cDNA cloning, gene structure, and expression of Broad-Complex (BR-C) genes in the silkworm, Bombyx mori

Ijiro, Tomoyuki; Urakawa, Hisayo; Yasukochi, Yuji; Takeda, Makio; Fujiwara, Yoshihiro

doi:10.1016/j.ibmb.2004.06.005

Cited by 50 publications

(37 citation statements)

References 21 publications

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“…The expression of these isoforms during the prepupal period appears to correspond to the time when the ecdysteroid titer rises prior to pupation in Tribolium and Tenebrio molitor (Hirashima et al, 1995;Quennedey and Quennedey, 1999). As in Bombyx penultimate stage larvae (Ijiro et al, 2004;Nishita and Takiya, 2004), low levels of br are present earlier in Tribolium larvae, and even the embryos (Konopova and Jindra, 2008), but no disruption of larval development has been noted after br dsRNA treatment in the penultimate (our study) or earlier (Konopova and Jindra, 2008) stages. Apparently, expression of br isoforms during larval life does not play a major role in external larval development of Holometabola, as it does in the hemimetabolous Oncopeltus .…”

Section: Evolution Of Brsupporting

confidence: 45%

“…All four br isoforms found in the more derived Lepidoptera (Zhou et al, 1998;Ijiro et al, 2004) (T. Koyama and L.M.R., unpublished), Diptera (DiBello et al, 1991;Chen et al, 2004) and Hymenoptera (Spokony and Restifo, 2007) are also found in Tribolium. The chromosomal isoform order of br-Z1, br-Z4, br-Z2 and br-Z3 is conserved among Tribolium, Bombyx and Drosophila.…”

Section: Evolution Of Brmentioning

confidence: 96%

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The role of Broad in the development ofTribolium castaneum:implications for the evolution of the holometabolous insect pupa

2008

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The evolution of complete metamorphosis in insects is a key innovation that has led to the successful diversification of holometabolous insects, yet the origin of the pupa remains an enigma. Here, we analyzed the expression of the pupal specifier gene broad (br), and the effect on br of isoform-specific, double-stranded RNA-mediated silencing, in a basal holometabolous insect, the beetle Tribolium castaneum. All five isoforms are weakly expressed during the penultimate instar and highly expressed during the prepupal period of the final instar. Application of hydroprene, a juvenile hormone analog, during the penultimate instar caused a repeat of the penultimate br expression patterns, and the formation of supernumerary larvae. Use of dsRNA against the br core region, or against a pair of either the br-Z2 or br-Z3 isoform with the br-Z1 or br-Z4 isoform, produced mobile animals with well-differentiated adult-like appendages, but which retained larval-like urogomphi and epidermis. Disruption of either the br-Z2 or the br-Z3 isoform caused the formation of shorter wings. Disruption of both br-Z1 and br-Z4 caused the appearance of pupal traits in the adults, but disruption of br-Z5 had no morphological effect. Our findings show that the br isoform functions are broadly conserved within the Holometabola and suggest that evolution of br isoform expression may have played an important role in the evolution of the pupa in holometabolous insects.

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Section: Evolution Of Brsupporting

confidence: 45%

Section: Evolution Of Brmentioning

confidence: 96%

The role of Broad in the development ofTribolium castaneum:implications for the evolution of the holometabolous insect pupa

2008

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“…Z1, Z4, Z2 and Z3; Fig. 1A) is conserved among Tribolium, Drosophila and Bombyx (DiBello et al, 1991;Bayer et al, 1996a;Ijiro et al, 2004;Nishita and Takiya, 2004;Reza et al, 2004). Although in these species and in mosquitoes (Chen et al, 2004) no more than four isoforms have been found, an additional exon in Tribolium (Fig.…”

Section: Tribolium Br-c Encodes Conserved and Novel Protein Isoformsmentioning

confidence: 96%

Broad-Complex acts downstream of Met in juvenile hormone signaling to coordinate primitive holometabolan metamorphosis

2008

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Metamorphosis of holometabolous insects, an elaborate change of form between larval, pupal and adult stages, offers an ideal system to study the regulation of morphogenetic processes by hormonal signals. Metamorphosis involves growth and differentiation, tissue remodeling and death, all of which are orchestrated by the morphogenesis-promoting ecdysteroids and the antagonistically acting juvenile hormone (JH), whose presence precludes the metamorphic changes. How target tissues interpret this combinatorial effect of the two hormonal cues is poorly understood, mainly because JH does not prevent larval-pupal transformation in the derived Drosophila model, and because the JH receptor is unknown. We have recently used the red flour beetle Tribolium castaneum to show that JH controls entry to metamorphosis via its putative receptor Methoprene-tolerant (Met). Here, we demonstrate that Met mediates JH effects on the expression of the ecdysteroid-response gene Broad-Complex (BR-C). Using RNAi and a classical mutant, we show that Tribolium BR-C is necessary for differentiation of pupal characters. Furthermore, heterochronic combinations of retarded and accelerated phenotypes caused by impaired BR-C function suggest that besides specifying the pupal fate, BR-C operates as a temporal coordinator of hormonally regulated morphogenetic events across epidermal tissues. Similar results were also obtained when using the lacewing Chrysopa perla (Neuroptera), a member of another holometabolous group with a primitive type of metamorphosis. The tissue coordination role of BR-C may therefore be a part of the Holometabola groundplan.

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“…In Aedes aegypti, M. sexta, and B. mori, expression studies have confirmed that BR-C expression is ecdysteroid-dependent (Zhou et al, 1998;Chen et al, 2004;Ijiro et al, 2004;Nishita and Takiya, 2004;Reza et al, 2004). Metamorphosis is one of the most emblematic processes regulated by BR-C (Karim et al, 1993;Zhou et al, 1998).…”

Section: Discussionmentioning

confidence: 99%

Molecular cloning, characterization, and expression analysis of a Broad-Complex homolog during development in the oriental river prawn Macrobrachium nipponense

et al. 2015

Genet. Mol. Res.

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ABSTRACT. Broad-Complex (BR-C) is an early ecdysone-responsive gene encoding a family of zinc-finger transcription factors. In this study, we isolated the full-length cDNA of a BR-C homolog from the testes of the oriental river prawn (Macrobrachium nipponense), according to established expressed sequence tag information, using the rapid amplification of cDNA ends technique. The homolog was designated as MnBR-C. The full-length cDNA of MnBR-C contained a 1095-bp open reading frame encoding a precursor protein of 365 amino acid residues. Comparative and bioinformatic analyses revealed that MnBR-C exhibited a high degree of homology with BR-C proteins, and contained the BTB and Zf-H2C2-2 domains. Real-time quantitative polymerase chain reaction (qPCR) analysis revealed that the MnBR-C expression level varied significantly in the developing embryo, postembryonic S.F. Jiang et al. 5142©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (2): 5141-5152 (2015) larva, and adult tissue. Real-time qPCR showed that the MnBR-C gene was expressed in all of the tissues investigated, with the highest level of expression in the brain. In addition, MnBR-C was more abundantly expressed in the testes than in the ovaries.

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cDNA cloning, gene structure, and expression of Broad-Complex (BR-C) genes in the silkworm, Bombyx mori

Cited by 50 publications

References 21 publications

The role of Broad in the development ofTribolium castaneum:implications for the evolution of the holometabolous insect pupa

The role of Broad in the development ofTribolium castaneum:implications for the evolution of the holometabolous insect pupa

Broad-Complex acts downstream of Met in juvenile hormone signaling to coordinate primitive holometabolan metamorphosis

Molecular cloning, characterization, and expression analysis of a Broad-Complex homolog during development in the oriental river prawn Macrobrachium nipponense

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