Finley K D, Taylor B J, Milstein M, McKeown M
Molecular Biology and Virology Laboratory, The Salk Institute, San Diego, CA 92186, USA.
Proc Natl Acad Sci U S A. 1997 Feb 4;94(3):913-8. doi: 10.1073/pnas.94.3.913.
Few mutations link well defined behaviors with individual neurons and the activity of specific genes. In Drosophila, recent evidence indicates the presence of a doublesex-independent pathway controlling sexual behavior and neuronal differentiation. We have identified a gene, dissatisfaction (dsf), that affects sex-specific courtship behaviors and neural differentiation in both sexes without an associated general behavioral debilitation. Male and female mutant animals exhibit abnormalities in courtship behaviors, suggesting a requirement for dsf in the brain. Virgin dsf females resist males during courtship and copulation and fail to lay mature eggs. dsf males actively court and attempt copulation with both mature males and females but are slow to copulate because of maladroit abdominal curling. Structural abnormalities in specific neurons indicate a role for dsf in the differentiation of sex-specific abdominal neurons. The egg-laying defect in females correlates with the absence of motor neuronal innervation on uterine muscles, and the reduced abdominal curling in males correlates with alteration in motor neuronal innervation of male ventral abdominal muscles. Epistasis experiments show that dsf acts in a tra-dependent and dsx-independent manner, placing dsf in the dsx-independent portion of the sex determination cascade.
很少有突变能将明确的行为与单个神经元及特定基因的活性联系起来。在果蝇中，最近的证据表明存在一条不依赖双性基因（doublesex）的途径来控制性行为和神经元分化。我们鉴定出了一个基因，名为不满基因（dissatisfaction，dsf），它影响两性的性别特异性求偶行为和神经分化，且不会导致相关的一般性行为衰退。雄性和雌性突变动物在求偶行为上表现出异常，这表明大脑中需要dsf。未交配的dsf雌性在求偶和交配过程中会抗拒雄性，并且无法产下成熟的卵。dsf雄性会积极地向成熟的雄性和雌性求偶并试图交配，但由于腹部卷曲不灵活，交配速度较慢。特定神经元的结构异常表明dsf在性别特异性腹部神经元的分化中起作用。雌性的产卵缺陷与子宫肌肉上运动神经元的缺失有关，而雄性腹部卷曲减少与雄性腹侧腹部肌肉的运动神经元支配改变有关。上位性实验表明，dsf以依赖transformer（tra）且不依赖双性基因（dsx）的方式起作用，将dsf置于性别决定级联反应中不依赖dsx的部分。
