Galkina Svetlana, Fillon Valerie, Saifitdinova Alsu, Daks Aleksandra, Kulak Maria, Dyomin Alexander, Koshel Elena, Gaginskaya Elena R
Biological Faculty, Saint Petersburg State University, Saint Petersburg, Russia.
Cytogenet Genome Res. 2017;152(1):46-54. doi: 10.1159/000475563. Epub 2017 Jun 1.
Lampbrush chromosomes are giant, transcriptionally active, meiotic chromosomes found in oocytes of all vertebrates with the exception of mammals. Lampbrush chromosomes offer a convenient tool for cytogenetic mapping and, in particular, have been instrumental in mapping genes and linkage groups on chicken (GGA) chromosomes. Whereas cytogenetic maps of macrochromosome GGA1-10 and microchromosome GGA11-16 lampbrush bivalents have been established, identification and description of smaller microchromosome bivalents are still missing. In this work, we used specific FISH probes for the identification of 12 chicken lampbrush chromosomes formed by GGA17-28. Our observations on chromomere and lateral loop arrangement and chiasma position allowed us to construct the respective cytogenetic maps for these microchromosomes. For the 10 smallest chicken microchromosomes, GGA29-38, no individual molecular tags are available, yet they can be collectively marked using the PO41 repeat. The reported results contribute to building of working cytogenetic maps of the chicken karyotype.
灯刷染色体是除哺乳动物外所有脊椎动物卵母细胞中发现的巨大的、具有转录活性的减数分裂染色体。灯刷染色体为细胞遗传学图谱绘制提供了便利工具，尤其在绘制鸡（GGA）染色体上的基因和连锁群方面发挥了重要作用。虽然已经建立了GGA1 - 10大染色体和GGA11 - 16小染色体灯刷二价体的细胞遗传学图谱，但较小的小染色体二价体的鉴定和描述仍缺失。在这项工作中，我们使用特异性荧光原位杂交（FISH）探针鉴定了由GGA17 - 28形成的12条鸡灯刷染色体。我们对染色粒和侧环排列以及交叉位置的观察使我们能够构建这些小染色体各自的细胞遗传学图谱。对于10条最小的鸡小染色体GGA29 - 38，尚无单个分子标签可用，但可使用PO41重复序列对它们进行集体标记。所报道的结果有助于构建鸡核型的实用细胞遗传学图谱。
