微卫星位点TUT1曾被认为位于松鸡科鸟类的常染色体上,只是多态性低于期望值,然而最近发现存在空基因现象.通过在45只斑尾榛鸡(Tetrastes sewerzowi)亲本和5巢双亲已知的幼鸟上扩增,发现TUT1在异配体的雌性中为纯合体,在84%的雄性中为杂合体,而且可从父本遗传给雌性和雄性后代,但从母本只能遗传给雄性后代.通过BLAST查询,含TUT1位点的序列(460 bp)与鸡Z染色体的序列最相似,分值329,期望值8e-87.以上结果表明TUT1位点位于松鸡科鸟类的Z染色体上;提示微卫星位点的空基因现象可能来自性别连锁,因此,在发表和应用微卫星位点时应当进行性别连锁检验.表1参17
The microsatellite TUT1 was used in several grouse species as an autosomal locus with "heterozygote deficit",but recently found with null alleles.By amplifying in 45 adult Chinese grouse(Tetrastes sewerzowi) and five broods with known parents,it was found that TUT1 was homozygous in heterogametic females and heterozygous in 84% males,and transmitted from fathers to both sons and daughters but from mothers to sons only.By BLAST query,a nucleotide sequence(460 bp) that contains TUT1 site was most similar to a portion of the sequence of Z chromosome of chicken(Gallus gallus),with the max score of 329 and expect value of 8e-87.Both methods showed that TUT1 was based on Z chromosome.These findings indicated that microsatellite "null alleles" might be originated from sex-linkage and highlighted the importance of gender-specific analysis when publishing and using microsatellites.Tab 1,Ref 17