a1和a2在二倍体细胞中协同抑制单倍体特异性功能 a function a function haploid function HMO MATa HMRa a haploid constitutive expressed Constitutive al Represses Diploid ot repressed haplold-speclfIc expressed pressee genes HMLa MATa HMRa la haploid repressed induced constitutive @ Induces Represses a mating mating functions functions
HML MAT HMRa HML MATa HMRa a1 SIR repression SIR repression Represses haploid-specific genes Induces mating functions Represses a mating functions a1和 2在二倍体细胞中协同抑制单倍体特异性功能
PRTF,a1,a1,a2协同激活或抑制特定基因的表达 a-specific genes a-specific genes PRTF activates genes constitutively genes off PRTF not bind no al a PRT haploid (PRTEXPRTE P box Q box CCATGTAATTACCCAAAAAGGAAATTTACATGG TTTCCTAATTAGTNCN TCAATGNCAC a2+PRTF repress a-specific genes almakes PRTF activate target genes haploid (PRTFXPRTF (PRTFXPRTE CCATGTAATTACCCAAAAAGGAAATTTACATGG TTTCCTAATTAGTNCN TCAATGNCAG a2+al repress haploid-specific genes 2 2 diploid al CCATGTNANTNNTACCATGG
a haploid haploid a/ diploid a-specific genes specific genes − PRTF activates genes constitutively genes off: PRTF not bind no CCATGTAATTACCCAAAAAGGAAATTTACATGG CCATGTAATTACCCAAAAAGGAAATTTACATGG TTTCCTAATTAGTNCN TCAATGNCAG TTTCCTAATTAGTNCN TCAATGNCAG PRTF PRTF PRTF PRTF PRTF PRTF PRTF 1 CCATGTNANTNNTACCATGG 2 2 a1 2 2 2+PRTF repress a-specific genes 1makes PRTF activate target genes + a repress haploid-specific genes PRTF P box Q box PRTF,a1, 1, 2协同激活或抑制特定基因的表达
HO内切酶在Y区的切割位点 region TTTCAGCTTTC CGCAACAGTATA AAAGTCGAAAGI GCGTTGTCATAT HO endonuclease TTTCAGCTTTCI CGCAACA GTATA AAAGTCGAAAGi GCG TTGTCATAT
TTTCAGCTTTC CGCAACAGTATA AAAGTCGAAAG GCGTTGTCATAT TTTCAGCTTTC CGCAACA AAAGTCGAAAG GCG Y region GTATA HO endonuclease HO内切酶在Y区的切割位点
酵母接合型的转换过程
酵母接合型的转换过程
Ya MATa Y MATa 1O endonuclease 酵母性转换模型双链模型 MATa MATO 5 to 3' exonuclease Ya PCR primer MATa MAT-distal PCR prime MATC Ya PCR primer MATa AT0 MAT-proximal PCR primer
酵母性转换模型--- 双链模型