Mubiru James N, Yang Alice S, Olsen Christian, Nayak Sudhir, Livi Carolina B, Dick Edward J, Owston Michael, Garcia-Forey Magdalena, Shade Robert E, Rogers Jeffrey
Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, Texas, United States of America.
Department of Biology, St. Mary's University, San Antonio, Texas, United States of America.
PLoS One. 2014 Apr 14;9(4):e94522. doi: 10.1371/journal.pone.0094522. eCollection 2014.
The function of prostate-specific antigen (PSA) is to liquefy the semen coagulum so that the released sperm can fuse with the ovum. Fifteen spliced variants of the PSA gene have been reported in humans, but little is known about alternative splicing in nonhuman primates. Positive selection has been reported in sex- and reproductive-related genes from sea urchins to Drosophila to humans; however, there are few studies of adaptive evolution of the PSA gene. Here, using polymerase chain reaction (PCR) product cloning and sequencing, we study PSA transcript variant heterogeneity in the prostates of chimpanzees (Pan troglodytes), cynomolgus monkeys (Macaca fascicularis), baboons (Papio hamadryas anubis), and African green monkeys (Chlorocebus aethiops). Six PSA variants were identified in the chimpanzee prostate, but only two variants were found in cynomolgus monkeys, baboons, and African green monkeys. In the chimpanzee the full-length transcript is expressed at the same magnitude as the transcripts that retain intron 3. We have found previously unidentified splice variants of the PSA gene, some of which might be linked to disease conditions. Selection on the PSA gene was studied in 11 primate species by computational methods using the sequences reported here for African green monkey, cynomolgus monkey, baboon, and chimpanzee and other sequences available in public databases. A codon-based analysis (dN/dS) of the PSA gene identified potential adaptive evolution at five residue sites (Arg45, Lys70, Gln144, Pro189, and Thr203).
前列腺特异性抗原（PSA）的功能是使精液凝块液化，以便释放出的精子能够与卵子融合。人类中已报道了PSA基因的15种剪接变体，但对于非人类灵长类动物中的可变剪接知之甚少。从海胆到果蝇再到人类，在与性别和生殖相关的基因中都报道了正选择；然而，关于PSA基因适应性进化的研究很少。在这里，我们使用聚合酶链反应（PCR）产物克隆和测序技术，研究了黑猩猩（Pan troglodytes）、食蟹猴（Macaca fascicularis）、狒狒（Papio hamadryas anubis）和非洲绿猴（Chlorocebus aethiops）前列腺中PSA转录变体的异质性。在黑猩猩前列腺中鉴定出6种PSA变体，但在食蟹猴、狒狒和非洲绿猴中仅发现2种变体。在黑猩猩中，全长转录本的表达量与保留内含子3的转录本相同。我们发现了PSA基因以前未鉴定的剪接变体，其中一些可能与疾病状况有关。利用这里报道的非洲绿猴、食蟹猴、狒狒和黑猩猩的序列以及公共数据库中可用的其他序列，通过计算方法对11种灵长类动物的PSA基因进行了选择研究。对PSA基因基于密码子的分析（dN/dS）在五个残基位点（Arg45、Lys70、Gln144、Pro189和Thr203）鉴定出潜在的适应性进化。
