Appio K T, Weber L I
Laboratório de Genética Molecular, CTTMar, Universidade do Vale do Itajaí, UNIVALI, Itajaí, SC, Brasil.
Genet Mol Res. 2007 Mar 22;6(1):127-36.
Perna perna is the most important cultivated mussel of Santa Catarina, Brazil, sustaining an important economic input for many local families. Natural stocks of P. perna are depleted by the extraction of adults and seeds for consumption and culture. The aim of the present study was to use the microsatellite locus pms-2 to study the variation of the genetic composition and diversity between natural and cultured stocks in samples of 2001 and 2005 from Penha, Santa Catarina. DNA was extracted from adductor muscle by Chelex/proteinase-K and phenol/chloroform protocols. Amplification by polymerase chain reaction was performed using specific primers for analyzing the pms-2 locus. Polymerase chain reaction products were submitted to vertical denatured 6% polyacrylamide gel electrophoresis and horizontal 2% agarose gel electrophoresis, and visualized by silver staining and ethidium bromide, respectively. Allele diversity and heterozygote deficiency were higher for samples of 2005 than for those of 2001. No significant genetic differentiation was found between natural and cultured stocks of 2001 by the chi(2) test, but G(2) (likelihood ratio) detected slight differences (I = 0.949; chi(2), P = 0.147; G(2), P = 0.046), while cultured and natural stocks of 2005 were very different (I = 0.798, P = 0.006). Between the years of 2001 and 2005, a large change in genetic composition was observed (I = 0.582; P < 0.001). Although nothing is known about natural changes in the genetic composition of this species with time, the results suggest a strong impact of human activities on natural stocks of P. perna, which is expected to be related to heavy extraction and farming.
秘鲁贻贝是巴西圣卡塔琳娜州最重要的养殖贻贝，为许多当地家庭提供了重要的经济收入。秘鲁贻贝的天然种群因捕捞成体和幼体用于食用及养殖而枯竭。本研究的目的是利用微卫星基因座pms - 2，研究2001年和2005年采自圣卡塔琳娜州佩尼亚的样本中，天然种群和养殖种群之间的遗传组成和多样性变化。通过Chelex/蛋白酶K法和苯酚/氯仿法从闭壳肌中提取DNA。使用分析pms - 2基因座的特异性引物进行聚合酶链反应扩增。聚合酶链反应产物分别进行垂直变性6%聚丙烯酰胺凝胶电泳和水平2%琼脂糖凝胶电泳，分别用银染和溴化乙锭染色观察。2005年样本的等位基因多样性和杂合子缺失高于2001年样本。通过卡方检验，2001年的天然种群和养殖种群之间未发现显著的遗传分化，但G(2)（似然比）检测到细微差异（I = 0.949；卡方，P = 0.147；G(2)，P = 0.046），而2005年的养殖种群和天然种群差异很大（I = 0.798，P = 0.006）。在2001年至2005年期间，观察到遗传组成发生了很大变化（I = 0.582；P < 0.001）。尽管对该物种遗传组成随时间的自然变化一无所知，但结果表明人类活动对秘鲁贻贝的天然种群有强烈影响，预计这与过度捕捞和养殖有关。
