A Genetic Screen for Mutants with Supersized Lipid Droplets in Caenorhabditis elegans.
To identify genes that regulate the dynamics of lipid droplet (LD) size, we have used the genetically tractable model organism Caenorhabditis elegans, whose wild-type LD population displays a steady state of size with an upper limit of 3 μm in diameter. From a saturated forward genetic screen of 6.7 × 10(5) mutagenized haploid genomes, we isolated 118 mutants with supersized intestinal LDs often reaching 10 μm. These mutants define nine novel complementation groups, in addition to four known genes (maoc-1, dhs-28, daf-22, and prx-10). The nine groups are named drop (lipid droplet abnormal) and categorized into four classes. Class I mutants drop-5 and drop-9, similar to prx-10, are up-regulated in ACS-22-DGAT-2-dependent LD growth, resistant to LD hydrolysis, and defective in peroxisome import. Class II mutants drop-2, drop-3, drop-6, and drop-7 are up-regulated in LD growth, are resistant to LD hydrolysis, but are not defective in peroxisome import. Class III mutants drop-1 and drop-8 are neither up-regulated in LD growth nor resistant to LD hydrolysis, but seemingly up-regulated in LD fusion. Class IV mutant drop-4 is cloned as sams-1 and, different to the other three classes, is ACS-22-independent and hydrolysis-resistant. These four classes of supersized LD mutants should be valuable for mechanistic studies of LD cellular processes including growth, hydrolysis, and fusion.
Laboratory of Metabolic Genetics, College of Life Sciences, Capital Normal University, Beijing 100048, China.
Shiwei
S
Li
Laboratory of Metabolic Genetics, College of Life Sciences, Capital Normal University, Beijing 100048, China.
Shibin
S
Xu
Laboratory of Metabolic Genetics, College of Life Sciences, Capital Normal University, Beijing 100048, China.
Yanli
Y
Ma
Laboratory of Metabolic Genetics, College of Life Sciences, Capital Normal University, Beijing 100048, China.
Shuang
S
Wu
Laboratory of Metabolic Genetics, College of Life Sciences, Capital Normal University, Beijing 100048, China.
Yu
Y
Feng
Laboratory of Metabolic Genetics, College of Life Sciences, Capital Normal University, Beijing 100048, China.
Qingpo
Q
Cui
Laboratory of Metabolic Genetics, College of Life Sciences, Capital Normal University, Beijing 100048, China.
Lifeng
L
Chen
Laboratory of Metabolic Genetics, College of Life Sciences, Capital Normal University, Beijing 100048, China.
Shuang
S
Zhou
Laboratory of Metabolic Genetics, College of Life Sciences, Capital Normal University, Beijing 100048, China.
Yuanyuan
Y
Kong
Laboratory of Metabolic Genetics, College of Life Sciences, Capital Normal University, Beijing 100048, China.
Xiaoyu
X
Zhang
Laboratory of Metabolic Genetics, College of Life Sciences, Capital Normal University, Beijing 100048, China.
Jialei
J
Yu
Laboratory of Metabolic Genetics, College of Life Sciences, Capital Normal University, Beijing 100048, China.
Mengdi
M
Wu
Laboratory of Metabolic Genetics, College of Life Sciences, Capital Normal University, Beijing 100048, China soz001@cnu.edu.cn.
Shaobing O
SO
Zhang
D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D016678:Genome; D006238:Haploidy; D066292:Lipid Droplets / Q000378:metabolism*; D050356:Lipid Metabolism / Q000235:genetics*; D009154:Mutation
D029742:Caenorhabditis elegans Proteins
C. elegans; drop; forward genetic screen; lipid droplet; peroxisome