<i>Eaf</i>s are required for specification of erythroid cells.

<p>(A) Erythroid defects in <i>eaf</i>s morphants were detected by o-dianisidine staining for hemoglobin. (B) <i>Eafs</i> morphants displayed erythroid defects, indicated by reduced mRNA of <i>βe3 globin</i>. (C) <i>Eaf</i>s morphants displayed reduced protein of <i>βe3 globin</i>.</p

<i>C-myb</i> suppressed specification of mature erythroid cells, and the phenotype of <i>c-myb</i> gain of function is specific.

<p>(A) Different dosage of <i>c-myb</i> on specification of mature erythroid cells (<i>βe3 globin</i>: A2, 50 pg per embryo; A4, 200 pg per embryo) and on erythroid progenitors (<i>gata1</i>: A6, A8). (B) <i>In situ</i> hybridization of <i>βe3 globin</i> showed that erythroid differentiation was blocked in embryos with ectopic <i>c-myb</i> expression (50 pg per embryo) (B2), the number of embryos displayed reduced <i>βe3 globin</i> was shown in (B2), and the <i>in situ</i> hybridization of <i>c-myb</i> shown its ectopic expression in corresponding embryos (B4). (B) Hematopoietic progenitor cells including <i>gata1</i> (C1, C2) and <i>scl</i> (C3, C4), and other mesoderm cells including <i>pax2a</i> and <i>myoD</i> (C5, C6) specified and maintained normally in embryos with ectopic <i>c-myb</i> expression. A1–A8, B1, B2, C1–C4, dorsal view, anterior to the up; B3, B4, C5, C6, lateral view, anterior to the left.</p

Genome-wide identification of genes probably relevant to the adaptation of schizothoracins (Teleostei: Cypriniformes) to the uplift of the Qinghai-Tibet Plateau

Abstract Background Molecular adaptation to the severe environments present during the uplift of the Qinghai-Tibet Plateau has attracted the attention of researchers. The divergence of the three specialization groups of schizothoracins (Primitive, Specialized and Highly Specialized) may correspond to the three phases of plateau uplift. Based on the transcripts of representative species of the three specialized groups and an outgroup, genes in schizothoracins that may have played important roles during the adaptation to new environments were investigated. Results The contigs of Gymnodiptychus dybowskii and Schizothorax pseudaksaiensis were compared with those of Gymnocypris przewalskii ganzihonensis and the outgroup Sinocyclocheilus angustiporus, and 5,894 ortholog groups with an alignment length longer than 90 nt after deleting gaps were retained. Evolutionary analyses indicated that the average evolutionary rate of the branch leading to the Specialized group was faster than that of the branch leading to the Highly Specialized group. Moreover, the numbers of gene categories in which more than half of the genes evolved faster than the average values of the genome were 117 and 15 along the branches leading to the Specialized and Highly Specialized groups, respectively. A total of 40, 36, and 55 genes were likely subject to positive selection along the branches leading to the Primitive, Specialized and Highly Specialized groups, respectively, and many of these genes are likely relevant to adaptation to the cold temperatures, low oxygen concentrations, and strong ultraviolet radiation that result from elevation. Conclusions By selecting representative species of the three groups of schizothoracins and applying next-generation sequencing technology, several candidate genes corresponding to adaptation to the three phases of plateau uplift were identified. Some of the genes identified in this report that were likely subject to positive selection are good candidates for subsequent evolutionary and functional analyses of adaptation to high altitude

Knockdown Wnt signaling in hs:dnTCF-GFP embryos by heat shock at the bud stage resulted in reduced progenitor cells and accelerated differentiation of erythroid cells.

<p>(A) Scheme of using hs:dnTCF-GFP fish to knockdown Wnt signaling in embryos. (B) Reduced progenitor blood cells, labeled by <i>c-myb</i> (B1, B2) and <i>gata1</i> (B3, B4), but accelerated erythroid cells differentiation, labeled by <i>βe3 globin</i> (B5, B6, B9, B10) and <i>band3</i> (B7, B8) displayed in hs:dnTCF-GFP positive embryos, and black arrow indicate the increased expression of <i>βe3 globin</i> expression in hs:dnTCF-GFP positive embryos (B10) compared to its control siblings (B9). Other mesoderm, labeled by <i>pax2a</i> and <i>myoD</i> (B9, B10, B11, B12), was normal in hs:dnTCF-GFP positive embryos. B1, B2, B7–B12, lateral view, anterior to the left; B3–B6 dorsal view, anterior to the up.</p

Knockdown Wnt signaling in <i>eaf</i>s morphants by transiently inducing <i>dn-Tcf</i> expression rescued defects of <i>c-myb</i> expression and erythroid cells specification.

<p>(A) Scheme of rescuing experiments in <i>eaf</i>s morphants by using hs:dnTCF-GFP embryos. (B) Increased <i>c-myb</i> expression and reduced <i>βe3 globin</i> expression were restored in <i>eafs</i> morphants by transiently inducing <i>dn-Tcf</i> in embryos at the bud stage. B1–B8, dorsal view, anterior to the up.</p

Interactive Effects of Rising Temperature, Elevated CO₂ and Herbivory on the Growth and Stoichiometry of a Submerged Macrophyte <i>Vallisneria natans</i>

Global climate changes are affecting organisms and their interactions in terrestrial and aquatic ecosystems, such as the increase in temperature and CO2 concentration. Herbivory interaction is a very important part of nutrient cycle and energy flow in freshwater ecosystem, and climate changes may directly or indirectly affect aquatic plants, aquatic herbivores and their interactions. In this study, we explored the effects of the rising temperature, elevated CO2 concentrations and herbivory by an herbivorous snail (Radix auricularia L.) on a submerged plant (Vallisneria natans L.). Our results showed that herbivory, temperature, and CO2 had specific effects on snail and plant growth, statistically there was only one interaction-a reduction in leaf number. Under different experimental conditions, snail herbivory always has negative effects on biomass accumulation and growth of V. natans. Moreover, the increases in temperature also inhibited its growth. Snail herbivory reduced the content of total carbon and total nitrogen of V. natans in all treatments, while the total phenols content increased. Our findings indicate that the rising temperature, elevated CO2 concentrations and herbivory have interactive effects on the growth and stoichiometry of submerged macrophytes, but further research is needed between aquatic plants and aquatic herbivores to aid prediction the impact of climate change on freshwater ecosystems

Additional file 1: Figure S1. of Genome-wide identification of genes probably relevant to the adaptation of schizothoracins (Teleostei: Cypriniformes) to the uplift of the Qinghai-Tibet Plateau

Sampling sites of the studied species. The triangle represents the sampling site of G. dybowskii and S. pseudaksaiensis collected in this study. The circle and diamond represent the sampling sites of G. p. ganzihonensis and the outgroup species S. angustiporus collected previously [32, 33]. The map was adopted from Sogou Map (map.sogou.com). (PPT 137 kb

Additional file 5: Table S3. of Genome-wide identification of genes probably relevant to the adaptation of schizothoracins (Teleostei: Cypriniformes) to the uplift of the Qinghai-Tibet Plateau

Profiles of candidate genes subject to positive selection along branches leading to the Primitive, Specialized and Highly Specialized groups of schizothoracins (branchesI, II and III in Fig. 1). (XLS 39 kb