Schröder R, Jay D G, Tautz D
Zoologisches Institut der Universität München, Luisenstrasse 14, 80333, Munich, Germany.
Mech Dev. 1999 Feb;80(2):191-5. doi: 10.1016/s0925-4773(98)00211-1.
The question of the degree of evolutionary conservation of the pair-rule patterning mechanism known from Drosophila is still contentious. We have employed chromophore-assisted laser inactivation (CALI) to inactivate the function of the pair-rule gene even skipped (eve) in the short germ embryo of the flour beetle Tribolium. We show that it is possible to generate pair-rule type phenocopies with defects in alternating segments. Interestingly, we find the defects in odd numbered segments and not in even numbered ones as in Drosophila. However, this apparent discrepancy can be explained if one takes into account that the primary action of eve is at the level of parasegments and that different cuticular markers are used for defining the segment borders in the two species. In this light, we find that eve appears to be required for the formation of the anterior borders of the same odd numbered parasegments in both species. We conclude that the primary function of eve as a pair rule gene is conserved between the two species.
果蝇中已知的成对规则模式形成机制的进化保守程度问题仍然存在争议。我们利用发色团辅助激光失活（CALI）技术，在面粉甲虫赤拟谷盗的短胚胚胎中使成对规则基因even skipped（eve）的功能失活。我们表明，有可能产生具有交替节段缺陷的成对规则型拟表型。有趣的是，我们发现缺陷出现在奇数节段，而不是像果蝇那样出现在偶数节段。然而，如果考虑到eve的主要作用是在副节水平，并且在这两个物种中使用了不同的表皮标记来定义节段边界，那么这种明显的差异就可以得到解释。据此，我们发现在这两个物种中，eve似乎是形成相同奇数副节前缘所必需的。我们得出结论，eve作为成对规则基因的主要功能在这两个物种之间是保守的。
