Search

Abstract Background Goat, one of the first domesticated livestock, is a worldwide important species both culturally and economically. The current goat reference genome, known as ARS1, is reported as the first nonhuman genome assembly using 69× PacBio sequencing. However, ARS1 suffers from incomplete X chromosome and highly fragmented Y chromosome scaffolds. Results Here, we present a very high-quality de novo genome assembly, Saanen_v1, from a male Saanen dairy goat, with the first goat Y chromosome scaffold based on 117× PacBio long-read sequencing and 118× Hi-C data. Saanen_v1 displays a high level of completeness thanks to the presence of centromeric and telomeric repeats at the proximal and distal ends of two-thirds of the autosomes, and a much reduced number of gaps (169 vs. 773). The completeness and accuracy of the Saanen_v1 genome assembly are also evidenced by more assembled sequences on the chromosomes (2.63 Gb for Saanen_v1 vs. 2.58 Gb for ARS1), a slightly increased mapping ratio for transcriptomic data, and more genes anchored to chromosomes. The eight putative large assembly errors (1 to ~ 7 Mb each) found in ARS1 were amended, and for the first time, the substitution rate of this ruminant Y chromosome was estimated. Furthermore, sequence improvement in Saanen_v1, compared with ARS1, enables us to assign the likely correct positions for 4.4% of the single nucleotide polymorphism (SNP) probes in the widely used GoatSNP50 chip. Conclusions The updated goat genome assembly including both sex chromosomes (X and Y) and the autosomes with high-resolution quality will serve as a valuable resource for goat genetic research and applications.

In this paper, GIS and RS spatial analysis techniques were used to establish a system for identifying sensitive targets of terrestrial ecosystems in Chishui River Basin, and to identify protection targets of terrestrial ecosystems in different regions. The result shows that the assessment of habitat sensitivity in Chishui River Basin was dominated by non-sensitive areas and highly sensitive areas, which highly sensitive areas account for 60.43% of the basin area, mostly concentrated in the mountainous areas at the junction of Chishui City, Xishui County and Gulin County; non-sensitive areas account for 39.13% and are mosaically distributed with highly sensitive areas; mildly sensitive areas, moderately sensitive areas and extremely sensitive areas account for a total of about 0.5% of the basin area and are more scattered throughout the basin. The distribution is scattered. The moderately sensitive areas in the Chishui River Basin are more than 60.7% of the basin area, indicating that the habitats in the Chishui River Basin are generally sensitive and the ecologically sensitive targets are mainly wooded areas, which need to be protected.

The technological process, technical parameters, operation cost and effect of zero discharge project for desulphurization wastewater of 1000MW coal-fired unit in East China are analyzed. The project mainly adopts the process of softening pretreatment, membrane concentration and evaporation crystallization, the direct cost of per ton water treatment is about ￥35.3, and the final product is high purity industrial salt. This technology fully realize the zero discharge requirement of desulphurization wastewater, and has good envir(can )tal and economic benefits.