reduction and male sterility resulting from spermatogenesis impairment. Moreover, linkage mapping of Hd revealed that an intragenic marker for Shbg, D10Wox12, was non-recombinant with Hd. Sequencing of the entire coding sequence of Shbg failed to identify any variation in hypodactylous animals, distinct from two control strains. However, RT-PCR analysis revealed a significantly higher level of the Shbg transcript in hypodactylous rats compared to SHR controls. Whether Shbg expression is upregulated due to a cis-acting mutation in regulatory elements of the Shbg gene or it is a secondary result of spermatogenesis failure remains to be determined.
Liska
F
F
Institute of Biology and Medical Genetics, Charles University, Prague, Czech Republic. fl@chl.cz
Gösele
C
C
Kren
V
V
Hübner
N
N
Krenová
D
D
D000818:Animals; D001483:Base Sequence; D008040:Genetic Linkage; D007248:Infertility, Male / Q000235:genetics; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D051381:Rats; D012738:Sex Hormone-Binding Globulin / Q000235:genetics* / Q000378:metabolism; D013091:Spermatogenesis / Q000235:genetics*; D013737:Testis / Q000378:metabolism*
D012738:Sex Hormone-Binding Globulin