The spatio-temporal expressed profiles of two kinds of chemical communication-related protein genes, the odorant-binding protein of Ac-ASP2 and chemosensory protein of Ac-ASP3, were identified by real-time polymerase chain reaction (PCR). Results obtained using the 2−ΔΔCt method showed that Ac-ASP2 was a gene coding antenna-specific protein that did not express in larvae and pupae, but had discontinuous high abundance periods at 1, 9, 15, 27 and 30 days. The expressing abundance at such periods was at least ten times higher than that at other periods. From the distribution of Ac-ASP3 mRNA observed in different tissues, the transcript levels seemed to be higher in the wings, abdomen and thorax (of order ~106), and lower in the legs, antennae and head (of order ~105). From highest to lowest, the original copy number was found in the various body parts in the following order: wings, abdomen, thorax, legs, antenna, and head. The results suggest that Ac-ASP3 has an intimate relation with the chemosensory behaviour of wings and abdomen in Apis cerana cerana.

Efficiency and specificity are key limiting factors for the production of transgenic animals. This review describes the recently developed animal gene transfer techniques, including non-site-specific methods of gene transfer into the testis and ovary for easy production of transgenic animals; gene targeting in embryonic stem cells, somatic cells and primordial germ cells for site-specific methods; methods to improve cloning efficiency in gene targeting; and site- and timing-specific gene targeting and controlled expression of transferred genes. In addition, methods of utilizing newly developed RNA interference, combined with the above techniques for controlling gene expression, to produce transgenic animals to spatio-temporally and reversibly knock down specific genes, are also discussed. The merits and disadvantages of each method are covered, as well as the potential use of these methods to develop transgenic animals for breeding new animal lines, to study disease models and to produce therapeutic medicines.