[Isothermal unidirectional elongation method of gene synthesis].

Gene synthesis is gaining popularity as a versatile means of cloning genes. The prevailing synthesis methods are PCR-based and ligase-based gene synthesis. Both of them are not independent of the sequence content of the target gene. In the present study, a new gene synthesis method-isothermal unidirectional elongation method (IUEM) is proposed, which involves the cooperation of three enzymes, and is independent or partially independent of the target gene sequence by the specially designed oligonucleotides that form hairpins. The synthesis process is isothermal and serial in IUEM. Several factors that affect the elongation were studied, and two DNA segments of length 254 bp and 300 bp were synthesized with IUEM. The synthesized segments could work as building blocks for the synthesis of longer DNA sequences.

[Correlation between adenylosuccinate lyase (ADSL) gene polymorphism and inosine monophosphate acid (IMP) content in domestic fowl and genetic relationship between red jungle fowl and domestic fowl].

This study investigates single nucleotide polymorphism (SNP) of the adenylosuccinate lyase(ADSL) gene in variety chicken breeds, including Recessive White chickens, Silkies chickens, Baier chickens, Tibetan chickens and two red jungle fowls. Primers for exon 2 in ADSL gene were designed based on the chicken genomic sequence and a SNP(C/T at 3484) was detected by PCR-SSCP and DNA sequencing. Three genotypes within all breeds were found and least square analysis showed that TT genotype birds had a significant higher inosine monophosphate acid (IMP) content than TC (P < 0.01) and CC (P < 0.05) genotype birds, TC genotype birds had a little higher IMP content than CC genotype birds, but the difference was not significant. We proposed this SNP site correlated with IMP content in chickens. A neighbour-joining dendrogram was constructed based on the Nei's genentic distance. The genetic relationship between Chinese red jungle fowl and Tibetan chickens was the nearest, whereas Baier chickens were more closer to Silkies chickens. The Chinese red jungle fowls were relatively closer to the domestic fowls, whereas Thailand red jungle fowls were relatively diverging to the Chinese native breeds. These results supported the theory concerning the independent origins of Chinese native fowl breeds.

[Advances on melatonin receptor gene].

Melatonin exerts its biological effects through pharmacological specific, high affinity G protein-coupled receptors. This review introduced the structure, function, and regulation of melatonin receptor,the cloning and structure, developmental expression, mapping and polymorphism of melatonin receptor gene. The relationship between melatonin receptor gene and reproductive seasonality was also discussed.