猕猴桃果实乙烯受体基因Ad-ETR1的克隆及其表达

以"布鲁诺"美味猕猴桃(Actinidia deliciosa cv.Bruno)果实为材料,根据其它植物乙烯受体氨基酸保守区序列,设计简并引物,通过RT-PCR扩增出1个657bp大小的cDNA片段(Ad-ETR1)该片段编码219个氨基酸,与其它植物乙烯受体及其基因的氨基酸及核苷酸同源性在72%～90%之间.Northern杂交结果表明,猕猴桃果实成熟衰老进程中Ad-ETR1 mRNA的积累趋于增加.这种积累的最大值出现在乙烯进入跃变之后;乙烯处理可以促使Ad-ETR1 mRNA最大值提前出现,乙酰水杨酸(ASA)处理则显著抑制Ad-ETR1表达.     

8. OBITUARY

Burger, A. E. 1980. Sexual size dimorphism and aging characters in the Lesser Sheathbill at Marion Island. Ostrich 51:39-43.

Mass and linear dimensions of adult, subadult and juvenile Lesser Sheathbills Chionis minor at Marion Island are given. Males were larger than females in all dimensions but were otherwise similar in external appearance. The larger size of males is attributed to selection favouring male dominance in aggressive territorial encounters. External features of the head and the voice could be used to differentiate adults, subadults and juveniles in the field.     

8. CORRESPONDENCE

This paper investigates, through experiments using surrogate predators, differences in intraspecific alarm calls between familiar and unfamiliar Bronze Mannikin Spermestes cucculatus groups. Four groups of mannikins were captured with mist nets from four areas in Durban (i.e. original groups) and randomly mixed (i.e. assorted groups). These groups were exposed to latex terrestrial snakes and mounted aerial raptors, and their alarm calls and predator response behaviours recorded. The Bronze Mannikins were able to discriminate between predators of different sizes, and increased their calling rate and decreased the end frequency of the alarm call in response to larger predators. This perhaps signalled increased threat, while simultaneously decreasing the conspicuousness of the flock. When the alarm call structure of the original and assorted groups in response to both raptors and snakes was compared, birds in original groups called more often, but paused longer between calls. Anti-predator behaviour differed in that assorted groups were less vigilant and aggressive toward the predators and panicked more frequently. In these groups, a failure to transfer the predation threat information might have caused the group to stop behaving cohesively and reliably. The manipulated experiments carried out in this study indicated that Bronze Mannikins were able to communicate predator size risk to conspecifics, but not as successfully to unfamiliar group members, showing that the investment, probability through altruistic payback, is greater in stable groups.     

8. SHORT NOTES

Stutterheim, C. J. 1980. Moult cycle of the Redbilled Oxpecker in the Kruger National Park. Ostrich 51:107-112.

This paper describes the pattern and rate of the complete moult cycle in the Redbilled Oxpecker Buphagus er ythrorhynchus. The average duration of primary moult in adult birds was 340 days and the mean time to replace a primary feather was calculated as 34 days. The moult of the secondaries is initiated at two points, at the first secondary and at the innermost secondary. Secondary moult takes seven months. The differentiated inner secondaries moult in the normal middle/inner/outer passeriform fashion. The rectrices moulted only once annually. The two body moult cycles correspond with the moult of the differentiated inner secondaries. First-year birds undergo a partial postjuvenile feather replacement at three months of age.