Nguyen Trung Thanh, Genini Sem, Bui Linh Chi, Voegeli Peter, Stranzinger Gerald, Renard Jean-Paul, Maillard Jean-Charles, Nguyen Bui Xuan
Vietnamese Academy of Sciences and Technology, Hanoi, Vietnam.
BMC Genet. 2007 Nov 6;8:77. doi: 10.1186/1471-2156-8-77.
The wild gaur (Bos gaurus) is an endangered wild cattle species. In Vietnam, the total number of wild gaurs is estimated at a maximum of 500 individuals. Inbreeding and genetic drift are current relevant threats to this small population size. Therefore, information about the genetic status of the Vietnamese wild gaur population is essential to develop strategies for conservation and effective long-term management for this species. In the present study, we performed cross-species amplification of 130 bovine microsatellite markers, in order to evaluate the applicability and conservation of cattle microsatellite loci in the wild gaur genome. The genetic diversity of Vietnamese wild gaur was also investigated, based on data collected from the 117 successfully amplified loci.
One hundred-thirty cattle microsatellite markers were tested on a panel of 11 animals. Efficient amplifications were observed for 117 markers (90%) with a total of 264 alleles, and of these, 68 (58.1%) gave polymorphic band patterns. The number of alleles per locus among the polymorphic markers ranged from two to six. Thirteen loci (BM1314, BM2304, BM6017, BMC2228, BMS332, BMS911, CSSM023, ETH123, HAUT14, HEL11, HEL5, ILSTS005 and INRA189) distributed on nine different cattle chromosomes failed to amplify wild gaur genomic DNA. Three cattle Y-chromosome specific microsatellite markers (INRA124, INRA126 and BM861) were also highly specific in wild gaur, only displaying an amplification product in the males. Genotype data collected from the 117 successfully amplified microsatellites were used to assess the genetic diversity of this species in Vietnam. Polymorphic Information Content (PIC) values varied between 0.083 and 0.767 with a mean of 0.252 while observed heterozygosities (Ho) ranged from 0.091 to 0.909 (mean of 0.269). Nei's unbiased mean heterozygosity and the mean allele number across loci were 0.298 and 2.2, respectively.
Extensive conservation of cattle microsatellite loci in the wild gaur genome, as shown by our results, indicated a high applicability of bovine microsatellites for genetic characterization and population genetic studies of this species. Moreover, the low genetic diversity observed in Vietnamese wild gaur further underlines the necessity of specific strategies and appropriate management plans to preserve this endangered species from extinction.
野生印度野牛（Bos gaurus）是一种濒危野生牛种。在越南，野生印度野牛的总数估计最多为500头。近亲繁殖和遗传漂变是当前对这一较小种群规模的相关威胁。因此，有关越南野生印度野牛种群遗传状况的信息对于制定该物种的保护策略和有效的长期管理至关重要。在本研究中，我们对130个牛微卫星标记进行了跨物种扩增，以评估牛微卫星位点在野生印度野牛基因组中的适用性和保守性。还基于从117个成功扩增的位点收集的数据，对越南野生印度野牛的遗传多样性进行了调查。
在一组11只动物上测试了130个牛微卫星标记。观察到117个标记（90%）有效扩增，共产生264个等位基因，其中68个（58.1%）呈现多态性条带模式。多态性标记中每个位点的等位基因数从2到6不等。分布在9条不同牛染色体上的13个位点（BM1314、BM2304、BM6017、BMC2228、BMS332、BMS911、CSSM023、ETH123、HAUT14、HEL11、HEL5、ILSTS005和INRA189）未能扩增野生印度野牛基因组DNA。3个牛Y染色体特异性微卫星标记（INRA124、INRA126和BM861）在野生印度野牛中也具有高度特异性，仅在雄性中显示扩增产物。从成功扩增的117个微卫星收集的基因型数据用于评估该物种在越南的遗传多样性。多态信息含量（PIC）值在0.083至0.767之间变化，平均值为0.252，而观察到的杂合度（Ho）范围为0.091至0.909（平均值为0.269）。Nei的无偏平均杂合度和各位点的平均等位基因数分别为0.298和2.2。
我们的结果表明，牛微卫星位点在野生印度野牛基因组中广泛保守。这表明牛微卫星在该物种的遗传特征分析和群体遗传学研究中具有很高的适用性。此外，越南野生印度野牛中观察到的低遗传多样性进一步强调了制定特定策略和适当管理计划以保护这一濒危物种免于灭绝的必要性。
