山羊睾丸和附睾头β防御素家族的表达谱及生物信息学分析

Expression Profiles and Bioinformatics Analysis of beta-defensin Family Genes in the Testes and Epididymal Caput of Bucks

为探明山羊睾丸和附睾头β防御素家族基因表达特点及其蛋白的特性。利用3只7日龄羔羊睾丸和3只成年种公羊睾丸和附睾头的Illumina HiSeqTM2000高通量转录组测序数据,筛选出β防御素家族基因并进行差异表达基因比较分析,利用生物信息学对β防御素家族蛋白特性进行预测。结果显示:在山羊7日龄睾丸、成年睾丸和附睾头中分别表达7、12和33种β防御素,其表达量最高的分别是gDB123、gDB119和gDB124,成年睾丸中特异性表达是gDB33,附睾头中特异表达有21种β防御素。山羊β防御素分子量在6.89~13.85ku,为小分子、极性、带正电荷、疏水性的强碱性多肽。山羊β防御素也是含高度保守6个半胱氨酸的空间构象,基本结构-C-X2-45-CX3-6-C-X3-13-C-X4-7-CC-,其中24种β防御素结构为-C-X5,6-C-X3,4-C-X9-C-X5,6-CC-。有16种β防御素是分泌型糖蛋白,除gDB126无磷酸化位点外,其余的β防御素蛋白均有磷酸化位点。山羊附睾头特异性高度表达有丰富β防御素,它们是一类抗微生物的阳离子肽,在精子成熟过程中形成精子膜上糖被,或精子运动获得的过程中发挥重要作用;也可作为信号分子,某些信号通路中发挥作用。

The study was conducted to investigate the expression characteristics and bioinformatics analysis of beta-defensin family genes in the testes and epididymal caput of bucks.The data were from the transcriptomes of three testes of 7-day-old kids,testes and epididymal caput of three adult bucks of known fertility analyzed by Illumina HiSeqTM2000high-throughput RNA sequencing.All beta-defensin family genes were sorted out according to annotation of unigenes and contigs for analysis of different expression.Protein profile of beta-defensins was analyzed by bioinformatics methods.The results showed that a total of 7,12 and 33β-defensins were discovered in testes of 7-day-old kids,testes and epididymal caput of adult bucks respectively,while gDB123,gDB119 and gDB124were the highest expression in the testes of 7-day-old kids,testes and epididymal caput of adult bucks respectively.gDB33 was specifically expressed in testes of adult bucks.Twenty-oneβ-defensins were specifically expressed in epididymal caput of adult bucks.The molecular weight ofβ-defensins was from 6.89 to 13.85 ku.The bioinformatics analy-sis showed that goatβ-defensins protein were small molecular,polar,hydrophobicity and basic polypeptide with positive charge.A high degrees of conservation in spacing pattern was 6cysteines in peptides sequence ofβ-defensins,which consensus pattern was-C-X2-45-C-X3-6-C-X3-13-CX4-7-CC-.However,the pattern of 24β-defensins was-C-X5,6-C-X3,4-C-X9-C-X5,6-CC-.A total of 16β-defensins were secreted glycoprotein.Except for gDB126,the rest of 24β-defensins had the phosphorylation sites.The goatβ-defensins family protein were also the antimicrobial cationic peptides.The rich specificepididymisβ-defensins were expressed in epididymal caput,which could coat sperm plasma membrane with glycocalyx in sperm maturation and play a vital role in making sperm motion.Andβ-defensins maybe were cell signal in some pathways.