Widespread divergence between incipient Anopheles gambiae species revealed by whole genome sequences

The Afrotropical mosquito Anopheles gambiae sensu stricto, a major vector of malaria, is currently undergoing speciation into the M and S molecular forms. These forms have diverged in larval ecology and reproductive behavior through unknown genetic mechanisms, despite considerable levels of hybridization. Previous genome-wide scans using gene-based microarrays uncovered divergence between M and S that was largely confined to gene-poor pericentromeric regions, prompting a speciation-with-ongoing-gene-flow model that implicated only about 3% of the genome near centromeres in the speciation process. Here, based on the complete M and S genome sequences, we report widespread and heterogeneous genomic divergence inconsistent with appreciable levels of interform gene flow, suggesting a more advanced speciation process and greater challenges to identify genes critical to initiating that process.     

Preservation of the gene pool of crossbred replacement heifers during directed growing

Directed growing of replacement heifers using various methods of rearing and rated feeding resulted in increase of the live weight and milk yield at first lactation and decrease in the feeding costs.     

Cell dynamics during somite boundary formation revealed by time-lapse analysis

We follow somite segmentation in living chick embryos and find that the shaping process is not a simple periodic slicing of tissue blocks but a much more carefully choreographed separation in which the somite pulls apart from the segmental plate. Cells move across the presumptive somite boundary and violate gene expression boundaries thought to correlate with the site of the somite boundary. Similarly, cells do not appear to be preassigned to a given somite as they leave the node. The results offer a detailed picture of somite shaping and provide a spatiotemporal framework for linking gene expression with cell movements.     

从mtDNA和SRY基因多态揭示云南大额牛杂交起源

从父系、母系全面揭示云南大额牛的遗传背景.采集了云南大额牛、印度野牛(Bosgaurus)、迪庆黄牛、怒江黄牛以及文山高峰牛共5个种群的血液样品,对其中70头牛mtDNA D-loop和39头公牛Y染色体非同源部分SRY基因序列多态检测,结合GenBank已经报道的相关序列,对所构建的单倍型NJ系统树和网络图进行了聚类分析.线粒体DNA数据显示,云南大额牛母系来源于瘤牛(B.indicus)和普通黄牛(B.taurus),云南本地牛母系也来源于瘤牛和普通黄牛;SRY基因序列信息显示,云南大额牛父系来源于大额牛(B.frontalis),云南本地牛父系来源于印度瘤牛.结果说明,云南大额牛为大额牛与黄牛的杂交后代,云南本地牛主要为瘤牛血统.     

Suppression of the neoplastic phenotype by replacement of the RB gene in human cancer cells

Mutational inactivation of the retinoblastoma susceptibility (RB) gene has been proposed as a crucial step in the formation of retinoblastoma and other types of human cancer. This hypothesis was tested by introducing, via retroviral-mediated gene transfer, a cloned RB gene into retinoblastoma or osteosarcoma cells that had inactivated endogenous RB genes. Expression of the exogenous RB gene affected cell morphology, growth rate, soft agar colony formation, and tumorigenicity in nude mice. This demonstration of suppression of the neoplastic phenotype by a single gene provides direct evidence for an essential role of the RB gene in tumorigenesis.     

Two new SINE insertion polymorphisms in pig Vertnin(VRTN) gene revealed by comparative genomic alignment

Despite one SINE retrotransposon insertion polymorphism(sRTIP) in the vertebrae development-associated(VRTN) gene was identified in pigs, the structural variations(SVs) in VRTN gene and its proximal flank regions were largely unknown. VRTN genic and flanking sequences from 14 breeds were assembled or downloaded from whole-genome shotgun contings(WGS) database, and aligned to identify the SVs with Clustalx, and retrotransposons in VRTN gene were annotated by RepeatMasker, the splicing patterns of VRTN gene were predicted by Genescan, and large SVs were evaluated by PCR. A total of 12 small SVs and three large SVs in intron of VRTN, derived from SINE insertion polymorphisms, were identified, and two of them(VRTN-sRTIP2 and VRTN-sRTIP3) were not reported before. These VRTN-sRTIPs may affect the splicing patterns of VRTN. They displayed polymorphisms in most detected eight breeds. VRTN-sRTIP2 and VRTN-sRTIP3 showed Hardy-Weinberg equilibrium distributions in most populations except the Chinese local Erhualian pigs, while VRTN-sRTIP1 showed genetic equilibrium in Erhualian pigs. Three VRTN-sRTIPs were identified, and displayed polymorphisms in pigs, and two of them were not reported before. These SVs provide a useful molecular markers for genetic analysis in pigs, and offer new information to facilitate the understanding the SVs of VRTN gene and their putative roles in the variation of vertebral number.     

Prevention of apoptosis by a baculovirus gene during infection of insect cells

Programmed cell death is an active process of self destruction that is important in both the development and maintenance of multicellular animals. The molecular mechanisms controlling activation or suppression of programmed cell death are largely unknown. Apoptosis, a morphologically and biochemically defined type of programmed cell death commonly seen in vertebrates, was found to be initiated during baculovirus replication in insect cells. A specific viral gene product, p35, was identified as being responsible for blocking the apoptotic response. Identification of the function of this gene will allow further definition of the molecular pathways involved in the regulation of programmed cell death and may identify the role of apoptosis in invertebrate viral defense systems.     

应用近红外反射光谱技术测定油菜芽期耐旱性的研究

针对油菜芽期耐旱鉴定,提出了用近红外反射光谱技术（NIR法）预测油菜吸胀24 h电导率、PEG模拟干旱条件下的相对发芽率、相对鲜重和鲜重耐旱指数等4个芽期耐旱相关性状的方法。以采集的49份不同耐旱水平甘蓝型油菜近红外光谱数据为基础,采用偏最小二乘法和多元回归算法建立了最优定标模型,并获得较高的决定系数(0.71～0.86)和较低的标准误差(1～15.65)。验证集评估结果表明,NIR法与室内鉴定法测定油菜4个芽期耐旱相关性状无显著差异,且具有极显著的相关关系(决定系数0.72～0.89)。研究表明,近红外光谱技术用于油菜芽期耐旱性鉴定是可行的,可用于耐旱育种早代选择。     

Changes in speciation,mobility and bioavailability of Cd,Cr and As during the transformation process of pig manure by black soldier fly larvae(Hermetia illucens)

The black soldier fly larvae(BSFL)(Hermetia illucens) are a good candidate for poultry and livestock manure treatment. The harvested insect bodies and feces can be used as animal feed and organic fertilizer. However, heavy metals have a negative impact on the transformation process of the manure by BSFL. Here we evaluated the effects of Cd, Cr and As in pig manure on the growth of BSFL, as well as the mobility and changes in speciation of the metals during the transformation process. The results showed that As significantly reduced the weight of BSFL, but Cr and Cd had no significant effects on BSFL growth. The bioaccumulation factors(BAFs) at various concentrations of Cd(2.8–3.7) were significantly higher than those of Cr(0.44–0.62) and As(0.43–0.45). The heavy metals in pig manure were mainly transferred to BSFL feces, and the distribution percentages of Cd, Cr and As in the BSFL feces were 52.6–62.0%, 90.3–94.2% and 93.0–93.3%, respectively. Cd concentrations in BSFL feces were significantly lower than those in the pig manure, while there were no significant differences in the concentrations of Cr and As between BSFL feces and pig manure(except for the treatment with the addition of 150 mg Cr kg~(–1)). The metal speciation(weak acid soluble, reducible, oxidizable and residual fractions) in BSFL feces obviously changed when compared with pig manure. In BSFL feces, the reducible proportion of Cr decreased while the oxidizable proportion increased. Cd mainly existed in the weak acid soluble and reducible states in pig manure and BSFL feces. For As, the proportions of weak acid soluble and reducible states decreased in BSFL feces. After the BSFL transformation process, the bioavailable fraction of Cr decreased by 17.3–23.1%, but those of Cd and As did not change significantly, except for As in the CK group. These findings contribute to our understanding of the roles of BSFL during the biotransformation process of livestock manure as well as the safe utilization of transformed products.