Molecular characterization,transcriptional regulation and association analysis with carcass traits of porcine TCAP gene

TCAP (also known as titin-cap or telethonin) is one of the titin interacting Z-disk proteins involved in the regulation and development of normal sarcomeric structure. In this study, we cloned the cDNA and promoter sequences of porcine TCAP gene, which contained a 504 bp full-length coding region. Quantitative real-time PCR (qRT-PCR) analyses showed that porcine TCAP was highly expressed in the skeletal muscle, heart, and kidney. During postnatal muscle development, TCAP expression was down-regulated from 30 days to 120 days in Large White and Meishan pigs. One single nucleotide polymorphism c.334G>A in exon 2 of the TCAP gene was identified and detected by allele-specific primer-polymerase chain reaction (ASP-PCR). Association analysis revealed that the polymorphism had significant associations (P < 0.05 and P < 0.01) with some carcass traits. Analysis of the porcine TCAP promoter in different cell lines demonstrated that it is a muscle-specific promoter. In addition, we found that the porcine TCAP promoter can be activated by MyoD, MyoG and MEF2 in myotubes, which indicated that TCAP may play a role in the regulation of porcine skeletal muscle development. These findings provide useful information for the further investigation of the function of TCAP in porcine skeletal muscle.     

Lipolysis - a highly regulated multi-enzyme complex mediates the catabolism of cellular fat stores

Lipolysis is the biochemical pathway responsible for the catabolism of triacylglycerol (TAG) stored in cellular lipid droplets. The hydrolytic cleavage of TAG generates non-esterified fatty acids, which are subsequently used as energy substrates, essential precursors for lipid and membrane synthesis, or mediators in cell signaling processes. Consistent with its central importance in lipid and energy homeostasis, lipolysis occurs in essentially all tissues and cell types, it is most abundant, however, in white and brown adipose tissue. Over the last 5years, important enzymes and regulatory protein factors involved in lipolysis have been identified. These include an essential TAG hydrolase named adipose triglyceride lipase (ATGL) [annotated as patatin-like phospholipase domain-containing protein A2], the ATGL activator comparative gene identification-58 [annotated as α/β hydrolase containing protein 5], and the ATGL inhibitor G0/G1 switch gene 2. Together with the established hormone-sensitive lipase [annotated as lipase E] and monoglyceride lipase, these proteins constitute the basic "lipolytic machinery". Additionally, a large number of hormonal signaling pathways and lipid droplet-associated protein factors regulate substrate access and the activity of the "lipolysome". This review summarizes the current knowledge concerning the enzymes and regulatory processes governing lipolysis of fat stores in adipose and non-adipose tissues. Special emphasis will be given to ATGL, its regulation, and physiological function.     

ZBTB38 gene polymorphism associated with body measurement traits in native Chinese cattle breeds

Body measurement traits, influenced by genes and environmental factors, play numerous important roles in the value assessment of productivity and economy. In this study, we investigated the association between genetic polymorphisms of the zinc finger and BTB domain containing 38 gene (ZBTB38) and body measurement traits in native Chinese cattle. Using direct DNA sequencing in 423 individuals of 8 different cattle subpopulations, 9 novel polymorphisms were identified for genotyping within 647 bp region of exon 1 of ZBTB38. Linkage disequilibrium and association analysis revealed that two coding exon polymorphisms (2323 G>A and 2325 C>T polymorphisms), missense mutations valine GTC(T) to isoleucine ATC(T), were associated with body length (BL), withers height (WH) and rump length (RL). Furthermore, the analysis of 2323 G>A and 2325 C>T SNP markers shows that there are significant effects on the BL (P = 0.0488), WH (P = 0.0044) and RL (P = 0.0314) in the total population. These results clearly suggest that the ZBTB38 gene is among the target genes for body measurement traits in bovine breeding, and provide data for establishment of an animal model using cattle to study big animal body type.     

Analysis on Frequency and Density of Microsatellites in Coding Seauences of Several Eukarvotic Genomes

Microsatellites or simple sequence repeats (SSRs) have been found in most organisms during the last decade. Since large-scale sequences are being generated, especially those that can be used to search for microsatellites, the development of these markers is getting more convenient. Keeping SSRs in viewing the importance of the application, available CDS (coding sequences) or ESTs (expressed sequence tags) of some eukaryotic species were used to study the frequency and density of various types of microsatellites. On the basis of surveying CDS or EST sequences amounting to 66.6 Mb in silkworm, 37.2 Mb in fly, 20.8 Mb in mosquito, 60.0 Mb in mouse, 34.9 Mb in zebrafish and 33.5 Mb in Caenorhabditis elegans, the frequency of SSRs was 1/1.00 Kb in silkworm, 1/0.77 Kb in fly, 1/1.03 Kb in mosquito, 1/1.21 Kb in mouse, 1/1.25 Kb in zebrafish and 1/1.38 Kb in C. elegans. The overall average SSR frequency of these species is 1/1.07 Kb. Hexanucleotide repeats (64.5%-76.6%) are the most abundant class of SSR in th     

牦牛AQP4基因CDS序列的克隆及其生物信息学特征分析

为了研究高原动物对青藏高原高寒、低氧等极端生境的适应机理,进一步探讨高原动物对高原反应——高原脑水肿抗性的分子机理,运用基因克隆与生物信息学相关技术和方法,对牦牛脑AQP4(水通道蛋白4,AQP4)基因CDS全长序列进行克隆、基因序列比对及其生物信息学特征分析。结果表明,牦牛AQP4的CDS含有一个966 bp的开放阅读框,编码322个氨基酸;牦牛AQP4基因编码蛋白分子量34.69 k D,理论等电点(p I)7.59,其编码蛋白含有6次跨膜结构,属于疏水性蛋白;二级结构主要由α-螺旋、延伸及无规则卷曲构成;AQP4基因编码产物氨基酸同源性及系统进化分析发现,牦牛AQP4基因编码氨基酸序列与黄牛、绵羊等物种间同源性较高,系统进化情况与其亲缘关系远近一致。     

Comparative genomic analysis shows that Streptococcus suis meningitis isolate SC070731 contains a unique 105 K genomic island

Streptococcus suis (SS) is an important swine pathogen worldwide that occasionally causes serious infections in humans. SS infection may result in meningitis in pigs and humans. The pathogenic mechanisms of SS are poorly understood. Here, we provide the complete genome sequence of S. suis serotype 2 (SS2) strain SC070731 isolated from a pig with meningitis. The chromosome is 2,138,568 bp in length. There are 1933 predicted protein coding sequences and 96.7% (57/59) of the known virulence-associated genes are present in the genome. Strain SC070731 showed similar virulence with SS2 virulent strains HA9801 and ZY05719, but was more virulent than SS2 virulent strain P1/7 in the zebrafish infection model. Comparative genomic analysis revealed a unique 105 K genomic island in strain SC070731 that is absent in seven other sequenced SS2 strains. Further analysis of the 105 K genomic island indicated that it contained a complete nisin locus similar to the nisin U locus in S. uberis strain 42, a prophage similar to S. oralis phage PH10 and several antibiotic resistance genes. Several proteins in the 105 K genomic island, including nisin and RelBE toxin–antitoxin system, contribute to the bacterial fitness and virulence in other pathogenic bacteria. Further investigation of newly identified gene products, including four putative new virulence-associated surface proteins, will improve our understanding of SS pathogenesis.     

Predicted structural change in erythropoietin of plateau zokors--adaptation to high altitude

Erythropoietin (EPO) is a glycoprotein hormone, expressed mainly in fetus liver and adult kidneys. EPO plays an important role in enhancing red blood cell formation in bone marrow under hypoxia. Plateau zokor (Myospalax baileyi), an subterranean burrowing endemic rodent inhabiting areas of 2 800-4 200 m above sea level on Qinghai-Tibet Plateau, is a typical high hypoxia tolerant mammal with high ratio of oxygen utilization in adaptation to the harsh plateau environment. To investigate the possible mechanisms of adaptation of plateau zokor EPO to high altitude, the complete cDNA and amino acid sequences of plateau zokor EPO have been described. Phylogenetic tree of Epo showed the convergence of the Spalax and Myospalax, indicating that, the convergent evolution was driven by similar hypoxic ecological niches. Our results showed that some common sites under positive selection in zokor (116M and 144A) and Spalax (102R, 116M, 144A and 152P) are the important sites for Epo biological activity. This study thus reports a gene level observation which may be involved in adaptation to underground life at high altitude.