Two hexamerin genes from the termite Reticulitermes flavipes: Sequence, expression, and proposed functions in caste regulation

Zhou, Xuguo; Tarver, Matthew R.; Bennett, Gary W.; Oi, Faith M.; Scharf, Michael E.

doi:10.1016/j.gene.2006.02.002

Cited by 77 publications

(98 citation statements)

References 47 publications

(70 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…First, based on the finding that a closely related locust hexamerin serves as a JH-binding protein (19), it is possible that the termite hexamerins are capable of JH sequestration. In agreement with this, we have observed that the Hex-1 protein is recognized by the anti-JH antiserum described by Goodman et al (31) and that immunoreactivity is reduced in the presence of competing JH and after stripping with apolar solvents (32). These observations agree with the earlier finding that RNAi-based silencing of honey bee vitellogenin, a putative JH-binding hemolymph protein, leads to increases in JH titers (22).…”

Section: Effects Of Rnai On Hexamerin Protein Expressionsupporting

confidence: 91%

“…At high titers, JH induces presoldier differentiation from workers, whereas at lower titers status quo worker-to-worker molts take place. membrane protein fractions and make up a substantial proportion of total worker protein (32). Previously, we observed that the Hex-2 protein is most readily inducible in JH-treated workers that are undergoing presoldier differentiation (11).…”

Section: Effects Of Rnai On Hexamerin Protein Expressionmentioning

confidence: 92%

See 1 more Smart Citation

Social exploitation of hexamerin: RNAi reveals a major caste-regulatory factor in termites

Zhou

Scharf

2006

Proc. Natl. Acad. Sci. U.S.A.

221

211

View full text Add to dashboard Cite

Lower termites express a unique form of eusocial polyphenism in that totipotent workers can differentiate into either soldier or reproductive caste phenotypes. In this initial effort using RNA interference in termites, we found that two hexamerin genes, Hex-1 and Hex-2, participate in the regulation of caste polyphenism. Our methodology involved a dual gene-silencing approach that used a single short-interfering RNA fragment to silence the two homologous hexamerin genes. We performed validation studies that evaluated effects on nontarget housekeeping genes, silencing of a nonhousekeeping control gene, and effects at the protein level. We found that the two hexamerin proteins, which are inducible by the morphogenetic juvenile hormone and which constitute a significant proportion of total termite protein, suppress juvenile-hormone-dependent worker differentiation to the soldier caste phenotype. This mechanism allows termite colonies to retain high proportions of altruistic worker caste members, thus apparently enhancing colony-inclusive fitness. These findings demonstrate a unique status quo regulatory mechanism for termite worker caste retention and provide an example of previously undescribed preadult developmental͞caste-regulatory genes from any social insect.sociogenomics ͉ RNA interference ͉ short-interfering RNA ͉ juvenile hormone ͉ phenotypic plasticity

show abstract

Section: Effects Of Rnai On Hexamerin Protein Expressionsupporting

confidence: 91%

Section: Effects Of Rnai On Hexamerin Protein Expressionmentioning

confidence: 92%

Social exploitation of hexamerin: RNAi reveals a major caste-regulatory factor in termites

Zhou

Scharf

2006

Proc. Natl. Acad. Sci. U.S.A.

221

211

View full text Add to dashboard Cite

show abstract

“…Just as honey bees appear to utilize Vg to pace caste development via interactions with the endocrine system, termites may use hexamerins, P450s, and possibly Vg, as these families have gone through termite-specific gene duplication and are differentially expressed among castes. Evidence from other termites strongly indicates that hexamerins interact with JH and that a high expression of hexamerins, through interaction with JH, inhibits soldier development 53,54 . Vg may play a similar role, although this remains to be tested.…”

Section: Discussionmentioning

confidence: 99%

“…The hexamerins sorted into three groups: one grouped with other insects, two were Blattodea-wide/specific and two grouped with hexamerins found in R. flavipes. These latter two are involved in modulating soldier differentiation, probably by controlling JH availability 53 . Specifically, it has been proposed that hexamerins reduce JH availability in workers and nymphal stages, thereby inhibiting soldier development 54 .…”

Section: Members Of Thementioning

confidence: 99%

Molecular traces of alternative social organization in a termite genome

et al. 2014

View full text Add to dashboard Cite

Although eusociality evolved independently within several orders of insects, research into the molecular underpinnings of the transition towards social complexity has been confined primarily to Hymenoptera (for example, ants and bees). Here we sequence the genome and stage-specific transcriptomes of the dampwood termite Zootermopsis nevadensis (Blattodea) and compare them with similar data for eusocial Hymenoptera, to better identify commonalities and differences in achieving this significant transition. We show an expansion of genes related to male fertility, with upregulated gene expression in male reproductive individuals reflecting the profound differences in mating biology relative to the Hymenoptera. For several chemoreceptor families, we show divergent numbers of genes, which may correspond to the more claustral lifestyle of these termites. We also show similarities in the number and expression of genes related to caste determination mechanisms. Finally, patterns of DNA methylation and alternative splicing support a hypothesized epigenetic regulation of caste differentiation.

show abstract

“…Although no primer pheromones have been identified in termites, JH has been proposed as a possible termite primer pheromone (Henderson, 1998). Previous studies have shown that ectopic exposure of worker termites to JH III readily induces soldier caste differentiation (Howard and Haverty, 1979;Scharf et al, 2003bScharf et al, , 2005Scharf et al, , 2007Scharf et al, 2003b;Scharf et al, 2005;Zhou et al 2006a,b, 2007Zhou et al, 2006aZhou et al, 2006b;Zhou et al, 2007), indicating that JH can act via exogenous exposure. Under natural conditions, high endogenous JH titers in worker termites cause differentiation into presoldiers, and then into soldiers (Park and Raina, 2004;Mao et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

Effects of Soldier-Derived Terpenes on Soldier Caste Differentiation in the Termite Reticulitermes flavipes

et al. 2009

View full text Add to dashboard Cite

-Primer pheromones play key roles in regulating division of labor, which is one of the most fundamental and defining aspects of insect sociality. Primer pheromones are chemical messengers that transmit hormone-like messages among colony members; in recipients these messages can either induce or suppress phenotypic caste differentiation. Here, we investigated soldier-caste-derived chemicals as possible primer pheromones in the lower termite Reticulitermes flavipes, a species for which no primer pheromones have yet been identified. We determined that soldier head extracts (SHE), when provided to totipotent workers along with the insect morphogenetic juvenile hormone (JH), significantly enhanced soldier caste differentiation. When applied alone, however, SHE had no impacts on caste differentiation, survivorship, or any other aspect of worker biology. These findings support that soldier-derived chemicals serve as primer pheromones which enhance the action of the endogenous morphogenetic hormone JH.Thus, SHE chemicals apparently have no effect when received under natural conditions by non-receptive individuals with presumably low JH titers. Gas chromatography-mass spectrometry analysis identified two terpenes as the most plentiful components of R.flavipes SHE. Through GC-MS and NMR analyses, these terpenes were identified as γ-cadinene and its corresponding aldehyde, γ-cadinenal. Validative bioassays with commercially available cadinene confirmed its activity. However, several other previously identified terpenes were also significantly active. These findings reveal a novel primer pheromone-like function for soldier-derived terpenes in termites, and further suggest convergent evolution of terpene functions in enhancing JH-dependent soldier caste differentiation.

show abstract

Two hexamerin genes from the termite Reticulitermes flavipes: Sequence, expression, and proposed functions in caste regulation

Cited by 77 publications

References 47 publications

Social exploitation of hexamerin: RNAi reveals a major caste-regulatory factor in termites

Social exploitation of hexamerin: RNAi reveals a major caste-regulatory factor in termites

Molecular traces of alternative social organization in a termite genome

Effects of Soldier-Derived Terpenes on Soldier Caste Differentiation in the Termite Reticulitermes flavipes

Contact Info

Product

Resources

About