The complete mitochondrial genome and phylogenetic analysis of Yanglong yak (Bos grunniens).

In this study, we assembled the complete mitochondrial genome of Yanglong yak (Bos grunniens) from Illumina sequencing reads. The mitochondrial genome is 16,323 bp long with an A + T-biased nucleotide composition, and encodes 13 protein-coding, 22 tRNA, and two rRNA genes along with a noncoding control region. In addition, its gene order is identical to those of the previously published mitochondrial genomes of its congeners. Phylogenetic analysis indicates that this breed is closely related to Datong yak, Pamir yak, Tianjun yak, polled yak, Seron yak, Sunnan yak, a series of Domestic Yak and wild yak, followed by Jinchuan yak and Gannan yak, and slightly far away from Bison and Bos taurus.

Determination of minor isotope ratios of individual uranium particles by accelerator mass spectrometry.

The determination of uranium isotope ratios in uranium particle is an essential technique in the analysis of environmental samples for nuclear safeguards. At present, mass spectrometry has been widely used to measure isotope ratios of uranium particles. We developed a new analytical method for measuring minor isotope ratios of individual uranium particles directly. The technique includes single particle identification by energy dispersive X-ray spectrometer (EDX), transfer by scanning electron microscope (SEM) combined with micromanipulator and isotope ratios analysis with accelerator mass spectrometry (AMS). The minor isotope ratios of individual uranium particles with four isotopic abundances and different sizes from certified reference materials were measured by AMS. The results show that the relative error (RE, i.e., the deviation of measured value from the certified value) of 234 U/235 U and 234 U/236 U isotope ratios was 9.0% and 19.3%, respectively, and the relative standard deviation (RSD) was within 9.9% and 16%, respectively. The minimum particle determined was about 2 µm. The method was found to be an alternative analytical means for nuclear safeguards.

Characterization of the complete mitochondrial genome of the Dayu yak (Bos grunniens).

Dayu yak (Bos grunniens) is a long-furred yak breed from the Qinghai-Tibetan Plateau, and is highly adapted to local high-altitude and cold environments. In this study, its mitochondrial genome was characterized via high-throughput sequencing technology. The genome is 16,323 bp long with an AT-biased base composition (61.0% A + T; light strand), and harbors the typical set of 37 mitochondrial genes and a noncoding control region. Its gene arrangement is identical to those of other bovid taxa. Phylogenetic analysis suggests that Dayu yak is most closely related to Maiwa, Niangya, Qinghai Plateau, Xueduo and Yushu yaks.