Matzke A J, Varga F, Gruendler P, Unfried I, Berger H, Mayr B, Matzke M A
Institute for Molecular Biology, Austrian Academy of Sciences, Salzburg.
Chromosoma. 1992 Dec;102(1):9-14. doi: 10.1007/BF00352284.
We cloned and characterized a new highly repetitive, species-specific DNA sequence from turkey (Meleagris gallopavo). This repeat family, which accounts for approximately 5% of the turkey genome, consists of a 41 bp repeated element that is present in tandem arrays longer than 23 kb. In situ hybridization to turkey metaphase chromosomes (2n = 80) demonstrated that this sequence was located primarily on certain microchromosomes: approximately one-third of the 66 microchromosomes showed a positive signal. With respect to the macrochromosomes, hybridization was seen only in a pericentric position on nos. 2 and 3. The turkey microchromosome (TM) sequence shares motifs (alternating A3-5 and T3-5 clusters separated by 6-8 bp) that have been found previously in other avian tandemly repeated elements, e.g. a chicken microchromosomes sequence, and W (female) chromosome-specific sequences of chicken and turkey. However, the TM sequence does not cross-hybridize under moderately stringent conditions with these other sequences. The spread and amplification of related repetitive sequence elements on microchromosomes and W chromosomes is discussed.
我们从火鸡（Meleagris gallopavo）中克隆并鉴定了一种新的高度重复、物种特异性的DNA序列。这个重复家族约占火鸡基因组的5%，由一个41bp的重复元件组成，该元件以串联阵列的形式存在，长度超过23kb。对火鸡中期染色体（2n = 80）进行原位杂交表明，该序列主要位于某些微染色体上：66条微染色体中约三分之一显示出阳性信号。对于大染色体，仅在第2号和第3号染色体的着丝粒周围位置观察到杂交信号。火鸡微染色体（TM）序列具有一些基序（由6 - 8bp间隔的交替A3 - 5和T3 - 5簇），这些基序先前已在其他鸟类串联重复元件中发现，例如鸡的微染色体序列以及鸡和火鸡的W（雌性）染色体特异性序列。然而，在适度严格的条件下，TM序列与这些其他序列不发生交叉杂交。本文讨论了相关重复序列元件在微染色体和W染色体上的分布及扩增情况。
