Bloom S E, Bacon L D
J Hered. 1985 May-Jun;76(3):146-54.
The linkage relationship and chromosomal locations of the major histocompatibility (B) complex and nucleolar organizers (18S + 28S ribosomal RNA genes) were studied in normal and aneuploid chickens. The Balloantigens were defined by hemagglutination, using monospecific alloantisera. A chicken having three B haplotypes was detected and used in test matings to normal disomic chickens. Additional cases of birds having three different haplotypes were generated in the progeny of such matings. Analysis of the segregation patterns of B haplotypes suggested that the chickens with an additional haplotype were trisomics. Chickens having three B haplotypes also displayed a maximum of three nucleoli in somatic cells instead of the normal two nucleoli of diploids. This indicated the presence of an additional nucleolus organizing region (NOR). Cytogenetic and cytochemical studies were performed on cells of normal and putative trisomic chickens. All chickens displayed a normal array of chromosomes for pairs 1 through 9. Silver staining differentiated Ag-NORs on the long arms of two and three microchromosomes in disomic and trisomic types, respectively. Viable tetrasomic chickens, produced from inter se matings of trisomics, displayed four nucleoli and four Ag-NORs in somatic cell preparations. These results indicate that the DNA sequences encoding the B histocompatibility antigens and the 18S + 28S ribosomal RNAs are linked on an acrocentric microchromosome in the domestic chicken.
在正常和非整倍体鸡中研究了主要组织相容性（B）复合体与核仁组织者（18S + 28S核糖体RNA基因）的连锁关系和染色体定位。使用单特异性同种异体抗血清通过血凝反应来定义Ballo抗原。检测到一只具有三种B单倍型的鸡，并将其用于与正常二体鸡的测交。在这种交配的后代中产生了更多具有三种不同单倍型的鸟类案例。对B单倍型分离模式的分析表明，具有额外单倍型的鸡是三体。具有三种B单倍型的鸡在体细胞中也最多显示三个核仁，而不是正常二倍体的两个核仁。这表明存在一个额外的核仁组织区（NOR）。对正常和假定三体鸡的细胞进行了细胞遗传学和细胞化学研究。所有鸡的1至9号染色体对都显示出正常的染色体排列。银染分别在二体和三体类型的两条和三条微小染色体的长臂上区分出Ag-NORs。由三体鸡相互交配产生的可存活四体鸡在体细胞制备物中显示出四个核仁和四个Ag-NORs。这些结果表明，编码B组织相容性抗原和18S + 28S核糖体RNA的DNA序列在家鸡的一条近端着丝粒微小染色体上是连锁的。
