猪睫状神经营养因子（CNTF）基因的分离、特性鉴定及染色体定位

Isolation, characterization and chromosomal localization of the porcine ciliary neurotrophic factor (CNTF) gene.

作者信息

Weaks R L, Ramsoondar J J, Gallagher D S, Nogues C, Piedrahita J A

机构信息

Department of Veterinary Anatomy and Public Health, College of Veterinary Medicine, Texas A&M University, College Station 77843-4458, USA.

出版信息

Anim Genet. 1997 Oct;28(5):354-7. doi: 10.1111/j.1365-2052.1997.00159.x.

DOI:10.1111/j.1365-2052.1997.00159.x

PMID:9363597

Abstract

In the mouse, ciliary neurotrophic factor (CNTF) maintains embryonic stem cells in an undifferentiated state; yet, the heterologous protein has no similar effects on porcine embryonic stem (ES) cells. Consequently, we cloned and sequenced the porcine CNTF gene and assigned it to chromosome 2. The CNTF gene was found to contain two exons, which encoded a deduced polypeptide of 200 amino acids in length with 83%, 82%, 82% and 81% amino acid similarity when compared to known sequences in the rabbit, rat, human and mouse, respectively. Eight non-conservative amino acid changes were identified in the porcine protein when compared with other species. Comparison of the 5' region of the porcine CNTF and other mammalian cytokines indicated the presence of several conserved transcription-factor binding motifs, suggesting their importance for controlling the specific expression of these proteins. In addition, CNTF was localized to porcine chromosomes by fluorescence in situ hybridization (FISH). Chromosome arm length ratios were calculated for 40 early metaphase chromosomes and 32 (80%) indicated that the pig CNTF gene is located on chromosome 2p1.6. This was confirmed by aligning R-banded FISH-labelled chromosomes to the standard porcine ideogram.

摘要

在小鼠中，睫状神经营养因子（CNTF）可使胚胎干细胞维持未分化状态；然而，这种异源蛋白对猪胚胎干细胞（ES细胞）却没有类似作用。因此，我们克隆并测序了猪CNTF基因，并将其定位到2号染色体上。发现CNTF基因含有两个外显子，它们编码一个推导的由200个氨基酸组成的多肽，与兔、大鼠、人和小鼠的已知序列相比，其氨基酸相似性分别为83%、82%、82%和81%。与其他物种相比，在猪蛋白中鉴定出8个非保守氨基酸变化。对猪CNTF的5'区域与其他哺乳动物细胞因子进行比较，结果表明存在几个保守的转录因子结合基序，这表明它们对于控制这些蛋白的特异性表达具有重要意义。此外，通过荧光原位杂交（FISH）将CNTF定位到猪染色体上。计算了40条早中期染色体的染色体臂长比，其中32条（80%）表明猪CNTF基因位于2号染色体短臂1.6区。通过将R带FISH标记的染色体与标准猪染色体 ideogram比对，证实了这一点。