Broad-complex functions in postembryonic development of the cockroach Blattella germanica shed new light on the evolution of insect metamorphosis.
Biochim Biophys Acta
; 1830(1): 2178-87, 2013 Jan.
Article
en En
| MEDLINE
| ID: mdl-23041750
ABSTRACT
BACKGROUND:
Insect metamorphosis proceeds in two modes hemimetaboly, gradual change along the life cycle; and holometaboly, abrupt change from larvae to adult mediated by a pupal stage. Both are regulated by 20-hydroxyecdysone (20E), which promotes molts, and juvenile hormone (JH), which represses adult morphogenesis. Expression of Broad-complex (BR-C) is induced by 20E and modulated by JH. In holometabolous species, like Drosophila melanogaster, BR-C expression is inhibited by JH in young larvae and enhanced in mature larvae, when JH declines and BR-C expression specifies the pupal stage.METHODS:
Using Blattella germanica as a basal hemimetabolous model, we determined the patterns of expression of BR-C mRNAs using quantitative RT-PCR, and we studied the functions of BR-C factors using RNA interference approaches.RESULTS:
We found that BR-C expression is enhanced by JH and correlates with JH hemolymph concentration. BR-C factors appear to be involved in cell division and wing pad growth, as well as wing vein patterning.CONCLUSIONS:
In B. germanica, expression of BR-C is enhanced by JH, and BR-C factors appear to promote wing growth to reach the right size, form and patterning, which contrast with the endocrine regulation and complex functions observed in holometabolous species. GENERALSIGNIFICANCE:
Our results shed new light to the evolution from hemimetaboly to holometaboly regarding BR-C, whose regulation and functions were affected by two innovations 1) a shift in JH action on BR-C expression during young stages, from stimulatory to inhibitory, and 2) an expansion of functions, from regulating wing development, to determining pupal morphogenesis.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Blattellidae
/
Evolución Biológica
/
Metamorfosis Biológica
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
Biochim Biophys Acta
Año:
2013
Tipo del documento:
Article
País de afiliación:
España