Martín-Blanco E, García-Bellido A
Centro de Biología Molecular "Severo Ochoa," Consejo Superior de Investigaciones Cientificas, Universidad Autónoma de Madrid, Spain.
Proc Natl Acad Sci U S A. 1996 Jun 11;93(12):6048-52. doi: 10.1073/pnas.93.12.6048.
In bilateral animals, the left and right sides of the body usually present asymmetric structures, the genetic bases of whose generation are still largely unknown [CIBA Foundation (1991) Biological Asymmetry and Handedness, CIBA Foundation Symposium 162 (Wiley, New York), pp. 1-327]. In Drosophila melanogaster, mutations in the rotated abdomen (rt) locus cause a clockwise helical rotation of the body. Even null alleles are viable but exhibit defects in embryonic muscle development, rotation of the whole larval body, and helical staggering of cuticular patterns in abdominal segments of the adult. rotated abdomen is expressed in the embryonic mesoderm and midgut but not in the ectoderm; it encodes a putative integral membrane glycoprotein (homologous to key yeast mannosyltransferases). Mesodermal cells defective in O-glycosylation lead to an impaired larval muscular system. We propose that the staggering of the adult abdominal segments would be a consequence of the relaxation of intrinsic rotational torque of muscle architecture, preventing the colateral alignment of the segmental histoblast cells during their proliferation at metamorphosis.
在两侧对称动物中，身体的左侧和右侧通常呈现不对称结构，其产生的遗传基础在很大程度上仍然未知[CIBA基金会（1991年）《生物不对称与利手性》，CIBA基金会专题讨论会162（威利出版社，纽约），第1 - 327页]。在黑腹果蝇中，旋转腹部（rt）基因座的突变会导致身体顺时针螺旋旋转。即使是无效等位基因也是可存活的，但在胚胎肌肉发育、整个幼虫身体旋转以及成虫腹部节段表皮图案的螺旋交错方面表现出缺陷。旋转腹部在胚胎中胚层和中肠中表达，但在外胚层中不表达；它编码一种假定的整合膜糖蛋白（与关键酵母甘露糖基转移酶同源）。O - 糖基化缺陷的中胚层细胞会导致幼虫肌肉系统受损。我们提出，成虫腹部节段的交错是肌肉结构固有旋转扭矩松弛的结果，这会阻止节段性组织母细胞在变态发育期间增殖时的侧向排列。
