Hayakawa Y, Shimada K, Noguchi H, Kostal V
Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
J Insect Physiol. 1998 Jul;44(7-8):605-614. doi: 10.1016/s0022-1910(98)00043-2.
Dopamine and two related catecholamines, L-3,4-dihydroxyphenylalanine (DOPA) and N-acetyl dopamine (NADA), were analyzed in whole body and tissue samples taken throughout late larval development of the drosophilid fly Chymomyza costata, which enters facultative diapause as a mature 3rd instar larva in response to short photophase. Wild-type (W) and mutant-nondiapause (M) strains reared under diapause inducing (d) and preventing (nd) photophases were compared. Developmental changes in the whole body of dopamine levels showed some general features irrespective of fly strain and rearing conditions: sharp major peaks during moult from second to third instar larva and during pupariation; lower minor peaks around the middle of both 2nd and 3rd instars. Significant differences between the strains and conditions were also found: dopamine levels were lower throughout the 2nd instar and during the 2nd to 3rd instar moult of mutant strain larvae (M/d) as compared to wild-type larvae (W/nd and W/d); while the late 2nd and late 3rd instar larvae destined to diapause (W/d) maintained relatively high dopamine concentrations, their counterparts destined to continuous development (W/nd and M/d) significantly decreased dopamine levels prior to the 2nd to 3rd instar moult or pupariation. Possible relationship between the dopamine levels and diapause induction/onset in C. costata larvae is discussed. Integument contained more than 90% of the dopamine found in the whole body. The gut and central nervous tissues showed relatively low pools of dopamine, only trace amounts were detected in haemolymph and no dopamine was found in fat body. DOPA levels were low and stable throughout larval development of both W and M strains and under both conditions. NADA levels peaked during second halves of 2nd and 3rd instars of both strains, then dropped to trace levels and were elevated again during 2nd to 3rd instar moult as well as in tanned prepupae. No elevation of NADA levels was recorded in 3rd instar W/d larvae which entered diapause.
在果蝇科昆虫科斯塔氏嗜腐蝇（Chymomyza costata）整个幼虫后期发育过程中采集的全身和组织样本中，对多巴胺以及两种相关的儿茶酚胺——L-3,4-二羟基苯丙氨酸（DOPA）和N-乙酰多巴胺（NADA）进行了分析。该果蝇作为成熟的三龄幼虫，在短光照期会进入兼性滞育。对在滞育诱导（d）和滞育阻止（nd）光照阶段饲养的野生型（W）和突变非滞育（M）品系进行了比较。多巴胺水平在果蝇全身的发育变化呈现出一些总体特征，与果蝇品系和饲养条件无关：在从二龄幼虫到三龄幼虫蜕皮期间以及化蛹期间出现明显的主要峰值；在二龄和三龄幼虫中期左右出现较低的次要峰值。在品系和条件之间也发现了显著差异：与野生型幼虫（W/nd和W/d）相比，突变品系幼虫（M/d）在整个二龄幼虫期以及从二龄幼虫到三龄幼虫蜕皮期间多巴胺水平较低；而注定进入滞育的二龄晚期和三龄晚期幼虫（W/d）保持相对较高的多巴胺浓度，它们注定持续发育的对应幼虫（W/nd和M/d）在从二龄幼虫到三龄幼虫蜕皮或化蛹前多巴胺水平显著降低。讨论了科斯塔氏嗜腐蝇幼虫中多巴胺水平与滞育诱导/开始之间的可能关系。体表含有的多巴胺占全身多巴胺的90%以上。肠道和中枢神经组织中的多巴胺含量相对较低，血淋巴中仅检测到微量多巴胺，脂肪体中未发现多巴胺。在W和M品系的整个幼虫发育过程中以及两种条件下，DOPA水平都较低且稳定。两种品系的二龄和三龄幼虫后半期NADA水平达到峰值，然后降至微量水平，并在从二龄幼虫到三龄幼虫蜕皮以及在鞣化的预蛹期再次升高。进入滞育的三龄W/d幼虫未记录到NADA水平升高。
