非侵襲的試料を用いたDNA分析

Abstract

Noninvasive genetics is one of the tools for clarifying society and ecology of wild primates. Here, I reviewed the methods of DNA analysis using noninvasive genetics. Although various types of noninvasive samples such as feces, urine, hair, and saliva have been used in wild mammals including primates, fecal samples are most common. The success rate of DNA analysis using the surface of feces is higher than that using the whole or inner part of feces. Numerous protocols for preserving fecal samples have been proposed, and one of the important points is to collect comparatively small amount of feces irrespective of the protocols. Temperature and rainfall before the collection of feces have negative impacts on DNA analyses, while diets have little impacts. The best ways to extract DNA might be to use QIAamp DNA Stool Mini Kit (QIAGEN) or modified CTAB methods. Although hair samples from nests of great apes have been used as noninvasive genetics, we should be aware that quantity of DNA which is extracted from a single dropped hair is low. When we conduct PCR amplification for reliable microsatellite genotype using noninvasive samples, we should take measures for PCR inhibitors present in extracts and genotyping errors such as allelic dropouts and false alleles. Multiple-tubes approach is necessary for most noninvasive samples and multiplex PCR method is a good way to reduce genotyping costs. Although noninvasive genetics can give us the estimates of relatedness which is useful for studying social behavior, pairwise relatedness estimates using less than 20 microsatellite loci has been shown to be unreliable. Development of an easy method to give robust data on pairwise relatedness might be important to understand the effect of relatedness on social behavior in the wild primate groups which have limited information about kinship due to short research period.