Assessing genetic diversity of wild populations of Prenantȁ9s schizothoracin, Schizothorax prenanti, using AFLP markers

Abstract

Prenant's schizothoracin, Schizothorax prenanti, an endemic fish to China, has undergone a dramatic decline in numbers due to human impacts. We studied its genetic diversity in three tributaries of the Yangtze River: the Qingyi River, which has many hydropower dams, and the Dadu River and Muli River where many hydropower dams are being proposed. Using amplified fragment length polymorphism (AFLP), 621 loci were amplified with seven AFLP primer combinations in 45 individuals. The loci were highly polymorphic and heterozygous (87% polymorphism, 30% heterozygosity). The genetic distances within populations were large. The analysis of molecular variance demonstrated that most variation occurred within populations. The estimated fixation index (F st ) value averaged over all polymorphic loci across the three rivers was 0.0837, indicating a moderate genetic differentiation. The differentiations between populations were significant, and population structure was strong. The results suggested that China had wild populations of Prenant's schizothoracin with considerable genetic diversity in the Muli, Dadu and Qingyi rivers. The proposals to dam these rivers should take into account the importance of conserving their genetic quality.

Genetic diversity among red swamp crayfish (Procambarus clarkii) populations in the middle and lower reaches of the Yangtze River based on AFLP markers

“…The pattern of genetic diversity observed has practical implications for the management of broodstocks and for selective breeding programs (Song et al, 2006). Genetic diversity information among and within populations of the red swamp crayfish in the Yangtze River also provides reliable information for the protection and restoration of wild resources.…”

“…The HZ population showed the most distinct difference with the highest allelic and gene diversity. High genetic diversity of introduced populations can be attributed to several factors: multiple introductions (Kolbe et al, 2004), a single introduction of a large number of individuals from different populations (Yue et al, 2010), and remote living locations and lower fishing pressure (Song et al, 2006). Yue et al (2010) have proved that the population in Nanjing, Jiangsu Province, may be the first invasive population of P. clarkii in China and that the translocation of P. clarkii from locations outside of China to Nanjing did not occur.…”

Population genetic diversity of Prenant’s schizothoracin, Schizothorax prenanti, inferred from the mitochondrial DNA control region

“…The eggs usually are laid on the gravel in the bottom of the shallow river with rapid current (Ding 1994). Song et al (2006) investigated the genetic diversity of wild populations of this species using AFLP markers. They found its genetic diversity was considerable in its main area of distribution, the Yalong, Dadu, and Qingyi rivers.…”

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“…The Schizothorax prenanti (S.prenanti), an endemic cold-water fish, is popular cultured fish in Southwest China and has become an important food fish because of its good meat quality and wide acceptance in the markets. However, this fish displays remarkably low growth rates in nature (Song et al, 2006). Given the critical roles that MRFs play in myogenesis and the expression of MRFs is associated with skeletal muscle growth, it is important to study the roles of MRFs in regulating the muscle development to accelerate the growth rate in the S. prenanti and the research about this in this fish is …”