Differential expression of Toll-like receptors in goat dominant and nondominant follicles.

The mechanism of dominant follicle selection is unclear because of its physiological complexity. However, some studies have reported that the immune system plays an important role in reproductive physiology. The objective of the current study was to investigate the differential expression of Toll-like receptors (TLRs) in the dominant (DFs) and nondominant follicles (NFs), and to determine the correlation between the expression of TLRs and the related genes, such as WNT4 and FOXL2. In this comparative study, the expression levels of TLRs, WNT4, and FOXL2 genes of DFs and NFs were obtained from three Dazu black goats were estimated using the real-time PCR. Our results showed no significant difference in the expression of seven TLRs (excluding TLR2, TLR5, and TLR8), WNT4, and FOXL2 between the DFs and NFs. In addition, the mRNA expression levels of WNT4 significantly correlated with the relative expression of TLR6 (r = 0.949739, P < 0.01); however, no significant expression of the TLR genes was found to be associated with FOXL2 mRNA expression. Our results support the fact that TLRs are not involved in the process of dominant follicle selection; however, TLR6 might play a role in the development of follicles by interacting with WNT4.

Desmoglein 4 diversity and correlation analysis with coat color in goat.

Desmoglein 4 (DSG4) has an important role in the development of wool traits in domestic animals. The full-length DSG4 gene, which contains 3918 bp, a complete open-reading-frame, and encodes a 1040-amino acid protein, was amplified from Liaoning cashmere goat. The sequence was compared with that of DSG4 from other animals and the results show that the DSG4 coding region is consistent with interspecies conservation. Thirteen single-nucleotide polymorphisms (SNPs) were identified in a highly variable region of DSG4, and one SNP (M-1, G>T) was significantly correlated with white and black coat color in goat. Haplotype distribution of the highly variable region of DSG4 was assessed in 179 individuals from seven goat breeds to investigate its association with coat color and its differentiation among populations. However, the lack of a signature result indicates DGS4 haplotypes related with the color of goat coat.

Translation of foot-and-mouth disease virus RNA: factors influencing alternative AUG selection.

The mechanism of alternative AUG usage in foot-and-mouth disease virus is not completely understood. Using simple computational approaches, we evaluated the contributions of overall codon bias, quantitative codon bias, and %GC of the region between the two alternative AUGs, Region-La, as well as the nucleotide bias of the sequence context flanking each AUG with respect to translation initiation efficiency. For all serotypes of this virus, we found that only a small component of the effect of RNA secondary structure on ribosome scanning was due to the low %GC of Region-La. In addition, we found that the nucleotide bias of the context from position -4 to +6 flanking the AUG(2nd) had a negative correlation with the overall codon bias, and that a strong purine bias existed in this AUG(2nd)context. However, the quantitative codon bias of Region-La was seen to be significantly lower than that of Region-Lb (the sequence following AUG(2nd)) in all serotypes except SAT 1-3. Taken together, our results suggest that the low codon bias of Region-La might impair the translation initiation efficiency at the AUG(1st) in all serotypes except SAT 1-3, and the specific AUG(2nd) context might be used as a strong signal to initiate translation from the AUG(2nd) in all serotypes.

Dynamic comparison of genetic diversity in a Small Tail Han sheep population using meta-analysis.

The aim of this research was to identify the dynamic diversity of Small Tail Han sheep in its main producing areas between different years, and provide a basis for a breeding and genetic resources conservation strategy. For this purpose, 15 microsatellites were genotyped for Small Tail Han Sheep sampled in 2014 from Heze, China, and a comparative analysis of these data with those from a previous study was undertaken using meta-analysis. The results reveal that inbreeding has caused a reduction in diversity of Small Tail Han Sheep from 2008 to 2014. Overall, our results are helpful in understanding the dynamic change in diversity, as well as providing information for a conservation strategy for this population.

Biological characterization of liver fatty acid binding gene from miniature pig liver cDNA library.

Liver fatty acid binding proteins (L-FABP) are a family of small, highly conserved, cytoplasmic proteins that bind to long-chain fatty acids and other hydrophobic ligands. In this study, a full-length enriched cDNA library was successfully constructed from Wuzhishan miniature pig, and then the L-FABP gene was cloned from this cDNA library and an expression vector (pEGFP-N3-L-FABP) was constructed in vitro. This vector was transfected into hepatocytes to test its function. The results of western blotting analysis demonstrated that the L-FABP gene from our full-length enriched cDNA library regulated downstream genes, including the peroxisome proliferator-activated receptor family in hepatocytes. This study provides a theoretical basis and experimental evidence for the application of L-FABP for the treatment of liver injury.

Brief Note Low diversity of the major histocompatibility complex class II DRA gene in domestic goats (Capra hircus) in Southern China.

DRA encodes the alpha chain of the DR heterodimer, is closely linked to DRB and is considered almost monomorphic in major histocompatibility complex region. In this study, we identified the exon 2 of DRA to evaluate the immunogenetic diversity of Chinese south indigenous goat. Two single nucleotide polymorphisms in an untranslated region and one synonymous substitution in coding region were identified. These data suggest that high immunodiversity in native Chinese population.

Short Communication: Diversity of TNF-α region in Chinese domestic goats.

Tumor necrosis factor-α is a cytokine with a wide range of effects on both lymphoid and non-lymphoid cells. In this study, we identified polymorphisms in major histocompatibility complex class III gene in the 4th exon and the 3' untranslated region of tumor necrosis factor-α to evaluate the immunogenetic diversity of Chinese south indigenous goat. Three single-nucleotide polymorphisms were identified and showed similar frequencies in different except MI loci. These data suggest that the high immunodiversity of the tumor necrosis factor-α region within these breeds can be used for strengthening variety improvement and promoting animal husbandry development in Chinese indigenous goats.

Construction and characterization of a cDNA expression library from the endangered Hu sheep.

Hu sheep is one of the most important species in China; it is also listed as one of the 78 nationally protected domestic animals by the Chinese government in 2000. The construction of cDNA expression library of Hu sheep is of great significance for protecting individual genomes, generating transgenic sheep, and conducting clinical research using cDNA from Hu sheep. In this study, the total RNA from the ear tissue of Hu sheep was extracted, and a cDNA expression library was constructed using the SMART(TM) technique. The titer of amplified cDNA library was 1.09 x 10(10) PFU/mL, the rate of recombination was above 91.6%, and the average size of fragments was 1.1 kb. This study has an important significance for the preservation of Hu sheep resources at the genome level.

Screening and analyzing genes associated with Amur tiger placental development.

The Amur tiger is a unique endangered species in the world, and thus, protection of its genetic resources is extremely important. In this study, an Amur tiger placenta cDNA library was constructed using the SMART cDNA Library Construction kit. A total of 508 colonies were sequenced, in which 205 (76%) genes were annotated and mapped to 74 KEGG pathways, including 29 metabolism, 29 genetic information processing, 4 environmental information processing, 7 cell motility, and 5 organismal system pathways. Additionally, PLAC8, PEG10 and IGF-II were identified after screening genes from the expressed sequence tags, and they were associated with placental development. These findings could lay the foundation for future functional genomic studies of the Amur tiger.

Identification of complete linkage disequilibrium in the DSG4 gene and its association with wool length and crimp in Chinese indigenous sheep.

The desmoglein 4 (DSG4) gene is a potential candidate in the search for genes that may affect wool traits, because of its function. This study aimed to screen for polymorphisms in partial exon 16 and 3ꞌUTR of the sheep desmoglein 4 DSG4 gene, and to test its possible association with wool length and crimp associated with fur. Overall, 326 sheep were scanned via single-strand conformational polymorphism assay, through three pairs of primers. The breeds included Tan, Han, and TanxHan from China, Polled Dorset from Australia, and Suffolk from Britain genotypes AA, BB, and AB for primer2 and genotypes DD, EE, and DE for primer3 were detected in native breeds. Six SNPs and 3-bp insertion/deletions were found in exon 16, of which 4 lead to amino acid substitutions. In addition, 1 SNP was found in 3ꞌUTR. The DSG4 genotype was found to be strongly associated with all wool traits that were considered in this study (P < 0.01). Sheep with the genotype MM had a higher least square mean compared to sheep with the genotype WW or WM with respect to birth scapular wool length (P < 0.01), crimp number of birth scapular wool crimp (P < 0.01), crimp number of weaning scapular wool crimp (P < 0.01), and crimp number of weaning rump wool crimp (P < 0.01, P < 0.05). In conclusion, our study is the first to demonstrate that the DSG4 gene may be a candidate, or major gene, which influences important wool traits.

Developmental changes in IGF-I and MyoG gene expression and their association with meat traits in sheep.

In the present study, real time-polymerase chain reaction was applied to analyze the expression of IGF-I and MyoG genes in Hu sheep longissimus dorsi at different growth stages and their association with meat traits. Expression of the IGF-I gene in Hu sheep differed significantly between males and females at the two day-old (0.01 < P < 0.05), one-month old (0.01 < P < 0.05), and three month-old (P < 0.01) stages. IGF-I gene expression in male longissimus muscles was higher than that of females at all growth stages, except for the three month-old stage. There was no significant difference (P > 0.05) between males and females at any growth stage in expression of the MyoG gene. MyoG gene expression in male longissimus muscles tended to be higher than that of females at all growth stages, except for the six month-old stage. IGF-I gene expression was significantly and positively correlated with live weight (P < 0.01) and carcass weight (0.01< P < 0.05), and was non-significantly positively correlated with net meat weight (P > 0.05). In contrast, MyoG gene expression was non-significantly and positively correlated with live weight, carcass, and net meat weight (P > 0.05). Carcass traits showed highly significant positive correlations (P < 0.01). Furthermore, expressions of IGF-I and MyoG genes showed highly significant positive correlations (P < 0.01). We conclude that the expressions of IGF-I and MyoG genes are significantly and positively correlated with early muscle traits of Hu sheep.

Genetic variations of ISL1 associated with human congenital heart disease in Chinese Han people.

Congenital heart disease (CHD) is the most common birth abnormality, but the etiology of CHD is unknown. ISL1 may play a fundamental role in cardiac morphogenesis, and mutations of this gene could cause CHD. To evaluate whether genetic variations of ISL1 are associated with CHD in Chinese Han people, polymerase chain reaction restriction fragment-length polymorphism and SNaPshot were used to examine 9 polymorphisms of ISL1 in 233 patients with CHD as well as 288 healthy controls. We found that one SNP (rs1017) in ISL1 was significantly associated with simple CHD. Genetic variation of ISL1 was confirmed to be associated with the risk of CHD. ISL1 is related to the atrial septal defect group and the ventricular septal defect group, and the genotypes were associated with the occurrence of CHD in the dominant mode of inheritance. We concluded that rs1017 contributed to the risk of CHD in Chinese Han people, and ISL1 may be involved in the formation and development of the heart.