Wójcik E, Smalec E
Department of Animal Genetics and Horse Breeding, Siedlce University of Natural Sciences and Humanities, Siedlce, Poland
Department of Animal Genetics and Horse Breeding, Siedlce University of Natural Sciences and Humanities, Siedlce, Poland.
Poult Sci. 2017 Jan 1;96(1):18-26. doi: 10.3382/ps/pew318. Epub 2016 Sep 23.
Constitutive heterochromatin is a highly condensed fraction of chromatin in chromosomes. It is characterized by a high degree of polymorphism. Heterochromatin is located in the centromeric, telomeric, and interstitial parts of chromosomes. We used the CBG ( C: banding using B: arium hydroxide by G: iemsa) staining technique to identify heterochromatin in chromosomes. Analysis of karyotypes of F1 hybrids resulting from intergeneric hybridization of ducks (A. platyrhynchos × C. moschata) and interspecific crosses of geese (A. anser × A. cygnoides) were used to compare the karyotypes of 2 species of duck and 2 species of geese, as well as to compare the hybrids with the parent species. The localization of C-bands and their size were determined. In the duck hybrid, greater amounts of heterochromatin were noted in the homologous chromosomes from the duck A. platyrhynchos than in the chromosomes from the duck C. moschata. In the goose hybrid more heterochromatin was observed in the homologous chromosomes from the goose A. cygnoides than in the chromosomes from the goose A. anser. Comparison of chromosomes from the duck hybrid with chromosomes of the ducks A. platyrhynchos and C. moschata revealed nearly twice as much constitutive heterochromatin in the chromosomes of the hybrid. When chromosomes from the goose hybrid were compared with those of the geese A. anser and A. cygnoides, differences in the average content of heterochromatin were observed on only a few chromosomes.
组成型异染色质是染色体中染色质的高度浓缩部分。其特点是具有高度多态性。异染色质位于染色体的着丝粒、端粒和中间部分。我们使用CBG（C：用氢氧化钡处理，B：使用吉姆萨染料进行C带染色）染色技术来鉴定染色体中的异染色质。通过对鸭（绿头鸭×番鸭）属间杂交和鹅（鸿雁×家鹅）种间杂交产生的F1杂种的核型分析，比较了两种鸭和两种鹅的核型，以及杂种与亲本物种的核型。确定了C带的定位及其大小。在鸭杂种中，来自绿头鸭的同源染色体中的异染色质含量比来自番鸭的染色体中的多。在鹅杂种中，来自家鹅的同源染色体中的异染色质比来自鸿雁的染色体中的多。将鸭杂种的染色体与绿头鸭和番鸭的染色体进行比较，发现杂种染色体中的组成型异染色质几乎是鸭染色体中的两倍。当将鹅杂种的染色体与鸿雁和家鹅的染色体进行比较时，仅在少数染色体上观察到异染色质平均含量的差异。
