Molecular characterization and developmental expression patterns of thyroid hormone receptors(TRs) and their responsiveness to TR agonist and antagonist in Rana nigromaculata

Considering some advantages of Rana nigromaculata as an experimental species, we propose that this species, like Xenopus laevis, could be used to assay thyroid hormone（TH） signaling disrupting actions. To validate the utilizability of R. nigromaculata, we investigated the responsiveness of R. nigromaculata to a TH receptor（TR） agonist（T3） and antagonist（amiodarone） by analyzing expression, based on characterizing TR cDNA and developmental expression patterns. With high levels of identity with the corresponding genes in X. laevis, both TRα and TRβ in R. nigromaculata exhibited roughly similar developmental expression patterns to those of X. laevis, in spite of some species-specific differences. Both TRα and TRβ expression had greater changes in the liver and intestine than in the tail and brain during metamorphosis. T3 exposure for 2 days induced more dramatic increases of TRβ expression in stage 27 than in stage34 tadpoles but not in stage 42 tadpoles, showing that the responsiveness of R. nigromaculata to TH decreased with development and disappeared at the onset of metamorphic climax.Corresponding to greater changes of TRβ expression in the liver and intestine than in the tail and brain during metamorphosis, the liver and intestine had higher responsiveness to exogenous T3 than the tail and brain. Amiodarone inhibited T3-induced TRβ expression. Our results show that R. nigromaculata can be used as a model species for assaying TH signaling disrupting actions by analyzing TRβ expression, and intestine tissues at stage 27 are ideal test materials due to high responsiveness and easy accessibility.

Developmental expression of amphioxus RACK1

Vertebrate RACK1 plays a key role in embryonic development. This paper described the cloning, phy- logenetic analysis and developmental expression of AmphiRACK1, the RACK1 homologous gene in amphioxus. Phylogenetic analysis indicated that amphioxus RACK1 was located at the base of verte- brate clade. AmphiRACK1 expression in lithium-treated embryos was also examined. During embryonic development, AmphiRACK1 was expressed strongly in cerebral vesicles, neural tubes and somites. In lithium-treated embryos, the segmental expression of AmphiRACK1 in somites became blurry and decreased. Its expression in cerebral vesicles and neural tubes was also weaker or disappeared. In the adult animal, AmphiRACK1 transcripts were detected in the epithelium of midgut diverticulus and gut, wheel organ, gill blood vessels and testis.

Characterization of the 19 Novel Cotton FLA Genes and Their Expression Profiling in Fiber Development and in Response to Phytohormones and Salt Stress

Fasciclin-like arabinogalactan proteins(FLAs),a subclass of arabinogalactan proteins(AGPs),are usually involved in cell development in plants.To investigate the expression profiling as well

BTG1 as a New Candidate Gene for Muscle Growth in Pigs: Cloning,Expression and Association Analysis

BTG1 （B-cell Translocation Gene 1） , a member of the BTG / TOB （Transducer of ErbB-2） family of anti-proliferation factors,has been proven to have an unfavorable effect on muscle fiber growth in several species. The porcine BTG1 gene was cloned and its 5＇ flanking promoter region sequence, and characterized the expression patterns in different tissues of adult pigs and in fetal skeletal muscle at different developmental stages in two breeds. The tissue distribution pattern analyses revealed that the mRNA of porcine BTG1 was ubiquitously expressed in the six tissues of both Landrace and Tongcheng pigs. Real-time quantitative reverse transcriptase-PCR results showed that BTG1 mRNA expression levels were significantly different among the three fetal ages in Tongcheng pigs,while no significant differences were found among the three ages in Landrace pigs. Furthermore,the expression of BTG1 in Landrace pigs was significantly lower than in Tongcheng pigs at all three ages. The temporal expression profiles of the BTG1 gene in mouse myoblast C 2 C 12 cells were shown to be consistent with those of the myogenin gene. A single nucleotide polymorphism （SNP） ,g. 281C 〉 T,was identified in the 3＇UTR and allele frequencies were detected in seven pig breed populations. Significant associations were found between the g. 281C 〉 T polymorphism and growth and meat quality traits. Our results indicate that the porcine BTG1 gene could play a potential role in markerassisted selection and as such may be a gene of economic importance.

Age-Related Alterations in DNA Methylation and APETALA2(AP2)Levels in Herbaceous Peony(Paeonia lactiflora Pall.)

The ornamental and commercial values of herbaceous peony(Paeonia lactiflora Pall.)are directly related to its flower pattern.However,the molecular mechanisms underlying the type formation of P.lactiflora flowers have not been studied in great detail.Previous studies identified,using integrated multipleomics analysis,revealed that APETALA2(AP2)is an important candidate gene that modulates type formation of P.lactiflora flowers.To further reveal the expression mechanism of AP2 in P.lactiflora petals,we examined the profile of AP2 expression in the inner and outer petals of‘ZiFengyu’at various developmental stages using qRT-PCR and BSP+Miseq methylation analysis.Based on our data,the AP2 levels in the outer petals were obviously increased,relative to the inner petals.In addition,the S3 levels at the bloom stage were significantly higher than at the flower-bud stage S1,thereby promoting bloom stage S2,while declining stage S4.Using chromosome walking,the 2000 bp of the 5′-end upstream promoter region was achieved.This region harbored a CpG island(−665∼−872 bp),with multiple essential transcription factor binding sites(TFBS)such as NF-kappa B,GATA-1,Sp1,and C/EBP.Methylation sequencing revealed 7 methylated CpG sites in the CpG island region of the AP2 promoter,thereinto,the methylation ratio of the CpG-3 site in the inner petals was significantly higher than in the outer petals.Correlation analysis revealed a negative association between the level of methylation(CpG-3,CpG-6),and AP2 mRNA expression.CpG-3 was located on the Sp1 transcription factor binding site.Thus,we speculated that the CpG-3 methylation may inhibit transcription factor Sp1 binding to the gene promoter,thereby regulating AP2 expression.Herein,we examined the role of AP2 in the determination of flower patterns in P.lactiflora.Our conclusion will provide theoretical guidance for the molecular breeding of the flower pattern in P.lactiflora.

NEDD9 promotes cancer stemness by recruiting myeloid-derived suppressor cells via CXCL8 in esophageal squamous cell carcinoma

Objective:Esophageal squamous cell carcinoma(ESCC)has high morbidity and mortality rates worldwide.Cancer stem cells(CSCs)may cause tumor initiation,metastasis,and recurrence and are also responsible for chemotherapy and radiotherapy failures.Myeloid-derived suppressor cells(MDSCs),in contrast,are known to be involved in mediating immunosuppression.Here,we aimed to investigate the mechanisms of interaction of CSCs and MDSCs in the tumor microenvironment.Methods:ESCC tissues and cell lines were evaluated.Neural precursor cell expressed,developmentally downregulated 9(NEDD9)was knocked down and overexpressed by lentiviral transfection.Quantitative PCR,Western blot,immunohistochemistry,cell invasion,flow cytometry,cell sorting,multiplex chemokine profiling,and tumor growth analyses were performed.Results:Microarray analysis revealed 10 upregulated genes in esophageal CSCs.Only NEDD9 was upregulated in CSCs using the sphere-forming method.NEDD9 expression was correlated with tumor invasion(P=0.0218),differentiation(P=0.0153),and poor prognosis(P=0.0373).Additionally,NEDD9 was required to maintain the stem-like phenotype.Screening of chemokine expression in ESCC cells with NEDD9 overexpression and knockdown showed that NEDD9 regulated C-X-C motif chemokine ligand 8(CXCL8)expression via the ERK pathway.CXCL8 mediated the recruitment of MDSCs induced by NEDD9 in vitro and in vivo.MDSCs promoted the stemness of ESCC cells through NEDD9 via the Notch pathway.Conclusions:As a marker of ESCC,NEDD9 maintained the stemness of ESCC cells and regulated CXCL8 through the ERK pathway to recruit MDSCs into the tumor,suggesting NEDD9 as a therapeutic target and novel prognostic marker for ESCC.

Myofiber development during embryonic to neonatal development in duck breeds differing in muscle growth rates

Little is known about the muscle developmental patterns during embryonic to neonatal development in ducks.We investigated the developmental patterns in the lateral gastrocnemius muscles of Gaoyou and Jinding ducks differing in their muscle growth rates during the final stages of egg incubation and the first week after hatching.Expression of the MyoD gene was quantified by quantitative real-time PCR（qRT-PCR）.The average cross-sectional area and diameter of the fibers increased from embryonic day 21（E21）,peaking at E27,and then declining slightly 7 d after hatching.The density of the fibers decreased initially but increased after hatching in both breeds and sexes.The within-breed variation in muscle fiber-type composition was greater than the average variation between the breeds.Overall,the percentage of type Ⅰ fibers increased and that of type lIb fibers decreased consistently.However,the percentage of type lla fibers was almost constant as development proceeded in both duck breeds.The profiles of MyoD mRNA expression were similar in both breeds,and a significantly positive relationship was observed between the expression of MyoD and the percentage of type lIb fibers.This study firstly revealed the characteristics of duck muscle development and differences between the two breeds differing in growth rates.Moreover,type lIb fibers might convert to type Ⅰ fibers in the lateral gastrocnemius,while MyoD may potentially function in controlling the muscle fiber phenotype during the secondary myogenesis of muscle development.

Identification of Differentially Expressed Genes Associated with Cotton Fiber Development in a Chromosomal Substitution Line(CS-B22sh)

One of the impediments in the genetic improvement of cotton fiber is the paucity of information about genes associated with fiber development.Availability of chromosome arm substitution line CS-

Genes Expressing Differences in Upland Cotton Fiber Development Between 12 DPA and 16 DPA

Cotton is the major dominant natural fiber crop on the earth.Although some current cotton genetics and breeding programs had made great progresses in cotton lint yield increases and disease resistance(tolerance),fiber quality has little improvement.Global understanding genes expression

GluN2A versus GluN2B:twins,but quite different

N-Methyl-D-aspartate receptors（NMDARs） play vital roles in the central nervous system,as they are primary mediators of Ca2＋influx during synaptic activity.The subunits that compose NMDARs share similar topological structures but are distinct in distribution and pharmacological properties,as well as physiological and pathological functions,which make the NMDAR one of the most complex and elusive ionotropic glutamate receptors.In this review,we focus on GluN2A and GluN2B,the primary NMDAR subunits in the cortex and hippocampus,and discuss their differences in developmental expression,brain distribution,trafficking,and functional properties during neuronal activity.

Identification of genes expressed during myocardial development

Objective To identify genes expressed in the fetal heart that are potentially important for myocardial development and cardiomyocyte proliferation.Methods mRNAs from fetal (29 weeks) and adult cardiomyocytes were use for suppression subtractive hybridization ( SSH) . Both forward (fetal as tester) and reverse ( adult as driver) subtractions were performed. Clones confirmed by dot-blot analysis to be differentially expressed were sequenced and analyzed.Results Differential expressions were detected for 39 out of 96 (41 %) clones on forward subtraction and 24 out of 80 (30%) clones on reverse. For fetal dominating genes, 28 clones matched to 10 known genes (COL1A2, COL3A1 , endomucin, HBG1 , HBG2, PCBP2, LOC51144, TGFBI, vinculin and PND), 9 clones to 5 cDNAs of unknown functions (accession AK021715, AF085867, AB040948, AB051460 and AB051512) and 2 clones had homology to hEST sequences. For the reverse subtraction, all clones showed homology to mitochondrial transcripts.Conclusions We successfully applied SSH to detect those genes differentially expressed in fetal cardiac myocytes, some of which have not been shown relative to myocardial development.