Genotyping sex in the amphibian, Xenopus (Silurana) tropicalis, for endocrine disruptor bioassays
Genotyping sex in the amphibian, Xenopus (Silurana) tropicalis, for endocrine disruptor bioassays
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DOI：
10.1016/j.aquatox.2010.01.012
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发表时间：
2010-06-01
影响因子：
4.5
通讯作者：
Degitz, Sigmund J.
中科院分区：
文献类型：
--
作者：
Olmstead, Allen W.;Lindberg-Livingston, Annelle;Degitz, Sigmund J.
内分泌干扰化合物已被证明在两栖动物、鸟类、鱼类、无脊椎动物和爬行动物物种中都能改变雄性和雌性个体的性腺分化。在某些情况下，这些受影响的个体完全是性别颠倒的，在形态上与正常的异性个体无法区分。检测化学物质暴露后性别比的变化通常需要大量的有机体来获得必要的统计能力，特别是在那些具有遗传性别决定和性染色体同态的物种(如两栖动物和许多鱼类)。评估个体遗传性别的能力将允许检测到性别逆转(基因-表型错配)，与检查性别比例的变化相比，这种能力具有更大的统计能力。利用扩增片段长度多态(AFLP)，我们建立了一种热带两栖动物非洲爪哇性别基因分型的方法，该方法可被纳入内分泌干扰物筛选试验，以检验化学物质对性腺分化的影响。用512对AFLP对热带管圆线虫的一个菌种进行了分析。每对引物平均产生100个片段。总共鉴定、分离和测序了17个与性别相关的AFLP。利用300多个个体生成了这些AFLP的重组图，其中4个AFLP在性别方面的重组率为0%。使用这些AFLP序列对热带X线虫基因组进行BLASTn搜索，结果鉴定出与性别相关的支架。对这些支架的区域进行搜索，寻找可用于性别基因分型的其他多态。回顾和展望了将性别基因分型与热带疟原虫结合到内分泌干扰物生物检测中的策略。蒙特卡洛模拟比较了性别比改变时的分析数据和使用基因分型评估性别逆转的数据，表明在处理性腺分化异常的研究中，通过对性别进行基因分型可以获得更大的统计能力。这种鉴定性别连锁标记和发展性别基因分型方法的方法也适用于其他具有性别决定基因的物种。爱思唯尔出版公司(Elsevier B.V.)
Endocrine disrupting compounds have been shown to alter gonad differentiation in both male and female individuals in amphibian, avian, fish, invertebrate, and reptile species. In some cases, these affected individuals are completely sex reversed and are morphologically indistinguishable from normal individuals of the opposite sex. Detecting shifts in sex ratios following chemical exposure often requires large numbers of organisms to achieve the necessary statistical power, especially in those species with genetic sex determination and homomorphic sex chromosomes (such as amphibians and many fish). The ability to assess the genetic sex of individuals would allow for detection of sex reversal (genotype-phenotype mismatches) that have greater statistical power compared to examining changes in sex ratios. Utilizing amplified fragment length polymorphisms (AFLPs), we developed a method for genotyping sex in the amphibian, Xenopus (Silurana) tropicalis, that can be incorporated into endocrine disruptor screening assays that examine the effects of chemicals on gonad differentiation. AFLPs from 512 primer pairs were assessed in one spawn of X. tropicalis. Each primer pair yielded, on average, 100 fragments. In total 17 sex-linked AFLPs were identified, isolated, and sequenced. A recombination map of these AFLPs was generated using over 300 individuals with four AFLPs having a recombination rate of 0% with regard to sex. A BLASTn search of the X. tropicalis genome using these AFLP sequences resulted in identification of sex-linked scaffolds. Areas of these scaffolds were searched for additional polymorphisms that could be utilized for genotyping sex. Retrospective and prospective strategies for incorporating genotyping sex in endocrine disruptor bioassays with X. tropicalis were developed. A Monte Carlo simulation comparing analyzing data as sex ratio shifts versus assessment of sex reversal using genotyping demonstrates the increase in statistical power that can be obtained by genotyping sex in studies dealing with altered gonad differentiation. This approach to identifying sex-linked markers and developing sex genotyping methods is applicable to other species with genetic sex determination. Published by Elsevier B.V.