Identification of a novel gene encoding the trehalose phosphate synthase in the cotton bollworm, Helicoverpa armigera

Abstract

Trehalose and trehalose metabolism are crucial for insect development. We measured the content of polyhydric compounds in the hemolymph of diapause- and nondiapause-destined individuals of Helicoverpa armigera. We found that the trehalose content is much higher in diapause-destined individuals than that in nondiapause individuals. The activity of trehalose-6-phosphate synthase (TPS) during H. armigera larval-pupal development is significantly higher in diapause-type individuals and is closely correlated with the changes in the trehalose content. The cDNA encoding TPS, which converts uridine-5'-diphosphoglucose and glucose-6-phosphate to trehalose-6-phosphate, was cloned from the fat body of H. armigera using rapid amplification of cDNA ends (RACE). The molecular characterization of the cDNA revealed that the mRNA encodes a precursor polypeptide of 826-amino-acid residues, containing Har-TPS at residues 6-507 and a putative trehalose-6-phosphate phosphatase, which converts trehalose-6-phosphate into free trehalose, at residues 512-783. The Har-TPS precursor polypeptide shows 73% identity with that of Drosophila melanogaster. The presence of a 2.8 kb transcript in the fat body and ovary was detected with a northern blot. The Har-TPS mRNA was detected at high levels in the late stage of sixth larval instar and the early middle stage of diapause-destined pupae, which are most likely to respond the changes in TPS activity and trehalose in the hemolymph. The Har-TPS protein was successfully overexpressed in the Bombyx mori baculovirus expression system, and the catalytic activity of Har-TPS was found to be approximately 5-fold higher in B. mori blood infected by the recombined-baculovirus than the control. When diapause is broken, the trehalose content drops significantly and glucose increases rapidly. These results suggest that trehalose is involved in regulating H. armigera pupal diapause.

Cloning and pattern of expression of trehalose-6-phosphate synthase cDNA from Catantops pinguis (Orthoptera: Catantopidae)

“…It is reported that SexTPS is specifically expressed in the fat body and ovaries in larval stages, which is consistent with the results of studies on H. armigera (Xu et al, 2009, Tang et al, 2010. In Locusta migratoria, TPS is expressed not only in the fat body, but also in gut, hemolymph, and leg muscle (Cui & Xia, 2009).…”

“…In non-diapausing and diapausing H. armigera, HarTPS mRNA expression was low and high, respectively (Xu et al, 2009). In addition, in S. exigua, semiquantitative RT-PCR results reveal that SexTPS mRNA is expressed in fat body at different levels from fifth instar larvae to pupae (Tang et al, 2010).…”

“…TPP and TPS genes have been cloned from plants, bacteria, and fungi, but none have been identified in mammals. In arthropods, TPS and TPP have been cloned or deduced from genomic sequences (according to GenBank) and are known to be very important for insect development; however, there are only a few studies on TPS genes and the details of protein characteristics in insects: D. melanogaster (Chen et al, 2002), Callinectes sapidus (Chung, 2008), Locusta migratoria (Cui et al, 2009), Helicoverpa armigera (Xu et al, 2009), and Spodoptera exigua (Tang et al, 2010). Catantops pinguis (syn.…”

Differential gene expression between summer and winter diapause pupae of the onion maggot Delia antiqua, detected by suppressive subtractive hybridization

“…Trehalose is the major sugar in the blood for insect growth and development; it is also thought to be involved in response to environmental stresses, including heat, cold, desiccation, and oxidation (Elbein et al, 2003). The up-regulation of this transcript contributes to the increase of trehalose content, which is most likely a response to a temperature cue and acts as a cryotectant in some insect species, including onion maggot (Nomura and Ishikawa, 2001) and cotton bollworm (Xu et al, 2009). Based on this preliminary result, we thought trehalose-6-phosphate synthase, serving as cryotectant or energy and carbon reserve, would play am important role in wintering survival of onion maggot.…”

Identification of the trehalose-6-phosphate synthase (tps) gene in desiccation tolerant and intolerant tardigrades

“…In metazoans, the tps gene has been found in several arthropods (Chen et al 2002;Chung 2008;Clark et al 2009;Xu et al 2009) and desiccation intolerant and tolerant nematodes (Pellerone et al 2003;Goyal et al 2005a). However, its presence in desiccation tolerant animals is not universal, as the tps gene was not found in anhydrobiotic bdelloid rotifers (Lapinski & Tunnacliffe 2003).…”