Identification of significant pathway cross-talk in rheumatoid arthritis by the Monte Carlo cross-validation method.

We attempted to identify significant pathway cross-talk in rheumatoid arthritis (RA) by the Monte Carlo cross-validation (MCCV) method. We therefore obtained and preprocessed the gene expression profile of RA. MCCV involves identifying differentially expressed genes (DEGs), identifying differential pathways (DPs), calculating the discriminating score (DS) of the pathway cross-talk, and random forest (RF) classification. We carried out 50 bootstrap iterations of MCCV to identify the key instances of pathway cross-talk involved in RA. We identified a total of 17 significant DEGs and 15 significant DPs by comparing RA samples and normal controls. We found the most significant difference between RA and the normal controls in the eIF4 and p70S6K signaling regulation pathway. Furthermore, we identified 10 instances of pathway cross-talk with the best classification performance for RA and normal controls, using the RF classification model. All of the top 10 pathway pairs involved cross-talk with eIF4 and p70S6K signaling regulation, and the other 10 pathways were immune-related. By MCCV, we identified one critical DP and 10 significant instances of pathway cross-talk in RA. We propose that the eIF4 and p70S6K signaling regulation pathway and the other significant instances of pathway cross-talk play key roles in the occurrence and development of RA, and are potential predictive and prognostic markers for RA.

RESEARCH ARTICLE Molecular cloning and expression analysis of a matrix Gla protein gene in the spinyhead croaker, Collichthys lucidus.

The matrix Gla (gamma-carboxyglutamic acid-rich) protein (MGP), a vitamin K-dependent and Gla-containing protein, is a calcification inhibitor that mainly functions in tissue calcification and mineralization. In this study, we obtained the complete cDNA sequence of MGP from the spinyhead croaker (Collichthys lucidus), which we named Cl-MGP. Cl-MGP was 923 bp long with a 384-bp open reading fragment that encoded 127 amino acids. The predicted MGP protein sequence contained a 19-residue hydrophobic signal peptide, suggesting that it possesses secretory characteristics. The Gla domain and the invariant unit ErraEtCedyspC, which has been identified in all known vitamin K-dependent vertebrate proteins, were highly conserved in Cl-MGP, suggesting that it uses the same mechanism to function as the known proteins. An alignment analysis revealed that Cl-MGP had the highest identity with Larimichthys crocea (93%), which had lost five amino acid residues in the C-terminal. A quantitative real-time polymerase chain reaction revealed that Cl-MGP expression was highest in the gill, followed by the cholecyst and spleen, with almost no expression in the blood, muscle, or testes. The high Cl-MGP expression in the gill is similar to that observed in other fish species, but the relatively high expression found in the cholecyst and spleen is not seen in all species. Future studies should investigate the tissue distributions of both mRNA and proteins in different species, in order to understand the function and evolution of MGP in different species.

Cloning, characterization, expression, and feeding response of thyrotropin receptor in largemouth bass (Micropterus salmoides).

Thyrotropin receptor (TSHR) is a G-protein-coupled receptor that regulates the synthesis, storage, and secretion of thyroid hormones in the thyroid tissue. The aims of the present study were to characterize the full-length TSHR cDNA in largemouth bass (Micropterus salmoides), and to determine the TSHR gene transcription levels in different tissues. In addition, the response of TSHR transcription levels to daily feeding in thyroid tissue was investigated. The results showed that the full-length cDNA sequence was 2743 bp with an open reading frame of 2340 bp encoding a 779-amino acid peptide. BLAST analysis indicated that the amino acid sequence displayed 58.4-90.2% identity and 5.6-125.8 divergence, compared with other known fish species. The most abundant TSHR transcription levels were found in the spleen, head kidney, and kidney. Feeding did not affect the transcription level of TSHR in thyroid tissue over the course of the day. Thus, the current study suggests that there was no relationship between daily nutritional status and TSHR transcription level in the thyroid tissue of largemouth bass. The spleen, head kidney, and kidney exhibited the most abundant TSHR transcription levels.

Molecular cloning and gene expression analysis of cystatin C-like proteins in spinyhead croaker Collichthys lucidus.

Cystatins are natural tight-binding reversible inhibitors of cysteine proteases. In this study, a cDNA library was constructed from Collichthys lucidus using the SMART technique. A complete cDNA sequence with high identity to the conserved sequence of the cystatin C gene was cloned from the library using EST analysis and rapid amplification of cDNA ends (RACE), then subjected to further investigation. The full-length cDNA of cystatin C from C. lucidus (Clcys) was 699 bp long, including a 5'-terminal untranslated region (5'-UTR) of 52 bp, a 3'-UTR of 290 bp, and an open-reading frame of 357 bp. The gene encoded a polypeptide of 118 amino acids, constituting a predicted molecular weight of 12.875 kDa and a theoretical isoelectric point of 8.81. The amino acid sequence of Clcys possessed typical features of type II cystatins and had the highest identity with cystatin C of Pseudosciaena crocea (89%); therefore, it clustered with the cystatin C group in the UPGMA phylogenetic tree. Quantitative real-time reverse transcription analysis revealed that the highest expression was found in the kidney, followed by the liver, heart, and testis, with the lowest expression in muscle. Interestingly, Clcys had relatively low identity with cystatin C genes from other fish and mammals, and its expression pattern did not possess features of a housekeeping gene. Based on these findings, we suspect that the classification of cystatins in fish is somewhat confusing, and the identification of more cystatin gene sequences is needed before a definite conclusion can be drawn.

Characterization, molecular cloning, and expression analysis of Ecsit in the spinyhead croaker, Collichthys lucidus.

Evolutionarily conserved signaling intermediate in Toll pathways (Ecsit) is reported to play an essential role in innate immunity, embryogenesis, and assembly or stability of the mitochondrial complex I. In this study, the full-length cDNA of Ecsit was cloned from the spinyhead croaker Collichthys lucidus based on the expressed sequence tags from our cDNA library constructed using the SMART technique. The cDNA was 1669 bp long, including a 5'-terminal untranslated region (UTR) of 121 bp, a 3'-terminal UTR of 183 bp, and an open reading frame of 1365 bp encoding a 454-amino acid polypeptide. The estimated molecular weight of C. lucidus Ecsit (ClEcsit) was 52.50 kDa with an isoelectric point of 6.14, and contained a typical Ecsit domain that is conserved in other Ecsits. Multiple alignment of ClEcsit with other selected Ecsits suggested that some amino acid residues were highly conserved. Phylogenetic analysis indicated that ClEcsit was more similar to its identities in Sciaenidae and grouped with Ecsits from other Perciformes. Quantitative real-time reverse transcription PCR analysis revealed broad expression of ClEcsit and the transcript was strongly expressed in the gill and weakly expressed in other tissues.

Molecular cloning and mRNA expression of a hepcidin gene from the spinyhead croaker, Collichthys lucidus.

Antimicrobial peptides are important components that participate in host innate immune activities and play crucial roles in host defense against microbial invasion. Hepcidin is an antimicrobial peptide and iron-regulatory molecule that primarily functions in the liver. In the present study, we first obtained a full-length cDNA sequence of hepcidin and its corresponding genomic DNA sequence from Collichthys lucidus using RT-PCR and rapid amplification of cDNA ends (RACE), and then analyzed these sequences using bioinformatics software. The results showed that C. lucidus hepcidin (CL-hepc) possesses two introns and three exons in the genomic DNA, with a length of 816 bp. The open reading frame was 264 bp, encoding an 87 amino acid peptide, and with high similarity (88.89%) to 83416593 Larimichthys crocea (ABC18307) and relatively low similarity (47.73%) to 158358729 L. crocea (ABY84845.1). The pre-peptide contained a signal peptide (28 amino acids), a prodomain (34 amino acids), and a mature peptide (25 amino acids). The predicted 25 amino acid hepcidin mature peptide included 8 conserved cysteine residues. Quantitative real-time reverse transcription-PCR analysis revealed specific expression patterns of CL-hepc, with the highest expression observed in the liver, relatively low expression observed in the gill and spleen, and almost no expression detected in other tissues analyzed. In conclusion, we identified a hepcidin from C. lucidus that has common expression patterns with other hepcidins. However, as this hepcidin is inconsistent with two other hepcidins from L. crocea in terms of the phylogenetic tree, the presence of another hepcidin gene warrants further investigation.

Characterization of hemocyanin from the mud crab Scylla paramamosain and its expression analysis in different tissues, at various stages, and under Vibrio parahaemolyticus infection.

Hemocyanin is an important respiratory protein in many arthropod and mollusk species. Here, four cDNAs (SpHc1, SpHc2, SpHc3, and SpHc4), encoding distinct hemocyanin subunits from Scylla paramamosain were cloned using EST analyses and the rapid amplification of cDNA ends. The four full-length cDNA fragments (SpHc1-4) were 2281, 2002, 2184, and 2069 bp, respectively, and they encoded four putative proteins (570-676 amino acids) with a molecular mass of ~65.0-76.8 kDa. Quantitative real-time PCR analyses revealed that the four genes were mainly expressed in the hepatopancreas, testis, and hemocytes. SpHc mRNA expression during continuous developmental stages in zoeal phases (Z1, Z2, Z3, Z4, and Z5), megalopa, and juvenile crab I stages were also detected. The expression levels of SpHc3 and SpHc4 were higher than that of SpHc1 and SpHc2 during the first six stages, and they sharply declined during the juvenile stage. After infection with Vibrio parahaemolyticus, the temporal expression of both the four SpHc mRNAs in the megalopa stage rapidly declined during the first 3 h, followed by upregulation and peak expression at 12 h after the challenge. The expression levels of the four SpHc subunits were upregulated at 48 h after the challenge, and were then gradually downregulated. These findings suggest that hemocyanin may potentially be involved in the crab immune response, and that the role of the four subunits may differ in different tissues and during various developmental stages.

Characterization and expression analysis of the prophenoloxidase activating factor from the mud crab Scylla paramamosain.

Prophenoloxidase activating factors (PPAFs) are a group of clip domain serine proteinases that can convert prophenoloxidase (pro-PO) to the active form of phenoloxidase (PO), causing melanization of pathogens. Here, two full-length PPAF cDNAs from Scylla paramamosain (SpPPAF1 and SpPPAF2) were cloned and characterized. The full-length SpPPAF1 cDNA was 1677 bp in length, including a 5'-untranslated region (UTR) of 52 bp, an open reading frame (ORF) of 1131 bp coding for a polypeptide of 376 amino acids, and a 3'-UTR of 494 bp. The full-length SpPPAF2 cDNA was 1808 bp in length, including a 5'-UTR of 88 bp, an ORF of 1125 bp coding for a polypeptide of 374 amino acids, and a 3'-UTR of 595 bp. The estimated molecular weight of SpPPAF1 and SpPPAF2 was 38.43 and 38.56 kDa with an isoelectric point of 7.54 and 7.14, respectively. Both SpPPAF1 and SpPPAF2 proteins consisted of a signal peptide, a characteristic structure of clip domain, and a carboxyl-terminal trypsin-like serine protease domain. Expression analysis by qRT-PCR showed that SpPPAF1 mRNA was mainly expressed in the gill, testis, and hemocytes, and SpPPAF2 mRNA was mainly expressed in hemocytes. In addition, SpPPAF1 and SpPPAF2 mRNA was expressed in a time-dependent manner after Vibrio parahaemolyticus challenge. The results showed that expression of both SpPPAF1 and SpPPAF2 was related to the bacterial challenge but the expression patterns differed. These findings suggest that SpPPAF is a serine proteinase and may be involved in the pro-PO activation pathway of the crab innate immune system.

Tissue- and breed-specific expression of the chicken fat mass- and obesity-associated gene (FTO).

The fat mass- and obesity-associated gene (FTO) is involved in energy metabolism, but little is known about the chicken FTO gene. The objective of the current study was to detect chicken FTO expression patterns in the hypothalamus, liver, and skeletal muscle during development, and analyze the effects of age and breed on FTO expression. Real-time quantitative polymerase chain reaction results revealed that chicken FTO mRNA was expressed in all of the tissues tested. Chicken FTO exhibited tissue- and breed-specific patterns in the recessive White Plymouth Rock chicken and the Qingyuan partridge chicken. The highest FTO expression level was in the hypothalami of 1-week-old chicks. FTO mRNA was expressed more in the breast muscles and livers of recessive White Plymouth Rock chickens than those of Qingyuan partridge chickens at 1 and 8 weeks of age. These results indicate that FTO probably plays a significant role in energy metabolism at 1 week old, when chicks have undergone metabolic adaptations from yolk dependence to the utilization of exogenous feed.

Molecular cloning and characterization of a novel Y-box gene from Sepiella maindroni.

Y-box proteins are a family of highly conserved nucleic acid binding proteins that interact with genome and transcription product to modulate the transcriptional and translational processes. In the present study, a complete mRNA of Y-box binding protein (designated SmYB) was obtained from Sepiella maindroni by amplification of flanking sequences. The full size of SmYB cDNA was 1502 bp, including 99 bp at the 5ꞌ untranslated region (UTR), a 3ꞌ UTR of 821 bp with a poly (A) tail, and an open reading frame of 582 bp, encoding a polypeptide of 193 amino acids with the predicted molecular weight of 16.48 kDa. The conserved cold-shock domain and two known RNA binding motifs identified in SmYB strongly suggested that SmYB was a new member of Y-box proteins. Quantitative real-time PCR was performed to examine the expression of SmYB mRNA in various tissues, embryos, and its temporal expression in liver after cold shock. The mRNA transcript of SmYB was detected in all examined tissues, with the highest expression level in testis and ovary. SmYB was abundant in early developmental stages of S. maindroni embryos but diminished in the late post-embryonic development. In addition, cold-shock treatment upregulated the transcription of SmYB mRNA in liver. These results demonstrated that SmYB is involved in embryonic development of S. maindroni and its tolerance to acute low temperatures.

CYFRA21-1 levels could be a biomarker for bladder cancer: a meta-analysis.

The proteolytic region of cytokeratin-19, referred to as CYFRA21-1, is a soluble molecule present in the serum and other body fluids, and is considered a tumor marker in several neoplastic diseases. To examine whether urinary or serum samples containing CYFRA21-1 can be used as biomarkers for bladder cancer, we conducted a comprehensive meta-analysis of 3 case-control studies. In all studies considered, patients with bladder cancer had a higher CYFRA21-1 level than healthy subjects. Subgroup analysis showed that patients with metastatic bladder cancer had a higher CYFRA21-1 level than those with locally invasive disease. However, no significant difference in CYFRA21-1 was observed between patients with stage I and stage II bladder cancer; there was also no difference in patients with stage II local bladder cancer and those with stage III local bladder cancer. Based on our results, CYFRA21-1 level may be a diagnostic biomarker for diagnosing bladder cancer as well as a possible biomarker for differentiation between local and metastatic bladder cancer. However, it cannot be used as a urinary or serum biomarker for differentiating histological stages of local bladder cancer for histological grades I-III.

Molecular cloning and expression analysis of MyD88 in spiny head croaker, Collichthys lucidus.

Myeloid differentiation factor 88 (MyD88) is an important adaptor protein involved in toll-like receptor signaling pathways. In this study, a cDNA library from Collichthys lucidus was constructed using the SMART technique. A complete cDNA sequence showing high identity with the conserved sequence of the MyD88 gene was cloned from the cDNA library using expressed sequence tag analysis and rapid amplification of cDNA ends, and then subjected to further investigation. The full-length cDNA of MyD88 from C. lucidus (ClMyD88) was 1580 bp, including a 5'-terminal untranslated region (UTR) of 102 bp, a 3'-terminal UTR of 614 bp, and an open reading frame of 864 bp. The gene encoded a polypeptide of 287 amino acids, constituting a predicted molecular weight of 33.03 kDa and a theoretical isoelectric point of 5.06. It contained a typical death domain at the N-terminal and a conservative toll/IL-1 receptor domain structure at the C-terminal. Quantitative real-time reverse transcription PCR analysis revealed broad expression of ClMyD88, with the highest expression in the gill and the weakest expression in the brain and muscle. These results indicated that MyD88 has an important role in the innate immune system in C. lucidus.

Role of TGFB1 polymorphism in the development of metastatic brain tumors in non-small cell lung cancer patients.

We conducted a case-control study to investigate the role of 3 single-nucleotide polymorphisms of the gene encoding transforming growth factor-b1 (TGFB1) in the development of metastatic brain tumors in non-small cell lung cancer patients. The polymorphisms in TGFB1 rs4803455, rs1800469, and rs1800470 were evaluated by polymerase chain reaction-restriction fragment length polymorphism. Odds ratios and their corresponding 95% confidence intervals were used to assess the influence of TGFB1 rs4803455, rs1800469, and rs1800470 on metastatic brain tumors. We found that cases were more likely to have a later disease stage when compared with control subjects, without brain metastasis. Individuals carrying the TGFB1 rs1800469 TT and CT+TT genotypes had an increased risk of developing brain metastasis compared with the rs1800469 CC genotype. Moreover, a significant interaction was observed between the rs1800469 polymorphism and disease stage. However, no significant association between polymorphisms rs4803455 and rs1800470 and the risk of developing brain metastasis were observed. We found that the TGFB1 rs1800469 polymorphism may be predictive biomarker for the risk of developing brain metastasis in non-small cell lung cancer patients.

Molecular characterization, expression, and functional analysis of NOD1 in Qingyuan partridge chicken.

Nucleotide-binding oligomerization domain-containing protein-1 (NOD1) is a cytoplasmic pattern recognition receptor (PRR) and a key member of the NOD-like receptor (NLR) family. It has been reported that NLRs recognize a variety of microbial infections to induce the host innate immune response via modulation of NF-κB signaling. However, no reports on chicken NOD1 have been reported to date. In the current study, the full-length cDNA sequence of NOD1 was cloned. The complete open reading frame of NOD1 contains 2856 bp and encodes a 951 amino acid protein. Structurally, it is comprised of one caspase recruitment domain at the N-terminus, seven leucine-rich repeat regions at the C-terminus, and one NACHT domain between the N and C-termini. Phylogenetic analyses showed that chicken NOD1 clusters with duck and turkey. Furthermore, tissue-specific expression analyses of chicken NOD1 were performed using quantitative reverse transcription-PCR. NOD1 is widely distributed in various tissues, with the highest expression observed in testes. Finally, induced expression of chNOD1 and its associated adaptor molecule receptor-interacting protein 2, as well as the effector molecule NF-κB, was observed following S. enterica serovar Enteritidis infection. These findings highlight the important role of chicken NOD1 in response to pathogenic invasion. The present study is the first report of the cloning, expression, and functional analysis of chicken NOD1 and provides the foundation for future research on the structure and function of chicken NOD1.

Identification of long non-coding RNA involved in osteogenic differentiation from mesenchymal stem cells using RNA-Seq data.

The aim of this study was to identify long non-coding RNA (lncRNA) associated with osteogenic differentiation from mesenchymal stem cells (MSCs) using high-throughput RNA sequencing (RNA-Seq) data. RNA-Seq dataset was obtained from the European Bioinformatics Institute (accession No. PRJEB4496), including two replicates each for immortalized mesenchymal stem cells iMSC#3 cultured in growth medium (GM) and differentiation medium (DM) for 28 days. The clean reads were aligned to a hg19 reference genome by Tophat and assembled by Cufflinks to identify the known and novel transcripts. RPKM values were calculated to screen for differentially expressed RNA. Novel lncRNA were screened based on various filter criteria. Subsequently, the underlying function of novel lncRNAs were predicted by functional annotation by ERPIN, a co-expression network was constructed by WGCNA and the KEGG pathway enriched by KOBAS. A total of 3171 RNA differentially expressed between the DM and GM groups (2597 mRNA and 574 lncRNA) were identified. Among the 574 differentially expressed lncRNA, 357 were known and 217 were novel lncRNA. Furthermore, 32 novel lncRNA were found to be miRNA precursors (including miR-689, miR-640, miR-601, and miR-544). A total of 14,275 co-expression relationships and 217 co-expression networks were obtained between novel lncRNA and mRNA. The differentially expressed lncRNA and mRNA were enriched into 6 significant pathways, including those for cancer, ECM-receptor interaction, and focal adhesion. Therefore, novel lncRNAwere identified and their underlying function predicted, which may provide the basis for future analyses of the role of lncRNA in osteoblastic differentiation.

Influence of adenosine on preservation of porcine pancreas in islet transplantation.

Ischemia time during transplantation has greatly restricted the quality and utilization of grafts. To improve the quality of islet transplantation, adenosine was added into the University of Wisconsin (UW) pancreas perfusate to assess its effect on islet yield and function in porcine pancreas. Ten pancreata from donation after cardiac death pigs were obtained and randomly divided into two groups: control group (N = 5) with UW perfusion solution, and experimental group (N = 5) with adenosine-enriched UW perfusion solution. The yield and purity of the islet cells were counted after they were collected, purified, and stained with dithizone. Acridine orange/propidium iodide staining was applied to determine islet cell viability. Islet function was assessed by glucose stimulated insulin secretion assays, and released insulin was quantified by enzyme-linked immunosorbent assay. The metabolic substrates of the pancreas were analyzed by trace dialysis technology. We found that the addition of adenosine in UW perfusion solution significantly increased the yield, purity and viability of islet cells, as well as enhanced their insulin release. In addition, the levels of metabolic substrates, pyruvate and lactate, were significantly reduced. The addition of adenosine could effectively increase islet cell viability during mechanical perfusions, which may improve islet transplantation. This perfusion protocol may be clinically feasible, and should be considered in the clinical setting.

Screening of genes related to ovarian development in the swimming crab, Portunus trituberculatus, by suppression subtractive hybridization.

The swimming crab, Portunus trituberculatus, is an important marine animal and is widely cultured in China. In the present study, suppression subtractive hybridization was applied to identify the differentially expressed genes in the ovaries of mature and immature P. trituberculatus. One hundred and seventy six expressed sequence tag (ESTs) were identified, of which 100 were down-regulated, and 76 up-regulated. BLAST analysis identified 51 unigenes, of which 27 were down-regulated, and 24 up-regulated. Quantitative real-time reverse transcriptase polymerase chain reaction results indicated that the SSH technique is valuable in screening genes related to ovarian development. Genes identified in this study encoded proteins corresponding to a wide range of functions and included immune response protein, transcription initiation factor, metabolic proteins, chromosome, histone h3, ovarian development-related protein, and vitellogenin. In addition, 64 metabolic pathways were annotated in differentially expressed ESTs by using the Kyoto Encyclopedia of Genes and Genomes pathway. Four annotated pathways (oxidative phosphorylation, carbon metabolism, fatty acid degradation, and protein digestion and absorption) appeared to be involved in ovarian development. In ontology analysis, 5.83% of the cellular process genes in reverse subtraction cDNA library are involved in reproduction, and 5.88% involved in developmental process. In up-regulated genes, myosin II-expressed polehole-like protein; histone h3; ovigerous-hair stripping substance; peritrophin 48; and ovarian development-related protein appeared to be involved in ovarian development. Identification of differentially expressed genes in the mature and immature ovary of the swimming crab provides new insights for further studies on the mechanism underlying ovarian development in this species.

mRNA expression profiles of heat shock proteins of wild and salinity-tolerant swimming crabs, Portunus trituberculatus, subjected to low salinity stress.

Challenged by the low salinity, 4 parts per thousand (4 ppt), for 72h, the survivals of swimming crabs (Portunus trituberculatus) were collected as the screened group (SG, tolerant to low salinity). Aiming at identifying the mechanism of low salinity tolerance, quantitative real-time PCR was employed to investigate the expression profiles of 4 HSP genes (HSP60, HSP70, HSP90-1, HSP90-2) in the hepatopancreas of wild (WG) and screened (SG) groups of P. trituberculatus exposed to low salinity (4 ppt). The results showed that 3 of the candidate genes (HSP60, HSP70, HSP90-1) exhibited similarly downregulated expression profiles in the first 3 h (P < 0.05), which became upregulated from 3 h to 72 h after being subjected to low salinity conditions. In contrast, the expression profile of the HSP90-2 gene was upregulated during the first 6 h for the WG, and during the first 12 h for the SG, after which it became downregulated. HSP90-1 and HSP90-2 were highly expressed at 12 h after low salinity challenge in the SG, but not the WG. The response of these 2 genes to salinity stress indicates their suitability as biomarkers to differentiate SG from WG crabs. The results indicate that HSP genes are involved in the adaptation of crabs to low salinity exposure, and that different HSPs have diverse functions in response to low salinity stress in P. trituberculatus. In addition, HSP expression in SG indicates that this group is more tolerant to low salinity conditions compared to WG.

Development of polymorphic expressed sequence tag-single sequence repeat markers in the common Chinese cuttlefish, Sepiella maindroni.

The common Chinese cuttlefish (Sepiella maindroni) is one of the popular edible cephalopod consumed across Asia. To facilitate the population genetic investigation of this species, we developed fourteen polymorphic microsatellite makers from expressed sequence tags of S. maindroni. The number of alleles at each locus ranged from 6 to 10 with an average of 7.9 alleles per locus. The ranges of observed and expected heterozygosity were from 0.615 to 0.962 and 0.685 to 0.888, respectively. Four loci were found deviated significantly from Hardy-Weinberg equilibrium. The polymorphism information content ranged from 0.638 to 0.833. These polymorphic microsatellite loci will be helpful for the population genetic, genetic linkage map, and other genetic studies of S. maindroni.

Association of chicken growth hormone polymorphisms with egg production.

Growth hormone (GH) has diverse functions in animals, together with other hormones from the somatotropic axis. Here, chicken GH (cGH) was investigated in recessive white chickens and Qingyuan partridge chickens as a candidate gene affecting egg production traits. Chicken egg production traits were studied in association with 4 selected single nucleotide polymorphisms (T185G, G662A, T3094C, and C3199T). Genotyping was performed by the polymerase chain reaction-ligase detection reaction method. T185G was significantly associated with the egg production traits of body weight at first egg (BW), egg weight at first egg (EW), and the total egg production of 300-day old birds (EN 300). T3094C was also significantly associated with certain egg production traits; however, it affected the 2 breeds differently. Haplotypes of the 4 single nucleotide polymorphisms were also significantly associated with egg production traits of chicken age at first egg laying, BW, EW, and EN 300. H1H6 was the most advantageous diplotype for egg production. We putatively concluded that polymorphisms in the cGH gene and its haplotypes could be used as potential molecular markers for egg production traits to enhance the breeding programs of indigenous chickens.