Reece Kimberly S, Stokes Nancy A
School of Marine Science, Virginia Institute of Marine Science, College of William and Mary, Gloucester Point, Virginia 23062, USA.
Dis Aquat Organ. 2003 Jan 22;53(1):61-6. doi: 10.3354/dao053061.
In the Austral summer and autumn of 2000 and 2001, mortalities of black-footed abalone Haliotis iris (Martyn, 1784) occurred in a commercial facility in New Zealand. Histological analyses suggested that infection by a haplosporidian parasite was responsible. To confirm identification as a haplosporidian and to help determine if this parasite represented a new, undescribed species, DNA was extracted from infected host tissues scored as positive for infection by histological examination. Small-subunit rRNA (SSU rRNA) gene sequences from both the host abalone and a parasitic organism were amplified by PCR and characterized. Although the sequence for this parasite was novel, not matching any known SSU rRNA gene sequences, phylogenetic analyses strongly supported grouping this parasite with the haplosporidians. Parsimony analyses placed the parasite at the base of the phylum Haplosporidia, ancestral to Urosporidium crescens and the Haplosporidium, Bonamia, and Minchinia species. Sequencing of multiple parasite DNA clones revealed a single polymorphic site in the haplosporidian SSU rRNA gene sequence.
在2000年和2001年的澳大利亚夏秋季，新西兰一家商业养殖场所中的黑足鲍（Haliotis iris，Martyn，1784）出现了死亡现象。组织学分析表明，感染一种单孢子虫寄生虫是导致死亡的原因。为了确认该寄生虫为单孢子虫，并确定其是否代表一个新的、未被描述的物种，从经组织学检查判定为感染阳性的宿主组织中提取了DNA。通过聚合酶链反应（PCR）扩增并鉴定了宿主鲍鱼和寄生生物的小亚基核糖体RNA（SSU rRNA）基因序列。尽管该寄生虫的序列是新的，与任何已知的SSU rRNA基因序列都不匹配，但系统发育分析有力地支持将该寄生虫与单孢子虫归为一类。简约分析将该寄生虫置于单孢子虫门的基部，是新月形尿孢子虫以及单孢子虫属、博纳米属和明钦属物种的祖先。对多个寄生虫DNA克隆的测序揭示了单孢子虫SSU rRNA基因序列中的一个单态位点。
