title: Hc-fau, a novel gene regulating diapause in the nematode parasite Haemonchus contortus.
abstract: Diapause induced in the early fourth stage of Haemonchus contortus is a strategy to adapt this nematode to hostile environmental conditions. In this study, we identified a new gene, Hc-fau, a homologue of human fau and Caenorhabditis elegans Ce-rps30. Hc-fau encodes two proteins through alternative RNA splicing, Hc-FAUA and Hc-FAUB, consisting of 130 and 107 amino acids, respectively. Hc-FAU possesses a diverged ubiquitin-like (UBiL) protein domain and a conserved ribosome protein S30 domain. The protein is ubiquitously expressed, except in the gonad. However Hc-fau transcripts decrease significantly in diapausing L4s of H. contortus. In C. elegans, knockdown of Ce-rps30 confers an extended lifespan, increased lipid storage in the intestine and shortened body length. These morphological characteristics are comparable with dauer larvae of C. elegans, in which the gonad is condensed considerably. In contrast, a shortened lifespan is observed in C. elegans over-expressing Hc-faua, and especially Hc-faub, with hatching failure detected. The genes of insulin/IGF-1 signalling (IIS), TGF-β, cGMP, dafachronic acid (DA), apoptosis (AP) and fatty acids (FA) metabolism are all down-regulated in Ce-rps30RNAi (RNA interference) worms, except for akt-1 and daf-16. However, daf-16 up-regulation is inconsistent with its target gene down-regulation and the result from a heat stress assay in these worms. Daf-16 RNAi conducted in Ce-rps30 (tm6034/nt1) mutants failed to rescue the worms. The S30 domain stays in the nucleus, while UBiL accumulates in the cytoplasm. Compared with Hc-FAUA, results of UBiL domain and S30 domain over-expression indicate synergism between UBiL and S30 in regulating lifespan and reproduction. These results suggest the potential functions of Hc-fau in regulating larval diapause in H.contortus.
authors: Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310058, China.
authors: Baolong
authors: B
authors: Yan
authors: Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310058, China.
authors: Xiaolu
authors: X
authors: Guo
authors: School of Marine Science, Ningbo University, Ningbo 315211, China.
authors: Qianjin
authors: Q
authors: Zhou
authors: Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310058, China.
authors: Yi
authors: Y
authors: Yang
authors: Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310058, China.
authors: Xueqiu
authors: X
authors: Chen
authors: Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, Qingdao 266003, China.
authors: Weiwei
authors: W
authors: Sun
authors: Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou 310058, China. Electronic address: afdu@zju.edu.cn.
authors: Aifang
authors: A
authors: Du
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary; D005786:Gene Expression Regulation / Q000502:physiology; D006189:Haemonchus / Q000235:genetics* / Q000254:growth & development / Q000502:physiology*; D015801:Helminth Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D029742:Caenorhabditis elegans Proteins; D018076:DNA, Complementary; D015801:Helminth Proteins; D012333:RNA, Messenger
keywords: Caenorhabditis elegans; Diapause; Haemonchus contortus; Hc-fau; Nematode