Menon Triveni, Bhattrai Janakraj, Nair Sreelaja
Department of Biological Sciences, Tata Institute of Fundamental Research.
Matters Sel. 2017 Oct 6;2017:201705000003. doi: 10.19185/matters.201705000003.
The phenomenon of phenotype manifestation when the single allele in a haploid is affected is desirable for uncovering recessive mutations expeditiously in a diploid organism. However, experimentally generated haploids manifest extensive lethality and a cluster of non-specific developmental defects known as the haploid syndrome. This precludes the use of experimentally generated haploids for genetic screens due to an insufficient number of embryos for screening and the possibility of phenotypes due to the affected gene being masked by the haploid syndrome. We show here that gynogenic haploid zebrafish can be generated by irradiation of spermatozoa with a lower UV dosage than is currently used. This strategy results in reduced haploid lethality, incidence and severity of haploid syndrome. When viewed in the context of zebrafish as a genetically tractable model organism for forward and reverse genetic strategies, these results place zebrafish in a unique niche as a vertebrate in which haploid genetic screens for developmental phenotypes could be successfully attempted.
单倍体中的单个等位基因受到影响时出现的表型表现现象，有利于在二倍体生物体中快速发现隐性突变。然而，实验产生的单倍体表现出广泛的致死性以及一系列称为单倍体综合征的非特异性发育缺陷。由于用于筛选的胚胎数量不足，以及受影响基因的表型可能被单倍体综合征掩盖，这使得实验产生的单倍体无法用于遗传筛选。我们在此表明，通过用比目前使用的更低的紫外线剂量照射精子，可以产生雌核发育单倍体斑马鱼。这种策略可降低单倍体致死率、单倍体综合征的发生率和严重程度。从斑马鱼作为用于正向和反向遗传策略的遗传易处理模型生物的角度来看，这些结果使斑马鱼作为一种脊椎动物处于独特的地位，在其中可以成功尝试针对发育表型的单倍体遗传筛选。
