Lawrence H A, Scofield R P, Crockett D E, Millar C D, Lambert D M
Allan Wilson Centre for Molecular Ecology and Evolution, Institute of Molecular BioSciences, Massey University, Auckland, New Zealand.
Heredity (Edinb). 2008 Dec;101(6):543-7. doi: 10.1038/hdy.2008.85. Epub 2008 Sep 3.
The Chatham Island Taiko (Tchaik, Pterodroma magentae) is one of the world's rarest seabirds. In the past there were millions of breeding pairs of Taiko and it was the most abundant burrowing petrel on Chatham Island. The present population consists of just 120-150 birds, including only 8-15 breeding pairs. Surprisingly high genetic variation was revealed by DNA sequencing of almost every known adult Taiko (N=90). Given the massive population decline, genetic variation may have been even larger in the past. Therefore, we investigated past genetic diversity by sequencing regions of the mitochondrial cytochrome b gene in 44 ancient Taiko bones. We identified a total of 12 haplotypes in Taiko. Eight haplotypes were revealed in the ancient DNA: four were unique to the bones and four corresponded to those found in the modern Taiko population. Surprisingly, despite the critically endangered status of the Taiko, no significant reduction in mitochondrial DNA haplotype diversity was observed between ancient samples (N=44) and modern adult Taiko (N=90). The modern population may have however lost four haplotypes present in the ancient populations.
查塔姆岛鹱（Tchaik，Pterodroma magentae）是世界上最稀有的海鸟之一。过去有数百万对鹱在此繁殖，它曾是查塔姆岛上数量最多的洞穴海燕。目前其种群仅由120 - 150只鸟组成，其中仅有8 - 15对繁殖对。通过对几乎每只已知成年鹱（N = 90）进行DNA测序，发现其遗传变异程度惊人地高。鉴于种群数量大幅下降，过去的遗传变异可能更大。因此，我们通过对44块古代查塔姆岛鹱骨骼的线粒体细胞色素b基因区域进行测序，来研究过去的遗传多样性。我们在查塔姆岛鹱中总共鉴定出12种单倍型。在古代DNA中发现了8种单倍型：其中4种是骨骼所特有的，另外4种与现代查塔姆岛鹱种群中发现的单倍型相对应。令人惊讶的是，尽管查塔姆岛鹱处于极度濒危状态，但在古代样本（N = 44）和现代成年鹱（N = 90）之间，未观察到线粒体DNA单倍型多样性有显著降低。不过，现代种群可能已经失去了古代种群中存在的4种单倍型。
