[Progress of the PCR amplification techniques for chromosome walking].

Various PCR-based methods are available for chromosome walking from a known sequence to an unknown region. It is promising in genome-related research for the following experiments: promoter cloning, obtaining non-conservative parts of genes in new species, identification of T-DNA or transposon insertion sites and filling in gaps or unknown chromosome regions in genome sequencing. These methods consisted of three types: inverse PCR, ligation-mediated PCR and specific primer PCR.

[A review on mitochondrial DNA of avian].

Mitochondrial DNA as a genetic marker has been successfully applied to the study of molecular evolution of birds. The apparently maternal inheritance of mitochondrial DNA and its fast evolution in primary sequence has made it attractive in population and evolutionary genetics. Mitochondrial DNA of birds displays two characteristics not seen in other vertebrates mtDNA, that is, a novel gene order and the absence of an equivalent to the light-strand replication origin.

[A high-efficiency method of sorting and sequencing of functional genes].

The implementation of the Human Genome Project preludes the analyzing of biologic genomes. Following the successful analysis of diverse biologic genomes, it becomes more and more important to research the functions of genes and to find new functional genes. In this article, we use the techniques of Megaclone, Megasort and MPSS to sort and sequence effectively different functional genes.

[Studies of the clone and cell expression of human lactoferritin gene].

In this paper,we directly cloned 2.366 Kb cDNA sequence of human lactoferrin gene and 800 bp 5'flank regulatory sequence of beta/lactoglobulin gene from goat by PCR,then connected them with the expression vector pLNCX. The recombinant plasmid pLNCXHLF containing human lactoferrin gene cDNA was transfected into mice mammary tumor cell line MA/782 after liposome transinfection.

[Compariative study of mitochondrial tRNA gene sequence and secondary structure among fifteen Predatory birds].

Three major clusters of mitochondrial tRNA genes (tRNA(Ile) -tRNA(Gln) -tRNA(Met), tRNA(Trp)- tRNA(Ala) -tRNA(Asn)- tRNA(CYs) -tRNA(Tyr) and tRNA(His) tRNA(Ser)(AGY) -tRNA(Leu)(CUN) from 13 species of Predatory birds were amplified and sequenced. The length of these tRNA clusters was similar among species (212 approximately 214 bp, 353 approximately 362 bp, 205 approximately 208 bp, respectively), and 47% of the sequences were variable, 67% of which were involved in the loop regions. The stem regions were relatively conserved, and the variable base pairs were under the restriction of compensatory changes or G-U wobble pairing which could be regarded as mechanisms for maintaining a stable secondary structure.

[Determination of transcription initiation site of chicken ovalbumin gene and construction of its expression vector].

To determine the core promoter of chicken ovalbumin gene and 5' upstream regions, the transcription initiation site of ovalbumin gene was confirmed by 5'RACE method, at the same time, the regulatory elements of chicken ovalbumin gene were determined by sequence analysis. To investigate the ability of regulatory elements to direct the exogenous gene expression, 1.5 kb fragment and 2.

[Sequence variation of mitochondrial cytochrome b gene and phylogenetic relationships among twelve species of Charadriiformes].

Studies of the phylogenetic relationships of the Charadriiformes have been largely based on conservative morphological characters. During the past 10 years, many studies on the evolutionary biology of birds adopted phylogenetic information obtained from mitochondrial DNA, but few work on the Charadriiformes has been reported to date. Therefore, phylogenetic relationships and classification of the Charadriiformes remains controversial.