Larson Joshua H, Kumar Charu G, Everts Robin E, Green Cheryl A, Everts-van der Wind Annelie, Band Mark R, Lewin Harris A
Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
Physiol Genomics. 2006 May 16;25(3):405-13. doi: 10.1152/physiolgenomics.00307.2005. Epub 2006 Mar 22.
Ten divergent homologs were identified using a subtractive bioinformatic analysis of 12,614 cattle placenta expressed sequence tags followed by comparative, evolutionary, and gene expression studies. Among the 10 divergent homologs, 8 have not been identified previously. These were named as follows: cattle cerebrum and skeletal muscle-specific transcript 1 (CSSMST1), cattle intestine-specific transcript 1 (CIST1), hepatitis A virus cellular receptor 1 amino-terminal domain-containing protein (HAVCRNDP), prolactin-related proteins 8, 9, and 11 (PRP8, PRP9, and PRP11, respectively) and secreted and transmembrane protein 1A and 1B (SECTM1A and SECTM1B, respectively). In addition, two previously known divergent genes were identified, trophoblast Kunitz domain protein 1 (TKDP1) and a new splice variant of TKDP4. Nucleotide substitution analysis provided evidence for positive selection in members of the PRP gene family, SECTM1A and SECTM1B. Gene expression profiles, motif predictions, and annotations of homologous sequences indicate immunological and reproductive functions of the divergent homologs. The genes identified in this study are thus of evolutionary and physiological importance and may have a role in placental adaptations.
通过对12614条牛胎盘表达序列标签进行消减生物信息学分析，随后进行比较、进化和基因表达研究，鉴定出了10个不同的同源物。在这10个不同的同源物中，有8个此前未被鉴定出来。它们分别被命名为：牛大脑和骨骼肌特异性转录本1（CSSMST1）、牛肠道特异性转录本1（CIST1）、含甲型肝炎病毒细胞受体1氨基末端结构域蛋白（HAVCRNDP）、催乳素相关蛋白8、9和11（分别为PRP8、PRP9和PRP11）以及分泌和跨膜蛋白1A和1B（分别为SECTM1A和SECTM1B）。此外，还鉴定出了两个先前已知的不同基因，即滋养层Kunitz结构域蛋白1（TKDP1）和TKDP4的一个新的剪接变体。核苷酸替代分析为PRP基因家族成员SECTM1A和SECTM1B中的正选择提供了证据。基因表达谱、基序预测和同源序列注释表明这些不同的同源物具有免疫和生殖功能。因此，本研究中鉴定出的基因具有进化和生理重要性，可能在胎盘适应中发挥作用。
